Nexen Chemicals

Canadian Occidental Petroleum is a diversified energy and chemicals company based in Calgary, Alberta. Nexen Chemicals is a fully owned subsidiary, engaged in the manufacturing, marketing and distribution of industrial chemicals. Nexen Chemicals used to be called CXY Chemicals.

The Nexen Chemicals facility in Brandon, Manitoba manufactures 100,000 tonnes of sodium chlorate a year, with 45 employees.

When CanadianOxy took over management in 1978, chlorate production was only 12,500 tonnes, the technology was outdated and there was an outstanding government order to reduce chlorine emissions. The waste generated from the cell regeneration, water softening and brine purification processes were transferred to one of five lagoons on the site. All effluent was pumped to an averaging pond before being discharged to the Assinaboine River. The CanadianOxy mandate was to bring the plant into a state of compliance and to make it profitable.

The company phased out all other chemical production except sodium chlorate, and began purchasing purified salt from the potash industry. As a result of these changes, discharges to the sludge lagoons were eliminated, and the volume and contamination level of effluents discharged to the Assinaboine River were reduced.

A waste-gas scrubbing system was installed, to bring chlorine emissions down to acceptable levels. As a result, permit violations were reduced to just two or three minor incidents a year.

By 1982 the effluent system was closed-looped, and the effluents were being recycled into the brine system. As a result, discharges to the Assinaboine River were eliminated altogether. Problems associated with impurities with in the system were tackled by eliminating impurities from the incoming raw materials. This expertise placed CanadianOxy years ahead of the competition.

In 1986 the plant underwent a 40% expansion at a cost of $11 million, and the manufacturing process was updated from the obsolete graphite technology to the modern metal technology. This offered several environmental advantages. Waste gases were recovered and purified so that chlorine levels were undetectable. The hydrogen was used as a fuel for the boiler rather than being discharged to the atmosphere. Graphite was no longer consumed during the production process, eliminating a significant waste problem.

Environmental and economic benefits arising from the upgrade included:

• The new process was 25% more energy-efficient;
• Graphite waste production of 62 tonnes a year eliminated;
• Chlorine emissions of 6.8 tonnes were virtually eliminated;
• Discharges to the Assinaboine River ceased;
• Burning hydrogen as a fuel reduced the consumption of natural gas by 95%;
• Approximately $2,000 a month of reusable chemicals previously discharged are recovered.

The Brandon facility is now ranked as one the most cost-effective sodium chlorate manufacturing facilities in North America.