sign in sign up
<<
Home , Syngas fermentation

Reducing the Footprint of and Petrochemicals DGMK Conference October 8 – 10, 2012, Berlin, Germany

Low Carbon and Chemical Production from Waste Gases S. Simpson; F.M. Liew, J Daniell, M. Köpke LanzaTech, Ltd., Auckland, New Zealand

Abstract LanzaTech has developed a gas platform for the production of alter native transport fuels and commodity chemicals from , and containing gases. LanzaTech technology uses these gases in place of sugars as the carbon and source for fermentation ther eby allowing a broad spectrum of resources to be considered as an input for product synthesis. At the core of the la nzatech process is a proprietary microbe capable of using gases as the only carbon and energy input for product synthesis. To harness this capability for the manufature of a diverse range of commercially valuable products, the company has developed a robust synthetic biology platform to enable a variety of novel molecules to be synthesised via gas fermentation.

LanzaTech initially focused on the fe rmentation of industrial waste gases for fuel et hanol production. The company has been operating pilot plant that uses direct feeds of stee l making off gas for production for over 24 months. This platform technology has been further successfully demonstrated using a broad range of gas inputs including gasified biomass and reformed natural gas. LanzaTech has developed the fermentation, engineering and control systems necessary to efficiently convert gases to valua ble products. A pre- commercial demonstration scale unit processing steel mill waste gases was commissioned in China during the 2nd quarter of 2012. Subsequent scale-up of this facility is projected for the 2013 and will represent the first world scale non-food based low carbon ethanol project.

More recently LanzaTe ch has d eveloped proprietary microbial cat alysts capable of converting carbon dioxide in th e presence of hydrogen directly to value added chemicals, where-in CO2 is the sole source of carbon for product synthesis. Integr ating the LanzaTech technology into a number of indu strial facilities, such as steel mills, oil refineries and other industries that emit Carbon bearing waste gases, can reduce while producing transportation fuels and chemicals to enhance overall profitability.

Introduction Rising demand for tra nsportation fuels and diminishing reserves of fossil-based fuel sources, coupled with concerns over carbon dio xide (CO2) emission-driven climate change have led to a compellin g need for new, more sources [1]. Biof uels have

DGMK-Tagungsbericht 2012-3, ISBN 978-3-941721-26-5 107 Reducing the Carbon Footprint of Fuels and Petrochemicals

been advocated as a promising alternative to the use of fossil re sources in the rapidly growing transportation fuels sector. Consumption mandates and fiscal incentives h ave been enacted to encourage a transition to biofuels [ 2]. For example, the European Union (EU) Directive requires that biofuels comprise 10% of the me mber states’ liquid fuels market by 2020 [3]. In the United States, the E nergy Independence and Security Act of 2007 mandates the consumption of 35 billion gallons of ethanol-equivalent biofuels by 2022 [4].

The use and production of biofuels has a long history, starting with the inventors Nikolaus August Otto and Rudolph Diesel, who already envisioned the use of biofuels such as ethanol and natural oils when developing the first Otto cycle co mbustion and diesel e ngines [5]. While fermentative production of et hanol has been used for thousands of years, mainly for brewing beer starting in Mesopotamia 5000 B.C., fermentative p roduction of another potential biofuel , has only been discovered over the last century, but had significan t impact. During the World War 1, Chaim Weiz mann successfully applied a proce ss called ABE (acetone-butanol-ethanol) fermentation using the anaerobic bacterium Clostridium acetobutylicum to generate industrial scale acetone (for cordites, the propellant of cartridges and shells) from starchy materials [ 5,6]. His contribution was later recognised in t he Balfour declaration in 1917 and he became the first president of the newly founded State of Israel [5,6]. Intriguingly, the e normous potential of butanol produced at that t ime was not realized and the substance was simply stored in huge containers [5]. ABE fer mentation became the second biggest ever biotechnological process ( after the ethanol fermentation process) ever performed, but the low demand of acetone following the conclusion of the war led to closure of all the plants [6]. Although ABE f ermentation briefly made a comeback during the Second World War, increasing substrate costs and increasing stable supply of low cost crude oil from the Middle East rendered the technology economically unviable.

Traditionally sugar substrates derived from food crops such as sugar cane, corn (maize) and sugar beet have been the preferred feedstocks for the production of biofuels. However, world raw sugar prices have witn essed significant volatility o ver the last decad e or so, ranging from US$216/ton in year 2000 to a 30 year high of US$795/ton in February 2011 due to global sugar deficit s and crop shortfall [7].This has created uncertainty and raised issues ab out its u se as a feedst ock for large scale biofuel production. This paper aims to shed light on the use of and industrial waste gas as feedstocks, and the emerging field of gas fermentation to generate not only biofuels, but also other high-value added products. The advantages of gas fe rmentation over conventional sug ar-based fermentation and thermochemical co nversions, and their flexibility in util izing a spectrum of feedstocks to generate syngas will be discussed.

DGMK-Tagungsbericht 2012-3 108 Reducing the Carbon Footprint of Fuels and Petrochemicals

Advantages of gas fermentation In recent times lignocellulosic biomass has been increasingly viewed as a wide ly available, sustainable, non-food resource that may be used as a feedstock for the production of fuels at scale. A range of technologies to convert the carbohydrate fraction of t his resource, such as the use of cellulolytic to ferment lignocellulosic biomass directly to fuels are being investigated. However, such strategies h ave been hampered by high-pre-treatment costs and an inability to utilize the lignin fraction of biomass, which can represent up to 40 wt% of this resource. An alternative approac h is gas fe rmentation, which uses biomass gasification as a pre-tre atment. Via this approach the fee dstock is gasified ent irely into a carbon monoxide (CO), carbon dioxide (CO2) and hydrogen (H2)-rich synthesis gas (syngas) and then microorganisms known as acetoge ns are employed to ferment the syngas into biofuels such as etha nol and bu tanol, and platform chemicals such as 2,3-b utanediol. Furthermore, some ind ustrial processes such as steel making, natural gas reforming, oil refining and chemical production ge nerate large volumes of CO-rich off gases which can be used as feedstocks for gas fermentation.

Microorganisms such as , carboxytro phs and methanogens are able to utilize the CO2 + H2, and/or CO available in such syngas as their sole source of carbon and energy for growth as well as th e production of biofuels and other valuable pro ducts. However, only acetogens are described to synthesize metabolic end produ cts that have potentials as liquid transportation fuels. While biological processes are gen erally considered slow er than chemical reactions, the use of these microbes to carry out syngas fermentation offers several key advantages over alt ernative thermo-chemical approaches such as the Fischer-Tropsch’ process (FTP). First, microbial processes o perate at ambient temperatures and low pressures which offer significant energy and cost savings. Second, the ambient conditions and irreversible natur e of biolo gical reactions also a void thermodynamic equilibrium relationships and allow near complete conversion efficiencies [8,9,10,11,12 ].Third, biological conversions are commonly more specific due to high enzymatic specificities, resulting in higher product yield with the formation of fe wer by-products. Fourth, unlike tr aditional chemical catalysts which require a set feed gas composition to yield desired product ratios or suite, microbial processes have freedom to operate for the production of the same suite of products across a wider range of CO:H2 ratios in the feed gas [10,1,12]. Fifth, biocatalysts exhibit a much higher t olerance to poisoning by tars, sulp hur and chlorine than inorganic catalysts [10,1,12].

The last tw o points, th e ability to i nterchangeably use a r ange of CO:H2 ratios f or the production of a specific product; and the ability to tolerate a range of compounds traditionally thought of as contaminants, are of particular significance and are exemplified by La nzaTech gas fermentation technology. LanzaTech has demonstrated its gas fermentation process with a range of gaseous resources, from CO-rich (H2-poor) off-gases prod uced as an inevitable consequence of steel manufacture, to reformed and bio mass syngas. These

DGMK-Tagungsbericht 2012-3 109 Reducing the Carbon Footprint of Fuels and Petrochemicals

examples represent input gases with a CO:H2 ra tio of between 50:1 (steel mill off gases) to 1:2. However, due to the operation of a biological water-gas-shift reaction within the bacteria, in each case the fermentation process can be operated such that it is able to efficiently and specifically produce fuel ethanol as by far the dominant product. Furthermore, each of these gas resources is associated with th e presence of a range o f potential process contaminants in the gas stream. LanzaTech has been operating a gas fermentation pilot facility at th e BlueScope Steel mill in Glenbrook, New Zealand for over 24 months. In this facility, off gases produced by the steel making pr ocess are delivered directly to th e gas fermentation installation with minimal intervening gas scrubb ing (gas cle aning consists of dust and O2 removal). The gas supply contains varying levels of different contaminating species such as H2S, SO2, CO2, and N2. This facility operates as a continuous fer mentation process to produce ethanol, unaffected by the varying contaminant content of the feed gas.

Production opportunities

Acetogens are a group of bacteria capable of fermenting CO and/or CO 2 and H2 into acetyl-CoA and from there into , ethanol and other metabolic end-products, via the reductive acetyl-CoA pathway. The reductive acetyl-CoA pathway, also known as the Wood- Ljungdahl pathway, was first chara cterised by Harland G. Wood and Lars G. Ljungdahl i n

1966 when they proposed a scheme for the synthesis of a cetate from CO2 by the Clostridium thermoaceticum, now classified as Moorella thermoacetica [13,14]. Variations of this pathway are also found in methanogenic and sulphate-reducing ; however, only acetogens are kno wn to synthesize metab olic end-products that can be used as liquid transportation fuels. The biochemistry of this pat hway has been comprehensively described in numerous reviews [13-18], inclu ding those by Wood and Ljungda hl themselves [13, 14, 15], Stephen W. Ragsdale and co-workers [16, 17], or Harold Drake and co-workers [18]. It is hypothesised that the reductive acetyl-CoA p athway was one of the first biochemical pathways, used by the first autotrophs ca. 3.8 billion years ago [19,2 0]. These o rganisms used CO a nd H2 as e nergy sources and CO 2 as an electron accept or approximately one billion years before significant quantities of O2 appeared in the earth’s atmosphere [19, 20].

LanzaTech have developed two p roprietary strains of gas fermenting bacteria from Clostridium autoethanogenum. These strains are able to co-produce ethanol and a four- carbon platform chemical 2,3-butanediol at various co-production ratios [21].

The main market for ethanol is a s a b lending agent in gasoline, and LanzaTech has demonstrated that ethanol can be produced by i ts gas fermentation technology at both low cost and in high volumes from a r ange of ga s resources. 2,3-Butanediol is a h igh value chemical used as a precursor in the manufactu re of industrial solvents methyl et hyl ketone (MEK), and 1,3-butadiene. Its downstream products have a global market of over $40 billion per annum, and it is traditionally produced petro-chemically. LanzaTech has been working with partners such as Orochem to optimise an economic separation technology to purify 2,3-

DGMK-Tagungsbericht 2012-3 110 Reducing the Carbon Footprint of Fuels and Petrochemicals

butanediol from fermentation broth, and Pacific Northwest National Laboratories ( PNNL) to demonstrate routes for the conve rsion of 2, 3-butanediol into derivatives such as 1,3- butadiene and MEK. Furthermore, the compa ny recently announced a partnership with global nylon producer INVISTA to produce bio-based 1,3 butadiene, first by a two-step process using LanzaTech's carbon monoxide-based 2,3-butanediol; and in the long-term, b y directly producing carb on monoxide-based butadiene in a single step process using gas fermentation.

Through metabolic engineering, routes to drop in fuels such as isobut anol or farnesene have been demonstrated in E. coli and yeast [ 22]. These molecular technologie s are now being developed for acetogens, providing a p ath for the production of an ever broadening spectrum of fuels an d traditional petrochemical products by feedstock-flexible gas fermentation. LanzaTech has, for the past se veral years, been build ing a capa bility to introduce stable genetic modifications into its proprietary bacterial strains in order that either process improvements or new produ ct capability can be conferred on new, modified, stains. Through this program t he company has demo nstrated modifications than allow enhanced ethanol tolerance, and the co-production of novel molecu les including butanol, propanol, acetone, succinic acid and 3-hydroxypropionate. The genome knowledge, genetic tools and genome modification capability, all focused on gas ferme nting acetogens, developed by LanzaTech is the found ation of a platform technology that will allow th e company to offer production systems for a multitude of fuel and chemical products from sustainable resources.

DGMK-Tagungsbericht 2012-3 111 Reducing the Carbon Footprint of Fuels and Petrochemicals

More recently LanzaTech has developed a n ew gas fermentation process cap able of converting carbon dioxide in th e presence of hydrogen directly to value added chemicals, where-in CO2 is the sole source of carbon for product synthesis, as illustrated below:

The pathway entails the conversion of CO 2 to acetate which is subsequently converted to fuels and chemicals. While still in a development and scale-up phase, this process promises to provide greater mo netization opportunities for CO2 streams via unique int egration schemes, whilst also ca pturing fossil carbon in valuable products, in eff ect carbon capture and utilization.

Process Scale up An optimum gas fermentation system r equires efficient mass transfer of gaseous substrates to the culture medium (liquid phase) and microbial catalysts (solid phase). While numerous designs of reactor have been tested and described in the literature, given the novel nature of at-sca le gas fermentation and th e need to e nsure process energy efficiency when producing commodities va lued, among other things, on their energy content, LanzaTech has opte d to develop and de monstrate at scale a proprietary reactor configuration. LanzaTech has successfully demonstrated the operatio n its rea ctor design, and at scal e process capability at its BlueScope Steel pi lot facility in Glenbrook, NZ. The company has recently started operating its 100,000 gallon per year bioethanol demonstration facility in Shanghai, China, using waste gas produced by an adjacent steel mill owned by its

DGMK-Tagungsbericht 2012-3 112 Reducing the Carbon Footprint of Fuels and Petrochemicals

Joint Venture partner Baosteel Group [23, 24] LanzaTech is planning to begin construction of a commercial facility with the capacity to produce 50 million gallon of bioethanol per annum in China in 2013 (243). The recent acquisiti on of a biorefinery facility in Georgia name s Freedom Pines, and a milestone signing of its first commercial customer, Concord Enviro Systems (India), highlighted LanzaTech’s intention to utilize MSW and lignocellulosic waste as feedstocks for biofuel and chemical production [23, 24]

Summary The use of gas fermentation for the production of low carbon biofuels such as ethanol or butanol from lignocellulosic biomass is an are a currently undergoing intensive research and development, with the first commercial unit s expected to commence o peration in t he near future. In this process, gas resources either produced through the gasification of r esources such as b iomass and municipal solid waste, reforming of natural ga s or availab le as by- product streams from establishe d industrial processe s such as steel manufacture are fermented to hydrocarbons by acetogenic bacteria. This strategy offers numerous advantages compared with established fermentation and purely thermochemical approaches to biofuel pr oduction in terms of feedstock f lexibility and p roduction cost. In rece nt times, metabolic engineering and synthetic biology techniques have been applied to gas fermenting organisms, paving the way for ga ses to be used as th e feedstock for the commercial production of increasingly energy dense fuels and more valuable chemicals.

LanzaTech has developed a gas fermentation technology platform for the production of a spectrum of fuel and chemical products from a board range of gas feedstocks. The company has not only begun demonstrating its te chnology at large scale with real-world industria l feedstocks for the production of etha nol, but has also create d an industry leading position in the production of new, valuable, products via this efficient path to fuels and chemical synthesis.

References 1. Stern, N. The Stern Review on the Economic Effects of Climate Change; 2006; Vol. 32. 2. Hertel, T. W.; Tyner, W. E.; Birur, D. K. The Global Imp acts of Biofuel Mandates. The Energy Journal 2010, 31. 3. European Parliament DIRECTIVE 2009/28/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL 2009. 4. 110th United States Congress Energy Independence and Security Act of 2007; 2007. 5. Köpke M, Noack S, Dürre P. The p ast, present, and future of biofuels – Biobutanol as Promising Alternative. In: dos Santos Bernades MA, editor.: InTech; 2011. p. 451-86. 6. Dürre P. Biobutanol: an attractive biofuel. Biotechnology journal. 2007;2(12):1525-34. 7. OECD-FAO. OECD-FAO Agricultural Outlook 2011-2020. 2011. 8. Klasson KT, Ackerson MD, Clausen EC, Gaddy JL. Bioreactor design for synthesis ga s . Fuel. 1991 May;70(5):605-1 PubMed PMID: WOS:A1991FL49400009.

DGMK-Tagungsbericht 2012-3 113 Reducing the Carbon Footprint of Fuels and Petrochemicals

9. Klasson KT, Ackerson MD, Clausen EC, Gaddy JL. Bioconversion of synthesis gas into liquid or gasesous fuels. enzyme and micr obial technology. 1992 Aug;14(8):602-8. PubMed PMID: WOS:A1992JE44900001. 10. Köpke, M.; Mihalcea, C.; Bromley, J. C.; Simpson, S. D. Fermentative productio n of ethanol from carbon monoxide. Current opinion in biotechnology 2011, 22, 320–5. 11. Mohammadi M, Najafpour GD, Younesi F, Lahijani P, Uzir MH, Mohamed AR. Bioconversion of synthesis gas to second generation biofuels: A review. Renewable & Sustainable Energy Reviews . 2011 Dec;15(9):4255-73. PubMed PMID: WOS:000298764400005. 12. Griffin, D. W.; Schultz, M. A. Fuel and Che mical Products from Bio mass Syngas: A Comparison of Gas Fermentation to Thermochemical Conversion Routes. Environmental Progress & Sustainable Energy 2012, 00, 1–6. 13. Ljungdahl, L. G.; Wood, H. Total synthesis of acetate from CO2 by heterotrophic bacteria. Annual review of microbiology 1969, 23, 515–38. 14. Wood, G. L ife with CO or CO2 an d H2 as a source of carbon. The FASEB Jou rnal: Official Publication of t he Federation of Am erican Societies for Expe rimental Biology 1991, 5, 156–163. 15. Ljungdahl, L. G. The a utotrophic pathway of acetate synth esis in acetogenic bacteria. Annual review of microbiology 1986, 40, 415–50. 16. Ragsdale, S. W.; Pier ce, E. Acet ogenesis and the Wood -Ljungdahl pathway of CO(2 ) fixation. Biochimica et biophysica acta 2008, 1784, 1873–98. 17. Ragsdale, S. W. Life with carb on monoxide. Critical r eviews in biochemistry and molecular biology 2004, 39, 165–95. 18. Drake, H. L.; Küsel, K.; Matthies, C.; Wood, H. G.; Ljungdahl, L. G. Acet ogenic Prokaryotes. In The Prokaryotes; Dworkin, M.; Falkow, S.; Rosenberg, E.; Schleifer , K.- H.; Stackebrandt, E., Eds.; Springer: New York, NY, 2006; pp. 354–420. 19. Russell, M. J.; Martin, W. The rocky roots of the acetyl-CoA path way. Trends in biochemical sciences 2004, 29, 358–63. 20. Schopf, W. Earth’s Earliest Biosphe re: Its Origin and Evolution; Princeton Univ Press: Princeton, USA, 1984; p. 610. 21. Köpke, M.; Mihalcea, C.; Liew, F.; Tizard, J. H.; Ali, M. S.; Conolly, J. J.; Al-Sinawi, B.; Simpson, S. D. 2,3-Butanediol Production By Acetogenic Bacteria, an Alternative Route To Chemical Synthesis, Using Industrial W aste Gas. Applied and environmental microbiology 2011, 77, 5467–75. 22. Peralta-Yahya, P. P.; Zhang, F. ; del Card ayre, S. B.; Keasling, J. D. Microbial engineering for the production of advanced biofuels. Nature 2012, 488, 320–328. 23. Guzman DD, Chang J. Bio-based 2,3 BDO set for 2014 sales. ICIS Chemical Business. 2012:24. 24. LanzaTech. Media Releases. Available from: http://lanzatech.com/media/media-releases.

DGMK-Tagungsbericht 2012-3 114