A team of researchers from Sasol and the Catalysis Institute at the University of Cape Town (UCT) in South Africa has made advancements in the use of commercial iron catalyst, produced cheaply and at large scale at Sasol’s Secunda plant, which would enable conversion of unavoidable or biogenically- derived carbon dioxide (CO2) and green hydrogen directly to a variety of green chemicals and jet fuel.
The collaboration with UCT has revealed that Sasol’s iron catalyst can achieve CO2 conversions greater than 40%, producing ethylene and light olefins which can be used as chemical feedstocks, and significant quantities of kerosene-range hydrocarbons (jet fuel).
For decades, Sasol has been using its Fischer Tropsch (FT) technology to convert low-grade coal and gas into synthetic fuels and chemicals. The largest scale example of the commercial application of this technology is its Secunda plant in Mpumalanga, which converts synthesis gas - a mixture of carbon monoxide (CO) and hydrogen (H2) – derived from coal gasification and supplemented by reformed natural gas into 160,000 barrels of products per day.
“Conversion of green hydrogen together with CO2, a process called CO2 hydrogenation, is gaining significant interest worldwide and is a promising way to produce sustainable aviation fuels and chemicals which have a significantly lower carbon footprint,” said Dr Cathy Dwyer, Vice President: Science Research at Sasol Research & Technology.
There are two ways to convert CO2 into a useful range of products using FT chemistry. In the indirect pathway, CO2 and green hydrogen are first converted to synthesis gas either by co-electrolysis or over a catalyst. The synthesis gas is then reacted over a suitable FT catalyst, to produce hydrocarbons and water. Sasol’s suite of cobalt catalysts is highly efficient for the latter process. Alternatively, hydrogen and CO2 can be converted directly over a single catalyst to a useful range of products, using what is termed “tandem” catalysis, and this is where the iron catalysts have been found to be advantageous.
In a separate development on the other side of the Atlantic, carbon transformation company Twelve and biotechnology company LanzaTech have partnered to produce what they claim is the world’s first polypropylene from CO2.
Twelve’s CO2Made®carbon transformation technology converts CO2 into materials that are traditionally made from fossil fuels. LanzaTech’s carbon recycling Pollution To Products™ technology, meanwhile, uses nature-based solutions to produce ethanol and other materials from waste carbon sources. The partnership will bring together the two platform technologies to enable additional product development from CO2 streams, representing just one of many pathways to scale carbon transformation solutions.
“We now have a way to produce [polypropylene] from CO2 and water instead of from fossil fuels, with no trade-offs in quality, efficacy or performance,” said Twelve Chief Science Officer, Dr. Etosha Cave.
To pursue the partnership, Twelve and LanzaTech have been awarded a $200,000 grant from Impact Squared, a $1.1 million fund that was designed and launched by British universal bank Barclays and Unreasonable, a catalytic platform for entrepreneurs tackling some of the world’s most pressing challenges. With the Impact Squared grant, Twelve and LanzaTech are taking a collaborative approach to reducing the fossil fuel impact of essential products.