Sustainable fuels and chemicals with solar energy and CO2
Significant research and development efforts are urgently needed:
Technologies for the transition to a low-emission society are not available on a large-scale level.
With the Paris climate agreement, the European member states engaged to mitigate global warming and to play a leading role in the fight against climate change. Recent IPCC reports point out the necessity to reduce carbon dioxide emissions to zero in the second half of the 21th century at latest. Technologies allowing the transition to a low-emission society are still not available on a large-scale level and significant research and development efforts are crucially needed.
The enormous increase of wind and photovoltaic capacity worldwide shows that a consolidated alternative to fossil energy carriers already exists for electricity production. However, storing efficiently and reliably surplus electric energy remains one of today’s top challenges. Storage processes converting electricity and solar energy into chemical energy would be highly desirable.
For the transport and heating sector, fossil fuels are an unmatched energy source, coming along with a huge, existing infrastructure. Also chemical industry, supplying a variety of indispensable bulk chemicals for every day life (e.g. hydrogen peroxide and ammonia), is completely dependent on fossil-based raw materials such as crude oil. Generating alternative fuels and chemical raw materials from renewable energy sources represents a game changer and one of today’s biggest challenges.
Our goal is to provide a sustainable alternative to the fossil-based, energy-intensive production of fuels and base chemicals. The needed energy will be provided by sunlight, the raw materials will be molecules abundantly available in the atmosphere, such as carbon dioxide, oxygen and nitrogen.
SUNRISE’s ambition is to convert up to 2500 tons of CO2 and to produce more than 100 tons of commodity chemicals per hectare per year, realizing a 300% energy gain over present best practices and deploying devices on the 1000 hectare scale by 2030. This requires new materials for absorbing more than 90% of light and storing more than 80% of the photogenerated electrons in fuels or chemicals. With its unconventional approaches, SUNRISE will overcome the critical hurdle of the conversion of atmospheric CO2, so far a distant promise. Over its running span of 10 years, from 2020 to 2030, the flagship aims to:
· Reach an operational production cost level of 0.4 €/L for fuel with competitive manufacturing of key enabling technologies.
· Bring atmospheric CO2 photoconversion to the prototype level in operational environments.
In the short-to-medium term, we primarily aim at a circular production of high-value chemicals using renewable electricity sources and waste carbon dioxide from industrial processes. Existing technologies with relatively high technology-readiness-levels have to be optimized regarding their efficiency, sustainability and up-scalability to industrial level. Taking the example of water electrolysis driven by renewable electricity to produce hydrogen, more efficient catalyst materials are urgently needed to make this technology a true alternative. In the medium term, devices based on photoelectro-catalysis permit to skip the primary step of electricity production through e.g. photovoltaic cells by converting solar energy, hydrogen and concentrated carbon dioxide directly into chemical products.
In the long term, the energy input for the chemical processes is provided by sunlight, which is directly converted into chemical products. Radically new approaches (based e.g. on photochemistry, electrochemistry or biology) allow to transform dilute carbon dioxide, nitrogen or oxygen from the atmosphere into chemical compounds, mimicking natural photosynthesis. This artificial leaf approach finally targets sustainable high-value chemicals that can be concentrated to any desired level, going beyond the natural photosynthesis process with higher efficiency and a wide selection of target molecules.
Key enablers for such an ambitious transition are information technology and new advanced materials. The former will enable optimized production processes, with savings of energy and feedstocks. New materials will allow cost-competitive, efficient and durable solutions across a number of renewable energy technologies. Given the interdisciplinary character of solar energy research and its intrinsic societal and economic implications, this flagship initiative requires key contributions from a wide spectrum of disciplines, including chemistry, biology, physics and engineering as well as social and environmental sciences and humanities.