Total is expected late this year or early in 1996 to decide whether to build a pilot plant at its Le Havre refinery, France, to test commercial viability of a biological process to remove sulfur from diesel fuel.
Total is studying results from a 5 b/d test unit built at Petrolite Corp.'s St. Louis headquarters. There the biocatalytic desulfurization (BDS) process developed by Energy Biosystems Corp., Houston, is being tested on middle distillates provided by Total (OGJ, Mar. 20, p. 42).
Jeff Nagel, director of marketing for Energy Biosystems, said Total is looking to build its own pilot plant at Le Havre, with the goal of scaling up to a 10,000 b/d commercial BDS unit if trials are successful.
Nagel sees increasing demand for desulfurization technology because of tightening fuels regulations and increasing use of high sulfur crude oil. Only hydrogen desulfurization (HDS) processes are available today, he said.
REQUIRED SPENDING
Refiners worldwide must add 1015 million b/d of desulfurization capacity under planned legislation, Nagel said. Total capital expenditure required will be $30 billion at an average rate of about $6 billion/year.
HDS involves high capital expenditure and high capital costs, Nagel pointed out. He reckons the BDS process will have a 50% capital advantage over HDS and even higher in greenfield projects, while operating costs for BDS are expected to be 10-20% lower than for HDS.
Because HDS is thought to be most effective at removing sulfur from light hydrocarbons, and BDS has been found to be particularly effective on heavier molecules, the most likely scenario is use of both HDS and BDS processes.
"There is a synergy between BDS and HDS technologies," Nagel said. "Middle distillates can be treated with BDS after an HDS run. It is cheaper to tack on a BDS unit than to ramp up HDS operation."
SUPERBUG
The organism Energy Biosystems is using, Rhodococcus erythropolic, was discovered by a U.S. government research project seeking ways to desulfurize coal. Energy Biosystems secured a license to develop a process using the bacteria for petroleum industry applications.
Nagel said design of the bioreactor must be fine-tuned ahead of Total's pilot project. Also, the bacteria must be genetically engineered to work faster and live longer. But Nagel is confident "superbug" will be ready in time.
Nagel hopes installation of the first commercial BDS unit will take place in 1996 or 1997. Beyond that he sees opportunities worldwide for the process: as much as 800 million bbl/year of diesel fuel desulfurization; 440 million bbl/year of gasoline treatment; and 12 billion bbl/year of crude oil desulfurization.
"Today, Europe is the most exciting market for diesel," Nagel said, "but the ability to desulfurize crude oil is the big thing for the future.Energy Biosystems has a contract with Texaco Inc. to develop its BDS process for crude oil desulfurization. Nagel said Texaco is particularly keen to apply the process to its Middle East, Texas, and Louisiana crudes.
Copyright 1995 Oil & Gas Journal. All Rights Reserved.
