COP26: Converting carbon into green chemicals

University of South Wales (USW) researchers are developing a process to recycle carbon-containing wastes into valuable platform chemicals.

Platform chemicals, such as Volatile Fatty Acids (VFAs), can be used as building blocks to manufacture a wide range of vital synthetic compounds and materials. Global demand for VFAs is constantly growing, but they are currently manufactured from fossil fuel-based feedstocks such as oil and gas. For every tonne of them produced in this way, 3.3 tonnes of CO2 is released into the atmosphere.'

A team led by Professor Alan Guwy at the USW’s Sustainable Environment Research Centre (SERC) is creating a new biorefining technology, known as H2ACE, which enables more environmentally-friendly production of platform chemicals. It revolves around a microbial process that converts CO2, in a microbial bioreactor, producing valuable green chemicals including VFAs. Therefore, it has the potential to change how we see CO2, reframing it not as just a problematic pollutant, but as a valuable resource for green, sustainable chemical manufacture.

The value of VFAs depends on their purity and their concentration. Without an effective method of continuous separation and purification, full-scale microbial VFA production has been held back. However, SERC researchers are now developing advanced separation technology, which dramatically increases the purity of the VFAs being collected while retaining vital nutrients critical to the microbial biorefining processes. This level of continuous, selective extraction has not been demonstrated at an industrially relevant scale before. These advancements allow the dynamics and operating parameters of the bioreactor to be re-evaluated in new ways, resulting in a more productive and efficient process.

H2ACE is one of several technologies in development at SERC for the biorefining of waste streams collectively forming the “VFA Factory” concept. The researchers are making use of novel microbial conversion processes, combined with continuous separation technologies, to produce and purify VFAs. The team  are also working on technologies to produce them from high-solids biomass waste (BIOACE) and from carbon monoxide rich substrates (COACE). H2ACE can also utilise renewable hydrogen to convert carbon dioxide into VFAs. The team is developing pilot-scale bioreactor systems for all of its new technologies and working with industrial partners such as Tata Steel and Welsh Water.

To meet environmental targets, industries need to find new ways of reducing, recovering and recycling their waste by-products. Biorefining technologies such as H2ACE can assist with this by capturing carbon and putting it to good use producing platform chemicals, instead of releasing it into the atmosphere.

Ben Burggraaf, Head of Energy Optimisation at Dwr Cymru Welsh Water. said: “Earlier this year, Welsh Water committed itself to reducing its total carbon emissions (including embedded emissions from its capital programme) by 90% by 2030 and to reaching net zero by 2040. As certain emissions sources will be challenging or even impossible to reduce to zero by 2040, there is a need to find cost-effective ways to capture, store, and utilise (biogenic) carbon dioxide and turn it into a value-added product, to offset the remaining emissions.

“The Bio-ACE and H2ACE projects incorporate at their heart this circular thinking and are innovative projects that could potentially create carbon-sinks i.e. remove more carbon from the atmosphere than emitted and offset some of the emission sources that are difficult and/or not cost-effective to abate.”

Gareth Lloyd, Steel Process Engineering and Functional Safety Manager at TATA Steel, said: “We are very conscious of the steel industry’s responsibility to help meet the global climate targets.  We are committed to transforming the way in which steel is produced and used, so that it remains the material of choice for our customers in a circular and low carbon economy.

“Steel is an essential material for society, and the UK needs a sustainable steel sector.  We continue to search for a decarbonisation route for UK steel making operations and a sustainable future for steel production.

“Our ambition is to reduce carbon dioxide emissions and reduce the impact of steelmaking on the environment as quickly as possible.  This ambition can only be achieved using innovative solutions that don’t currently exist within our industry.

“TATA’s involvement in the H2ACE project will enable the development of technology to substantially reduce its carbon emissions by using them as substrates for biorefinery technologies that can convert them into green sustainable platform chemicals which themselves have a significant financial value. 

 “TATA will benefit from a programme of research that tailors these technologies to their needs to reduce and derive value from its carbon emissions”

Based on a article featured in Advances Wales – which showcases the latest news, research and developments in science, technology, and engineering in Wales.