Bacteria & Catalysts: A One-Two Punch For Purifying Crude Oil?

Speaking today at the national meeting of the American ChemicalSociety here, chemist Devinder Mahajan described a system known a BIOCAT/CHEM CAT, which he and his BNL colleagues Mow Lin and Eugene Premuzicare developing.

If successful, their two-part approach is expected to purify oilbetter than the one-step bacteria- or chemical-based treatments that arecurrently commercially available.The scientists have already begun selecting and breedingheat-loving, or thermophilic, bacteria that thrive at temperatures near theboiling point of water, the temperatures used in processing crude oil.

They have shown that the bacteria can remove almost half the sulfur andnitrogen, and up to 92 percent of the heavy metals, in crude oil.

Now, they hope to develop water-soluble catalysts that will also beeffective in the same temperature range, rather than the hottertemperatures usually used.

The catalysts are based on a concept developed at BNL for anotherpurpose. Used in a slurry, or soluble, form, their small particles makeincreased surface area available to catalyze the chemical reactions thatremove impurities. The goal is nearly complete removal of the impurities.The lower temperature needed for the catalysis will allow both thebacteria and the catalysts to be used on the same oil, and will preserve asmuch of the crude's fuel potential as possible.

Getting rid of such impurities raises the grade of the oil, makingit more valuable as fuel. And deriving useful, light oil from crude helpsstretch the world's oil reserves.The process would also decrease air pollution, as such impuritiesare released as gases when oil is burned and contribute to both smogformation and greenhouse gas buildup in the atmosphere. Environmentalregulations and global emissions treaties are driving a push towardcleaner-burning fuel.