Syngas production via high-temperature steam/CO2 co-electrolysis: an economic assessment

TLDR

High‑temperature steam/CO₂ co‑electrolysis can convert low‑carbon electricity into syngas for Fischer–Tropsch fuel synthesis, preserving existing infrastructure, yet its economic competitiveness depends on cost‑effective electricity (e.g., nuclear or surplus wind) and its biomass‑independent, solar‑friendly deployment. The study performs an economic assessment of the high‑temperature steam/CO₂ co‑electrolysis process through process modelling and sensitivity analysis. The assessment uses process modelling and sensitivity analysis to evaluate preferred electricity sources such as nuclear and surplus wind, comparing synthetic fuel costs with those of the biomass‑to‑liquid process.

Abstract

Although it is not yet technologically mature, the high-temperature steam/CO2 co-electrolysis process offers potentially a feasible and environmentally benign way to convert carbon-free or low-carbon electrical energy into chemical energy stored in syngas with a desired H2 to CO ratio for further processing. An attractive application is to convert the as-produced syngas further into synthetic liquid fuels through the Fischer–Tropsch (F-T) process. The synfuel can be used as alternative fuels in the transportation sector while keeping the existing infrastructure and motor engine technology unchanged. The combination of the high-temperature steam/CO2 co-electrolysis process and the F-T process thus offers an efficient way to store electricity in transportation fuels. The implementation of such a quasi carbon-neutral process depends on its economic competitiveness. In the present paper, an economic assessment of this process is performed through process modelling and sensitivity analysis. As an energy-intensive process, the availability of cost-effective electricity is crucial for its economic competitiveness. Preferred electricity sources are probably nuclear power and surplus wind power, with which synthetic fuels could be produced at a cost comparable to BTL (Biomass to Liquid) process. The present process is biomass-independent, and can also be located in regions where solar energy is abundant.