Projects aim to make the most of captured CO2

The US Department of Energy is to help fund six projects that aim to find ways of converting captured CO2 emissions from industrial sources into useful products such as fuel, plastics, cement, and fertilisers.

The projects will be supported with $106m (£69m) from the American Recovery and Reinvestment Act, and matched with $156m in private money.

With its share of the funds, aluminium giant Alcoa is to optimise a pilot-scale process that converts flue gas CO2 into soluble bicarbonate and carbonate using an in-duct scrubber system featuring an enzyme catalyst. The carbonate product could then be used as construction fill material, soil amendments, and green fertiliser.

Novomer, on the other hand, has teamed up with Albemarle Corporation and Eastman Kodak to develop a process for converting waste CO2 into a number of polycarbonate products (plastics) for use in the packaging industry. Novomer’s novel catalyst technology enables CO2 to react with petrochemical epoxides to create a family of thermoplastic polymers that are up to 50 per cent by weight CO2.

For their part, researchers at Touchstone Research will pilot-test an open-pond algae production technology that can capture at least 60 per cent of flue gas CO2 from an industrial coal-fired source to produce biofuel and other high-value co-products. Lipids extracted from harvested algae will be converted to a biofuel, and an anaerobic digestion process will be developed and tested for converting residual biomass into methane.

Another effort relating to algae will see Phycal complete the development of a system designed to produce liquid biocrude fuel from microalgae cultivated with captured CO2. The algal biocrude can be blended with other fuels for power generation or processed into a variety of renewable drop-in replacement fuels such as jet fuel and biodiesel. Phycal will design, build, and operate a CO2-to-algae-to-biofuels facility while the Hawaii Electric Company will qualify the biocrude for boiler use, and Tesoro will supply CO2 and evaluate fuel products.

In Austin, Texas, engineers at Skyonic Corporation will continue the development of their SkyMine mineralisation technology — a potential replacement for existing scrubber technology. The SkyMine process transforms CO2 into solid carbonate and/or bicarbonate materials while also removing sulphur oxides, nitrogen dioxide, mercury and other heavy metals from flue gas streams of industrial processes. The project team plans to process CO2-laden flue gas from a cement manufacturing plant owned by Capital Aggregates.

Over in California, Calera Corporation is developing a process that directly mineralises the CO2 in flue gas to carbonates that can be converted into useful construction materials. The project team will complete the detailed design, construction, and operation of a production system that at smaller scales has produced carbonate-containing aggregates suitable as construction fill or partial feedstock for use at cement production facilities.