Electrochemical processes for fluctuating energy and raw materials systems
The energy transition in Germany is in full swing. Renewable energy sources contributed 24 percent of the 630 TWh of electrical power generated in 2013. Their proportion is estimated to climb to 80 percent by 2050, while at the same time greenhouse gas emissions are expected to fall to 80 percent of the comparative 1990 figures. The associated expansion of wind power and photovoltaics will result in a considerably increasing rise of power available from fluctuating energy sources. As an industrialized country, Germany is confronting the pressing question of whether and how the expected excess in the electrical grid can be coupled cost-effectively to energy-intensive manufacturing operations.
The goal: power to chemicals
The Fraunhofer-Gesellschaft views the energy transition and the cost-effective excess electrical power it will increasingly generate as an opportunity for electricity-intensive manufacturing. The goal of the Fraunhofer Lighthouse Project “Electricity as a Raw Material” is to develop new electrochemical processes in order to utilize excess electrical power for manufacturing chemicals. For subsequent pilot production and system integration, it means the processes must be modularized and distributed, and electrochemical production at existing Fraunhofer Group facilities made more adaptive. New technologies and scientific expertise are being developed for future “Power-to-Chemicals" industrial processes that will subsequently be marketed as part of long-established value-added chains. This should lay the scientific and technological foundations for manufacturing products using an increasingly CO2-free mix of electrical power sources.
Synthesis pathways – hydrogen peroxide or CO2 conversion
The technological focus of the Fraunhofer Lighthouse Project is to develop new electrochemical processes, concentrating on two synthesis pathways.
- One pathway is oriented toward electrochemical manufacture of hydrogen peroxide (H2O2) from oxygen and hydrogen, with prototype demonstrations of the process in a distributed facility. H2O2 is employed as an environmentally friendly oxidant for diverse applications in the chemical, paper, and textile industries. Responsibility for this sub-project lies with the Fraunhofer Institute for Chemical Technology ICT.
- The second pathway’s goal is to electrochemically or electrocatalytically convert CO2 for manufacturing fundamental hydrocarbon compounds like alkenes and alcohols, demonstrating the technology at the pilot-plant scale. Development of a demonstration setup for one-step electrosynthesis of ethylene from CO2 by means of gas diffusion electrodes is being led by Fraunhofer IGB. Another setup for one-step electrosynthesis of C1-C4 alcohols from CO2 using high-pressure techniques is being led by the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, while a third setup using two-step activation of CO2 by H2 for synthesizing C4-C20 alcohols is being led by the Fraunhofer Institute for Ceramic Technologies and Systems IKTS.
All of these development projects are being paralleled by process simulations (at the Fraunhofer Institute for Industrial Mathematics ITWM) as well as by joint development of electrochemical components and process analysis systems by Fraunhofer ISC, IST, and IAP. A work package for system analysis and sustainability considerations carried out by Fraunhofer IGB and UMSICHT rounds out the project.