Electrochemistry

Challenge and concept

The energy transition in Germany is in full swing. The associated expansion of wind power and photovoltaics will result in a considerably increasing rise of power available from fluctuating energy sources. With electrochemical syntheses the temporarily available excess in the electrical grid can be used for energy-intensive manufacturing operations.

Our offer

When surplus electricity is used to balance out peaks of power supply to the grid as a consequence of intermittent, regenerative power generation, basic chemicals can be synthesized cost-effictively.

We investigate and evaluate gas diffusion electrodes for electrosynthesis in order to produce chemicals on site and to offset power peaks caused by fluctuating regenerative electricity supply, by converting flexibly the electric energy into basic chemicals.

To develop the process, scalable and adaptable continuous flow cells are available that enable a wide range of development tests by changing the gas diffusion layer.

Electrosynthesis

© Fraunhofer IGB

Demonstrator with the circuits to the electrolyte (left) and gas supply (right).

© Fraunhofer IGB

Electrochemical cell for CO2 reduction.

Automatic demonstrator with electrolytic cell

For the single-stetp synthesis of ethylen, a demonstrator equipped with a process control system for fully automatic operation was designed and built within the  lighthouse project "Electricity as a raw material". The core component is an electrolytic cell with an integrated gas diffusion electrode (GDE). With this demonstrator, the electrosynthesis process with an electrode area of 130 cm2 and in-house catalysts was investigated and demonstrated in flow-through operation. In recent studies we were able to achieve ethylene concentrations in the product gas of 1700 ppm, corresponding to a Faraday efficiency of 8.5 percent. According to the state of the art in science and technology, comparable values have so far only been achieved on a laboratory scale, with electrode surfaces of a few square centimeters.

The plant also allows the specific analysis of the products that are created in a gaseous or liquid form in each case. Further process parameters can be adjusted and monitored in order to optimize the technology and process and to be able to make statements about efficiency and long-term stability.

Adaptation to further electrosynthesis processes, screening, scale-up

With the system, results achieved on a laboratory scale so far can now be transferred to a first industry-relevant scale. Besides, the design of the demonstrator can also be transferred to other electrosynthesis processes and enables screening of catalyst and electrode materials.

Gas diffusion electrodes

We investigate and evaluate gas diffusion electrodes for electrosynthesis in order to produce chemicals on site and to offset power peaks caused by fluctuating regenerative electricity supply, by converting flexibly the electric energy into basic chemicals. To develop the process, scalable and adaptable continuous flow cells are available that enable a wide range of development tests by changing the gas diffusion layer.

Reference projects

CELBICON – Cost-effective CO2 conversion into chemicals via combination of Capture and ELectrochemical and BIochemical CONversion technologies

Project duration: March 2016 – January 2020

The aim of the CELBICON project is the development of new "CO2-to-chemicals" technologies. This goal is achieved by the combination of absorption of CO2 from the air, electrochemical CO2 conversion to C1 intermediates and a final fermentation of the intermediates to high-quality chemicals.

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Fraunhofer Lighthouse Project "Electricity as a raw material"

Project duration: August 2015 – September 2018

A new approach to use fluctuating excess electricity from renewable energies is to produce chemicals. This makes the electrochemical synthesis of chemicals not only economical, but also represents – in addition to store electricity – a sensible utilization path to compensate for electricity oversupply. In the Fraunhofer lighthouse project "Electricity as a raw material", Fraunhofer IGB is developing an electrochemical process for the production of ethene in just one process step.

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OxFloc – Integrated water treatment in a one-stage oxidative-adsorptive process to degrade and remove harmful substances

Project duration: September 2013 – August 2015

The OxFloc project is concerned with water treatment, aiming to degrade and remove hazardous substances in an integrated approach using a one-step oxidation-adsorptive process. This will not only reduce the operating costs of waste water treatment in the future, but also provide a substantial environmental benefit.

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SteamBio – Flexible Superheated Steam Torrefaction and Grinding of Indigenous Biomass from Remote Rural Sources to Produce Stable Densified Feedstocks for Chemical and Energy Applications

Project duration: February 2015 – July 2018

The project “SteamBio”, which is coordinated by Fraunhofer IGB, aims to provide stable, densified feedstock for the process industries by upgrading lignocellulosic biomass (e.g. agro-forestry residues from remote rural sources) through a flexible superheated steam torrefaction and grinding process mounted on mobile units. Eleven project partners from four European countries are doing research from February 2015 for three years together in this challenging project.

more info