DOCSLIB.ORG

Activated Carbon from Biomass Sustainable Sources

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Activated Carbon from Biomass Sustainable Sources Journal of C Carbon Research Review Activated Carbon from Biomass Sustainable Sources Yong X. Gan Department of Mechanical Engineering, California State Polytechnic University Pomona, 3801 W Temple Avenue, Pomona, CA 91768, USA; [email protected]; Tel.: +1-909-869-2388 Abstract: Biomass wastes are abundant around us. They are renewable and inexpensive. Product manufacturing from renewable resources has caught increasing interest recently. Activated carbon preparation from biomass resources, including various trees, leaves, plant roots, fruit peels, and grasses, is a good example. In this paper, an overview of activated carbon production from biomass resources will be given. The first part will be on the processing technologies. The second part will focus on the carbon activation methods. The third part will introduce the biomass resources. The fourth part will be on surface modification of activated carbon through the addition of various components. Finally, the development of product applications will be discussed with an emphasis on adsorption, filtration, water purification, energy conversions, and energy storage. Keywords: activated carbon; porous carbon; biomass resources; sustainable resources; processing technology; surface modification; adsorption; water purification; energy storage and conversions 1. Introduction One of the most important forms of carbon, called activated carbon, has a high surface area and a large volume of micropores. The specific surface area of activated 2 Citation: Gan, Y.X. Activated Carbon carbon can reach as high as 3000 m /g, which makes it very effective in the removal of from Biomass Sustainable Sources. C inorganic pollutants such as heavy metals from water [1]. Activated carbon has also been 2021, 7, 39. https://doi.org/10.3390/ studied for mercury removal from water [2,3]. Activated carbon is sometimes called active c7020039 carbon because it can participate in chemical reactions or it can be used as the support for catalysis. Recent applications of activated carbons are in the field of energy storage and Academic Editors: Jorge Bedia and conversions [4]. What are the differences between porous carbon and activated carbon? Martin Oschatz Generally speaking, porous carbon is characterized by its physicochemical properties, such as large surface area, large pore size range, relatively low density, etc. Activated carbon Received: 8 March 2021 refers to carbon materials experienced with the activation of their surfaces or modification Accepted: 26 April 2021 on the structures via functionalization, metal or oxide deposition, etc., for well-defined Published: 27 April 2021 applications. All activated carbons are porous carbons. However, not all porous carbons are activated carbons. The porosity of porous carbons spans a very wide range of pore Publisher’s Note: MDPI stays neutral sizes, while the activated carbons are, in essence, microporous materials. Although this with regard to jurisdictional claims in fundamental difference should not be overlooked, sometimes the boundary between the published maps and institutional affil- activated carbons and porous carbons may not be so distinct, especially from processing iations. and application perspectives. As will be discussed in next section, the pore generation and activation of carbon materials happen in the same process. Surface functionalization and activation result in pore generation simultaneously. Traditionally, activated carbon is made from coal or charcoal. However, making Copyright: © 2021 by the author. activated carbon from renewable resources is more intriguing because it is sustainable. The Licensee MDPI, Basel, Switzerland. carbonizing of naturally grown grass and tree leaves has been studied for various potential This article is an open access article industrial applications [5]. Date palm-tree branches (DPB) generated from the regular distributed under the terms and trimming of palm-trees were carbonized to generate an activated carbon product for toluene conditions of the Creative Commons adsorption [6]. Although some biomass may be directly used for the adsorption of cationic Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ dyes with high concentration at lower cost [7], activated sorbents after carbonization 4.0/). showed higher efficiency in dye removal [8]. Usually, curry tree (Murraya koenigii) stem C 2021, 7, 39. https://doi.org/10.3390/c7020039 https://www.mdpi.com/journal/carbon C 2021, 7, 39 2 of 33 is considered as an agricultural waste [9]. It is present in various vegetable markets. To convert it to a value-added product, carbonization of curry tree bark was conducted to generate activated carbon. The activated carbon was used to effectively remove the crystal violet dye from wastewater [9]. The abundance and diversity of bioresources are other reasons for the preparation of new activated carbon from woods, tree barks and leaves, grasses, and roots. In the following sections, recent development in various techniques for generating high performance and low cost activated carbon from representative renewable sources will be dealt with. The physical and chemical activation methods will be discussed. In the last part of the paper, typical applications of the activated carbons for gas adsorption, water purification, and energy storage will be presented. 2. Processing Techniques Activated carbon materials are made through three required processes. The first process is the pretreatment of biomass raw materials. The second process is carbonization. The third process is activation. During the pretreatment process, most of the nutrients and solvable impurities are removed. The carbonization process allows organic lignin and cellulose to be converted into carbonaceous materials. Carbonization also reduces the amount of water, nutrients, oxygen, hydrogen, sulfur, and other elements. Carbon loss may happen in the carbonization process due to heating to temperatures above 400 ◦C. With the increase of temperature, the grains in raw materials are dehydrated. The oxygen in the raw materials is released in forms of H2O, CO, CO2, etc. Such reaction products facilitate subsequent activation reactions [10]. Typically, the activation process follows carbonization. However, they may be conducted at the same time. The carbonaceous materials (biochars) can be activated by two different approaches: physical activation (PA), and chemical activation (CA). In the physical activation process, a raw material is activated in the temperature range from 750 to 1000 ◦C in a vacuum or inert gas atmosphere. In the chemical activation process, chemical agents are incorporated into raw materials. They are heated up together in an inert gas, and carbonization and activation occur simultaneously. Recently, chemical activation has been studied for processing high-performance activation carbons. There are some challenges associated with the chemical activation of carbon as well. A washing step is always required to remove byproducts following chemical activation. This washing, followed by drying, is typically time consuming, which is why physical activation is claimed as a more mature process used for producing most commercially available activated carbons. Considering the increased research interest in the chemical activation process, in the following subsections, the activated carbon processing techniques based mainly on the chemical activation approach will be discussed. 2.1. Pretreatment and Carbonization Activated carbon is made through the general procedures including pre-carbonization, carbonization, and activation. Sometimes a pre-treatment procedure is needed. As shown in [4], tamarisk-tree branches were collected as the starting material, and the pre-treatment was performed by soaking the tamarisk-tree branch in distilled water for 12 h. Then the sample was air dried at 60 ◦C for a sufficiently long period of time. The whole process for making activated carbon from the tree branch is schematically shown in Figure1a [ 4]. The abbreviation of FLC@BC in Figure1a stands for the “few-layer carbon@bulk carbon”, a unique structure due to the activation treatment of the tamarisk tree sample with the KOH solution. The pre-carbonization was carried out at 320 ◦C for 5 h. The carbonization and activation of the sample are shown in more detail in [4]. Briefly, a typical pre-carbonized sample with a weight of 1 g was soaked in 20 mL KOH solution for a day. For multiple experiments, the mass ratios of the pre-carbonized product to KOH were kept as 1:1, 2:1, 3:1, 5:1, and 7:1, respectively. The samples were dried and then carbonized at 700 ◦C for 2 h in N2. Then, the samples were washed by 1 wt% HCl solution and distilled water until the pH value reached 7. For comparative studies, the product carbonized at 700 ◦C for C 2021, 7, x FOR PEER REVIEW 3 of 33 C 2021, 7, 39 3 of 33 kept as 1:1, 2:1, 3:1, 5:1, and 7:1, respectively. The samples were dried and then carbonized at 700 °C for 2 h in N2. Then, the samples were washed by 1 wt% HCl solution and distilled water until the pH value reached 7. For comparative studies, the product carbonized at 2700 h without °C for 2 soakingh without in soaking KOH solution in KOH wassolution made. was Figure made.1b Figure shows 1b optical shows images optical ofimages the tamariskof the tamarisk tree and tree branches. and branches. Under scanningUnder scan electronning electron microscope, microscope, the tamarisk the tamarisk tree branch tree samplebranch demonstratedsample demonstrated a porous a microstructure,
Load more

Recommended publications
  • Capture and Reuse of Carbon Dioxide (CO2) for a Plastics Circular Economy: a Review
    processes Review Capture and Reuse of Carbon Dioxide (CO2) for a Plastics Circular Economy: A Review Laura Pires da Mata Costa 1 ,Débora Micheline Vaz de Miranda 1, Ana Carolina Couto de Oliveira 2, Luiz Falcon 3, Marina Stella Silva Pimenta 3, Ivan Guilherme Bessa 3,Sílvio Juarez Wouters 3,Márcio Henrique S. Andrade 3 and José Carlos Pinto 1,* 1 Programa de Engenharia Química/COPPE, Universidade Federal do Rio de Janeiro, Cidade Universitária, CP 68502, Rio de Janeiro 21941-972, Brazil; [email protected] (L.P.d.M.C.); [email protected] (D.M.V.d.M.) 2 Escola de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, CP 68525, Rio de Janeiro 21941-598, Brazil; [email protected] 3 Braskem S.A., Rua Marumbi, 1400, Campos Elíseos, Duque de Caxias 25221-000, Brazil; [email protected] (L.F.); [email protected] (M.S.S.P.); [email protected] (I.G.B.); [email protected] (S.J.W.); [email protected] (M.H.S.A.) * Correspondence: [email protected]; Tel.: +55-21-3938-8709 Abstract: Plastic production has been increasing at enormous rates. Particularly, the socioenvi- ronmental problems resulting from the linear economy model have been widely discussed, espe- cially regarding plastic pieces intended for single use and disposed improperly in the environment. Nonetheless, greenhouse gas emissions caused by inappropriate disposal or recycling and by the Citation: Pires da Mata Costa, L.; many production stages have not been discussed thoroughly. Regarding the manufacturing pro- Micheline Vaz de Miranda, D.; Couto cesses, carbon dioxide is produced mainly through heating of process streams and intrinsic chemical de Oliveira, A.C.; Falcon, L.; Stella transformations, explaining why first-generation petrochemical industries are among the top five Silva Pimenta, M.; Guilherme Bessa, most greenhouse gas (GHG)-polluting businesses.
    [Show full text]
  • Polycyclic Aromatic Hydrocarbon Migration from Creosote-Treated Railway Ties Into Ballast and Adjacent Wetlands
    United States In cooperation Department of with the Agriculture Polycyclic Aromatic United States Forest Service Department of Transportation Hydrocarbon Migration Forest Products Federal Laboratory Highway Administration From Creosote-Treated Research Paper FPL−RP−617 Railway Ties Into Ballast and Adjacent Wetlands Kenneth M. Brooks Abstract from the weathered ties at this time. No significant PAH loss was observed from ties during the second summer. A Occasionally, creosote-treated railroad ties need to be small portion of PAH appeared to move vertically down into replaced, sometimes in sensitive environments such as the ballast to approximately 60 cm. Small amounts of PAH wetlands. To help determine if this is detrimental to the may have migrated from the ballast into adjacent wetlands surrounding environment, more information is needed on during the second summer, but these amounts were not the extent and pattern of creosote, or more specifically poly- statistically significant. These results suggest that it is rea- cyclic aromatic hydrocarbon (PAH), migration from railroad sonable to expect a detectable migration of creosote-derived ties and what effects this would have on the surrounding PAH from newly treated railway ties into supporting ballast environment. This study is a report on PAH level testing during their first exposure to hot summer weather. The PAH done in a simulated wetland mesocosm. Both newly treated rapidly disappeared from the ballast during the fall and and weathered creosote-treated railroad ties were placed in winter following this initial loss. Then statistically insignifi- the simulated wetland. As a control, untreated ties were also cant vertical and horizontal migration of these PAH suggests placed in the mesocosm.
    [Show full text]
  • Characterization of Activated Carbon Produced from Coffee Residues by Chemical and Physical Activation
    Activated carbon Characterization of activated carbon produced from coffee residues by chemical and physical activation JAVIER SÁNCHEZ AZNAR KTH Chemical Science and Engineering Master Thesis in Chemical Engineering Stockholm, Sweden, March 2011 - 1 - Activated carbon List of figures PART 1 Fig 1.1 Representation of the structure of activated carbons (H. Fritzst Oeckli 1990)(47).7 Fig 1.2 The six isotherm types according to IUPAC……………………………………...8 Fig 1.3 Representation of the three types of pores according to the IUPAC………….....14 Fig 1.4 Texture of dust activated carbon………………………………………………...19 Fig 1.5 Texture of granular activated carbon…………………………………………….19 Fig 1.6 Structure of a coffee bean………………………………………………………..23 PART 2 Fig 2.1 Furnace employed for carbonization…………………………………………….31 Fig 2.2 Magnetic stirrer during HCL washing…………………………………………..32 Fig 2.3 Steam activation system…………………………………………………………33 Fig 2.4 ASAP instrument………………………………………………………………...34 PART 3 Fig 3.1 Results of yields for 30%, 40% and 50% samples by chemical activation at different temperatures…………………………………………………………………....38 Fig 3. 2. Results of yields for samples activated by steam at different temperatures……39 Fig 3.3 Results of volatile and ash content by chemical and steam activation…………..40 Fig 3.4 Results of BET surface area (m 2/g)……………………………………………...42 Fig 3. 5 Isotherm of the sample CA_3_500……………………………………………...44 Fig 3.6 Isotherm of the sample CA_3_600……………………………….……………...44 Fig 3.7 Isotherm of the sample CA_3_700……………………………….……………...44 Fig 3.8 Isotherm of the
    [Show full text]
  • Hardwood-Distillation Industry
    HARDWOOD-DISTILLATION INDUSTRY No. 738 Revised February 1956 41. /0111111 110 111111111111111111 t I 1, UNITED STATES DEPARTMENT OF AGRICULTURE FOREST PRODUCTS LABORATORY FOREST SERVICE MADISON 5, WISCONSIN. In Cooperation with the University of Wisconsin 1 HARDWOOD-DISTILLATION INDUSTRY— By EDWARD BEGLINGER, Chemical Engineer 2 Forest Products Laboratory, — Forest Service U. S. Department of Agriculture The major portion of wood distillation products in the United States is obtained from forest and mill residues, chiefly beech, birch, maple, oak, and ash. Marketing of the natural byproducts recovered has been concerned traditionally with outlets for acetic acid, methanol, and charcoal. Large and lower cost production of acetic acid and methanol from other sources has severely curtailed markets formerly available to the distillation in- dustry, and has in turn created operational conditions generally unfavor- able to many of the smaller and more marginal plants. Increased demand for charcoal, which is recovered in the largest amount as a plant product, now provides a compensating factor for more favorable plant operation. The present hardwood-distillation industry includes six byproduct-recovery plants. With the exception of one smaller plant manufacturing primarily a specialty product, all have modern facilities for direct byproduct re- covery. Changing economic conditions during the past 25 years, including such factors as progressively increasing raw material, equipment, and labor costs, and lack of adequate markets for methanol and acetic acid, have caused the number of plants to be reduced from about 50 in the mid- thirties to the 6 now operating. In addition to this group, a few oven plants formerly practicing full recovery have retained the carbonizing equipment and produce only charcoal.
    [Show full text]
  • Bibliography of Wood Distillation
    Bibliography of WoodDistillation T.CL[). Compiled by Gerald A.Walls Arranged by Morrie Craig BibliographY 5 October 1966 For.stProductsResearch FOREST RESEARCHLABORATORY OREGON STATEUNIVERSITY Corvallis PROGRAM AND PURPOSE The Forest Research Laboratoryof the School of Forestry combines a well-equipped laboratory witha staff of forest and wood scientists in program designed to improve the forestresource and promote full uti- lization of forest products. Theextensive research done by the Labora tory is supported by the forest industryand by state and federal funds. The current report results fromstudies in forest products, where wood scientists and technologists,chemists, and engineers are con- cerned with properties, processing,utilization, and marketing of wood and of timber by-products. The PROGRAM of research includes identifying and developing chemicals fromwood, improving pulping of wood and woodresidues, investigating and improving manufacturingtechniques, extending life of wood by treating, developing better methods ofseasoning wood for higher quality and reduced costs, cooperating with forest scientists to determineeffects of growing conditionson wood properties, and evaluating engineering properties ofwood and wood- based materials and structures. The PURPOSE of researchon forest products is to expand markets, create new jobs, and bringmore dollar returns, thus advancing the interests of forestry and forestindustries, by > developing products from residuesand timber now wasted, and > improving treatment and designof present wood products. Table of Contents INTRODUCTION 3 BOOKS 4 ARTICLES AND BULLETINS 5 PATENTS 46 Australia 46 Austria 46 Be1giun 46 Canada 47 Czechoslovakia 47 Denmark 47 France 47 Germany 51 Great Britain 52 India 55 Italy 55 Japan 55 Netherlands 56 Norway 56 Poland 56 Russia 56 Spain 57 Sweden 57 Switzerland 58 United States 59 Bibliography of Wood Distillation INTRODUCTION This bibliography is a revision and extension to1964 of Bibli- ography of Wood Distillation, 1907-1953published in 1955.
    [Show full text]
  • 1343-1351, 2007 © 2007, Insinet Publication
    Journal of Applied Sciences Research, 3(11): 1343-1351, 2007 © 2007, INSInet Publication Effects of H34PO and KOH on Pyrolysis of Bituminous Coal in Preparation of Activated Carbon 11Baba Jibril, Rashid S. Al-Maamari, 2Omar Houache, 1Mousa Al-Aamri and 1AlMutasim Al-Qalhati 1Petroleum and Chemical Engineering Department, Sultan Qaboos University, PO Box 33, Al Khod, PC 123, Muscat, Oman. 2Oman Polypropylene LLC, Sohar Industrial Port Complex, P.O. Box 277, Postal Code 322, Flag Al-Qabail, Sohar, Sultanate of Oman. Abstract: Effects of H34PO and KOH on the degree of pyrolysis of bituminous coal to obtain activated carbon were studied. Different chemicals to coal impregnation ratios - H34PO /coal (0.0 – 4.25) and KOH/coal (0.0 - 3.0) - were carbonized at different temperatures (450, 450 or 600 oC). The respective acid or base addition to the precursor exhibited marked differences in the true densities, SEM micrographs, BET surface areas and pore volumes of the activated carbon. Microporous samples were obtained with average pore diameters in the range of 17.4 to 21.4 Å. Increase in H34PO concentration showed increase in porosity and surface area at all temperatures. Addition of KOH led to higher surface area, more porous structure with wider pore size distributions than that of acid. At high temperatures (550 or 650 oC), the average pore diameters were observed to be less dependent on the nature of the chemical used. Keyword: activated carbon, chemical activation, SEM, surface area, porosity INTRODUCTION could lead to a more microporous structure suitable for gas storage[15]. However, similar post-treatment attempt Coals are favored precursors for preparation of using air gasification exhibited no significant changes activated carbon.
    [Show full text]
  • INVESTIGATION of POLYCYCLIC AROMATIC HYDROCARBONS (Pahs) on DRY FLUE GAS DESULFURIZATION (FGD) BY-PRODUCTS
    INVESTIGATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) ON DRY FLUE GAS DESULFURIZATION (FGD) BY-PRODUCTS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Ping Sun, M.S. ***** The Ohio State University 2004 Dissertation Committee: Approved by Professor Linda Weavers, Adviser Professor Harold Walker Professor Patrick Hatcher Adviser Professor Yu-Ping Chin Civil Engineering Graduate Program ABSTRACT The primary goal of this research was to examine polycyclic aromatic hydrocarbons (PAHs) on dry FGD by-products to determine environmentally safe reuse options of this material. Due to the lack of information on the analytical procedures for measuring PAHs on FGD by-products, our initial work focused on analytical method development. Comparison of the traditional Soxhlet extraction, automatic Soxhlet extraction, and ultrasonic extraction was conducted to optimize the extraction of PAHs from lime spray dryer (LSD) ash (a common dry FGD by-product). Due to the short extraction time, ultrasonic extraction was further optimized by testing different organic solvents. Ultrasonic extraction with toluene as the solvent turned out to be a fast and efficient method to extract PAHs from LSD ash. The possible reactions of PAHs under standard ultrasonic extraction conditions were then studied to address concern over the possible degradation of PAHs by ultrasound. By sonicating model PAHs including naphthalene, phenanthrene and pyrene in organic solutions, extraction parameters including solvent type, solute concentration, and sonication time on reactions of PAHs were examined. A hexane: acetone (1:1 V/V) ii mixture resulted in less PAH degradation than a dichloromethane (DCM): acetone (1:1 V/V) mixture.
    [Show full text]
  • Indirect Drying and Coking Characteristics of Coking Coal with Soda Residue Additive
    energies Article Indirect Drying and Coking Characteristics of Coking Coal with Soda Residue Additive Ze Zhang and Shuting Zhang * School of Environment Science and Engineering, Tianjin University, Tianjin 300350, China; [email protected] * Correspondence: [email protected]; Tel.: +86-150-7687-5579 Abstract: To improve indirect drying efficiency, the effect of soda residue on the drying characteristics of coking coal were studied using a self-made indirect drying system. A tube furnace was used in the dry distillation of coal samples with soda residue, and the coke properties were analyzed. The results indicated that the soda residue has a significant influence on the increase in the heating rate of coal samples in the temperature distribution range of 90 to 110 ◦C. With the addition of 2%, 5%, and 10% soda residue, the drying rates increased by 11.5%, 25.3%, and 37.3%, respectively at 110 ◦C. The results of dry distillation show that addition of 2%, 5% and 10% soda residue decreases the carbon loss quantity by 4.67, 4.99, and 8.82 g, respectively. The mechanical strength of coke samples satisfies the industrial conditions when the soda residue ratio ranges from 2% to 5%. Soda residue can improve the active point of coke dissolution reaction and inhibit coke internal solution. Economically, coking coal samples mixed with soda residue have an obvious energy saving advantage in the drying process. Energy saving analysis found that it can reduce cost input by 20% than that of the normal drying method. Keywords: coking coal; soda residue; indirect drying; coking characteristics; benefits Citation: Zhang, Z.; Zhang, S.
    [Show full text]
  • Modern Technology of Dry Distillation of Wood
    Modern technology of dry distillation of wood Michał LEWANDOWSKI, Eugeniusz MILCHERT – Institute of Chemical Organic Technology, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin Please cite as: CHEMIK 2011, 65, 12, 1301-1306 Nowadays the process of dry (destructive) distillation of wood is Wood gas from dry distillation contains (%wt.): CO2 40-55, carried out in a periodical (batch) or continuous manner. In the former CO 26-35, CH4 3-10, C2H4 2, H2 1-4. It is often used for steam case steel (mobile) retort furnaces are used, while in the latter case, generation for captive use at the distillation plant or in nearby facilities, science • technique retorts included in automated plants. In both cases temperature during or directly as fuel for heating the retort. The mean heating value the process is gradually increased from 200°C to 600°C, with limited of the gas is 8.4-12.6 MJ/m3. This gas under war conditions was used admission of air. The products of the processes taking place include, for driving internal combustion engines. in addition to charcoal, a distillate comprising gases and vapours. Liquid distillates, upon collection and settling in tanks, separate The gaseous components include carbon dioxide, carbon monoxide, and form a settled tar layer and a water solution called pyroligneous hydrogen, methane and ethylene. Vapours contain mainly methanol, acid, the latter containing acetic acid, methanol, acetone, methyl acetic acid, acetone, formic acid, propionic aldehyde and acid. They acetate and tar components. After vacuum distillation in multiple- also contain components that condense to form wood tar.
    [Show full text]
  • Activated Carbons Derived from High-Temperature Pyrolysis of Lignocellulosic Biomass
    Journal of C Carbon Research Article Activated Carbons Derived from High-Temperature Pyrolysis of Lignocellulosic Biomass Cristian I. Contescu 1,* , Shiba P. Adhikari 1 , Nidia C. Gallego 1,*, Neal D. Evans 2 and Bryan E. Biss 2 1 Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; [email protected] 2 Proton Power, Inc., Lenoir City, TN 37771, USA; [email protected] (N.D.E.); [email protected] (B.E.B.) * Correspondence: [email protected] (C.I.C.); [email protected] (N.C.G.); Tel.: +1-865-241-3318 (C.I.C.); +1-865-241-9459 (N.C.G.) Received: 17 August 2018; Accepted: 10 September 2018; Published: 12 September 2018 Abstract: Biomass pyrolysis to produce biofuel and hydrogen yields large amounts of charred byproducts with low commercial value. A study was conducted to evaluate their potential for being converted into higher value activated carbons by a low-cost process. Six chars derived from various ◦ lignocellulosic precursors were activated in CO2 at 800 C to 30–35% weight loss, and their surface area and porosity were characterized by nitrogen adsorption at 77 K. It was found that, in similar activation conditions, the surface area of the activated carbons correlates with the activation energy of the oxidation reaction by CO2, which in turn varies inversely with the carbon yield after thermolysis in nitrogen at 1000 ◦C. Since lignin is the most thermally-stable component of lignocellulosic biomass, these results demonstrate, indirectly, that robust, lignin-rich vegetal precursors are to be preferred to produce higher quality activated carbons.
    [Show full text]
  • Hydrothermal Carbonization of Municipal Waste Streams
    ARTICLE pubs.acs.org/est Hydrothermal Carbonization of Municipal Waste Streams ,† ‡ § † || Nicole D. Berge,*^ Kyoung S. Ro, Jingdong Mao, Joseph R. V. Flora, Mark A. Chappell, and Sunyoung Bae † Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, South Carolina 29208, United States ‡ USDA-ARS Coastal Plains Soil, Water, and Plant Research Center, 2611 West Lucas Street, Florence, South Carolina 29501, United States §Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, Virginia 23529, United States Environmental) Laboratory, U.S. Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States ^ Department of Chemistry, Seoul Women’s University, 139-774 126 Gongreung-Dong, Nowon-Gu, Seoul, Korea bS Supporting Information ABSTRACT: Hydrothermal carbonization (HTC) is a novel thermal conver- sion process that can be used to convert municipal waste streams into sterilized, value-added hydrochar. HTC has been mostly applied and studied on a limited number of feedstocks, ranging from pure substances to slightly more complex biomass such as wood, with an emphasis on nanostructure generation. There has been little work exploring the carbonization of complex waste streams or of utilizing HTC as a sustainable waste management technique. The objectives of this study were to evaluate the environmental implications associated with the carbonization of representative municipal waste streams (including gas and liquid products), to evaluate the physical, chemical, and thermal properties of the produced hydrochar, and to determine carbonization energetics associated with each waste stream. Results from batch carbonization experiments indicate 49À75% of the initially present carbon is retained within the char, while 20À37% and 2À11% of the carbon is transferred to the liquid- and gas-phases, respectively.
    [Show full text]
  • Characterization of Chemically and Physically Activated Carbons From
    energies Article Characterization of Chemically and Physically Activated Carbons from Lignocellulosic Ethanol Lignin-Rich Stream via Hydrothermal Carbonization and Slow Pyrolysis Pretreatment Edoardo Miliotti 1 , Luca Rosi 1,2 , Lorenzo Bettucci 1, Giulia Lotti 1, Andrea Maria Rizzo 1 and David Chiaramonti 1,3,* 1 Renewable Energy Consortium for Research and Demonstration—RE-CORD, Viale Kennedy 182, Scarperia, 50038 Florence, Italy; [email protected] (E.M.); luca.rosi@unifi.it (L.R.); [email protected] (L.B.); [email protected] (G.L.); [email protected] (A.M.R.) 2 Department of Chemistry, University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy 3 “Galileo Ferraris” Energy Department, Polytechnic of Turin, Corso Duca Degli Abruzzi 24, I-10129 Torino, Italy * Correspondence: [email protected] Received: 24 June 2020; Accepted: 5 August 2020; Published: 7 August 2020 Abstract: The aim of the present work is to investigate the possibility of producing activated carbons from the residual lignin stream of lignocellulosic ethanol biorefineries, as this represents an optimal opportunity to exploit a residual and renewable material in the perspective of sustainable bioeconomy, increasing biorefinery incomes by producing value-added bioproducts in conjunction with biofuels. Activated carbons (ACs) were produced via chemical (KOH) and physical (CO2) activation. Char samples were obtained by slow pyrolysis (SP) and hydrothermal carbonization (HTC). Several HTC experiments were carried out by varying residence time (0.5–3 h) and reaction temperature (200–270 ◦C), in order to evaluate their influence on the product yield and on the morphological characteristics of the hydrochar (specific surface area, total pore volume and pore size distribution).
    [Show full text]