Drilling/Production Natural gas-diesel process headed for market

Sasol Ltd. of South Africa and Haldor Topsoe AS of Lyngby, Denmark, plan to market a new process designed to convert natural gas to diesel fuel.

The companies say the process could enable development of gas reserves currently deemed unviable. They have signed an agreement calling for combined promotion of Sasol's slurry phase distillate technology and Topsoe's natural gas conversion technology.

Sasol estimates a plant designed to produce 1 million b/d of diesel fuel using this process, requiring about 85 billion cu m/year of gas feedstock, could be built for $300-400 million. That compares with $3-4 billion for a natural gas liquefaction plant.

Topsoe said the cost difference makes it attractive to build a conversion plant at sites where significant volumes of gas are flared or a gas discovery is far from a potential market.

Combined processes

Sasol has decades of experience of converting coal to gasoline during the years when South Africa was cut off from international markets. Sasol's process for converting synthesis gas to diesel fuel is derived from its synthetic gasoline technologies.

Topsoe's experience has been in conversion of natural gas to synthesis gas for use as feedstock in producing liquid fuels.

Combining the two processes is said to allow economic conversion of any viable gas source worldwide to high quality diesel fuel and to offer potential for petrochemicals production.

Topsoe said, "One obvious target market for this process is places where gas is being flared-Nigeria, the North Sea, Canada, parts of the U.S., and South America.

"Remote gas fields in Russia, for example, could be developed in order to produce diesel fuel. And it could enable development of relatively small, remote gas fields. One advantage of this process is that you would not need a large unit to make it viable."

Topsoe also said the two companies are in contact with "quite a number" of companies around the world about application of the technology.

Sasol said a natural gas/diesel fuel plant based on this process could be built in a modular fashion, with units added as demand increases.

"But the biggest advantage is that you would not have to transport gas by pipeline to a conversion plant or to market.

"You could set up a plant close by the field and convert straight from gas to middle distillates."

Copyright 1996 Oil & Gas Journal. All Rights Reserved.