Power to Chemicals ～Recycling of carbon dioxide using renewable energy～

TOSHIBA CORPORATION

Outline

As a way of both making effective use of CO2 and expanding renewable energy, we are promoting development of Power to Chemicals technology. This technology can be installed adjacent to equipment that emits large amounts of CO2, using surplus power produced from renewable energy as its power source for recycling the gas.

Although artificial photosynthesis can be used to convert carbon dioxide into carbon monoxide, which is used as a raw material for producing plastics and jet fuel, traditional technology suffers limitations in terms of costs and installation locations due to its slow conversion speed. As such, we have studied catalysts and electrode structures for CO2 conversion and developed unique catalyst electrode, the speed of which is at the world’s highest level.. Using this technology as the foundation, we will first verify a 1-kW-class CO2 recycling system by using variable power supplies such as solar power. Following that, we aim to achieve a CO2 reduction effect of 1 million tons per year by installing MW-class plants at various CO2 emitting facilities in the future.

Description

We will create an economically feasible CO2 recycling model by developing a high-throughput artificial photosynthesis technology to convert carbon dioxide into carbon monoxide and using surplus power produced from renewable energy as its power source.

The first step will be to demonstrate a 1-kW-class CO2 recycling system during FY2022, using the simulated recovery of CO2 gas from thermal power plants. In future work, we aim to develop this demonstration system into a MW-class plant that can be installed adjacent to facilities that emit large amounts of CO2. If such a 100-MW-class plant is implemented into society, the expected reduction in CO2 emissions gained through replacing chemical products derived from fossil resources would be roughly 1 million tons per year (compared with a process to manufacture methanol from coal).

Conventional artificial photosynthesis technology has suffered limitations in terms of costs and installation locations when it has been turned into a system, due to its slow conversion speed. To solve this problem, we have been developing catalyst electrodes that achieve high-throughput CO2 electrolysis. These catalyst electrodes can eliminate the lowering in current density (conversion speed) by reacting CO2 in gas form with water without dissolving it in water. In addition, by adopting a unique structure which incorporates macropores that serve as passages for CO2, as well as nanosized pores for the catalytic layer, these catalyst electrodes efficiently supply high-density CO2 to the catalyst surface. As a result, we have succeeded in converting CO2 at the world's highest level of current density, 645 mA/cm2. Going forward, with the aim of implementing this technology at the public level as soon as possible and using our unique catalyst electrode technology as the foundation, we will consider scaling up the electrode area, stacking electrolysis cells, and so on, and check the operation of a system using a variable power supply such as solar power. Finally, we will verify a low cost, high-throughput CO2 recycling model.

Partner(s)

This technology is being demonstrated as part of the "Project to Promote Models for a Carbon-Recycling Society through Carbon Dioxide Recycling" a project commissioned by the Ministry of the Environment Government of Japan.