Preliminary Evaluation of High-Pressure Circulating Fluidized Bed Biomass to Fuels Technology

Pyrolysis of second generation biomass, such as crop residues or non-food crops, seems to be a very promising option for generating clean, renewable, drop-in biofuels. Presently, there are several pyrolysis technologies that must be evaluated to determine the most cost effective technology to use for commercialization as the United States energy catalog lacks an effective way to convert biomass into useful liquids for fuels and other uses. Southwest Research Institute® (SwRI®) employees have devised a way to combine circulating fluidized bed reactor conversion with a combination of catalysts and conditions to efficiently convert general biomass into a broad-boiling point range product ready for refining into transportation fuels. 

The University of Texas at San Antonio (UTSA) and SwRI through a cooperative program CONNECT are currently working on a project to develop and demonstrate a novel biomass conversion technology (high-pressure circulating fluidized bed hydropyrolysis) to enable the goal of making biofuels cost-competitive with corn-based ethanol and petroleum based fuels. This project aims to improve the performance and test the commercial viability of this new technology considering uncertainties and risks and taking a holistic cradle-to-grave approach to test the economic viability of producing biofuels and other biobased products (byproducts).

This presentation/paper analyzes the experimental results obtained from the preliminary bench scale experiments completed to validate SwRI’s initial design.  Experiments to evaluate SwRI’s proposed technology at bench scale are addressed by performing a set of experiments in SwRI’s high-pressure, high-temperature, Parr reactor system.  One type of feedstock (switchgrass) is tested at supercritical and subcritical pressures, with and without sodium carbonate, and at various catalyst blend ratios.  A mass balance is completed for each run including solid, liquid, and gas yields and analysis of products and feedstock.