ERA-IB 5: Biological conversion of CO2 to the platform chemical 3-hydroxypropanoic acid

Current energy and chemical needs are met by the extraction and processing of the fossil fuels.Such resources are finite and their use causes environmental pollution and greenhouse gas (GHG) emissions. The challenge facing humankind is, therefore, to identify new, sustainable and cleaner processes for chemical and energy generation. Biological routes represent a promising option, but strategies to date rely on the use of microbes to convert through fermentation the easily accessible carbohydrates (sugar and starch) of plants (such as sugar cane or corn) into chemicals and fuels. This has led to concerns over competition with the use of these carbohydrates as food, and a re-focussing of efforts on non-food, plant cell wall material (lignocellulose). However, lignocellulose is extremely resistant to being broken down into the sugar needed for fermentation. Overcoming this recalcitrance in a cost effective manner is proving extremely challenging.

There is, however, an exciting low-cost alternative, and that is to directly capture carbon, by harnessing the ability of certain bacteria to 'eat' single carbon GHG gases such as CO2. The gas is injected into the liquid medium of fermentation vessels where it is consumed by the bacteria and converted into the chemicals we need. Fortunately, such gases are an abundant resource, and may be derived from non-food sources such as waste gases from industry as well as 'synthesis gas' produced from the gasification (heating) of non-food biomass and domestic/ agricultural wastes. In this project, we will use this technology to make the platform chemical hydroxypropanoic acid. It has a multitude of uses, including the manufacture of plastics, coatings, adhesives, floor polishes and paints. By using non-food, waste gas as a feedstock, competition with food and land resources is avoided while at the same time providing benefits to the environment and society through a reduction in GHG emissions.

One of the greatest challenges facing industry and society are the future sustainable production of chemicals and fuels from non-food feedstocks while at the same time reducing Green House Gas (GHG) emissions. To compete with existing petrochemical-based chemical manufacturing processes, low cost feedstocks for biological fermentation processes are essential, since the feedstock typically equates to over 60% of the overall production cost. To date, the focus has been to use lignocellulosic feedstocks. Their use is reliant on an energy intensive pre-treatment step, and thereafter, the addition of costly exogenous hydrolytic enzymes needed to convert the partially deconstructed biomass into the sugars needed by the fermentative process organisms. The costs involved are making the development of economic processes extremely challenging.

An innovative solution is to use waste gases as the feedstock. Gas fermenting microbes are able to grow on C1 compounds, such as carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) derived from non-food sources such as waste gases from industry (steel manufacture, oil refining, coal and natural/shale gas) as well as 'synthesis gas' (CO/CO2 and H2) produced from sustainable resources, such as biomass and domestic/agricultural wastes. This enables the production of fuels and chemicals in any industrialized geography without the consumption of valuable food or land resources. Moreover, by consuming gases otherwise destined for atmospheric release, a real contribution to the environment will be made through reductions in GHG emissions.

In this project, we will establish an alternative commercial process for the production of a major platform chemical via gas fermentation, from synthetic biology and genome modeling through fermentation process development and finally technoeconomic (TEA) and life cycle analysis (LCA) of a modelled integrated future commercial process.

Successful completion of CO2CHEM will provide a novel route to the platform chemical 3-HP, based on the use of the cheap and abundant carbon source CO2. Multiple novel pathway enzymes will be characterized and their expression optimized in the production organism.

Primary outcomes will be a new platform microorganism, A. woodii, with a commercial process for fermentation of CO2 and H2. The project will develop general molecular biology methods needed for efficient engineering of future production organisms. Genome scale models will be developed and implemented for optimization of production organisms as well as media and fermentation conditions. These tools will advance the field of industrial biotechnology through future research collaborations and dissemination of project results.

The project will deliver key information needed for commercialization of CO2 + H2 fermentation: 1) target products; 2) optimized process conditions from lab-scale experiments, with integrated commercial process models; 3) TEA and LCA, showing benefits in GHG and pollution reductions; and 4) recommended commercial deployment scenarios. The novel combination of water electrolysis with gas fermentation can also be a means for large scale and long-term energy storage, important for load balancing in future energy systems with high shares of renewable power generation.

The CO2CHEM concept directly enhances the global competitiveness of biorefinery industries, which are expected to expand significantly in the coming decades. Successful proof-of-concept for CO2 + H2 fermentation will provide an offering to customers in CO2 intensive industries to monetize gaseous waste streams while lowering emissions. The project opens new markets for the industry partners. Post-project steps for commercial are: demonstration of the integrated process at pre-commercial scale, followed by commercial offering to LanzaTech's extensive current and future industrial customer base. In addition, Siemens will take individual technologies to the market, including water electrolyser, carbon capture processes, and gasifiers.

Dissemination Plan

The dissemination strategy has been defined to target different groups: researchers and students, equipment suppliers, and potential end-users of the technology (energy intensive industry, biorefineries and related industry). Every effort will be made to disseminate information about the goals of the project, on-going activities, progress, results and the potential benefits and opportunities afforded by the development of the project concepts. The goals of this strategy will be to:

- Enhance partners' visibility at national and international level
- Stimulate the interaction between industry partners and scientific community
- Attract the interest of related energy intensive industries
- Attract the interest of biorefineries and potential investors

During the project, the consortium will provide periodic reports including summaries that will be published in the public domain. It will include information on the expected final results and their wider societal implications, and the text will be understandable for a lay audience. The consortium will establish a website (open domain) for general dissemination, and a private (password protected) domain for dissemination among the consortium members. Each partner will ensure that the foreground generated is disseminated as swiftly as possible, once relevant IP has been protected.

The dissemination among stakeholders and potential end-users will be carried out through presentations and/or exhibition stands in industry relevant conferences. Moreover, the partners will seek to disseminate knowledge through the dedicated channels provided in European Technology Platforms, Cordis, other relevant EU websites and www.c1net.co.uk, the website of the BBSRC NIBB, C1net: Chemicals from Gas.