#04-064

Complete

Date Full Report Received

12/21/2005

Date Abstract Report Received

12/21/2005

Investigation

Institution:
Primary Investigator:
Co-Investigators: Jeanne Koger, Preston Burnette

Gasification offers many advantages for processing undesirable waste materials. Tests on gasifier emissions reveal very low levels of NOx, SOx and volatile organic carbons in the flue gas, well within emission guidelines. The only products, typically, are a combustible gas and a sterile mineral ash. The process occurs at temperatures in excess of 600 ?C (~1100 ?F) in an oxygen-starved environment. Some gasifiers cannot efficiently process such high moisture feedstocks as sludge. The Brookes gasifier, however, is able to handle up to 70% moisture. Although driving off the moisture incurs an energy “penalty,” this can be diminished by using waste heat from the unit to further dry the feedstock prior to loading it into the reaction chamber. The Brookes design uses a batch-feed approach to indirectly heat the biomass, combust the product gases to sustain the reaction and reduce operating costs, and recover a sterile ash that has minimal carbon contamination. The small amount of nitrogen remaining in the sludge is converted to N2 gas. Not only is the Brookes gasifier ideally suited to this application, it is versatile enough to function as a mobile unit that can move from site to site for processing the sludge, thereby minimizing transportation costs. Another major benefit is that the design is very simple. An ‘of the shelf’ blower and door are the only moving parts. Thus, it can be easily maintained and operated by a person after only minimal training.