A Multi-Scale Environmental-Kinetic Study on the Pyrolysis of Sustainable Biomass Feedstock
Joseph J. Biernacki
Department of Chemical Engineering, Tennessee Technological University
May 13, 2011 at 1:00pm
Ben Bandy Conference Center
UK Center for Applied Energy Research
Pyrolysis of lignocellulosic biomass offers a flexible alternative for renewable energy production. Feedstock are not required to be inherently high-yielding or easily degraded enzymatically, as is the case for biochemical conversion; nevertheless, they should be environmentally and economically sustainable over the long-term. In the production of infrastructure-ready biofuels, the challenge is to view thermochemical conversion processes in the more macroscopically apparent environmental and economic domains. This presentation discusses a multi-scale, multi-disciplinary approach that focuses on various aspects of biomass pyrolysis from nano- to macroscopic lengths.
Starting at the macro-environmental scale, sustainable lignocellulosic feedstock are often obtained from agricultural residues, woody crops, and grasses. Herbaceous feedstock, however, often grow in poor quality soil with minimal production inputs. Here we consider five different grass hays for pyrolysis. An understanding of pyrolysis kinetics of such materials is needed to maximize bio-oil yields and to identify useful biobased intermediate by-products. Experiments at the meso-scale are being used to explore the pyrolysis reaction kinetics at slow heating rates and for domestically productive grass varieties including, tall fescue hay, sorghum-sudangrass hay, alfalfa hay, switchgrass, and bermudagrass. The physical and chemical characteristics of each grass hay varieties are also being studied using X-ray diffraction, near infrared spectroscopy (NIR) and electron microscopy to examine the microstructure and the content of lignin, cellulose, and hemicellulose. This work is paving the way for further study at microscopic and nano-scales and at conditions that will enable the scalability of kinetic information.