The nature of the oil sands makes them energy-intensive to produce. Energy is needed to transport the earth, to break it down into smaller pieces and to heat the water used to separate the oil from the sand. Energy is also used in other processes, such as producing the hydrogen needed to upgrade the heavy crude. All these steps produce greenhouse gas (GHG) emissions such as CO2 – a contributing factor to climate change.
The challenge is to reduce greenhouse gas emissions while the demand for energy – and the amount of energy the world is consuming – is growing. Global demand for energy is expected to increase 40% by 2035, according to the International Energy Agency.
Canada’s oil sands industry continues to reduce GHG emissions intensity. According to Environment Canada, between 1990 and 2012, GHG emissions associated with every barrel of oil sands crude produced have been reduced by 30%.
Work is in progress on a variety of new technologies to lower GHG emissions, and capture and store CO2.
Through Canada’s Oil Sands Innovation Alliance (COSIA) GHG Environment Priority Area (EPA), oil sands companies are working together and collaborating with universities, government and research institutes to develop innovative technologies to reduce energy use and associated GHG emissions for oil sands in situ and mining operations.
Some of the key areas COSIA’s GHG EPA is looking at include:
- Improving energy efficiency in all aspects of oil sands operations, including the production of steam for in situ (in place) recovery of bitumen;
- Recovering waste heat for reuse;
- Reducing flaring, venting, and fugitive emissions;
- Carbon Capture and Storage of CO2 from steam generators and other large oil sands facilities;
- Producing alternative energy;
- Exploring regional opportunities to reduce GHG emissions with non-industry parties
The amount of GHG emissions released for each barrel of crude oil produced is called the GHG intensity. To understand what would be required to bring the GHG intensity of oil sands crude more line with its competition, a study was undertaken to identify processes and technologies that will reduce energy use and GHG emissions from all aspects of oil sands production, including in situ and mined bitumen extraction, and upgrading. Suncor Energy, with funding from Climate Change Emissions Management Corporation (CCEMC) and support from Alberta Innovates – Energy and Environment solutions, teamed with Jacobs Consultancy Canada Inc. to complete the Oil Sands Energy Efficiency and Greenhouse Gas (GHG) Emissions Roadmap Study in nine months.
In the study, Suncor’s Firebag operation represented a typical in situ facility while the Suncor Millennium mine and base plant extraction facility represented typical mining and extraction facilities. Suncor’s Upgrader No. 2 represented a typical upgrading facility.
The study provided a high-level evaluation of GHG reduction opportunities. Some of these opportunities could be implemented now, however, most will require more detailed technology and economic evaluation and development before they can move forward. More importantly, the study provides a foundation and direction for future efforts to improve the energy efficiency of Alberta’s oil sands operations, which will reduce GHG emissions.
Find out more about the GHG Roadmap
The Algae Process
Natural Resources Limited (Canadian Natural) is testing this technology at a pilot-scale biorefinery scheduled to be operating by mid-2014. The biorefinery will take carbon dioxide and waste heat from oil sands facilities put it into large tanks with algae and treated waste water and promote photosynthesis with LED lights. Then the algae are pressed to release bio-oil that can be used for jet plane fuel or blended into heavy oil or synthetic crude oil. The leftover biomass can then be used to feed livestock and for land reclamation.
Learn more about the Algae project
Gas-Turbine Once Through Steam Generator
Steam generation is a central part of the bitumen production process at steam assisted gravity drainage (SAGD) facilities. Most SAGD facilities have Once-Through Steam Generators (OTSG) which burn natural gas to boil water, producing steam that is injected into the ground to soften bitumen. The bitumen is then extracted through a producing well and the majority of the water is treated and recycled. The Gas-Turbine OTSG (GT-OTSG) works on the same premise, except the gas turbine produces electricity that can be used to power the facility. Waste heat in the turbine exhaust is utilized in the OTSG to produce steam.
The GT-OTSG’s gas turbine is the key to producing electricity at the same time it produces steam for a SAGD facility. This technology is being tested in a pilot scale demonstration at Surmont, a joint venture between ConocoPhillips Canada (CPC) and Total E&P Canada. The enabling technology of the GT-OTSG process is a burner developed by CPC. It burns the natural gas and the hot turbine exhaust, allowing the unit to operate more efficiently than competing co-generation configurations. When hot exhaust from the turbine is delivered to the burner, it improves the efficiency of the OTSG, further reducing the facility’s overall emissions.
Learn more about GT-OTSG
Waste Heat Recovery
In both the CSS and SAGD process, steam is produced by heating water through the combustion of natural gas in large steam generators. To reduce energy use and associated GHG emissions, oil sands producers like Devon are working to use the low-grade waste heat from their bitumen recovery processes to generate clean electricity. Devon is currently evaluating plans to install a low-grade waste heat recovery Organic Rankine Cycle (ORC) unit at its Jackfish 1 SAGD in situ operation. It is expected to generate 8 to 10 per cent of the facility’s electricity.
Converting waste heat to power is not a new technology. Recovery of high-grade waste heat, with a temperature greater than 130C, especially in exhaust gas waste heat, has been used commercially to generate power for more than 20 years. Many turbines/expanders have been developed for the working fluids (refrigerants) used in this process. However, in situ operations typically have an excess of low-grade waste heat, which has a temperature of 70C to 90C. In the past, the low-grade waste heat ORC units were limited to less than 200 kilowatts (kW), making larger projects uneconomic and requiring a large footprint.
However, recent technological advances in ORC waste heat recovery have resulted in the development of an economical system. The advancements include an efficient turbine that uses the higher efficiency working fluids while producing larger quantities of power. Devon’s proposed Jackfish 1 installation will differ from the U.S. installation in that it will use air cooling rather than cooling water towers.
Learn more about Waste Heat Recovery