Partnering on pyrolysis
Thomas Lübberstedt and Marjorie Rover
A project jointly funded by the Plant Sciences Institute and the ConocoPhillips Company will define the most desirable feedstock traits for optimum bio-oil production through fast pyrolysis.
Bio-oil can be produced from renewable biomass sources, such as the non-grain portions of corn and perennial grasses via a thermochemical process called fast pyrolysis. But some feedstock properties appear able to yield better bio-oil than others.
In fast pyrolysis processing, ground biomass is rapidly heated to a high temperature (450 degrees C) in an oxygen-free environment—pyrolyzing the biomass constituents of lignin, cellulose and hemicelluloses—then rapidly cooled to yield bio-oil and bio-char.
Bio-oil quantity and quality is influenced by the reactor and the process conditions under which the thermochemical conversion occurs.
But biomass qualities, such as the relative amounts of cellulose, hemicelluloses, lignin, and minerals, also play a large part. Thomas Lübberstedt, director of the Raymond F. Baker Center for Plant Breeding, Kenneth J. Frey Professor and associate professor in the Department of Agronomy, will be identifying these qualities with the goal of applying them to a feedstock breeding program.
“Traits we identify in corn should be easily transferrable to other bioenergy grasses, as these are related species,” says Lübberstedt.
Using a micro-pyrolyzer attached to a gas chromatograph/mass spectrometer for instant chemical analysis, “significant progress will be achieved with the ability to screen 30 samples per day,” says Marjorie Rover, one of the scientists at the Center for Sustainable Environmental Technologies, who will pyrolyze biomass for the project.
The initial study will involve 3,200 samples of well characterized corn plants, including a set bred for high and low lignin content and others representing exotic germplasm. Different plant parts, including cobs, above-ear and below-ear stover, will also be analyzed.
From these analyses, Lübberstedt will work to identify genomic regions and specific genes controlling desirable bio-oil promoting traits and look to develop genetic markers that will speed along a bio-oil breeding program, be it corn or related bioenergy grasses.
Preliminary analyses suggest high lignin and low mineral content are qualities the group is expecting will be important for yielding the best quality oil.
