Large-scale energy storage and conversion
In recent years the concept of using captured CO2 to make certain chemicals and products, also known as carbon capture and utilisation (CCU), has gained interest as a potential carbon abatement option.
There are a number of processes under development, one of these being the production of methanol-based transportation fuels. By combining captured CO2 with renewable hydrogen – produced through water electrolysis – these fuels can be produced with lower lifecycle carbon emissions than gasoline and diesel.
As a global first-of-a-kind project, ALIGN-CCUS will build and test a fully integrated CCU chain at pilot scale in a real industrial environment. The pilot will be constructed at RWE’s Coal Innovation Centre in Niederaussem, Germany, where the company has operated a CO2 capture system since 2009. The site will also house a highly efficient electrolyser module provided by Asahi Kasei, which uses renewable electricity to convert water into hydrogen and oxygen. The captured CO2 and hydrogen will then be converted to methanol-based products, DME and OME, in a synthesis unit provided by Mitsubishi Hitachi Power Systems Europe.
The construction and extensive testing of the CCU-chain pilot will allow the validation of this innovative approach, highlight any operational challenges and provide an insight into the overall economic and energetic efficiencies of this particular CCU process.
The fuels being produced in the CCU pilot are interesting because they can replace gasoline and diesel in vehicles which cannot be easily electrified. Whereas batteries can power electric vehicles such as cars and vans, this is currently less feasible for heavier vehicles: lorries, agricultural machinery and ships. Furthermore, the combustion of methanol-based fuels are associated with very low particulate and sulphur emissions compared to diesel, which has clear benefits for human health in urban environments.
Minor modifications to the storage and injector systems of the internal combustion engine will be required in order to use DME and OME. To fully assess the suitability of these fuels, RWTH Aachen University and FEV will develop an optimised injection system in a vehicle and test it for CO2 and other pollutant emissions. An existing peak power plant (power output: 240 kW) will also be calibrated to operate on DME.
Once the results of the CCU pilot testing and product applications become available, Forschungszentrum Jülich will complete full life-cycle assessments (LCAs) of DME/OME production and use. The outcomes of these assessments will provide much needed empirical evidence on environmental performance of this CCU route, in particular the CO2 savings potential.
ALIGN-CCUS will, therefore, be contributing to both technical understanding of CCU and also informing policy makers and wider society of the benefits and challenges associated with this technology.