Water and oil don’t mix, but they do work together at the Co-op Refinery Complex (CRC), thanks to a new wastewater treatment facility at the refinery.
The refinery requires an enormous amount of water to function. Water is used by the CRC to warm pipes, to drive turbines and to assist in chemical processes. It also cools process units. The refinery even runs its own firefighting equipment.
But water, as we all know, is a scarce resource in Saskatchewan. Both Regina’s and Saskatchewan’s water use has climbed steadily over the years. The city’s growing population and the increased use of water in the resource sector have combined to put Regina’s water supply under ever-increasing pressure. “The turning point for us was the Section V expansion. Even before it was complete, we knew we were going to need significantly more water to operate,” says utilities engineer John Hilts, P.Eng. Although the refinery had enough water to continue to operate even after the expansion, the company’s leadership anticipated that a more innovative solution would be needed down the road as outside sources came under more pressure.
The provincial Water Security Agency (WSA) tightly regulates Saskatchewan’s water resource and sets strict quotas for industrial and resource sector users. As its use continued to grow, the CRC was faced with the prospect of bumping up against those quotas. The amount of fresh water needed from the City of Regina’s source would have climbed higher than what CRC was allowed by the WSA.
“We were using all the water from on-site wells and supplementing this with City of Regina water. We needed to develop a more sustainable way to meet our water needs,” says Gil Le Dressay, P.Eng., vice-president of operations at CRC.
To meet this need, recycled water will be used more often. To achieve this, the CRC launched its ambitious Wastewater Improvement Project (WIP). Although it has garnered little media attention, at a price tag of over $200 million, this cutting-edge environmental initiative is one of the largest megaprojects under way in Saskatchewan.
“This is really leading-edge technology. We have faced challenges along the way, which is natural because it has been a learning process for everyone involved. The sheer scale of the project has created challenges in juggling all of the contractors involved,” says the operations superintendent, Jack Holizki. “But we are getting there. We are still in start up mode. We are slowly commissioning and phasing into a full start. The big payoff will be when it is fully functional,” Holizki adds.
“The Wastewater Improvement Project, when fully operational, will allow the refinery to recycle up to 65 per cent of its waste water,” says Le Dressay. “We are the first refinery in North America to recycle so much of our waste water for reuse in the oil refining processes.”
The CRC’s wastewater treatment plant will recycle its waste water using biological technology that can treat the process water more effectively than previous solutions. In the past, the water would have been manually treated to separate oil and solids from the water. Then the City of Regina would have to further treat the refinery waste water at its own treatment plant.
By recycling, the CRC has made impressive strides in reducing its fresh water use. Even though the Section V expansion has increased water use by 30 per cent, the WIP will cut the refinery’s fresh water use by roughly 28 per cent. That’s the equivalent of the water used by 3,100 households.
Not only will the WIP reduce CRC’s water use but it will also deliver a host of other environmental benefits. “We have four major objectives in this project. First, we want to reduce our general well water use. Then we want to improve the quality of the waste water we produce. Third, we want to reduce the quantity of waste water sent to the city. Finally, we want to improve the air emissions from the water treatment process,” says Hilts.
How Refinery Water is Purified
The CRC’s recycling technology depends on a combination of biological, mechanical and electrical filtration systems:
Stage 1. Separation.
Floating oil is skimmed off and reprocessed within the refinery. Sediment and oily sludge on the bottom are removed and disposed of safely. The remaining water continues on to stage 2.
Stage 2. Dissolved Gas Flotation Unit.
Microscopic nitrogen bubbles help the remaining oil particles float to the surface of the water where they are removed.
Stage 3. Membrane Bioreactor.
Special bacteria break down biodegradable volatile organic compounds and ammonia in the water.
Stage 4. “Zee Weed.”
The water is filtered through spaghetti-like, hollow fibre membranes to remove remaining solids.
Stage 5. Centrifuge.
The biological material removed in stages 3 and 4 retains some moisture. This is extracted by spinning the materials through a centrifuge.
Stage 6. Demineralization Plant.
A combination of filters, air pressure, electrical systems and reverse osmosis procedures are used to strip out undesirable chemical compounds.
Something in the Air
The WIP will not only improve CRC’s use of water. It will also improve the air. “WIP will also significantly reduce what is technically known as volatile organic compounds or VOCs. In everyday terms, that means bad smells. I think all of us are in favour of fewer bad smells in our city,“ says Le Dressay.
Air quality and odours have long been sticking points for any refinery located in an urban area. “VOCs have been a major topic of discussion in the oil and gas industry. There are currently no federal or provincial regulations for VOCs. Refinery staff members are participating in a federal panel to conduct baseline studies so that we can start monitoring and controlling these emissions,” says Kendi Young, CRC’s environmental affairs supervisor.
The refinery has gotten ahead of regulations on VOCs by investing in the WIP.
“The WIP will reduce VOCs dramatically. Currently our wastewater is aerated in on-site ponds before going to the city. Those ponds obviously give off a lot of odour. Once the WIP has been operational for a while, those will become clean water ponds with little odour,” says Young.
It is common for industrial projects to throw around the terms “cutting edge,” “leading edge” and “world-class innovation” casually. But in CRC’s case, they’ve got the hardware to prove it.
On April 24, 2017, the WIP was named Industrial Water Project of the Year at the annual Global Water Awards held in Madrid, Spain. The award recognizes the project that represents the most impressive technical or environmental achievement of the year in the field of industrial water.
“This award belongs to every member of our hard-working team at the refinery. Their dedication and innovation has put the Co-Op Refinery Complex at the cutting edge of sustainable wastewater technology. I want to thank everyone at the refinery for their contributions to this achievement,” says Le Dressay.