(405e) Liquid Fuel Production From Biomass Via High Temperature Steam Electrolysis

A new process called Bio-Syntrolysis is being researched at the Idaho National Laboratory (INL) investigating syngas production from biomass that is assisted with high temperature steam electrolysis (HTSE). The INL is the world leader in researching HTSE and has recently produced hydrogen from high temperature solid oxide cells running in the electrolysis mode setting several world records along the way. A high temperature (~800°C) heat source is necessary to heat the steam and carbon dioxide feed as it goes into the electrolytic cells. Biomass provides the heat source and the carbon source for this process. Syngas, a mixture of hydrogen and carbon monoxide, can be used for the production of synthetic liquid fuels via Fischer-Tropsch processes. This concept, coupled with fossil-free electricity, provides a possible path to reduced greenhouse gas emissions and increased energy independence, without the major infrastructure shift that would be required for a purely hydrogen-based transportation system. Furthermore, since the carbon source is obtained from biomass, the entire concept is climate-neutral.

A process model flowsheet has been developed with a biomass gasification system integrated with an HTSE system. The oxygen from that is produced by electrolytically splitting water is fed to the gasifier and controls the amount of carbon monoxide and carbon dioxide that is produced. The gasifier products are cleaned and scrubbed and mixed with the electrolytic hydrogen to produce a very clean syngas ready for the Fischer-Tropsch process. Various types of biomass such as corn stover, barley straw, bark, and switchgrass have been simulated in the process model flowsheet. Varying amounts of moisture content in the biomass was also investigated. High pressure and atmospheric pressure simulations were also performed. Low temperature electrolysis efficiency was compared to high temperature electrolysis.

This paper will provide process model results of large scale biomass gasification with high temperature electrolysis for the production of synthetic fuels. The oxygen source for the gasification process is a by-product of the electrolysis process. Syngas production efficiency, carbon conversion efficiency will be presented.

A thorough economic analysis will be discussed showing in-depth analysis for this process to be built. Current economic forecasts show that a feedstock blend can be produced at $2.50 per gallon.