Carbon Capture and Storage and Climate Change

Jeffrey Michel | Jul 30, 2013

There are many good reasons for capturing carbon dioxide emissions from coal power plants. Regrettably, the prevention of climate change is not one of them.

Since the 1970s, over 4,000 miles of pipelines in North America have transported carbon dioxide from natural gas purification, coal gasification, and natural sources to conventionally depleted oilfields. Water-miscible CO2 flooding revitalizes these reservoirs by significant incremental amounts.

The global recovery potential of such enhanced oil recovery techniques approaches a trillion barrels. However, leaving the CO2 underground is of no ultimate benefit for climate stabilization when additional hydrocarbons have been extracted in exchange. Under current best practices, one ton of injected carbon dioxide yields an additional 3.6 barrels of crude oil, which will subsequently emit 1.4 tons of CO2 when refined and burned.

Incremental oil revenues make CO2 enhanced extraction commercially viable, but the opportunities are limited to a tiny fraction of total emissions. Storing many hundred times the carbon dioxide from power stations in inert saline aquifers throughout the world requires economic incentives of appropriate scale. In Europe, the EU Emissions Trading Scheme (ETS) has not fulfilled expectations in this regard. Depending on assumptions, CO2 trading prices between 40 to 90 euros (about 50 - 120 dollars) would be needed to sustain an expansive carbon capture and storage infrastructure.

The current ETS pricing level below 5 euros per tonne is inadequate to cover even pipeline transport charges. The United Kingdom emits sufficient carbon dioxide to cover expected oil recovery requirements in the North Sea. Far greater CO2 tonnage from coal and lignite power stations on the Continent would necessitate offshore aquifer storage financed entirely by customers who are already burdened by the world’s highest electricity prices.

Since Europe is responsible for only about a tenth of global CO2 emissions, international CCS efforts would have to be multiplied accordingly. One impediment to wide-ranging strategies is coal availability. A CCS power plant consumes considerably more fuel per generated kWh for separating and compressing CO2. The longer the pipeline to the geological storage location, the greater the additional energy required.

China and India are already dependent on coal imports to sustain conventional power generation. Foreign mining and delivery rights have been secured to help meet growing demand. The two countries account for almost a third of global carbon emissions, yet there is no economic rationale for importing additional coal simply to bury CO2 underground.

More fuel per kWh also translates to increased cooling water employed for CO2 separation and compression. CCS proposals often prove impractical for this reason along thermally stressed rivers. Many of the 1,100 new coal power projects counted globally by the World Resources Institute could prove unsuitable for carbon capture retrofits due to additional cooling demands not specified in water withdrawal and discharge permits.

The most precious resource is time. The International Energy Agency postulates over 3,000 CCS power plants and industrial installations realized by 2050 for providing 19 percent of the CO2 reductions needed to limit global warming to 2 degrees C. Yet current emissions trajectories imply accelerated implementation.

Climatologists estimate that maximally 1,000 billion tonnes (Gt) of CO2 could be emitted after the year 2000 for 2 degree target compliance. 440 Gt of this budget has already been expended. Compressing the IEA strategy into the remaining time frame would necessitate dedicating a new CCS plant complete with pipeline and geological storage every two days before 2030, a prospect of no evident practicability.

The European Commission has estimated that achieving climate stabilization by 2050 would be 70% more costly without CCS. However, the Arctic sea may now be seasonally ice-free by 2025 according to the Center for Climate and Energy Solutions. Later CO2 reductions could not reverse ocean thermal inertia.

Asian interest in climate protection is visibly declining as the warming world opens new polar sea routes and Greenland mining opportunities. Prevailing market mechanisms already treat CO2-induced ocean acidification with impunity despite the foreseeable breakup of marine food chains. The intrinsic culpability of coal emissions cannot be alleviated by token CCS projects, particularly since intensified fuel and water usage undercuts overall resource efficiency objectives.

The ultimate climate challenge of leaving fossil fuels in the ground presumes the contagious development of alternatives that must reach epidemic proportions before coastal regions have been swamped by rising sea levels.

The column was written in response to a recent one by Ken Silverstein, called Capturing Carbon is Real and Used to Enhance Oil Recovery.

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