WATCHING THE WORLD

David Knott
London
[email protected]

The petroleum industry is looking towards Qatar for the next major step in the evolution of gas-to-liquids (GTL) technology: confirmation by Exxon Corp. of a plan to build a full scale GTL plant (OGJ, June 23, 1997, p. 16).

Yet, while Qatar's huge gas reserves allow Exxon to think big, a GTL project has been quietly taking shape in India, which may prove the adage that "small is beautiful."

The seed of India's GTL project was sown at Pueblo, Colo., by Rentech Inc., Denver. The company has developed a GTL process, and built a 250 b/d plant at Pueblo in 1993 to prove the technology.

Rentech's process involves steam reforming of methane to make synthesis gas that is bubbled through a slurry containing a proprietary iron catalyst to produce straight chain hydrocarbons.

Mark Koenig, director of investor relations at Rentech, explained that the process was developed beginning in 1982 to fill a perceived niche for small-scale GTL plants.

Gas shortfall

The Pueblo plant proved that the technology was commercially viable on this scale, but had to be shut down the same year it began operating because of inadequate gas supply.

"Gas was supplied from a landfill site operated by Public Service Co. of Colorado," said Koenig. "They thought it could provide 5 MMcfd of gas, but it produced too little to run the plant.

"Now the same plant has been shipped to Kumchai field in Northeast India, where construction work is about to begin. India has long had a problem with flaring, which accounts for about 25% of natural gas produced," he said.

India's Oil & Natural Gas Commission (ONGC) approached Rentech 2 years ago, after a feasibility study into ways of using up to 4 MMcfd of gas that's flared from Kumchai.

Koenig said ONGC's study was inspired by a government drive to reduce pollution and improve air quality. Clean diesel and waxes will find a ready market locally.

Wax will be the main product, so an extra processing plant will be added to the rebuilt unit. The steam reformer will be increased in size, and the plant configured for different gas composition.

Growing interest

The Indian plant capacity will be 360 b/d. Koenig said this fits with the Rentech concept of taking GTL to remote areas, where small plants can be built and operated cost effectively.

"This plant will be at about the minimum capacity for cost-effectiveness," said Koenig. "We are initially looking at up to 5,000 b/d for our process, but reckon it can be scaled up to 10,000 b/d, 15,000 b/d, or 20,000 b/d like the others."

Rentech claims the ONGC study showed its process was the most cost-effective and efficient GTL technology available.

"Everyone wants to see this first plant operating," said Koenig. "It is due on stream in mid-1998. We have been contacted by Oil India Ltd. about the process, and ONGC is interested in building more GTL plants.

"The world is starting to watch what's happening in gas-to-liquids. We are prepared, with eight patents surrounding our technology and seven more pending."

Taking particular note of the Indian plant's progress will be Texaco Inc., which, Koenig said, is negotiating with Rentech to accelerate commercial exploitation and licensing of the process.