UNIVERSIDAD DE INVESTIGACIÓN DE TECNOLOGÍA EXPERIMENTAL YACHAY

Escuela de Ciencias Biológicas e Ingeniería

TÍTULO: Sugarcane byproducts potential uses and vinasse as feedstock to generate bioenergy

Trabajo de integración curricular presentado como requisito para la obtención del título de Ingeniero Biomédico

Autor: Aldaz Luna Bryan Patricio

Tutor: Ph.D. Santiago Vispo Nelson

Urcuquí, agosto 2020

Urcuquí, 2 de diciembre de 2020 SECRETARÍA GENERAL ( Vicerrectorado Académico/Cancillería ) ESCUELA DE CIENCIAS BIOLÓGICAS E INGENIERÍA CARRERA DE BIOMEDICINA ACTA DE DEFENSA No. UITEY-BIO-2020-00043-AD

A los 2 días del mes de diciembre de 2020, a las 16:30 horas, de manera virtual mediante videoconferencia, y ante el Tribunal Calificador, integrado por los docentes:

Presidente Tribunal de Defensa Dra. SPENCER VALERO, LILIAN MARITZA , Ph.D. Miembro No Tutor Dra. RODRIGUEZ CABRERA, HORTENSIA MARIA , Ph.D. Tutor Dr. SANTIAGO VISPO, NELSON FRANCISCO , Ph.D.

El(la) señor(ita) estudiante ALDAZ LUNA, BRYAN PATRICIO, con cédula de identidad No. 0704398759, de la ESCUELA DE CIENCIAS BIOLÓGICAS E INGENIERÍA, de la Carrera de BIOMEDICINA, aprobada por el Consejo de Educación Superior (CES), mediante Resolución RPC-SO-43-No.496-2014, realiza a través de videoconferencia, la sustentación de su trabajo de titulación denominado: SUGARCANE BYPRODUCTS POTENTIAL USES AND VINASSE AS FEEDSTOCK TO GENERATE BIOENERGY, previa a la obtención del título de INGENIERO/A BIOMÉDICO/A.

El citado trabajo de titulación, fue debidamente aprobado por el(los) docente(s):

Tutor Dr. SANTIAGO VISPO, NELSON FRANCISCO , Ph.D.

Y recibió las observaciones de los otros miembros del Tribunal Calificador, las mismas que han sido incorporadas por el(la) estudiante.

Previamente cumplidos los requisitos legales y reglamentarios, el trabajo de titulación fue sustentado por el(la) estudiante y examinado por los miembros del Tribunal Calificador. Escuchada la sustentación del trabajo de titulación a través de videoconferencia, que integró la exposición de el(la) estudiante sobre el contenido de la misma y las preguntas formuladas por los miembros del Tribunal, se califica la sustentación del trabajo de titulación con las siguientes calificaciones:

Tipo Docente Calificación Presidente Tribunal De Defensa Dra. SPENCER VALERO, LILIAN MARITZA , Ph.D. 10 , 0 Miembro Tribunal De Defensa Dra. RODRIGUEZ CABRERA, HORTENSIA MARIA , Ph.D. 10 , 0

Tutor Dr. SANTIAGO VISPO, NELSON FRANCISCO , Ph.D. 10 , 0

Lo que da un promedio de: 10 (Diez punto Cero), sobre 10 (diez), equivalente a: APROBADO

II

Para constancia de lo actuado, firman los miembros del Tribunal Calificador, el/la estudiante y el/la secretario ad-hoc.

Certifico que en cumplimiento del Decreto Ejecutivo 1017 de 16 de marzo de 2020, la defensa de trabajo de titulación (o examen de grado modalidad teórico práctica) se realizó vía virtual, por lo que las firmas de los miembros del Tribunal de Defensa de Grado, constan en forma digital.

ALDAZ LUNA, BRYAN PATRICIO

Estudiante

Dra. SPENCER VALERO, LILIAN MARITZA , Ph.D.

Presidente Tribunal de Defensa

Hacienda San José s/n y Proyecto Yachay, Urcuquí | Tlf: +593 6 2 999 500 | [email protected] www.yachaytech.edu.ec

Dr. SANTIAGO VISPO, NELSON FRANCISCO , Ph.D. Tutor

Dra. RODRIGUEZ CABRERA, HORTENSIA MARIA , Ph.D. Miembro No Tutor

ALARCON FELIX, KARLA ESTEFANIA

Secretario Ad-hoc

III

IV

V

DEDICATORIA Quisiera dedicar este trabajo final a mis padres, por todo el apoyo brindado a lo largo de estos cinco años en Yachay Tech.

A todos mis amigos que hicieron de la universidad mi segundo hogar y un lugar mejor, Cristhian, Demetrio, Freddy, Hector, Isaac, Luis, Sebastian, David, Milena, Maria Fernanda, Maria Daniela, y Fernanda.

A mis amigos con lo que no perdi contacto y estuvieron apoyándome a la distancia, Axel, Debbie, Victor, Michael, Andres y Paul.

Un pedazo de este trabajo es de todos ustedes.

VI

AGRADECIMIENTOS Quisiera agradecer a todos mis profesores en Yachay Tech. Desde que inicié mi etapa universitaria ustedes aportaron de la mejor manera a mi formación profesional y personal.

Gracias por todos los consejos, enseñanzas, lecciones y regaños que me dieron en estos últimos años. Especialmente, muchas gracias a mi tutor Nelson Santiago Vispo y a mi profesor Carlos Esteban Pazmiño por su ayuda y mentoría a lo largo de este trabajo.

VII

Resumen

Hoy en día, los ingenios azucareros usan la caña de azúcar y su jugo para obtener productos como la azúcar de mesa, miel y etanol. A lo largo de los diferentes procesos de obtención, muchos desperdicios se producen impactando negativamente a suelos y ríos. Los principales desechos de la industria azucarera son el bagazo, la paja, la cachaza y la vinaza. Gracias a los avances en procesos biotecnológicos, de la mano de la biorefinería, estos desechos pueden ser vistos y tratados como subproductos dándoles un valor agregado y produciendo energía, por ejemplo biogás, la cual puede ser aprovechada económicamente. Al mismo tiempo, el aprovechamiento de estos subproductos ayuda a mitigar el impacto negativo al medioambiente. En específico, la vinaza es el principal subproducto líquido de la fermentación del jugo de la caña de azúcar para producir etanol. En Ecuador, aproximadamente 1.000.000 m3 de vinaza son producidos anualmente generando una gran cantidad de desperdicios. Sin embargo, esta enorme cantidad de vinaza puede ser vista como materia prima para obtener biogás. En esta revisión bibliográfica, se reportan los resultados obtenidos de la simulación de un modelo simplificado de digestión anaerobia, basado en BNRM No. 2 por sus siglas en inglés para Biological Nutrient Removal Model, de la vinaza para producir metano y posteriormente biogás en un reactor tipo Batch. La concentración de metano fue de 22,9931.72 mg/L y la remoción de la carga orgánica fue del 99.96 % en 0.66 días de proceso. Con estos resultados, se pueden obtener aproximadamente 10,416.65 kg de metano lo cual se traduce en 103,056.75 kW.h y a la vez como $10,233.54.

Palabras clave: Caña de azúcar, subproductos, vinaza, bioenergía, biogás.

VIII

Abstract

Around the world, the sugarcane industries are obtaining products such as table sugar, honey, and ethanol. At the same time, these industries are generating many wastes that impact negatively on soils and rivers. Bagasse, straw, cachaça, and vinasse are the primary wastes of the sugar industry. With the proper biotechnological processes, hand in hand with the biorefinery, these wastes can be seen and treated as byproducts giving them an added value producing bioenergy that can be economically exploited. Furthermore, the use of these byproducts helps to mitigate the negative impact on the environment. Specifically, vinasse is the main liquid subproduct of the fermentation of sugarcane juice to produce ethanol. In Ecuador, approximately 1,000,000 m3 of vinasse are produced per year, generating a large amount of waste. Vinasse can be seen as a raw material for producing biogas. In this thesis, the results obtained from the simulation of a simplified model, based on Biological Nutrient Removal Model 2 (BNRM No.2), for anaerobic digestion of vinasse to produce methane and later biogas in a batch reactor are reported. Methane concentration was 22,931.72 mg/L, with 99.96% of organic matter degradation in 0.66 days of the process. With these results, 10,416.65 kg of methane can be attained, which translates into 103,056.75 kWh, which means a profit of $ 10,233.54.

Keywords: Sugarcane, byproducts, vinasse, bioenergy, biogas.

IX

Content

Resumen...... VIII Abstract ...... IX List of Figures ...... XII List of Tables ...... XIII List of Annexes ...... XIII 1. Introduction ...... 1 Chapter 2 ...... 4 2.1. Hypothesis ...... 4 2.2. General Objective ...... 4 2.3. Specific Objectives ...... 4 Chapter 3 ...... 6 3. Sugar Industry Feedstock ...... 6 3.1. Sugarcane, (Saccharum officinarum) ...... 6 3.2. Sugarcane Bagasse and Straw ...... 8 3.3. Filter Cake (Cachaça) and Honey ...... 9 3.4. Vinasse ...... 10 Chapter 4 ...... 12 4. Biotechnology for industrialization ...... 12 4.1. Biotechnology application ...... 12 4.2. Biorefinery ...... 14 4.3. Bioenergy ...... 15 Chapter 5 ...... 17 5. Sugarcane Bagasse Applications ...... 17 5.1. Second-Generation Ethanol production ...... 17 5.2. Paper production ...... 18 Chapter 6 ...... 20 6. Filter Cake applications ...... 20 6.1. Filter cake for bioethanol production ...... 20 6.2. Biofertilizer complement ...... 21 Chapter 7 ...... 23 7. Vinasse Applications ...... 23 7.1. Vinasse as culture media ...... 23

X

7.1.1. Biosurfactant production ...... 23 7.1.2. Fungi growth ...... 24 7.2. Pectin and Chitosan Fertilizers Production ...... 25 7.3. Biogas Production ...... 26 7.4. Ecuador ...... 28 7.4.1. Ecuadorian productive matrix...... 28 7.4.2. Sugarcane in Ecuador and Vinasse Contamination...... 28 Chapter 8 ...... 33 8. Mathematical Models for Anaerobic Digestion ...... 33 Chapter 9 ...... 36 9.1. BNRM No.2 for Biogas Production using vinasse ...... 36 9.2. Results of the simulation ...... 36 9.3. Discussion of the simulation...... 38 Chapter 10 ...... 40 10. Conclusions and Recommendation ...... 40 Annex ...... 41 References ...... 42

XI

List of Figures

Figure 1. Schematic representation of the sugarcane genome adapted from Garsmeur et al. (2018) ...... 7

Figure 2. Sugarcane general composition adapted from Canilha et al. (2012) ...... 7

Figure 3. Biotechnology applications...... 13

Figure 4. Biomass is transformed into bioenergy...... 15

Figure 5. 2G ethanol production...... 17

Figure 6. Scheme of potential vinasse applications...... 27

Figure 7. Behavior of methane (blue line) and DBO (red line) concentration...... 37

XII

List of Tables

Table 1. Straw and bagasse composition adapted from Rabelo et al. (2011) and Costa at al. (2013)...... 8

Table 2. Filter Cake estimated amounts adapted from 16...... 9

Table 3. Components of cachaça adapted from 16...... 9

Table 4. Vinasse composition...... 10

Table 5. Summary and characteristics of the biorefinery concept...... 14

Table 6. Bioenergy processes...... 15

Table 7. Physical and mechanical properties of sugarcane rind and core paper...... 18

Table 8. Filter cake composition...... 20

Table 9. Soluble phosphorous (P2O5), pH, and organic matter content...... 21

Table 10. Physical characteristics showed by the evaluated plants...... 21

Table 11. Vinasse chemical characterization...... 30

Table 12. Discharge limits to the freshwater body (rivers, streams, etc.) ...... 31

Table 13. Parameters of the guide levels of water quality for irrigation...... 31

Table 14. Bacteria for specific substrate. a degrading and b consuming bacteria...... 33

Table 15. Results of the simulation at 0.6633298 day...... 37

XIII

List of Annexes Anex 1. Stoichiometric matrix ...... 41

Anex 2. Differential equations for the mathematical model...... 41

XIII

XIV

Chapter 1 1. Introduction

Throughout history, sugarcane has been harvested only with two main objectives: to attain sugar and to ferment the sugarcane juice to produce ethanol. The complexity of the sugarcane genome was the barrier that blocked the depth study of sugarcane and the involved applications. During the last years, sugarcane has been considered one potential source of raw materials with application in bioenergy due to the composition of its byproducts (bagasse, strew, filter cake, vinasse). Due to the high demand for sugar and ethanol and the considerable size of the country, Brazil is the leading country in the region in sugarcane investigation because of the soil and weather conditions. The biotechnology application plays an essential role in the development of new processes taking into account the quality of the product and the environmental impact.

Ecuador presents favorable conditions to exploit these kinds of technologies, millions of hectare for cultivation with a subtropical climate and fertile soil. However, the country is still exporting products such as banana, shrimps, sugar, flowers, and cacao, among others. The growth and development of technologies related to bioenergy are low due to the lack of information, interest, investment, and investigation. For example, vinasse is the leading liquid waste of sugarcane juice fermentation yielding 10 – 15 liters per liter of attained ethanol using 12.5 kg of sugarcane, and the most common practice is to dispose of vinasse into rivers or use it as liquid fertilizer.

Ecuador is facing this problem: The misuse of vinasse/cachaça – filter cake/strew/bagasse. Cachaça is the term in portuguese used to refer to filter cake. In the case of vinasse, many studies have reported that the application of crude vinasse causes direct damage to soils and rivers such as salinization and Zn and Mn contamination. Investigations related to vinasse characterization demonstrated that crude vinasse does not fulfill with the requirements imposed by the Ecuadorian government, to be discharged presenting elevated levels of nitrogen, chemical oxygen demand, biochemical oxygen demand, and acidic pH, to mention a few. To solve the problem, Ecuador proposed the change of the productive matrix involving the development of biotechnology to leverage

1

the sugarcane byproducts. The biorefinery is a crucial concept at a time to transform the wastes (biomass), now considered feedstock, into goods and services. Such investigations have resulted in the use of the byproducts mentioned above to produce second-generation ethanol, culture media for biosurfactants and fungi, biodiesel, fertilizers, and biogas.

This study aims to advertise the benefits of using sugarcane byproducts as raw materials and specifically the use of vinasse to produce bioenergy. To achieve this objective, the simplified BNRM No.2 was performed in Excel to simulate the production of methane using the characterization data of vinasse taken from Cabrera (2016). The methane yielding leads to biogas production, demonstrating the potential use of vinasse in fields of biotechnology and bioenergy.

2

3

Chapter 2

2.1. Hypothesis

Biogas can be obtained by anaerobic digestion using vinasse as feedstock. 2.2. General Objective

To review different sources about the potential uses of sugarcane byproducts and how they can be used to generate/produce energy and other products, and to simulate the anaerobic digestion of vinasse to attain methane and further biogas using a simplified model adapted from the Biological Removal Nutrient Model No. 2 in silica.

2.3. Specific Objectives

i. To review the potential uses of bagasse, straw, filter cake and vinasse. ii. To review the current situation of sugarcane vinasse in Ecuador. iii. To review the different mathematical models for anaerobic digestion. iv. To simulate a simplified model based on BNRM No. 2 in silica using the vinasse characterization data.

4

5

Chapter 3 3. Sugar Industry Feedstock

3.1. Sugarcane, (Saccharum officinarum)

Taxonomically, sugarcane belongs to the genus Saccharum, family Poaceae, subfamily Panicoideae, tribe Andropogoneae, and subtribe Sacharinae under the group Saccarastrae1. The term sugarcane is used to refer to a class of tall perennial tropical grass species that are harvested for sugar production2. India set the basements of the procedure of crystal sugar production by crushing and boiling the sugar juice3. Nowadays, sugar production overcomes the rice, wheat, and maize production by weight; the production process has not suffered significant changes maintaining the same principle4. Humanity knows sugarcane for thousands of years; however, the scientific community has not put attention in the field of research. One of the reasons was the complexity of sugarcane genome5. Notwithstanding the lack of interest and in-depth study, sugarcane investigation has provided relevant discoveries such as C4 photosynthesis6.

During the last years, Brazil and Australia were the leading countries interested in sugarcane research due to the high demand for sugar and the harvested sugarcane per year. However, sugarcane has taken the limelight for other countries because of the potential application for bioenergy and biomaterial production5. As a result, Garsmeur et al. described the sugarcane genome as polyploid, aneuploid, heterozygous, and interspecific; Figure 1 shows the schematic representation of sugarcane genome7.

Sugarcane is mainly constituted by an organic soluble fraction (fiber), inorganic substances (nonsoluble solids), sucrose, and waxes in a smaller proportion (soluble solids fraction) and water8. Figure 2 shows the general composition of sugarcane.

6

Figure 1. Schematic representation of the sugarcane genome adapted from Garsmeur et al. (2018)

Figure 2. Sugarcane general composition. Sugarcane is mainly composed by broth and fiber, in each one there are byproducts (e.g. cellulose, soluble solids, lignin) that can be exploited. Adapted from Canilha et al. (2012)

7

3.2. Sugarcane Bagasse and Straw

Bagasse and straw are the outcomes of sugarcane after harvesting and milling process to attain juice for further sugar and ethanol production. The literature reports three main components for bagasse and straw (Table 1). The polymers cellulose, hemicellulose, and lignin are the building blocks of these byproducts of sugarcane8, 9.

Cellulose is a highly ordered crystalline polysaccharide consisting of parallel arrays of b-1,4-linked glucose chain10. Hemicellulose is a heteropolysaccharide since it is composed of hexoses, pentoses, acetic acids, among others9, 11. Lignin is a racemic heteropolymer composed of aromatic subunits derived from phenylalanine. In nature, lignin provides mechanical support to plant cell walls; it is synthesized from the oxidative coupling of three hydroxycinnamyl alcohol monomers that differ in their methoxylation degree: p-coumaryl, coniferyl, and sinapy12. Hydrolysis is the process by which these polymers must pass through to attain sugar that subsequently can be fermented in ethanol8, 9.

Many authors are investigating the potential applications of bagasse and straw due to their considerable amount per year. For example, only in the 2012/13 harvest, there were around 169 million tons of bagasse and 84 million tons of straw8, 13, 14.

Table 1. Straw and bagasse composition. Adapted from Rabelo et al. (2011) and Costa at al. (2013).

Component (%) Sugarcane Bagasse Sugarcane Straw Cellulose 38.4 33.5 Hemicellulose 23.2 27.1 Lignin 25 25.8 Ash 1.5 2.5

8

3.3. Filter Cake (Cachaça) and Honey

The filter cake, also known as cachaça, is the first solid waste from the sugarcane industry, it is produced between 30-50kg per ton of raw material processed. Worldwide filter cake production had reached 29 million tons per year (Table 2). Cachaça is produced during the sugarcane juice clarification, typically using calcium hydroxide as a spongy, amorphous dark filter cake. It is removed from the juice using rotation vacuum filters. It contains many organic matter colloids, organic and inorganic anions, urea, soil, wax, calcium, albuminoid substances, magnesium, zinc, nitrogen, and phosphorus. Like bagasse and straw, cachaça is also made up of cellulose, hemicellulose, and lignin (Table 3). Besides, it has a carbon: nitrogen ratio (C: N) greater than 20:115-17.

Table 2. Filter Cake estimated amounts adapted from George et al (2010).

Product Million ton Sugarcane harvested 961 Sugarcane crop 172 Liquid effluents 413 Filter Cake 29 Molasses 25

Table 3. Components of cachaça , cellulose represent the main component. Adapted from George (2010).

Component (%) Filter Cake or Cachaça Cellulose 8.9 Hemicellulose 2.4 Lignin 1.2 Sugarcane honey is a black syrup produced from fresh sugarcane. The process for sugarcane honey attainment consists of three steps: (i) the mechanical pressing to collect the juice, (ii) the repeated filtration and heating, and finally (iii) a new filtration process until obtaining the characteristic viscous black syrup18. Moreover, this syrup does not contain additives, colorants, nor preservatives. Sugarcane honey is rich in carbohydrates, proteins, and minerals such as Fe, Ca, Mg, and Cu. Literature had classified sugarcane honey as a source of vitamins (niacin, riboflavin, and thiamin), antioxidants (flavonoids and non-flavonoid19.

9

3.4. Vinasse

Vinasse is a liquid residue mainly attained from sugarcane and sugar beet. It is jointly produced with ethanol when fermenting sugarcane juice in the alcohol industry20, 21. Approximately 10-15 liters of vinasse is attained per one liter of ethanol21. For collecting vinasse is necessary a separation process from the fermented mash ethanol. In concordance with the Centro de Investigación de la Caña de Azúcar del Ecuador (CINCAE), vinasse also can be considered as a liquid byproduct of the industry above, with color brown, and sweet smell20, 22. España et al. reported that nitrogen, phosphorous, and potassium are the main components of sugarcane vinasse (Table 4). Besides, the principal organic components of sugarcane vinasse are glycerol, lactic acid, ethanol, and acetic acid. The primary organic acids are oxalate, lactate, acetate, and malate. Finally, vinasse also contains other alcoholic compounds, carbohydrates, and a high content of phenols23.

Table 4. Vinasse composition.

Component (mg/L) Vinasse Nitrogen 102 – 628 Phosphorous 71 – 130 Potassium 1733 – 1952 Copper 4 Iron 16

10

11

Chapter 4

4. Biotechnology for industrialization 4.1. Biotechnology application

In industrial biotechnology, microbial cell factories use renewable resources to generate energy and produce materials and chemicals. Industrial biotechnology occupies an increasingly important position in solving the resource, energy, and environmental concerns24. To date, the world faces a significant number of environmental challenges. The transition from the dependence on fossil fuels to a scenario where agriculture (rice, wheat, oak, sugarcane, among others) does not only provides food but also biomass as feedstock for the industry is the basis of sustainability25. Recently, biotechnology has been improving and revolutionizing agricultural techniques promoting efficacy concerning the quantity and quality of products while reducing their environmental impact. The use of appropriate approaches (Figure 3) (e.g., molecular breeding, tissue culture, genetic engineering, and molecular diagnosis tools) in biotechnology will also facilitate business and international development co-work24, 26.

Biotechnology has several sectors includes biological products for plant growth promotion and disease suppression. Biotechnology areas in agribusiness include: biopesticides, biofertilizers and, biostimulants, the correct utilization of these technologies will positively impact the environment by reducing fecal nutrient levels found inland preventing contamination24, 27, 28.

12

Figure 3. Biotechnology has many applications including research in laboratories and direct application in the industry. Biotechnology helps reserachers to design novel processes to reduce the negative impact to the environment. Besides biotechnology has been using to understand the biochemistry process in humans and animals.

13

4.2. Biorefinery

Nowadays, biomass from animals and plants has emerged as the most promising alternative natural resource base. In this sense, the biorefinery aims to use biomass to produce different goods with added value in several sectors29, 30. A biorefinery system is a facility that integrates biomass conversion processes and equipment for energy generation (e.g., biodiesel, biogas and, bioethanol) and chemical production with zero or negligible negative impact to the environment29 - 31. The possibilities of growth and development of the sugar-energy sector and biorefineries in the use of biomass are enormous for the future. Industries such as petrochemical, pharmaceutical, automotive, civil construction and, agribusiness can apply the concept of biorefinery to develop biofuels, chemical specialties, and additives32.

Biorefinery systems can be classified based on feedstock, type of technology, and the phase of development of the technology (Table 5) as follow: 1. Green Biorefineries (GBR), 2. Whole Crop Biorefineries (WCBR), 3. Lignocellulosic Feedstock Biorefineries (LCBR), 4. Thermo Chemical Biorefineries (TCBR) and 5. Marine Biorefineries (MBR)33.

Table 5. Summary and characteristics of the biorefinery concept.

Biorefinery Definition GBR Use fresh biomass (e.g. green grass and cereals) and convert it into a press cake rich in fiber and press juice rich in nutrient. WCBR Use grains and straw as raw biomass. WCBR’s converts the feedstock into biomaterials, feeds, and chemicals. LCBR It is based on the processing of celluloses, hemicelluloses and lignin. The results of these processes are: chemicals, biopolymers, and biomaterials. Besides, the residues are ignited to generate energy. TCBR The biomass goes through pyrolysis, gasification, torrefaction processes to attain products that could be used as substitute of fossil fuels. MBR It is based on marine crops such as microalgae and macroalgae and their derived products.

14

4.3. Bioenergy

Bioenergy is the renewable energy produced by living organisms or by any biological resource (biomass)34. For example, the energy from the sun stored through photosynthesis is one kind of bioenergy. The cycle of biomass energy is summarized in Figure 4. Biomass must pass through several processes (Table 6) depending on the aim before attained bioproducts such as biodiesel, biohydrogen, bioethanol, or biogas35, 36.

Table 6. Bioenergy processes.

Bioenergy Procedures Reference Bioethanol Separated hydrolysis and fermentation. Yeast 37,38,39,40,41,42,43,44,45,46. fermentation, saccharification of cellulose. Microalgae growth. Acid and alkaline oxidative pre- treatments. Biodiesel Microalgae. Fixed bed continuous flow microwave 47,48,49,50,51,52,53,54. irradiation. Microwave-assisted pyrolysis. Transesterification. Catalysis. Biogas Cell disruption techniques. Anaerobic digestion. 53,54,55,56,57,58,59. Biodegradability of lignocellulosic silages. Biohydrogen Electrolysis. Hydrogen-forming bacterium. Dark and 60,61,62,63,64,65. photo fermentation. Lime mud filtrate pretreatment

Figure 4. Biomass is transformed into bioenergy. In this specific example, the raw material (wood) is attained from nature (trees, plants, forest) or commercial products, the feedstock is treated and processed in a biomass power plant and converted into energy. The bioenergy power plant emits CO2 that is taken by trees closing the cycle.

15

16

Chapter 5

5. Sugarcane Bagasse Applications 5.1. Second-Generation Ethanol production

As reported before, sugarcane bagasse is rich in cellulose (approx. 40%)13, 14. Cellulose in sugarcane bagasse represents high efficiency for second-generation (2G) ethanol production when pass through hydrolysis reactions (Figure 5). A study conducted by Pereira (2015) demonstrated that the use of sugarcane bagasse for the production of 2G ethanol could be a promising alternative to provide to the economic development of this process66. Sugarcane bagasse is a promising feedstock for ethanol production due to its low cost and high availability since it is a byproduct of the first-generation of ethanol production; thus people do not have to invest in another raw material or harvest sugarcane again67. Besides, novel technologies can produce larger quantities of energy from bagasse68. The authors summarize the process by which bagasse has to be submitted to attain 2G ethanol. The procedure consists of two steps: (i) Hydrolysis process to disrupt the cell wall and purifies the fermentable sugar (glucose). (ii) Further fermentation of the resulted cellulose to produce ethanol. As an outcome, the authors attained 280 L of ethanol from 1 tonne of bagasse.

Figure 5. The cellulose goes under the hydrolysis to be converted into glucose that will be fermented to attain 2G ethanol.

17

5.2. Paper production

Nowadays, there are approximately 30 or more countries using sugarcane bagasse in the industry for paper production. Sugarcane bagasse covers the four main paper categories: (i) packaging and boxes, (ii) printing, writing and photocopier paper, (iii) tissues, and (iv) newsprint69. Many studies developed the production of paper using cellulosic sources, in this case, sugarcane bagasse70, 71. Novo et al. have successfully demonstrated that rind and core fractions can be utilized to manufacture pulp and paper72. The paper production was performed using an automatic sheet-making device by the standard method. At the end of the production, the authors assessed the physical (weight, thickness, and specific volume), mechanical (burst, tensile, and fiber tensile strength) properties (Table 7) and water absorption and air permeability72. Compared with the commercial paper, the paper produced from the rind and core fraction of the sugarcane bagasse showed similar quality in all aspects. Considering the results obtained in the previous study (Novo, 2018), sugarcane bagasse (as raw material) utilization with biorefinery approaches can be a promising path to new possibilities for the valorization of sugarcane.

Table 7. Physical and mechanical properties of sugarcane rind and core paper. Sugarcane rind Crushed sugarcane core paper paper Basis weight (g/m2) 69.10±0.63 64.26±0.66 Thickness (µm) 96±6 75±7 Specific volume (cm3/g) 1.4±0.1 1.2±0.1 Burst index (KPa·m2/g) 3.71±0.18 4.74±0.10 Water absorption (g/m2) 156.5±18.6 86.9±6.5 Air permeability 12.81±1.37 0.22±0.03 (µm/Pa·s) Tensile strength (N·m/g) 13.75±1.08 13.16±0.76 Young's module (GPa) 4.97±0.42 8.64±0.58 Tensile Index (N·m/g) 52.10±4.72 89.15±5.88

18

19

Chapter 6

6. Filter Cake applications 6.1. Filter cake for bioethanol production

The amount of filter cake produced per year overcomes the 25 million of tonnes. For that reason, in agricultural sectors, farmers are using cachaça as fertilizer and compost. Nevertheless, these approaches can bring serious problems such as adverse health effects due to the pathogen load, water contamination, soil eutrophication, and emission of greenhouse gases16, 73. Cachaça is a raw material very suitable to ferment due to the appropriate amount of carbohydrates, which are reduced to sugar74-77. Previous studies theoretical proved that filter cake and vinasse could be used as a complement to increase bioethanol yields from sweet sorghum (approx.500 liters more per hectare). Moreover, farmers can use the only cachaça for bioethanol production78.

For example, Sanchez et al. demonstrated the potential application of ferment filter cake using ammonium sulfate and Saccharomyces cerevisiae to produce bioethanol. Fist, the filter cake was characterized (Table 8) and hydrolyzed, converting the non- reducing sugars into reducing sugars for easily yeast metabolisation. In their study, the ethanol generation from fermented cachaça was about 50 g/L79. Finally, the authors recommend the use of filter cake to produce bioethanol at larger scales; even it can be used for H2 production, which could be used in hydrogen fuel cells for energy production.

Table 8. Filter cake composition.

Parameter Analytical Method wt % (Wet Basis) Moisture Gravimetric 51.66 Solid content Calculus 48.34 Total carbohydrates Calculus 41.10 Reducing sugar Volumetric 28.50 Wax Gravimetric 3.05 Protein Volumetric 2.35 Ash Gravimetric 1.84 Nitrogen Volumetric 0.38

20

6.2. Biofertilizer complement

A study performed by Castellanos et al. assessed the use of cachaça as a complement to biofertilizers (Azotofos® and Ecomic®) to elevate the level of phosphorous (P) (Table 9) in the soil promoting the absorption of P in sugarcane plantations80. Besides, filter cake proved its efficacy as a complement to chemical fertilization. Results were measured, taking into account the following morphological parameters: plant height, number of pods per plant, leaves number, stem diameter, number of grains per pod, fresh weight of 10 grains, leaf area and, dry and fresh phytomass of stem and leaves. The results showed a high yield when using 50% filter cake and 50% chemical fertilization81

On the other hand, the results applying filter cake and the biofertilizers aforementioned (Table 10) showed a significant difference in the examined plants and soil80.

Table 9. Soluble phosphorous (P2O5), pH, and organic matter content.

Treatments Soluble Phosphorous pH Organic Matter (mg/100g soil) (G/kg) Control 53.72 7.6 0.58 Filter Cake 66.29 7.2 0.65 Filter Cake + Azotofos® 93.31 7.3 0.64 Filter Cake + Ecomic® 91.66 7.2 0.53

Table 10. Physical characteristics showed by the evaluated plants.

Treatments Height (cm) Thickness (mm) Bud (unit) Control 16.50 8.09 4.33 Filter Cake 18.33 9.01 8.66 Filter Cake + Azotofos® 19.33 8.29 8.33 Filter Cake + Ecomic® 19.17 8.99 10

21

22

Chapter 7

7. Vinasse Applications

Currently, there are several approaches in the industry where vinasse can be studied, such as promising byproducts for fungal growth, production of fertilizers, biosurfactants, to mention a few (Figure 6). The potential use of vinasse or another agroindustry waste could bring a new kind of revolution to Ecuador. Some of the following applications are summarized next82-88.

7.1. Vinasse as culture media 7.1.1.Biosurfactant production

In 2017, Naspolini et al. noticed that the agro-industrial wastes containing a high level of carbohydrates could be used as a carbon source to produce biosurfactants (rhamnolipid). A study performed by submerged fermentation of Pseudomona aeruginosa, conducted by the authors, assessed the use of vinasse (raw material) as a culture medium for the production of biosurfactants. As mentioned before, raw vinasse has a pH value very acidic; hence, the author diluted the vinasse using distilled water and added NaOH until achieving neutral pH (7.0), with this diluted vinasse, authors prepared the culture medium. The yield using a vinasse-based medium was lower than the conventional medium 2.7 g/L and 3.2 g/L, respectively. Nevertheless, the yield from vinasse presented similar chemical and physical characteristics to biosurfactants obtained by the conventional method. Besides, the cost of production using vinasse was cheaper than the conventional; this is due to the nutrients (P, Mg, and others) found in vinasse. Moreover, the authors added glycerol, waste from the production of biodiesel, as an additional carbon source due to its chemical consumption. Finally, the authors concluded that the application of vinasse with a biotechnology study is feasible due to the high added value that vinasse can have after treated82.

23

7.1.2.Fungi growth

Similarly to Naspolini, Sartori et al. demonstrated the potential application of vinasse as a culture medium. In this case, the authors used vinasse for Pleurotus biomass production. The authors evaluated the biomass production from P. sajor-caju, P. ostreatus, P. albidus and P. flabellatus. Fungi were inoculated into 100 mL of crude vinasse and autoclaved. Once the medium reached the room temperature, they inoculated three plugs containing fungal mycelia in the culture medium. The authors used Danio rerio fish as an animal model to test the biomass produced by the fungi. In this way, the authors fed D. rerio fish for 28 days. Finally, the authors obtained the following outcomes: 8.20 g/L, 12.73 g/L, 13.27 g/L, and 16.27 g/L for P. flabellatus, P. sajor-caju, P. ostreatus, and P. albidus, respectively. At the time to compare the Pleurotus biomass with the usual rations, authors performed a bromatological analysis and realized that the organic matter, dry matter, and mineral material values were similar. Besides, fishes fed with Pleurotus biomass showed weight gain and increased length. Toxicology assessment showed no toxicity in the fishes after consumption of the produced biomass. Hence, the authors suggest that vinasse is a promising byproduct for fungal growth, and the biomass produced can be included as nutritional complement83.

24

7.2. Pectin and Chitosan Fertilizers Production

Pectin and chitosan particles wee manufactured using vinasse as a solvent, Pec-V, and Chi-V, respectively. The procedure was performed by a technique of drip addition into a crosslinking solution. Carreiro et al. dissolved the particles in 100 mL of vinasse for 24 h, then, the prepared particles were put into a crosslinking solution (CaCl2•2H2O 0.07 mol/L) for 30 min. At the end of the experimental work, authors attained 70 g of particles (pectin and chitosan) per liter of vinasse. The resulted particles were compared with control particles, Pec-C and Chi-C, showing better water retention and swelling, more excellent stability, and enhanced mechanical properties such as the compressive strength that was within the normal limits of the commercial fertilizers. These particles were assessed in two kinds of soils, clayey and sandy. For clayey soil, the particles did not show a significant difference in water evaporation under the study conditions. On the contrary, the water evaporation rate in sandy soil was lower, indicating the potential use of particles added vinasse in arid soils or drought seasons since the Pec-V and Chi-V particles keep the moisture longer. Finally, the authors highlighted the use of vinasse due to the improvements above given to particles for fertilizer soils84.

25

7.3. Biogas Production

Another eco-friendly destination of vinasse is its use to produce biogas and then convert it, throughout anaerobic digestion, into energy. The possibility of generating energy from anaerobic digestion of the stillage has been studied for many authors. These studies have corroborated the presence of significant energy potential in vinasse. In this practice, the exceptionally high load of vinasse is reduced, leaving residues, and large amounts of biogas are produced from these, previously treated, residues. Besides, vinasse can also be applied as fertilizer after treatment85, 86.

According to Gould, anaerobic digestion is a complex biochemical reaction carried out by several groups of microorganisms that do not require oxygen to live. As stated by Souza et al., the most appropriate reactor for vinasse treatment is the up-flow anaerobic sludge blanket (UASB). This reaction produces biogas, which is fundamentally consisting of methane and CO2. Many organic materials can be utilized as source/feedstock, in this case, vinasse, for producing biogas87.

A previous review directed by Bundhoo et al. demonstrated the potential use of sugarcane byproducts as feedstock to produce biogas, including vinasse, which generated 124 TJ/year on the island of Mauritius88.

26

Figure 6. Scheme of potential vinasse applications. Treated vinasse has several usages in different areas such as energy generation, laboratory culture media and agricultural applications.

27

7.4. Ecuador 7.4.1.Ecuadorian productive matrix

Throughout history, the Ecuadorian productive matrix has been based on oil, shrimp, banana, and tourism, to mention a few for the international market. Ecuador always has depended on oil exploration and exportation. For that reason, in 2016 and 2020, when the oil price dropped, the Ecuadorian economy also dropped. In 2008, Ecuador implemented a new constitution where the change of productive matrix appeared as one of the most important national objectives, including the investment in education to improve the competence level of the Ecuadorians. However, to date, Ecuador is still importing and exploiting the products above89.

According to Palacios and Reyes, a productive matrix is based on the sectors of goods and services. Inside the productive matrix, the sectors are sorted by the relative importance of generating investment, employment, production of commodities, innovation, and exportation of goods, services, and technologies. In their work, the authors identified 14 potential productive sectors and 5 strategic industries for the change of Ecuadorian productive matrix, including fresh and processed food, biotechnology (biomedicine and biochemistry), clothing and footwear, renewable energy, pharmaceuticals, metalworking, petrochemicals, forest wood products, environmental services ( e.g. sucarcane byproducts treatment), technology (software, hardware, and IT services), vehicles, automobiles, construction, transport and logistics, and tourism90.

7.4.2.Sugarcane in Ecuador and Vinasse Contamination

Sugar is one of the most consumed products in daily life, as it is the raw material for the preparation of other products such as bread, sweets, alcoholic and non-alcoholic beverages. Ordinary sugar or table sugar is obtained from sugarcane, beets sorghum, and sugar maple. Sugarcane represents 65-70% of the sugar production worldwide, whereas 30% of this production belongs to sugar beets91. In Ecuador, sugar production represents 1.4% of the GDP of the national economy, and concerning agricultural GDP it is 12%92. The industrial use of sugarcane focuses on obtaining raw, white, refined sugar, alcohol, molasses, and brown sugar93. In Ecuador, most of the sugarcane fields are in the province of Guayas, representing 80-90% of the national production. Moreover, the biggest sugar

28

mills in Ecuador are San Carlos, Valdez, ECOpais, Ecudos S.A., Ingenio Azucarero del Norte, Monterrey, Isabel María and Azucarero del Norte94, 95.

Ecuador produces 793.283,38 tons of residues per year which includes, vinasse, sewage, bagasse, chaff, and filter cake96. These sub-products can be reused. For example, bagasse can be used to feed animals, or to produce paper and cellulose, as a biofuel or to produce ethanol and furfural. The vinasse, on the other hand, can be used as a high protein food fertilizer or as a biodigester to produce biogas (boilers), fertilizers, o methane (vehicles). Moreover, the chaff can be used as fuel for heat and electricity generation97, 98.

Due to the high demand for ethanol to produce commercial alcohol in Ecuador, the environmental impact of the industry is higher. It has a direct incidence over the population, whether due to the emission of particles, polluting gases, and solid or liquid residuals that causes severe damage to the surrounding ecosystems. The chemical composition of the vinasse will depend on the yeast used in the fermentation process and the feedstock. According to Cabrera et al., several studies have been demonstrated that vinasse contains a requisite amount of organic matter, potassium and calcium, a moderate amount of nitrogen, and phosphorus99 - 104(Table 11).

Crude vinasse is discharged into rivers, and also in few sugar refineries are used to water their crops. Quiroz and Pérez have successfully proven that treated vinasse favors the soil because of the significant amount of potassium and organic load provided, treated vinasse promotes the deepness root growth, the water infiltration. It increases the microbiological activity and surface gas exchange105. On the other hand, the application of crude vinasse constitutes a risk of salinization and contamination by Zn and Mn. Moreover, vinasse has acidic pH (4.9 – 5.4) that makes it corrosive, causing direct damage to rivers and soils106.

Other studies confirmed the adverse effects of crude vinasse in soils and rivers107. For example, raw vinasse could become a severe environmental problem due to the large volume of production, high organic matter content with high BOD (6,000 - 25,000 mg O2/L), and COD (15,000 - 65,000 mg O2/L) demands. As mentioned before, vinasse presents high dark brown components (melanoidins) that can cause dangerous conditions in marine life, reducing sunlight penetration and photosynthesis activity108.

29

Table 11. Vinasse chemical characterization

Component Raw Vinasse pH 4.67 COD(g/L) 50±1.65 BOD(g/L) 24±0.12 Conductivity(mS/cm) 12.2±0.61 N(g/L) 0.65±0.1

Ptotal(g/L) 0.019±0.002 Ca2+(g/L) 1.6±0.25 Mg2+(g/L) 0.98±0.22 K+(g/L) 4.5±1.1 Total Solids(g/L) 46.9±1.24 Turbidity(UNT) 20843±286 Color(UPt-Co) 7329±52.3

. In Ecuador, as in Brazil, the predominant system is fertirrigation, using channel systems with applications diluted with irrigation water or applications of pure vinasse using tankers. As reported by CINCAE (Centro de Investigación de la Caña de Azúcar en Ecuador), 1.000.000 m3 of vinasse were produced in 2017 only taking account the COAZÚCAR, San Carlos and Valdez sugar mills109.

Currently, sugar mills in Ecuador apply vinasse as a source of potassium, to replace synthetic potassium fertilizer. However, research projects related to the use of vinasse as fertilizer are needed to determine the physical and chemical changes, both in soil and water, as well as improvements in sugar cane production and sugar yield. Most of the sugar mills in Ecuador do not follow the regulations about treated vinasse and discard raw vinasse into rivers and soils109.

Therefore, the enormous amount of vinasse produced by years in the country suggests a considerable amount of crude vinasse that is discarded to rivers or used for irrigation. Therefore, the Ecuadorian government prohibits the discard of untreated waters to rivers or soils in articles 6 and 10 of the Ley de Prevención y Control de la Contaminación Ambiental110. The Ecuadorian government has regulations about the disposal of untreated waters. These regulations can be found in the articles 4.2.1.3,

30

4.2.1.6, 4.2.1.21, 4.2.3.4 (Table 12), and 4.2.3.7 (Table 13) of the Norma de Calidad Ambiental de Descarga de Efluentes: Recurso Agua111. Unfortunately, several vinasse characterization studies have confirmed that raw vinasse exceeds the established parameters99 - 104.

Table 12. Discharge limits to the freshwater body (rivers, streams, etc.)

Component Maximum allowed Cl(mg/L) 0.5 BOD(mg/L) 100 COD(mg/L) 250 P(mg/L) 10 N(mg/L) 15 Total solids (mg/L) 1600 Temperature (°C) <35 Ni(mg/L) 2.0 Color Invaluable in solution

Table 13. Parameters of the guide levels of water quality for irrigation.

Component Maximum allowed pH 6.5 – 8.4 N(mg/L) 30

In 2009-2013 the "Plan Nacional del Buen Vivir" was established in which the Ecuadorian government prioritized the transformation of the productive matrix as one of the main avenues for the selective substitution of imports. In this document, one of the strategies to achieve this is the change of the energetic matrix aiming to improve agricultural yields of the crops and using byproducts (e.g. sugarcane) to produce energy. Ecuador, despite having its own oil, has adequate conditions for the development of bioenergy, such as semi-tropical climate, fertile organic soil, water, and abundant sunshine and sizeable commercial sugarcane industry.

31

32

Chapter 8

8. Mathematical Models for Anaerobic Digestion

The American Council of Biogas defines anaerobic digestion as biological processes performed by microorganisms that disintegrate biodegradable raw material without oxygen. Biogas is one of the final products of anaerobic digestion, which is combusted to produce energy (e.g., electricity) and heat. On the other hand, biogas can be processed into natural gas and fuels112.

One of the formers mathematical models was described by Costello et al. in 1991. In this model, bacteria such as acidogenic, acetogenic, and methanogenic develop anaerobic processes and as outcome is attained methane (CH4), hydrogen (H2) and carbon dioxide (CO2). Besides, the authors considered the latter gas the only one with a significant degree of solubility113.

Later, Siegrist et al. in 1993 described an anaerobic digestion model that works under mesophilic conditions. The authors presented the model in matrix notation applying the continuity equations to the chemical oxygen demand (COD), nitrogen, and carbon. The model considers five groups of microorganisms, and each one consumes a different substrate (Table 14).

Table 14. Bacteria for specific substrate. a degrading and b consuming bacteria.

Bacteria Substrate Acidogenica Amino acids and sugar Acetogenicb Fatty acids Acetogenica Propionic acid Acetotrophic methanogensa Acetic acid Hydrogenotrophic methanogensa Hydrogen

.

33

The Siegrits model considers necessary gas desorption, acetate and propionate degradation, hydrolysis of particulate biodegradable COD, and inhibition due to pH, ammonia, hydrogen, and acetic acid. Moreover, the model differentiates between amino acid-consuming bacteria and sugar-degrading bacteria114, 115.

Batstone et al. consider the anaerobic digestion model no. 1 (ADM1) as the most used for modeling. This model consists of two kinds of processes, physic-chemical (reversible) and biochemical (irreversible). It is relevant to mention that physic-chemical methods do not use microorganisms, and for biochemical processes, the contrary is true. The model also includes charge balance equations and chemical equilibrium equations of the ions considered in the reactor's liquid phase to calculate the pH and transfer equations between the liquid and gas phases. Besides, the model includes pH inhibition functions for all bacterial groups, inhibition by free ammonia in the acetoclastic methanogenic group and the hydrogenic acetogens, and inhibition by lack of inorganic nitrogen in the system. Finally, the ADM1 includes the increase in organic matter concentration because of the cell death of the degrading agents of the soluble compounds116.

The model gathers seven groups of microorganisms: (i) acidogenic bacteria that degrade sugars, (ii) acidogenic bacteria that degrade amino acids, (iii) acetogenic bacteria that consume long-chain fatty acids, (iv) acetogenic bacteria that degrade valerate and butyrate, (v) acetogenic propionotrophic bacteria, (vi) acetotrophic methanogenic arches and (vii) hydrogenic methanogenic arches116.

In 2004, the CALAGUA research group developed the Biological Nutrient Removal Model No. 1 (BNRM1). The BNRM1 included biological, chemical, and physical processes such as organic matter, nitrogen and phosphorous removal (acidogenesis, acetogenesis, and methanogenesis), acid-base processes and, volatile fatty acids elutriation, among others117. However, this first model was not complete; for example, the model did not consider the nitrogen removal via nitrite. For that reason, the CALAGUA research group presented an extension of BNRM1. The BNRM2 includes all the components of the BNRM1, but it also incorporates the nitrogen removal via nitrites through ammonia-oxidizing organisms (AOO) 117, 118. In BNRM2 one process can be performed by multiple bacteria species. The most common processes are presented here below: aerobic hydrolysis, anaerobic hydrolysis, aerobic growth, anaerobic growth, to name a few119.

34

35

Chapter 9

9.1. BNRM No.2 for Biogas Production using vinasse

The simplified model for anaerobic digestion (based on BNRM No.2) was performed in Excel using the stoichiometric matrix, coefficients/constants, and equations (Annex 1, Annex 2) for anaerobic digestion in a Batch bioreactor.

The stoichiometric matrix, coefficients, constants, solved equations and primary data can be found in https://cutt.ly/5faHPL4.

9.2. Results of the simulation

The results of the mathematical model are presented in Table 15. The differential equations were solved using Euler method in Excel. The number of iterations was 663,298, using 0.000001 as an interval between each iteration. The simulation was stopped when there were no significant changes in the values. The DQO final concentration was 30,766.74066 mg/L.

The concentration of CH4 (22931.72938 mg/L) was growing with time, while the concentration of DBO was mostly removed, as shown in Figure 7. Thanks to the concentration of CH4 is correct to think biogas can be attained from vinasse in Ecuador.

The percentage of removed DBO is 99.96, and the final concentration of DBO is 0.748495758 mg/L, which is relevant because this percentage could be translated into "most of the organic load was used/degraded to generate biogas."

To stablish the amount of methane that can be produced from vinasse, the approx. 1.000.000 m3 will be taken as data. Using this information is possible to calculate the liquid volume (VL) and the biogas volume (VB) of the bioreactor; in this case the VL is 3 1,816.986301 m . As the golden rule of Batch bioreactors, the VL occupies 80% and VB 3 the 20% of the total volume (VT) of the bioreactor (2,271.232876 m ). Thus, the VB is 454.2465752 m3.

36

Table 15. Results of the simulation at 0.6633298 day. Component Initial Concentration (mg/L) Final Concentration (mg/L) Sf 24000 0.164359128 Si 26000 26,624.21706 Sa 0 0.137247605 Spro 0 0.44688963

SCH4 0 22,931.72938

SH2 0 0.0056634

SCO2 0 258.133

SNH2 650 1,622.1733

SPO4 19 332.75167 Xacid 48440 92,425.45 Xact 48440 47,844.799 Xmac 48440 47,734.973 Xmh2 48440 45,432.319 Xs 46900 50,985.753 Xi 0 4,142.5236

Figure 7. Behavior of methane (blue line) and DBO (red line) concentration. The methane concentration increase meanwhile the DBO concentration decrease. Then, the organic load is taking advantage to produce further biogas.

CH4, CO2 compose the VB, and H2, representing 98.88%, 1.11%, and 0.01%, respectively. Methane is important for energy generation; in this case, the anaerobic digestion of vinasse yielded 10,416.65953 kg of methane. 1 m3 of biogas represents 6.5 kWh. Then, 15,854.88513 m3 of attained biogas yield 103,056.7533 kWh. In Ecuador,

37

the kWh costs 0.0993 dollar. Hence, the 103,056.7533 kWh could represent $10,233.53 at 0.6 days.

9.3. Discussion of the simulation

Nowadays, workers in small and medium-sized sugar mills still see sugarcane byproducts as wastes. Not to mention that large sugar mills use these wastes only to produce second-generation ethanol, which mixed with 15% gasoline, could reduce by 53% the importation of high-octane gasoline, in the case of the filter cake15.

In this literature review, many applications of filter cake, bagasse, strew, and vinasse and their potential use as feedstock for bioenergy generation have been studied. It is relevant to mention and reflect that the lack of knowledge and investment in these fields are the main enemies of not having developed technologies to take advantage of the use of these products to benefit66-88.

On the other hand, these wastes continue causing damage to the environment in the long term when they are thrown into rivers, lagoons, streams, or when used as fertilizers causing direct damage to the soil105.

In Ecuador, some regulations require waste to be treated before it is dumped in rivers or used in soils. However, many sugar mills do not follow these regulations, as demonstrated when comparing Table 12 and Table 13 with Table 11, because of the lack of technology and knowledge in these fields110,111.

For that reason, it is necessary to adopt these technologies and practices to seek the best way to treat these wastes. For example, vinasse is very versatile, having many fields of application from laboratory culture media to feedstock to produce biogas82-88, 98.

Following the last idea, the BNRM No.2 was applied to prove whether vinasse can be used as a raw material to produce methane and later, biogas (bioenergy) or whether not, attained positive results. However, the values of CH4, CO2, and H2 are ideal and do not represent the reality; it is necessary the characterization of vinasse and its anaerobic digestion for better and real results, the mathematical model only shows an estimate of the real values.

38

39

Chapter 10

10. Conclusions and Recommendation

Throughout this review paper, it was described the sugarcane byproducts, the application of each one, how biotechnology with biorefinery will help to treat and take advantage of sugarcane byproducts, and mathematical models that could be used to simulate anaerobic digestion to attain biogas using vinasse.

The results of the mathematical model indicate that vinasse can be used as raw material to attain CH4 to produce bioenergy in Ecuador. Ideally, CH4 yield was 10,416.659533 kg, which can be seen as $10,233.5356 per year.

Moreover, the results of this investigation seem encouraging. However, all the data presented here come from in silica studies, then, it is recommended to perform the characterization and anaerobic digestion of vinasse to attain better results.

In my personal opinion and recommendation, the big and small sugar mills in Ecuador must consider treating bagasse, straw, filter cake and vinasse not only to help to the environment but due to their potential applications that can generate an extra income.

40

Annex

Anex 1. Stoichiometric matrix

푋 푠⁄ 푋푎푐푖푑 푟1 = 퐾퐻 ∙ ∙ 푋푎푐푖푑 푋푠 퐾푥 + ⁄ 푋푎푐푖푑

푆퐹 푆푁퐻4 푆푃푂4 퐾퐼퐻2 푟2 = 휇푎푐푖푑 ∙ ∙ ∙ ∙ ∙ 푋푎푐푖푑 퐾퐹 + 푆퐹 퐾푁퐻4 + 푆푁퐻4 퐾푃푂4 + 푆푃푂4 퐾퐼퐻2 + 푆퐻2

푆푃푟표 푆푁퐻4 푆푃푂4 퐾퐼퐻2 푟3 = 휇퐴푐푒푡 ∙ ∙ ∙ ∙ ∙ 푋퐴푐푒푡 퐾푃푟표 + 푆푃푟표 퐾푁퐻4 + 푆푁퐻4 퐾푃푂4 + 푆푃푂4 퐾퐼퐻2 + 푆퐻2

푆퐴 푆푁퐻4 푆푃푂4 푟4 = 휇푀푎푐 ∙ ∙ ∙ ∙ 푋푀푎푐 퐾퐴 + 푆퐴 퐾푁퐻4 + 푆푁퐻4 퐾푃푂4 + 푆푃푂4

푆퐻2 푆푁퐻4 푆푃푂4 푆퐶푂2 푟5 = 휇푀퐻2 ∙ ∙ ∙ ∙ ∙ 푋푀퐻2 퐾퐻2 + 푆퐻2 퐾푁퐻4 + 푆푁퐻4 퐾푃푂4 + 푆푃푂4 퐾퐶푂2 + 푆퐶푂2

푟6 = 푏퐴푐푖푑 ∙ 푋퐴푐푖푑

푟7 = 푏퐴푐푒푡 ∙ 푋퐴푐푒푡

푟8 = 푏푀푎푐 ∙ 푋푀푎푐

푟9 = 푏푀퐻2 ∙ 푋푀퐻2

푟10 = 퐾퐿푎퐶푂2 ∙ (푆퐶푂2 − 푆푎푡퐶푂2)

푟11 = 퐾퐿푎퐶퐻4 ∙ (푆퐶퐻4 − 푆푎푡퐶퐻4)

푟12 = 퐾퐿푎퐻2 ∙ (푆퐻2 − 푆푎푡퐻2)

Anex 2. Differential equations for the mathematical model.

41

References

1. Amalraj VA, Balasundaram N. On the Taxonomy of the Members of ‘Saccharum Complex.’ Genet Resour Crop Evol [Internet]. 2006 Feb 10;53(1):35–41. Available from: http://link.springer.com/10.1007/s10722- 004-0581-1 2. Paterson AH. Genomics of the Saccharinae [Internet]. Paterson AH, editor. Genomics of the Saccharinae. New York, NY: Springer New York; 2013. 1– 567 p. Available from: http://link.springer.com/10.1007/978-1-4419-5947-8 3. Gopal L. Sugar-Making in Ancient India. Journal of the Economic and Social History of the Orient. 1964;7(1–3):57–72. 4. FAOSTAT [Internet]. Fao.org. 2020 [cited 21 July 2020]. Available from: http://www.fao.org/faostat/en/?#data 5. Thirugnanasambandam PP, Hoang N V., Henry RJ. The Challenge of Analyzing the Sugarcane Genome. Front Plant Sci [Internet]. 2018 May 14;9(May):1–18. Available from: http://journal.frontiersin.org/article/10.3389/fpls.2018.00616/full 6. Hatch MD. C 4 photosynthesis : discovery and resolution. Advances in Photosynthesis Respiration. 2005;20:875–80. Available from: http://dx.doi.org/ 10.1023/A:1020471718805 7. Garsmeur O, Droc G, Antonise R, Grimwood J, Potier B, Aitken K, et al. A mosaic monoploid reference sequence for the highly complex genome of sugarcane. Nat Commun [Internet]. 2018;9(1). Available from: http://dx.doi.org/10.1038/s41467-018-05051-5 8. Canilha L, Kumar Chandel A, dos Santos Milessi TS, Fernandes Antunes FA, da Costa Freitas WL, das Graças Almeida Felipe M, et al. Bioconversion of sugarcane biomass into ethanol: an overview about composition, pre- treatment methods, detoxification of hydrolysates, enzymatic saccharification, and ethanol fermentation. J Biomed Biotechnol. 2012;2012:989572. Available from: http://dx.doi.org/ 10.1023/A:1020471718805

42

9. Rabelo SC, Carrere H, Maciel Filho R, Costa AC. Production of bioethanol, methane and heat from sugarcane bagasse in a biorefinery concept. Bioresour Technol [Internet]. 2011;102(17):7887–95. Available from: http://dx.doi.org/10.1016/j.biortech.2011.05.081 10. Peng B, Yao Z, Wang X, Crombeen M, Sweeney DG, Tam KC. Cellulose- based materials in wastewater treatment of petroleum industry. Green Energy Environ [Internet]. 2020;5(1):37–49. Available from: https://doi.org/10.1016/j.gee.2019.09.003 11. Hemicellulose | chemical compound [Internet]. Encyclopedia Britannica. 2010 [cited 22 July 2020]. Available from: https://www.britannica.com/science/hemicellulose 12. Boerjan W, Ralph J, Baucher M. LIGNIN BIOSYNTHESIS. Annu Rev Plant Biol [Internet]. 2003 Jun;54(1):519–46. Available from: http://www.annualreviews.org/doi/10.1146/annurev.arplant.54.031902.1349 38 13. Rabelo SC, Carrere H, Maciel Filho R, Costa AC. Production of bioethanol, methane and heat from sugarcane bagasse in a biorefinery concept. Bioresour Technol [Internet]. 2011;102(17):7887–95. Available from: http://dx.doi.org/10.1016/j.biortech.2011.05.081 14. Costa SM, Mazzola PG, Silva JCAR, Pahl R, Pessoa A, Costa SA. Use of sugar cane straw as a source of cellulose for textile fiber production. Ind Crops Prod [Internet]. 2013;42(1):189–94. Available from: http://dx.doi.org/10.1016/j.indcrop.2012.05.028 15. Basanta R, Delgado MAG, Martínez JEC, Vázquez HM, Vázquez GB. SOSTENIBILIDAD DEL RECICLAJE DE RESIDUOS DE LA AGROINDUSTRIA AZUCARERA: UNA REVISIÓN SUSTAINABLE RECYCLING OF WASTE FROM SUGARCANE AGROINDUSTRY: A REVIEW. Cienc y Tecnol Aliment [Internet]. 2007 Jul;5(4):293–305. Available from: http://www.tandfonline.com/doi/abs/10.1080/11358120709487704 16. George PAO, Eras JJC, Gutierrez AS, Hens L, Vandecasteele C. Residue from sugarcane juice filtration (filter cake): Energy use at the sugar factory. Waste and Biomass Valorization. 2010;1(4):407–13. Available from: http://link.springer.com/10.1007/s12649-010-9046-2

43

17. Riachi LG, Santos A, Moreira RFA, De Maria CAB. A review of ethyl carbamate and polycyclic aromatic hydrocarbon contamination risk in cachaça and other Brazilian sugarcane spirits. Food Chem [Internet]. 2014;149:159–69. Available from: http://dx.doi.org/10.1016/j.foodchem.2013.10.088 18. Silva P, Freitas J, Silva CL, Perestrelo R, Nunes FM, Câmara JS. Establishment of authenticity and typicality of sugarcane honey based on volatile profile and multivariate analysis. Food Control [Internet]. 2017 Mar;73:1176–88. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0956713516305795 19. Silva P, Silva CL, Perestrelo R, Nunes FM, Câmara JS. Fingerprint targeted compounds in authenticity of sugarcane honey - An approach based on chromatographic and statistical data. Lwt [Internet]. 2018;96:82–9. Available from: https://doi.org/10.1016/j.lwt.2018.04.076 20. Christofoletti CA, Escher JP, Correia JE, Marinho JFU, Fontanetti CS. Sugarcane vinasse: Environmental implications of its use. Waste Manag [Internet]. 2013 Dec;33(12):2752–61. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0956053X1300408X 21. Moran-Salazar RG, Sanchez-Lizarraga AL, Rodriguez-Campos J, Davila- Vazquez G, Marino-Marmolejo EN, Dendooven L, et al. Utilization of vinasses as soil amendment: consequences and perspectives. Springerplus [Internet]. 2016 Dec 7;5(1):1007. Available from: http://springerplus.springeropen.com/articles/10.1186/s40064-016-2410-3 22. CINCAE | Centro de Investigación de la Caña de Azúcar del Ecuador [Internet]. Cincae.org. 2020 [cited 23 July 2020]. Available from: http://cincae.org/ 23. España-Gamboa E, Mijangos-Cortes J, Barahona-Perez L, Dominguez- Maldonado J, Hernández-Zarate G, Alzate-Gaviria L. Vinasses: characterization and treatments. Waste Manag Res [Internet]. 2011 Dec 16;29(12):1235–50. Available from: http://journals.sagepub.com/doi/10.1177/0734242X10387313 24. Zheng X., Zheng P., Sun J. Systems biology for industrial biotechnology. Chinese Journal of Biotechnology. 2019;35(10):1955-1973. Available from: https://doi.org/10.13345/j.cjb.190217

44

25. Lokko Y, Heijde M, Schebesta K, Scholtès P, Van Montagu M, Giacca M. Biotechnology and the bioeconomy—Towards inclusive and sustainable industrial development. N Biotechnol [Internet]. 2018;40:5–10. Available from: https://doi.org/10.1016/j.nbt.2017.06.005 26. Pertry I, Sabbadini S, Goormachtig S, Lokko Y, Gheysen G, Burssens S, et al. Biosafety capacity building: Experiences and challenges from a distance learning approach. N Biotechnol [Internet]. 2014;31(1):64–8. Available from: http://dx.doi.org/10.1016/j.nbt.2013.08.008 27. Lugtenberg B. Principles of Plant-Microbe Interactions: Microbes for Sustainable Agriculture. Cham: Springer International Publishing; 2015. 1– 448 p. Available from: http://link.springer.com/10.1007/978-3-319-08575-3 28. Biofertilizers Market Worth 2.31 Billion USD by 2022 [Internet]. Prnewswire.com. 2016 [cited 23 July 2020]. Available from: https://www.prnewswire.com/in/news-releases/biofertilizers-market-worth- 231-billion-usd-by-2022-595798531.html 29. Celiktas MS, Alptekin FM. Biorefinery concept : Current status and future prospects. International Conference on Engineering Technologies. 2019;(December 2017). Available from: https://www.researchgate.net/publication/331166360_Biorefinery_concept_ Current_status_and_future_prospects 30. Hughes SR, López-Núñez JC, Jones MA, Moser BR, Cox EJ, Lindquist M, et al. Sustainable conversion of coffee and other crop wastes to biofuels and bioproducts using coupled biochemical and thermochemical processes in a multi-stage biorefinery concept. Appl Microbiol Biotechnol [Internet]. 2014 Oct 11;98(20):8413–31. Available from: http://link.springer.com/10.1007/s00253-014-5991-1 31. Berntsson T, Sanden B, Olsson L, Asblad A. What Is a Biorefinery? Syst Perspect Biorefineries [Internet]. 2014;(2008):16–25. Available from: http://publications.lib.chalmers.se/records/fulltext/185710/local_185710.pdf 32. Guerra SPS, Denadai MS, Saad ALM, Spadim ER, da Costa MXR. Sugarcane: biorefinery, technology, and perspectives [Internet]. Sugarcane Biorefinery, Technology and Perspectives. Elsevier Inc.; 2020. 49–65 p. Available from: http://dx.doi.org/10.1016/B978-0-12-814236-3.00003-2

45

33. Gavrilescu M (2014) Biorefinery Systems: An Overview. Bioenergy Res Adv Appl 219–241. Available from: https://doi.org/10.1016/B978-0-444- 59561-4.00014-0 34. Bioenergy | Definition of Bioenergy by Oxford Dictionary on Lexico.com also meaning of Bioenergy [Internet]. Lexico Dictionaries | English. 2020 [cited 24 July 2020]. Available from: https://www.lexico.com/en/definition/bioenergy 35. Sheehan NP, Plante L, Martinez E, Murray K, Bier P, Ouellette C. Sustainable Bioenergy from Biofuel Residues and Waste. Water Environ Res [Internet]. 2018 Oct 1;90(10):1073–90. Available from: http://doi.wiley.com/10.2175/106143018X15289915807173 36. Chirat C. Use of vegetal biomass for biofuels and bioenergy. Competition with the production of bioproducts and materials? Comptes Rendus Phys [Internet]. 2017 Sep;18(7–8):462–8. Available from: https://linkinghub.elsevier.com/retrieve/pii/S1631070517300701 37. Febrianti F. Bioethanol Production from Tofu Waste by Simultaneous Saccharification and Fermentation (SSF) using Microbial Consortium. Int J Technol [Internet]. 2017 Oct 31;8(5):898. Available from: http://ijtech.eng.ui.ac.id/article/view/872 38. Hossain N, Zaini JH, Mahlia TM. A Review of Bioethanol Production from Plant-based waste by Yeast Fermentation. Int J Technol. 2017;8(1):5–18. Available from: http://dx.doi.org/ 10.1017/CBO9781107415324.004 39. Liu Y-K, Chen W-C, Huang Y-C, Chang Y-K, Chu I-M, Tsai S-L, et al. Production of bioethanol from Napier grass via simultaneous saccharification and co-fermentation in a modified bioreactor. J Biosci Bioeng [Internet]. 2017 Aug;124(2):184–8. Available from: https://linkinghub.elsevier.com/retrieve/pii/S1389172316305254 40. Sanchez Rizza L, Sanz Smachetti ME, Do Nascimento M, Salerno GL, Curatti L. Bioprospecting for native microalgae as an alternative source of sugars for the production of bioethanol. Algal Res [Internet]. 2017;22:140–7. Available from: http://dx.doi.org/10.1016/j.algal.2016.12.021 41. Adams JMM, Bleathman G, Thomas D, Gallagher JA. The effect of mechanical pre-processing and different drying methodologies on bioethanol production using the brown macroalga Laminaria digitata (Hudson) JV

46

Lamouroux. J Appl Phycol [Internet]. 2017;29(5):2463–9. Available from: http://dx.doi.org/10.1007/s10811-016-1039-5 42. Ho S-H, Chen Y-D, Chang C-Y, Lai Y-Y, Chen C-Y, Kondo A, et al. Feasibility of CO2 mitigation and carbohydrate production by microalga Scenedesmus obliquus CNW-N used for bioethanol fermentation under outdoor conditions: effects of seasonal changes. Biotechnol Biofuels [Internet]. 2017 Dec 31;10(1):27. Available from: http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068- 017-0712-5 43. Aguilar-Reynosa A, Romaní A, Rodríguez-Jasso RM, Aguilar CN, Garrote G, Ruiz HA. Comparison of microwave and conduction-convection heating autohydrolysis pre-treatment for bioethanol production. Bioresour Technol [Internet]. 2017;243:273–83. Available from: http://dx.doi.org/10.1016/j.biortech.2017.06.096 44. Domínguez E, Romaní A, Domingues L, Garrote G. Evaluation of strategies for second generation bioethanol production from fast growing biomass Paulownia within a biorefinery scheme. Appl Energy [Internet]. 2017 Feb;187:777–89. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0306261916317457 45. Martínez-Patiño JC, Ruiz E, Romero I, Cara C, López-Linares JC, Castro E. Combined acid/alkaline-peroxide pre-treatment of olive tree biomass for bioethanol production. Bioresour Technol [Internet]. 2017;239:326–35. Available from: http://dx.doi.org/10.1016/j.biortech.2017.04.102 46. Carrillo-Nieves D, Ruiz HA, Aguilar CN, Ilyina A, Parra-Saldivar R, Torres JA, et al. Process alternatives for bioethanol production from mango stem bark residues. Bioresour Technol [Internet]. 2017;239:430–6. Available from: http://dx.doi.org/10.1016/j.biortech.2017.04.131 47. Arenas EG, Rodriguez Palacio MC, Juantorena AU, Fernando SEL, Sebastian PJ. Microalgae as a potential source for biodiesel production: techniques, methods, and other challenges. Int J Energy Res [Internet]. 2017 May;41(6):761–89. Available from: http://doi.wiley.com/10.1002/er.3663 48. Naraharisetti PK, Das P, Sharratt PN. Critical factors in energy generation from microalgae. Energy [Internet]. 2017;120:138–52. Available from: http://dx.doi.org/10.1016/j.energy.2016.12.117

47

49. Tangy A, Pulidindi IN, Perkas N, Gedanken A. Continuous flow through a microwave oven for the large-scale production of biodiesel from waste cooking oil. Bioresour Technol [Internet]. 2017;224:333–41. Available from: http://dx.doi.org/10.1016/j.biortech.2016.10.068 50. Callegari A, Hlavinek P, Capodaglio AG. Production of energy ( biodiesel ) and recovery of materials ( biochar ) from pyrolysis of urban waste sludge. Rev Ambient Agua. 2018;13(2). Available from: http://dx.doi.org/ 10.4136/ambi-agua.2128 51. R S, R V, J R. Transesterification of Waste Cooking Oil Catalysed by Crystalline Copper Doped Zinc Oxide Nanocatalyst. J Adv Chem [Internet]. 2016 Dec 22;12(12):5798–808. Available from: https://cirworld.com/index.php/jac/article/view/7343 52. Silveira Junior EG, Justo OR, Perez VH, Reyero I, Serrano-Lotina A, Campos Ramirez L, et al. Extruded Catalysts with Magnetic Properties for Biodiesel Production. Adv Mater Sci Eng [Internet]. 2018 Dec 30;2018:1– 11. Available from: https://www.hindawi.com/journals/amse/2018/3980967/ 53. Yadav M, Sharma YC. Process optimization and catalyst poisoning study of biodiesel production from kusum oil using potassium aluminum oxide as efficient and reusable heterogeneous catalyst. J Clean Prod [Internet]. 2018 Oct;199:593–602. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0959652618320250 54. Zhao C, Yang L, Xing S, Luo W, Wang Z, Lv P. Biodiesel production by a highly effective renewable catalyst from pyrolytic rice husk. J Clean Prod [Internet]. 2018 Oct;199:772–80. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0959652618322315 55. Sumprasit N, Wagle N, Glanpracha N, Annachhatre AP. Biodiesel and biogas recovery from Spirulina platensis. Int Biodeterior Biodegradation [Internet]. 2017;2017:196–204. Available from: http://dx.doi.org/10.1016/j.ibiod.2016.11.006 56. Khuntia HK, Chanakya HN, Siddiqha A, Thomas C, Mukherjee N, Janardhana N. Anaerobic digestion of the inedible oil biodiesel residues for value addition. Sustain Energy Technol Assessments [Internet]. 2017;22:9– 17. Available from: http://dx.doi.org/10.1016/j.seta.2017.05.006

48

57. Dębowski M, Zieliński M, Kisielewska M, Krzemieniewski M. Anaerobic Co-digestion of the Energy Crop Sida hermaphrodita and Microalgae Biomass for Enhanced Biogas Production. Int J Environ Res [Internet]. 2017 Aug 29;11(3):243–50. Available from: http://link.springer.com/10.1007/s41742-017-0024-4 58. Tsapekos P, Kougias PG, Treu L, Campanaro S, Angelidaki I. Process performance and comparative metagenomic analysis during co-digestion of manure and lignocellulosic biomass for biogas production. Appl Energy [Internet]. 2017;185:126–35. Available from: http://dx.doi.org/10.1016/j.apenergy.2016.10.081 59. Neshat SA, Mohammadi M, Najafpour GD, Lahijani P. Anaerobic co- digestion of animal manures and lignocellulosic residues as a potent approach for sustainable biogas production. Renew Sustain Energy Rev [Internet]. 2017;79(July 2016):308–22. Available from: http://dx.doi.org/10.1016/j.rser.2017.05.137 60. Ito M, Hori T, Teranishi S, Nagao M, Hibino T. Intermediate-temperature electrolysis of energy grass Miscanthus sinensis for sustainable hydrogen production. Sci Rep [Internet]. 2018 Dec 1;8(1):16186. Available from: http://www.nature.com/articles/s41598-018-34544-y 61. Li Y, Zhang Q, Deng L, Liu Z, Jiang H, Wang F. Biohydrogen production from fermentation of cotton stalk hydrolysate by Klebsiella sp. WL1316 newly isolated from wild carp (Cyprinus carpio L.) of the Tarim River basin. Appl Microbiol Biotechnol [Internet]. 2018 May 19;102(9):4231–42. Available from: http://link.springer.com/10.1007/s00253-018-8882-z 62. Monroy I, Bakonyi P, Buitrón G. Temporary feeding shocks increase the productivity in a continuous biohydrogen-producing reactor. Clean Technol Environ Policy [Internet]. 2018;20(7):1581–8. Available from: https://doi.org/10.1007/s10098-018-1555-x 63. Sekoai PT, Daramola MO. Effect of metal ions on dark fermentative biohydrogen production using suspended and immobilized cells of mixed bacteria. Chem Eng Commun [Internet]. 2018;205(8):1011–22. Available from: https://doi.org/10.1080/00986445.2018.1428958 64. Sekoai PT, Yoro KO, Bodunrin MO, Ayeni AO, Daramola MO. Integrated system approach to dark fermentative biohydrogen production for enhanced

49

yield, energy efficiency and substrate recovery. Rev Environ Sci Biotechnol [Internet]. 2018;17(3):501–29. Available from: https://doi.org/10.1007/s11157-018-9474-1 65. Zhang J, Yao C, Fan C. Enhancement of Solubility and Biohydrogen Production from Sewage Sludge with Lime Mud Filtrate. Water, Air, Soil Pollut [Internet]. 2018 Apr 27;229(4):129. Available from: http://link.springer.com/10.1007/s11270-018-3779-0 66. Pereira S, Maehara L, Machado C, Farinas C. 2G ethanol from the whole sugarcane lignocellulosic biomass. Biotechnol Biofuels [Internet]. 2015;8(1):44. Available from: http://www.biotechnologyforbiofuels.com/content/8/1/44 67. Cardona CA, Quintero JA, Paz IC. Production of bioethanol from sugarcane bagasse: Status and perspectives. Bioresour Technol [Internet]. 2010;101(13):4754–66. Available from: http://dx.doi.org/10.1016/j.biortech.2009.10.097 68. Santos F, Eichler P, de Queiroz JH, Gomes F. Production of second- generation ethanol from sugarcane [Internet]. Sugarcane Biorefinery, Technology and Perspectives. Elsevier Inc.; 2020. 195–228 p. Available from: http://dx.doi.org/10.1016/B978-0-12-814236-3.00011-1 69. Rainey TJ, Covey G. Pulp and paper production from sugarcane bagasse. In: Sugarcane-Based Biofuels and Bioproducts [Internet]. Hoboken, NJ, USA: John Wiley & Sons, Inc; 2016. p. 259–80. Available from: http://doi.wiley.com/10.1002/9781118719862.ch10 70. Khristova P, Kordsachia O, Patt R, Karar I, Khider T. Environmentally friendly pulping and bleaching of bagasse. Ind Crops Prod [Internet]. 2006 Mar;23(2):131–9. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0926669005000634 71. Amalraj VA, Rakkiyappan P, Neelamathi D, Chinnaraj S, Subramanian S. Wild cane as a renewable source for fuel and fibre in the paper industry. Curr Sci. 2008; Available from: https://www.jstor.org/stable/24105519 72. Novo LP, Bras J, Belgacem MN, Da Silva Curvelo AA. Pulp and paper from sugarcane: Properties of rind and core fractions. J Renew Mater. 2018;6(2):160–8. Available from: http://www.techscience.com/jrm/v6n2/28824

50

73. Adorna JC, Crusciol CAC, Rossato OB. Fertilization with filter cake and micronutrients in plant cane. Rev Bras Ciência do Solo [Internet]. 2013 Jun;37(3):649–57. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100- 06832013000300011&lng=en&tlng=en 74. Ansari KB, Gaikar VG. Pressmud as an Alternate Resource for Hydrocarbons and Chemicals by Thermal Pyrolysis. Ind Eng Chem Res [Internet]. 2014 Feb 5;53(5):1878–89. Available from: https://pubs.acs.org/doi/10.1021/ie401961y 75. 1. López González LM, Pereda Reyes I, Dewulf J, Budde J, Heiermann M, Vervaeren H. Effect of liquid hot water pre-treatment on sugarcane press mud methane yield. Bioresour Technol [Internet]. 2014 Oct;169:284–90. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0960852414009614 76. Janke L, Leite AF, Nikolausz M, Radetski CM, Nelles M, Stinner W. Comparison of start-up strategies and process performance during semi- continuous anaerobic digestion of sugarcane filter cake co-digested with bagasse. Waste Manag [Internet]. 2016;48:199–208. Available from: http://dx.doi.org/10.1016/j.wasman.2015.11.007 77. Janke L, Leite A, Batista K, Weinrich S, Sträuber H, Nikolausz M, et al. Optimization of hydrolysis and volatile fatty acids production from sugarcane filter cake: Effects of urea supplementation and sodium hydroxide pre-treatment. Bioresour Technol [Internet]. 2016;199:235–44. Available from: http://dx.doi.org/10.1016/j.biortech.2015.07.117 78. Lucena E, Dutra E, Pedrosa E, Menezes R, Tabosa J, Carvalho A, et al. Ethanol Production Potential from Sweet Sorghum Fertilized with Filter Cake and Vinasse from the Sugarcane Industry. J Exp Agric Int [Internet]. 2018 Jul 5;24(4):1–13. Available from: http://www.sciencedomain.org/abstract/25433 79. Sanchez N, Ruiz R, Infante N, Cobo M. Bioethanol Production from Cachaza as Hydrogen Feedstock: Effect of Ammonium Sulfate during Fermentation. Energies [Internet]. 2017 Dec 12;10(12):2112. Available from: http://www.mdpi.com/1996-1073/10/12/2112

51

80. González LC, Jiménez MA, Silva C, Espinosa RR, Romero IF, et al. Efecto De La Adición De Cachaza, Roca Fosfórica Y Biofertilizantes En El Suelo Sobre El Contenido De Fósforo Y El Desarrollo De Plántulas De Caña De Azúcar. Cultiv Trop. 2016;37(4):145–51. Available from: http://dx.doi.org/ 10.13140/RG.2.2.17308.08324 81. Estupiñan-Fernández CE, Garzón-Amaya GM, Forero-Ulloa F. Efecto de la aplicación de tres dosis de cachaza al cultivo de fríjol (Phaseolus vulgaris L.) en Tunja, Boyacá. Cienc Y Agric [Internet]. 2013 Jan 2;10(1):67. Available from: http://revistas.uptc.edu.co/revistas/index.php/ciencia_agricultura/article/view /2829 82. Naspolini BF, Machado AC de O, Cravo Junior WB, Freire DMG, Cammarota MC. Bioconversion of Sugarcane Vinasse into High-Added Value Products and Energy. Biomed Res Int [Internet]. 2017;2017:1–11. Available from: https://www.hindawi.com/journals/bmri/2017/8986165/ 83. Sartori SB, Ferreira LFR, Messias TG, Souza G, Pompeu GB, Monteiro RTR. Pleurotus biomass production on vinasse and its potential use for aquaculture feed. Mycology [Internet]. 2015;6(1):28–34. Available from: http://dx.doi.org/10.1080/21501203.2014.988769 84. Carreiro Cerri B, Matos Borelli L, Martins Stelutti I, Soares MR, da Silva MA. Evaluation of new environmental friendly particulate soil fertilizers based on agroindustry wastes biopolymers and sugarcane vinasse. Waste Manag [Internet]. 2020;108:144–53. Available from: https://doi.org/10.1016/j.wasman.2020.04.038 85. Santos RF, Borsoi A, Secco D, Melegari de Souza SN, Constanzi RN. Brazil’s Potential for Generating Electricity from Biogas from Stillage. In: Proceedings of the World Renewable Energy Congress – Sweden, 8–13 May, 2011, Linköping, Sweden [Internet]. 2011. p. 425–32. Available from: http://www.ep.liu.se/ecp/article.asp?issue=057%26volume=1%26article=57 86. Salomon KR, Lora EES, Rocha MH, del Olmo OA. Cost calculations for biogas from vinasse biodigestion and its energy utilization. Sugar Ind [Internet]. 2011;136(4):217–23. Available from: https://sugarindustry.info/paper/11311/

52

87. Gould MC. Bioenergy and Anaerobic Digestion [Internet]. Bioenergy. Anju Dahiya; 2015. 297–317 p. Available from: http://dx.doi.org/10.1016/B978-0- 12-407909-0.00018-3 88. Bundhoo ZMA, Mauthoor S, Mohee R. Potential of biogas production from biomass and waste materials in the Small Island Developing State of Mauritius. Renew Sustain Energy Rev [Internet]. 2016;56:1087–100. Available from: http://dx.doi.org/10.1016/j.rser.2015.12.026 89. Villafuerte J, Intriago E. Productive Matrix Change in Ecuador and the Petroleum Crisis. Case Study: Entrepreneurs and Productive Associations. J Bus [Internet]. 2016 Mar 21;1(2):01. Available from: http://journalofbusiness.us/index.php/site/article/view/18 90. Palacios D, Reyes P. Cambio de la matriz productiva del Ecuador y su efecto en el comercio exterior. Dominio las Ciencias [Internet]. 2016;2:418–31. Available from: dominiodelasciencias.com/ojs/index.php/es/article/download/183/pdf 91. Campos H, Caligari PDS. Genetic Improvement of Tropical Crops [Internet]. Genetic Improvement of Tropical Crops. Cham: Springer International Publishing; 2017. 1–320 p. Available from: http://link.springer.com/10.1007/978-3-319-59819-2 92. Prado-Pérez de Corcho R, Herrera-Suárez M, Ramírez-Moreira KR, Lucas- Grzelczyk MM, Jarre-Cedeño C, Perez de Corcho-Fuentes JS. Restrictive Factors for the Mechanization of Sugarcane Cultivation in Manabí Province, Ecuador. Rev Ciencias Técnicas Agropecu. 2018;27(4). Available from: https://www.researchgate.net/publication/329197392_Factores_limitantes_pa ra_la_mecanizacion_de_la_cana_de_azucar_en_la_provincia_Manabi_Ecua dor_Restrictive_Factors_for_the_Mechanization_of_Sugarcane_Cultivation_ in_Manabi_Province_Ecuador 93. Da Silva AS, De Sá LRV, Aguieiras ECG, de Souza MF, Teixeira RSS, Cammarota MC, et al. Productive Chain of Biofuels and Industrial Biocatalysis: Two Important Opportunities for Brazilian Sustainable Development [Internet]. Biotechnology of Microbial Enzymes: Production, Biocatalysis and Industrial Applications. Elsevier Inc.; 2017. 545–581 p. Available from: http://dx.doi.org/10.1016/B978-0-12-803725-6.00020-0

53

94. Producción de azúcar está en 8 ingenios [Internet]. El Universo. 2013 [cited 4 August 2020]. Available from: https://www.eluniverso.com/noticias/2013/07/11/nota/1146451/produccion- azucar-esta-8-ingenios 95. Herrmann P, Gordillo M. San Carlos: El proyecto de cogeneración eléctrica [Internet]. Revistalideres.ec. 2013 [cited 4 August 2020]. Available from: https://www.revistalideres.ec/lideres/san-carlos-proyecto-cogeneracion- electrica.html 96. Instituto Nacional de Preinversión. ATLAS Bioenergético del Ecuador. Atlas bioenergético del Ecuador. 2014. 150 p. Available from: http://historico.energia.gob.ec/biblioteca/ 97. Silva Lora EE, Escobar Palacio JC, García Núñez JA, Barrera Hernandez JC. Bioenergía y biorrefinerías para caña de azúcar y palma de aceite*. Palmas [Internet]. 2016;37(Especial Tomo II):290–4. Available from: https://publicaciones.fedepalma.org/index.php/palmas/article/view/11928/11 921 98. Parsaee M, Kiani Deh Kiani M, Karimi K. A review of biogas production from sugarcane vinasse. Biomass and Bioenergy [Internet]. 2019 Mar;122:117–25. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0961953419300431 99. Ibarra-Camacho R, León-Duarte L, Osoria-Leyva A. Physicochemical characterization of distillery vinasse. Rev Cuba Química. 2019;31(2). Available from: http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2224- 54212019000200246&lng=es&nrm=iso 100. Quintero-Dallos V, García-Martínez JB, Contreras-Ropero JE, Barajas- Solano AF, Barajas-Ferrerira C, Lavecchia R, et al. Vinasse as a Sustainable Medium for the Production of Chlorella vulgaris UTEX 1803. Water [Internet]. 2019 Jul 24;11(8):1526. Available from: https://www.mdpi.com/2073-4441/11/8/1526 101. Rodrigues Reis CE, Hu B. Vinasse from Sugarcane Ethanol Production: Better Treatment or Better Utilization? Front Energy Res [Internet]. 2017 Apr 10;5(APR):1–7. Available from: http://journal.frontiersin.org/article/10.3389/fenrg.2017.00007/full

54

102. Cabrera-Díaz A, Pereda-Reyes I, Dueñas-Moreno J, Véliz-Lorenzo E, Díaz- Marrero MA, Menéndez-Gutiérrez CL, et al. COMBINED TREATMENT OF VINASSE BY AN UPFLOW ANAEROBIC FILTER-REACTOR AND OZONATION PROCESS. Brazilian J Chem Eng [Internet]. 2016 Dec;33(4):753–62. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104- 66322016000400753&lng=en&tlng=en 103. de Jesus GC, Gaspar Bastos R, Altenhofen da Silva M. Production and characterization of alginate beads for growth of immobilized Desmodesmus subspicatus and its potential to remove potassium, carbon and nitrogen from sugarcane vinasse. Biocatal Agric Biotechnol [Internet]. 2019;22(September):101438. Available from: https://doi.org/10.1016/j.bcab.2019.101438 104. Fuess LT, Rodrigues IJ, Garcia ML. Fertirrigation with sugarcane vinasse: Foreseeing potential impacts on soil and water resources through vinasse characterization. J Environ Sci Heal - Part A Toxic/Hazardous Subst Environ Eng [Internet]. 2017;52(11):1063–72. Available from: https://doi.org/10.1080/10934529.2017.1338892 105. Quiroz Guerrero I, Pérez Vázquez A. Vinaza y compost de cachaza: efecto en la calidad del suelo cultivado con caña de azúcar. Rev Mex Ciencias Agrícolas [Internet]. 2018 Jun 11;(5):1069–75. Available from: http://cienciasagricolas.inifap.gob.mx/editorial/index.php/agricolas/article/vi ew/1313 106. Bautista Zúñiga, Francisco, Durán de Bazúa, María del Carmen, Lozano, Rufino, Cambios químicos en el suelo por aplicación de materia orgánica soluble tipo vinazas. Revista Internacional de Contaminación Ambiental [Internet]. 2000;16(3):89-101. Available from: https://www.redalyc.org/articulo.oa?id=37016301 107. Carvalho L., Meurer I., Junior C., Santos C., Libardi PL. Spatial variability of soil potassium in sugarcane areas subjected to the application of vinasse. An Acad Bras Cienc [Internet]. 2014 Dec;86(4):1999–2012. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001- 37652014000401999&lng=en&tlng=en

55

108. Satyawali Y, Balakrishnan M. Wastewater treatment in molasses-based alcohol distilleries for COD and color removal: A review. J Environ Manage [Internet]. 2008 Feb;86(3):481–97. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0301479706004245 109. Salazar M. Vinaza proveniente de la caña de azúcar. 2018. Available from: http://cincae.org 110. Comisión de legislación y codificación. Ley De Prevención Y Control De La Contaminación. 2004;(907040):10–3. Available from: http://www.ambiente.gob.ec/wp-content/uploads/downloads/2012/09/LEY- DE-PREVENCION-Y-CONTROL-DE-LA-CONTAMINACION- AMBIENTAL.pdf 111. Ministerio del Ambiente. Norma de Calidad Ambiental y Descarga de Efluentes: Recuso Agua. Available from: https://www.ambiente.gob.ec/wp- content/uploads/downloads/2018/05/Acuerdo-097.pdf 112. What is Anaerobic Digestion? | American Biogas Council [Internet]. Americanbiogascouncil.org. [cited 7 August 2020]. Available from: https://americanbiogascouncil.org/resources/what-is-anaerobic-digestion/ 113. Costello DJ, Greenfield PF, Lee PL. Dynamic modelling of a single-stage high-rate anaerobic reactor—I. Model derivation. Water Res [Internet]. 1991 Jul;25(7):847–58. Available from: https://linkinghub.elsevier.com/retrieve/pii/004313549190166N 114. Siegrist H, Renggli D, Gujer W. Mathematical Modelling of Anaerobic Mesophilic Sewage Sludge Treatment. Water Sci Technol [Internet]. 1993 Jan 1;27(2):25–36. Available from: https://iwaponline.com/wst/article/27/2/25/2314/Mathematical-Modelling- of-Anaerobic-Mesophilic 115. Siegrist H, Vogt D, Garcia-Heras JL, Gujer W. Mathematical Model for Meso- and Thermophilic Anaerobic Sewage Sludge Digestion. Environ Sci Technol [Internet]. 2002 Mar;36(5):1113–23. Available from: https://pubs.acs.org/doi/10.1021/es010139p 116. Batstone DJ, Keller J, Angelidaki I, Kalyuzhnyi SV, Pavlostathis SG, Rozzi A, et al. The IWA Anaerobic Digestion Model No 1 (ADM1). Water Sci Technol [Internet]. 2002 May 1;45(10):65–73. Available from:

56

https://iwaponline.com/wst/article/45/10/65/6034/The-IWA-Anaerobic- Digestion-Model-No-1-ADM1 117. Barat R, Serralta J, Ruano M V., Jiménez E, Ribes J, Seco A, et al. Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants. Water Sci Technol [Internet]. 2013 Apr 1;67(7):1481–9. Available from: https://iwaponline.com/wst/article/67/7/1481/17562/Biological-Nutrient- Removal-Model-No-2-BNRM2-a 118. Duran Pinzón F. Modelación Matemática de Tratamiento Anaerobio de Aguas Residuales Urbanas incluyendo las Bacterias Sulfatorreductoras. Aplicación a un Biorreactor Anaerobio de Membranas. 2013. Available from: https://riunet.upv.es/handle/10251/34778?show=full 119. Navarrete C. Análisis de Sensibilidad de la Caracterización del Agua y de los Principales Parámetros del Modelo en el Tratamiento de Agua Residual Urbana mediante un Biorreactor Anaerobio de Membranas. 2016. Available from: https://riunet.upv.es/handle/10251/67875

57