A small but promising start has been made on biological engineering to eat — literally — an obstacle to producing about one-fourth of Canadian natural-gas reserves — so-called “sour” deposits laced with lethal hydrogen-sulphide.

The first commercial, field-scale use in North America of a method that harnesses bacteria which gobble up hydrogen-sulphide like candy is under way at a plant operated by Canada’s top gas producer, EnCana Corp. It works, according to company specialists who put the installation into production without fanfare Sept. 12.

The project follows about five years of work by a Canadian specialty firm, New Paradigm Gas Processing Ltd. It applies a technique devised in Europe by an arm of Royal Dutch-Shell, Shell Global Solutions International B.V., and Dutch environmental specialty firm Paques Natural Solutions.

The approach was inspired by discoveries of thriving, sulphur-based ecosystems around volcanic hydrothermal vents on sea floors off Japan, Hawaii and Washington State since the 1970s. Titled Bantry, the site of the gas production pioneering is a classic case of a bad and worsening headache in the Canadian industry. That is well-known, economical reserves potentially stranded beyond exploitation by rising public concerns over health and safety.

The field, in the Alberta farming community of Princess a two-hour drive southeast of Calgary, lies in a plains region of shallow drilling that shows signs of aging after being a Canadian supply mainstay for generations. EnCana found reserves to extend the life of the field by tapping new geology, but the gas turned out to be sour.

At levels ranging from 60 to 1,400 parts per million (0.006-0.14 per cent), the hydrogen-sulphide impurity at Bantry was slight by standards of an industry that successfully produces up to 500,000-ppm (50%) sour gas. But a preliminary canvass of the community confirmed that anxiety over health, safety and environmental risks has reached a height where the company faced determined public resistance, hearings before the Alberta Energy and Utilities Board, certain delay, and the possibility of strict, expensive conditions on production permits.

The Canadian gas industry has tapped sour deposits for virtually all of its history. But much of the activity on a large scale began when it was beyond the attention of a less touchy Alberta population less than one-third its current size, now exceeding three million and spreading fast into formerly almost empty countryside. The potency of hydrogen-sulphide has become well known everywhere in western Canada, thanks to celebrated cases of environmental and landowner resistance against industry projects.

Establishing a reliable science of risks, controls and public safeguards is a top priority at the AEUB, with help from a blue-ribbon independent panel of specialists. The impurity’s rotten-eggs odor becomes detectable to humans with good noses at concentrations of one part per million (0.001%). Over 20 ppm, protective equipment has to be worn. At 700 ppm (0.07 per cent), exposure rapidly causes unconsciousness. Victims stop breathing and die unless rescued promptly.

Unconsciousness is instantaneous at 1,000 ppm (0.1%) or more. The biological ingredient at the Bantry plant — a hungry but natural and not genetically-engineered strain of a common, harmless micro-organism, Thiobacillus — not only eats hydrogen-sulphide. It does the job well enough to eliminate a standard industry practice for getting rid of last bits of the compound not captured by conventional methods: incineration by flaring, which produces sulphur-dioxide that smells like burnt matches and has become the second-most disliked side-effect of sour-gas production.

The only waste product of the biological method is elemental sulphur, as a powder clean enough to be disposed of at a landfill site. So far, EnCana and New Paradigm alike say the new approach remains in its infancy, capable of filling only a niche market of small-volume sour gas production. The biggest use so far is a plant in Egypt that produces sulphur at a rate of 15 tons per day. Alberta sour-gas operations produce up to 5,000 tons daily.

The Canadians aim to scale up the technology. The small start has already proven the method can pay a big dividend. The technical story is so intriguing and easily understood that the Bantry project went ahead without a hearing by the AEUB because the companies persuaded the community that the new method would work.

©Copyright 2002 Intelligence Press Inc. All rights reserved. The preceding news report may not be republished or redistributed, in whole or in part, in any form, without prior written consent of Intelligence Press, Inc.