The Quest Carbon Capture and Storage project could be the first step to capture and store greenhouse gas emissions from Canada’s energy-intensive tar sands operations. The Canadian government agreed this summer to underwrite nearly two-thirds of the $1.35 billion project cost. It still needs to go through a regulatory pathway before a consortium (oil companies Chevron and Marathon are partners) led by Shell decides whether to go forward with its share of the investment.
Large efforts for little gain
Quest would be among the largest CO2 capture and storage (CCS) projects in the world, sequestering 1.2 million metric tons of CO2 per year in saline formations (basal Cambrian sands, about two kilometres underground near the Scotford site). But 1.2 million tons of CO2 is still just a small fraction of the total greenhouse gas (GHG) emissions from tar sands operations (the conversion of bitumen from the sands into crude oil releases 60% more greenhouse gases than conventional oil production, according to the Canadian government’s environmental agency).
The Scotford Upgrader
Quest would be placed at the Scotford Upgrader around 600 km away from the tar sands in a region near Edmonton. Since 2003 the upgrader has turned bitumen from the Athabasca oil sands into synthetic crude oil. It involves facilities for heating and compressing the bitumen while adding hydrogen to the naturally carbon-rich mix to produce synthetic crude oil. The unit producing hydrogen by heating steam and methane subsequently creates a concentrated stream of CO2. This is where the CCS would take its effect.
An expansion of the upgrader came onstream this spring increasing the capacity of the upgrader by 16 000 m3/day, – an increase in capacity and CO2 emissions of around 60%. The US$9-11.3 billion expansion contract was awarded to KBR in May 2007 (Wikipedia February 2010).
Shell claims that Quest will hinder about 1.2 of the around 3.4 million tons of CO2 from the upgrader to reach the atmosphere.
CCS on tarsands are not environmental CCS
The extraction of oil from tar sand produces vast levels of GHG because the process is technically challenging and energy intensive.
The huge amount of energy required to strip heavy oil from the sand and upgrade it to usable petroleum products, mostly comes from burning natural gas. In this way tar sand uses the least CO2 emitting fossil fuel (natural gas) whilst contributes significantly to global warming.
In order to reduce GHG by 85% in time for 2050 as recommended by the Intergovernmental Panel on Climate Change (IPCC), the extraction of oil from tar sand is not a viable option, with or without CCS. Environmentally sound CCS projects needs to have a satisfactory Life Cycle Analysis taking into account the total CCS value chain (e.g. Koree, A. et al. 2009).
– “The emissions from producing, upgrading and combusting tar sands are so high compared to other oil production, that we can not call this CCS project a good project”, says energy advisor in Bellona Gøril Tjetland.