Under contract with the National Renewable Energy Laboratory, Harris Group has completed a comprehensive review of biomass gasifier technologies.

“Biomass Gasification Technology Assessment” examines variables in multiple gasification technologies, compares capital costs and includes a gasifier cost estimating tool. It specifically focuses on assessing gasification and tar reforming technologies that are capable of producing a syngas suitable for further treatment and conversion to liquid fuels.

Harris Group reported that, though expected, it was very difficult to obtain detailed information from gasification and tar reforming technology vendors, because most vendors were not interested in sharing confidential cost or engineering information for a study. However, HG did manage to gather sufficient information to analyze three gasification and tar reforming systems.

The three analyzed in the report all have a feed rate of 1,000 dry metric tons of wood residue per day, a system size described in the report as being more manageable with current mature designs of available feedstock handling equipment, and also considered to be near the maximum size that could be modularized and/or shop fabricated, thus lending themselves to potential cost savings over stick built systems erected in the field.

Two of the three examined technologies utilize oxygen-blown autothermal (partial oxidation) bubbling fluidized bed designs, and the other an allothermal (indirect heating) circulating fluidized bed design. The report summarizes the equipment, general arrangement of the equipment, operating characteristics and operating severity for each technology.

NREL plans to use the review, which can be downloaded free here, to guide and supplement their research and development efforts.