Carbon Capture and Storage

Introduction

This wiki page is compilation of research done for Professor Nicola Tynan's Environmental Economics class. Contributors include Quinn Biros, Eric Benzenberg, Anna Martinez, Amanda Stevens, and Charles Umberger. The purpose of this site is to give the reader a brief overview of the economic and environmental implications of carbon capture and storage (CCS) with an emphasis placed on coal burning power plants.

Coal Mining

Definition

Carbon capture and storage (CCS) is defined as the technological process of mitigating carbon dioxide (CO2) emissions from point sources such as coal burning power plants and permanently storing the CO2.

Relevance

Carbon dioxide (CO2) has been proven to be a potent greenhouse gas and controlling CO2 emissions must be an integral part of any plan to fight human induced climate change. Carbon capture technology has been in use for years by oil and natural gas extraction firms but only recently has the technology gained environmental relevance due to international concerns about climate change. The vast majority of point source CO2 emissions are from fossil fuel burning power plants. In addition coal is a cheap, abundant resource that is a major part of the US energy portfolio. Since coal is such a aspect of the economy and the infrastructure for burning it already exists, eliminating coal as a power source is not economically feasible, thus mitigating harmful emissions and cleaning the industry should be a major focus of research.

Carbon Capture and Storage (CCS) Technology

CCS can be separated into three distinct steps: isolating and capturing the CO2 from the flue gases, compressing and transporting the CO2 to storage facilities, and permanently storing the CO2.

Carbon Capture

Post-Combustion

Coal is a very dirty fuel and when combusted, generates a whole slew of noxious gases called flue gases. With post-combustion carbon capture, CO2 is separated from the general flue gases after the coal has been burned by absorbing the carbon in a solvent filter. After collection the solvent is heated so that the trapped vapor is released and a pure stream of CO2 results. CO2 is exhausted in the flue gases at atmospheric pressure and a concentration of 10-15 volume percent. Post-combustion carbon capture can prevent 80 to 90 percent of a power plant's carbon emissions from entering the atmosphere. Another benefit of using post-combustion carbon capture is that existing coal-fired power plants can be retrofitted with the technology. Post-combustion carbon capture presents challenges as a technology in three main ways: the low pressure and dilute concentration dictate a high actual volume of gas to be treated, trace impurities in the flue gas tend to reduce the effectiveness of the CO2 adsorbing processes, and compressing captured CO2 from atmospheric pressure requires a massive amount of energy.

Precombustion

With precombustion carbon capture, CO2 is trapped before the coal is burned. This avoids the challenge of separating the CO2 from the flue gases. Before combustion, coal is heated in pure oxygen resulting in a mixture of carbon monoxide and hydrogen. This mix is then treated in catalytic converter with steam, which then produces more hydrogen along with carbon dioxide (CO2). These gases are mixed with amine which binds with the CO2 separating it from the hydrogen. The amine/CO2 mixture is heated, releasing pure CO2, and the amine is recycled for further use. One of the benefits of precombustion carbon capture is that the hydrogen byproduct can be used for further energy production resulting in a lower parasitic energy loss. Precombustion carbon capture is lower in cost, but cannot be retrofitted on existing power plants. Like post-combustion carbon capture, 80 to 90 percent of CO2 can be captured.

Oxy-Fuel Combustion

With oxy-fuel combustion carbon capture, coal is combusted in an oxygen rich chamber to produce a stream of CO2 and steam. The CO2 is captured by condensing the steam and separating the CO2 from the water using filters. The need for pure oxygen makes the technology very expensive, but extensive research is being conducted to try and bring the costs down. Oxy-fuel combustion carbon capture can prevent 90 percent of CO2 emissions from entering the atmosphere.

Carbon Transportation

Since most power plants are not located near carbon storage sites, the captured CO2 needs to be transported from the power plant to the storage site. CO2 can be transported in three states: gas, liquid, and solid (dry ice). Since CO2 pipeline infrastructure already exists, it is much more economical to transport the CO2 in a gaseous or liquid state than a solid state.

Pipeline

Carbon dioxide pipelines are an existing part of the U.S. infrastructure with over 1,500 miles of CO2 pipelines in the U.S. A compressor pumps the gas through the pipeline and depending on the distance the CO2 needs to travel, several compressors may be needed at intermittent intervals to keep the gas flowing. The CO2 must be clean of impurities including hydrogen sulfide and water to minimize corrosion and maximize the lifespan of the pipeline. Typical pipelines are made of carbon manganese steel and are at a higher risk of corrosion than the more expensive pipelines made of stainless steel.

Trucking and Shipping

Sometimes CO2 needs to travel further than a pipeline goes. In these instances, CO2 is condensed into a liquid and loaded onto either a tanker truck or ship. This process requires that the CO2 be pressurized and refrigerated requiring additional energy.

Economics of Coal Mining

Coal is a fossil fuel primarily used for electricity production. Any solution has impacts economy wide. There are towns that were created around a coal mine. There are states, like WV, that are coal states. Despite the economic reliance on coal, there is also a social movement against coal surrounding the environmental impact. Of the possible solutions, one discussed is the use of Carbon Capture and Storage. (CCS)

CCS and Cap and Trade

Cap and trade functions by capping the emissions and bringing the cap down over time. Each company would be given a certain number of allowances. Some emitters will be able to reduce their emissions at a lower cost and will do so. Others will not be able to reduce their emissions at a lower cost, and will have to buy more allowances from the ones that can. As a result, the buyers and sellers will create a market.

Example

The buyers and sellers would benefit from this market. One projection for the price of using CCS to abate a ton of carbon is $25 by 2030. [1] Not all companies will be able to abate for this cost. Pretend there are two companies with the ability to abate for $25 and $28. The company that can abate at the lower cost will abate more than their share. These extra credits can then be sold to the higher cost abater. The cost they will settle on will be between $25 and $28.

They both benefit from trading. The $25 abater would get a profit for their dedication to reducing their carbon footprint. The $28 abater will be able to reach their reduction level at a price cheaper than if they were required to abate on their own.

Spurs Innovation

The low and high cost abaters recognize that there is an incentive to reduce their emissions at the lowest cost possible. The desire for lower costs and the declining cap will make it necessary for new cheaper ways to be created to abate carbon. As a result, money will be invested in perfecting and cheapening CCS technology.

Possible Consequences

The market is imperfect and subject to fluctuations. Although there is an economic incentive, implementing cap and trade with CCS technology could have obstacles to overcome. Since cap and trade with CCS would be a new factor in the US market, people could have issues with complying at first. The investment in perfecting CCS technology could have a slow start. If the investment does not come as planned and the cap keeps increasing the amount companies have to pay for coal, it could have economy wide consequences.

“Buffett sees Burlington Northern as a growth vehicle to earn more on the billions in cash Berkshire has on its books carrying coal, wheat and other resources across the nation.”[2] This quotation refers to Warren Buffett’s purchase of Burlington Northern, a rail road. One of the possible consequences of an increase in the cost of coal is a decrease in the demand for it. If there is a decrease in the demand for coal, then there is a decreased need for the railroad to move it. As a result, not only will the coal industry be hurt, but also the railroad and transportation industry.

Charlie