Publications

Abstract not provided.

Rapid detection and identification of bacteria and other pathogens is important for many civilian and military applications. The taxonomic significance, or the ability to differentiate one microorganism from another, using fatty acid content and distribution is well known. For analysis fatty acids are usually converted to fatty acid methyl esters (FAMEs). Bench-top methods are commercially available and recent publications have demonstrated that FAMEs can be obtained from whole bacterial cells in an in situ single-step pyrolysis/methylation analysis. This report documents the progress made during a three year Laboratory Directed Research and Development (LDRD) program funded to investigate the use of microfabricated components (developed for other sensing applications) for the rapid identification of bioorganisms based upon pyrolysis and FAME analysis. Components investigated include a micropyrolyzer, a microGC, and a surface acoustic wave (SAW) array detector. Results demonstrate that the micropyrolyzer can pyrolyze whole cell bacteria samples using only milliwatts of power to produce FAMEs from bacterial samples. The microGC is shown to separate FAMEs of biological interest, and the SAW array is shown to detect volatile FAMEs. Results for each component and their capabilities and limitations are presented and discussed. This project has produced the first published work showing successful pyrolysis/methylation of fatty acids and related analytes using a microfabricated pyrolysis device.

Biomass feedstocks contain roughly 10-30% lignin, a substance that can not be converted to fermentable sugars. Hence, most schemes for producing biofuels (ethanol) assume that the lignin coproduct will be utilized as boiler fuel to provide heat and power to the process. However, the chemical structure of lignin suggests that it will make an excellent high value fuel additive, if it can be broken down into smaller molecular units. From fiscal year 1997 through fiscal year 2001, Sandia National Laboratories was a participant in a cooperative effort with the National Renewable Energy Laboratory and the University of Utah to develop and scale a base catalyzed depolymerization (BCD) process for lignin conversion. SNL's primary role in the effort was to utilize rapidly heated batch microreactors to perform kinetic studies, examine the reaction chemistry, and to develop alternate catalyst systems for the BCD process. This report summarizes the work performed at Sandia during FY97 and FY98 with alcohol based systems. More recent work with aqueous based systems will be summarized in a second report.

Alkylation reactions of benzene with propylene using zeolites were studied for their affinity for cumene production. The current process for the production of cumene involves heating corrosive acid catalysts, cooling, transporting, and distillation. This study focused on the reaction of products in a static one-pot vessel using non-corrosive zeolite catalysts, working towards a more efficient one-step process with a potentially large energy savings. A series of experiments were conducted to find the best reaction conditions yielding the highest production of cumene. The experiments looked at cumene formation amounts in two different reaction vessels that had different physical traits. Different zeolites, temperatures, mixing speeds, and amounts of reactants were also investigated to find their affects on the amount of cumene produced. Quantitative analysis of product mixture was performed by gas chromatography. Mass spectroscopy was also utilized to observe the gas phase components during the alkylation process.

Abstract not provided.