Project: CO2 capture from air and conversion to hydrocarbon fuels

REMARK: All references cited [in brackets] are contained in a list at the end of this form. All figures cited (in parenthesis) are contained in a list at the end of this form. _x000D__x000D_Long-term storage and long-range transport of renewable energy resources is essential for a transition away from fossil energy. Liquid fuels, derived from CO2 and H2O, offer exceptional energy density and convenience for the transportation sector using the existing global infrastructure. However, their production using solar energy input has reCOed a grand challenge [1]. Furthermore, when the source of CO2 employed for fuel synthesis is atmospheric air, the carbon material cycle is closed for CO2 emissions released by distributed sources (e.g., cars, airplanes, ships). In the framework of this project, we combine the CO2 capture from air with the co-electrolysis of CO2 and H2O using renewable electricity, to produce CO and H2 as precursor for the processing of CO2-neutral liquid hydrocarbon fuels such as diesel, jet fuel, methanol, and others synthetic fuels. The objective of the present project is to further develop and optimize both technologies in terms of thermal efficiency and process engineering, and to integrate them in a energy conversion system for achieving maximum energy efficiency and, consequently cost competitiveness. _x000D__x000D_Based on on-going research being carried out at the Professorship in Renewable Energy Carriers (PRE-ETH) at ETH Zurich (www.pre.ethz.ch) in cooperation with the ETH spin-off company Climeworks LLC (www.climeworks.com), a novel technology for capturing CO2 from ambient air using solar energy has been developed. This work evolved over a period of 7 years of research, initially based on carbonation-calcination cycles [2-7], but lately focused on the more energy efficient adsorption-desorption cycles presented in this proposal. The technology proposed herein is based on the adsorption of CO2 on an amine-modified solid adsorbent and the desorption of the trapped CO2 from the adsorbent through the application of low-grade solar process heat at below 90C (see Fig. 1). The extraction of pure CO2 from air has been experimentally demonstrated on a laboratory-scale prototype reactor. The process is scalable and does not create any concomitant greenhouse gas emissions. Pure CO2 captured from air will then be used as feedstock for the synthesis of CO2-neutral liquid hydrocarbons (see Fig. 2). The H2O required for the fuel synthesis is obtained from atmospheric moisture as a co-product of the CO2 capture process. _x000D__x000D_The Fuel Cells and Solid State Chemistry Division, Risoe National Laboratory for Sustainable Energy, The Technical University of Denmark (short Risoe DTU) has since 2002 been researching on how to electrolyze CO2 + H2O (steam) simultaneously (co-electrolysis) into CO + H2, a gas mixture called synthesis gas or short syngas. Using suitable catalytic reactors syngas may be converted to almost any kind of hydrocarbon fuel. The catalysis has been well established commercially through several decades. The principle of co-electrolysis was demonstrated 30 years ago but has so far not reached commercialization. Further work is necessary to further increase performance (Nm3 syngas h-1) and the durability at high workload. The cell type used is the solid oxide electrolysis cell (SOEC), which preferably operates in a temperature window from 700 to 900 °C. This reversible cell was COly developed for the fuel cell application (SOFC). Risoe DTU has done R&D on SOFC since 1989. M. Mogensen, Risoe DTU, has been one of the leading scientists in this from the start in the late 1980'ies. Today a group of ca 20 persons are doing R&D on SOEC at Risoe DTU and ca. 80 on SOFC. _x000D__x000D_The project consortium is made up of the Professorship in Renewable Energy Carriers at ETH Zurich (PRE-ETH), Climeworks LLC and The Fuel Cells and Solid State Chemistry Division at Risoe DTU._x000D_

Acronym	CAPFUEL (Reference Number: 6691)
Duration	01/01/2012 - 31/12/2014
Project Topic	In the framework of this project, we combine a technology to capture CO2 from air with the co-electrolysis of CO2 and H2O using renewable electricity, to produce CO and H2 as precursor for the processing of CO2-neutral liquid hydrocarbon fuels such as diesel, jet fuel, and others synthetic fuels.
Project Results (after finalisation)	The project activities at Department of Energy Conversion and Storage, Technical University of Denmark (DTU) (previously Risoe National Laboratory) were: 1) Development of a model comprising the process steps CO2 capture, co-electrolysis of CO2 and H2O to syngas, and conversion of syngas to synthetic fuels; 2)Optimization of the integrated fuel synthesis system by maximization of internal heat recuperation using the model; 3) Electrode poisoning risk analysis; and 4) Electrode poisoning experimental campaign. _x000D_All activities were carried out as planned, and all milestones were met. _x000D_The CO results were a PhD thesis by Soeren L. Ebbehoej, who defended his work successfully on April 17th, 2015. Part of the thesis content is being published. The developed model was used for a theoretical process optimization as planned. Besides the planned work the model was, also as part of the project, used as basis for an economic modeling and a life assessment analysis. The result of all work is an identification of problems that future R&D work must focus on in order to commercialize this CO2 capture and utilization technology._x000D__x000D_Climeworks LLC has during the project period made demonstration of the technology and may in the future benefit from the analysis and modeling work carried out at DTU.
Network	Eurostars
Call	Eurostars Cut-Off 6

Project partner

Number	Name	Role	Country
3	Climeworks LLC, Switzerland	Coordinator	Switzerland
3	Risoe National Laboratory for Sustainable Energy, Technical University of Denmark	Partner	Denmark
3	Swiss Federal Institute of Technology, Zurich	Partner	Switzerland