Ordinarily, no modern industrial operation wants to be known for stinginess. But the Algar Oil Sands Project in Alberta, being an extraordinary facility, is likely rather proud of its stinginess — with its use of water, that is.
Project operator Great Divide Oil Sands Partnership, an affiliate of Connacher Oil and Gas Ltd., has selected GE Water and Process Technologies’ water evaporator and zero liquid discharge (ZLD) system to dramatically cut water usage and protect regional water resources.
The new two-stage evaporation process deployed at the Algar project uses successive evaporation, crystallization and drying processes to separate clean water from impurities. The clean water is then reused to make high-purity steam for bitumen extraction, while impurities are reduced to dry solids. The system recycles up to 98 per cent of the water recovered from the steam-assisted gravity drainage (SAGD) bitumen extraction process and eliminates all wastewater discharge to the environment. It also allows the use of lower quality, brackish water sources for makeup water.
The process is expected to reduce electricity demand by as much as 25 per cent and significantly decrease plant size, compared to previous configurations. The use of standard drum boilers to produce steam also cuts natural gas consumption by five per cent over conventional once-through steam generators.
The system will treat up to 1,000 gallons of produced water per minute at the Algar site, and will decrease makeup water requirements by more than 200,000 gallons per day. Because nearly all of the water recovered from the extraction process is reused, wastewater discharge to the environment will be eliminated by an equivalent amount.
Annual water savings of up to 73 million gallons will go a long way towards helping to diminish the project’s carbon and water footprints.