Process for producing high quality pyrolysis oil from biomass

Abstract

This invention relates to a process to utilize a torrefaction pretreatment step for biomass pyrolysis process. This pretreatment improves the quality of the pyrolysis oil by reducing acidity. The inventive process shows that as a pretreatment to pyrolysis, resulting pyrolysis oil obtained from torrefied biomass has approximately 25% lower acetic acid than that from untorrefied biomass pyrolysis oil.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]None.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]None.FIELD OF THE INVENTION[0003]The present invention relates generally to the conversion of biomass to fuel range hydrocarbons.BACKGROUND OF THE INVENTION[0004]Due to governmental legislation as mandated in the Renewable Fuels Standards (RFS), the use of renewable energy sources is becoming increasingly necessary to reduce emissions of carbon based fuels and provide alternatives to petroleum based energy and feedstock. One of the alternatives being explored is the use of biomass. Biomass is any carbon containing material derived from living or formerly living organisms, such as wood, wood waste, crops, crop waste, waste, and animal waste.[0005]Pyrolysis is the chemical decomposition of organic materials by heating in the absence of oxygen or other reagents. Pyrolysis can be used to convert biomass (such as lignocellulosic biomass) into pyrolysis oil or so-called b...

AI Technical Summary

Benefits of technology

This patent describes a process for making high-quality pyrolysis oil from biomass using a torrefaction pretreatment step. The torrefaction step improves the quality of the oil by reducing acidity. The process involves subjecting the biomass to a thermal treatment in a reactor under specific conditions to produce a torrefied biomass feedstock, and then pyrolyzing this feedstock in a reactor under specific conditions to form the pyrolysis oil product. The resulting oil has a high quality, indicated by a low TAN number between 80 and 200.

Problems solved by technology

However, pyrolysis oil obtained from biomass fast pyrolysis process is chemical complex compounds comprising generally a mixture of water, light volatiles, and non-volatiles.

They are in general of relatively low quality.

Since pyrolysis liquids typically contain between 30 to 50 wt % of oxygen, complete removal of oxygen requires a substantial consumption of hydrogen which represents a major and prohibitive cost.