CARBON RECYCLING: CONVERTING WASTE DERIVED GHG INTO CHEMICALS, FUELS AND ANIMAL FEED (CCnet).

CONTEXT

The continued use of fossil fuels is no longer tenable. A finite resource, their extraction, processing and exploitation results in environmental pollution and increased greenhouse gas (GHG) emissions in the form of carbon dioxide (CO2) and methane (CH4). Worldwide, net emissions have increased about 40 percent since the Industrial Revolution began in 1750, the majority of which has taken place in recent times, ie., 35 percent between 1990 and 2010. GHG emissions are the drivers of climate change. Thus, over the last 50 years average air and sea temperatures have risen dramatically, concomitant with melting of the polar ice caps and a general reduction in snow. These changes are resulting in increased frequencies of droughts and heat waves, flooding, tropical cyclones and hurricanes, more extreme precipitation events and rising sea levels. The latter threaten the continued existence of coastal communities (8 of the 10 largest cities in the world are near a coast) and even entire low-lying island nations such as the Maldives, while the former are causing destructive wildfires, failed crops, and low water supplies. The extreme effects on agricultural activity exacerbate one of the major challenges facing humankind - increases in population size. Thus, the global human population has grown from 1 billion in 1800 to 7.616 billion in 2018 and is predicted to 11.2 billion by 2100.
The world is at a crossroads. How can we feed the world's burgeoning population in the face of the destructive forces of climate change? Equally important, how can prevent further GHG emissions by finding new ways to make the chemicals and fuels society needs from a source other than fossil fuels.

AIMS AND OBJECTIVES.

A unifying solution is to use the very single carbon (C1) GHGs that are causing the problem as the building block for chemical, fuel and food manufacture. This is made possible by the existence of 'gas-eating' bacteria that can use the carbon in CO2 and CH4, and convert it to the chemicals we need, and even to make single cell protein (SCP) that can be used to feed the dairy and meat livestock humankind rely on. Most microbes grow on sugar, such as the yeast used to make beer and wine. But the bacteria under investigation in this community of researchers consume single carbon gases, such as CO2 and CH4.
Funded by the BBSRC and EPSRC, it is the purpose of the Carbon reCycling Network (CCnet) to develop the biological processes required to recycle the carbon in GHG and convert it into the chemical and food resources we need. Success will require the participation of many different fields of science to design, test and build the biological processes needed. It will require the amalgamated efforts of biologists, chemists, engineers and mathematics if the breakthroughs are to be made. Crucially, the systems to be developed and their eventual operation will require the involvement of social scientists to ensure that the work undertaken is performed in a responsible way and there are no un-thought of consequences to humankind or the planet. Crucially it will need the involvement of industry who can take on the ideas and processes developed and turn them into real world solutions.

APPLICATIONS AND BENEFITS

CCnet will act as the focus for the academic and industrial researchers needed who together can change the world we live in for the better. It will train and inform young reseachers, hold the meetings, workshops and forums needed to discuss and formulate planned experiments. The best concepts will receive seed corn funding to test the assumptions made and to amass the data need to attract the larger sums of money needed to translate their ideas into the real world. Through this collegiate approach, and by working with industry, CCnet will make a difference. It will help reduce GHG emissions, helping the UK to meet its targets, and sustainably generate the chemicals and fuels our society and the world needs.

Two of the greatest challenges facing society are the future sustainable production of chemicals, fuels and protein for animal feed, while at the same time reducing GHG emissions. One of the few, readily available UK feedstocks are single carbon gases, generated either as side products of existing industrial processes or through the deliberate processing of biomass wastes and residues. They are available in high volumes and at low cost UK-wide. Autotrophic or phototrophic microbial chassis able to utilise these resources can be engineered to synthesise a broad array of requisite molecules in scalable biological processes. The Network will focus on the development of the requisite engineered chassis and the required scalable processes. It will expand the scope of C1net, which focussed specifically on gas fermentation, to include closed, photosynthetic processes reliant on waste CO2. The Network will be underpinned by sustainable exploitation of AD-derived biogas (CO2 and CH4) as a feedstock for C1 chassis process development.

CCnet WILL PROMOTE:-

Systems & Synthetic Biology approaches to improved C1 chassis performance

Metabolic Engineering of chassis for manufacture of chemicals, fuels and single cell protein, inc. genome scale models

Fermentation and process development technologies to improve productivity and product recovery

Improved reactor design, of systems that both use C1 feedstocks and anaerobic digesters as a supplier of gaseous feedstocks

Optimisation of C1 and H2 inputs from biological and thermal sources, eg. by pre-processing (biomethanisation of CO2) or physico-chemical pre-treatment (syngas & flue gas upgrading etc).

Integration of anaerobic digestion into a C1-based gas fermentation

Research that underpins the use of biogas-derived CO2 (eg., improved photoreactors for phototrophs) and routes to H2 generation for autotrophic chassis, eg., photovoltaics and electrolysis.

Integration of RRI practices into CCnet goals.

Two of the greatest challenges facing society are the future sustainable production of chemicals, fuels and protein for animal feed, while at the same time reducing GHG emissions. One solution is to us GHG as the feedstock for biological processes. Such single carbon gases are generated either as side products of existing industrial processes or through the deliberate processing of biomass wastes and residues. Recycling GHG can be undertaken in any industrialised geography without competing with food or feed supplies. GHG recycling technologies are feedstock flexible and provide products, from low carbon fuels to commodity and speciality chemicals, to single cell protein useful as animal feed. Current commercial processes focus on ethanol (LanzaTech) and animal feed (Calysta). Research is targeting higher alcohols, ketones, and diols, organic acids, alkenes, and amines as well as fatty acids, terpenoids, aromatic compounds, biodegradable plastics (PHAs), and medium to long chain alkanes. These have many uses, as fuels, solvents, and food additives. They may be further processed to drop-in fuels (jet fuel), biodegradable polymers for food packaging and biomedical and engineering applications, and high value chemicals.

ENVIRONMENTAL & SOCIAL BENEFITS

Reduction of GHG emissions: The UK (2008 Climate Change Act) is committed to reducing GHG emissions by 80% by 2050. GHG recycling can play a key role. E4tech's LCA of LanzaTech ethanol from steel mill off gas shows up to 70% GHG emissions reduction compared to gasoline.

Promotion of Industrial Growth: GHG recycling will enable industries to add value to a waste stream while reducing their carbon footprint. This promotes regional industrial growth and employment in industrial zones.

Promotion of a Circular Economy: Recycling GHG enables industries to be resource efficient, creating new products by recycling waste. It also provides for deriving a wide range of products from biomass.

Aviation Fuel: Low carbon fuels have an important role in helping the UK aviation industry to achieve its goal of halving net GHG emissions by 2050.

Feeding the World: Carbon recycling of GHG represents a sustainable route to feed ingredients for fish, livestock and pets. Whilst the first plants (Calysta and Cargill) will use methane from natural gas, renewable methane from biogas can be used. Further opportunities exist for making single cell protein from CO2 using autotrophic chassis, eg., Avecom.

UK RESEARCHERS & INDUSTRY

There is great potential for the deployment of GHG recycling technologies in the UK and a large opportunity globally. These range from processes operating at commercial scale outside of the UK, to new routes to chemical products being developed in UK academia and research organisations. The UK has high quality research and innovation capabilities in biotechnology and specifically gas fermentation, and companies are attracted to the UK to leverage these skills, eg, Calysta and LanzaTech.

The UK has globally recognised strength in biotechnology; 8th in the world for biotechnology patents filed. CCnet will be underpinned by the BBSRC/EPSRC Synthetic Biology Research Centre-Nottingham, the Algal Innovation Centre in Cambridge, the Industrial Biotechnology Innovation Centre (IBioIC) and the Centre for Process Innovation (CPI). The latter have invested £1.2M in gas fermentation facilities as part of industry collaborations, including INVISTA. US company Calysta located its market introduction facility at CPI, expanding CPI facilities and skills. UK chemical companies can benefit from the development of low carbon chemical intermediates or building blocks. INVISTA (Teesside) has a joint development agreement with LanzaTech to develop processes for nylon production. As other gas fermented products near commercialisation, collaborations with UK companies will be commonplace.