A European consortium is developing a carbon capture photonics device that uses LEDs and sunlight to convert carbon dioxide and hydrogen into clean energy products.
The ‘Spotlight’ consortium is looking to process up to one megaton of carbon dioxide per year with its new device, intending it to be complementary to existing large-scale carbon capture processes.
The device triggers a chemical process (also developed by Spotlight) that converts carbon dioxide and green hydrogen – produced from water using renewable electricity – into methane and carbon monoxide as starting materials for producing methanol liquid fuel.
While liquid methanol is used to make safe, clean energy for cars, wind turbines and energy storage applications, it is usually created by reforming natural gas with steam and then converting and distilling the resulting gas mixture into pure methanol. Changing carbon dioxide into a useful product like methanol is typically done with many chemicals in an alkali hydroxide-based system.
‘Climate change, one of the biggest societal challenges of our day, can be tackled with light technologies by taking greenhouse gases that trap heat close to the Earth and turning them into something useful,’ said Nicole Meulendijks, the project coordinator at Spotlight. ‘Our goal is to develop and validate a photonic device and chemical process concept for the sunlight-powered conversion of CO2 and green H2 to the chemical fuel methane (CH4, Sabatier process), and to carbon monoxide (CO, reverse water gas shift (rWGS) process) as starting material for the production of the chemical fuel methanol (CH3OH). Both CH4 and CH3OH are compatible with our current infrastructure and suited for multiple applications such as car fuel, energy storage, and starting material to produce valuable chemicals.’
Spotlight’s photonic device will comprise a transparent flow reactor, optimised for light incoupling in the catalyst bed. Furthermore, it will comprise secondary solar optics to concentrate natural sunlight and project it onto the reactor, and an energy-efficient LED light source to ensure continuous 24/7 operation. Spotlight's catalysts will be plasmonic catalysts, capable of absorbing the entire solar spectrum.
The consortium says that its chemical processes can be scaled up to offset the CO2 emitted by small to medium ‘point sources’ or places that emit carbon dioxide with emissions lower than one megatonne per year.
‘Worldwide, there are approximately 11,000 carbon dioxide “point sources” with emissions lower than one megatonne per year,’ said Meulendijks. ‘When combined, all these point sources emit a cumulative annual total of around 2.7 billion tonnes of CO2 – approximately 16 per cent of all CO2 from point sources globally every year. So, potentially, the process we envision at Spotlight could convert 2.7 billion tonnes of CO2 per year into useful chemical fuels.’
Specifically, the consortium calculates that its photonic device and sunlight-powered process can be tailored to the size of CO2 sources up to one megatonne per year with sufficient land coverage of approximately five football fields. Addressing all current carbon dioxide point sources up to that size would enable 2.7 billion tonnes of CO2 to be converted to 982 megatonnes of chemical fuel methane per year.
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The Spotlight consortium is coordinated in the Netherlands and is made up of partners: Chemtrix Bv, Signify Bv (Netherlands); Universiteit Hasselt, Interuniversitair Micro-Electronica Centrum (Belgium); Eidgenoessische Technische Hochschule Zuerich, Ecole Polytechnique Federale De Lausanne (Switzerland); Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forschung E.V., Deutsches Zentrum Fur Luft - Und Raumfahrt Ev (Germany); Rina Consulting Spa, Acea Pinerolese Industriale Spa (Italy); and Fundacion Para El Desarrollo De Las Nuevas Tecnologias Del Hidrogeno En Aragon (Spain). It is coordinated by Nederlandse Organisatie Voor Toegepast Natuurwetenschappelijk Onderzoek TNO.
