(482c) Demonstration Scale Alkali Passivation for the Pyrolysis of Biomass

Lysle Whitmer and Robert C. Brown

Center for Sustainable Environmental Technologies

Department of Mechanical Engineering          

Iowa State University

Ames Iowa – 50010 U.S.A.

Abstract

The objective of this research is to evaluate the ability to passivate alkali laden biomass feedstock for use in thermochemical conversion processing at demonstration scale.  Laboratory Pyrolysis-GC/MS results indicate that naturally occurring mineral matter found in all biomass catalyzes the decomposition of cellulose during pyrolysis to yield light oxygenated compounds in bio-oil such as formic acid and acetaldehyde, rather than uncatalyzed pyrolysis which tends to depolymerize the cellulose to produce anhydrosugars¹.  Acid infusion of the biomass has been shown to form stable salts with the naturally occurring alkali and alkaline earth metals (AAEM), rendering the AAEM less catalytically active and producing bio-oil that is rich in anhydrosugars. 

This research focuses on the scale up of AAEM passivation technology to produce consistently pretreated biomass feedstock in large quantities suitable for demonstration scale reactors.  A number of independent variables have been investigated and a response surface methodology (RSM) developed for the pretreatment technology.  Micro-pyrolysis and the subsequent analysis of the products produced from the pretreated biomass samples served as a proxy for effective passivation. 

1.            Kuzhiyil, N., et al., Pyrolytic Sugars from Cellulosic Biomass. Submitted.