Addressing carbon dioxide emissions from power projects

China is planning numerous carbon capture and storage projects, which often combine enhanced oil recovery ventures. As we know, the power industry is the largest greenhouse gas and carbon dioxide emitter globally; and means of recovering, utilising, sequestering, and recycling CO2 (carbon dioxide) is the key to a healthier planet, and a stronger power industry worldwide.

Since the beginning of the Industrial Revolution, various natural mechanisms which balance atmospheric CO2 levels have been unable to maintain such a balance prior to this event. These mechanisms are the constant exchange of CO2 among the atmosphere, ocean, land surface, microbes, plants and animals.

In a much shorter time span, and as humanrelated industrial activity has grown significantly, since the 1960s, in some 40 years, CO2 presence in the atmosphere has grown by a factor of 20%; at this rate, the effects of climate change will be unsustainable.

Various measurements surrounding CO2 content in the atmosphere indicate a broad range over 300 ppm (parts per million) in recent years, and now, measurements indicate a concentration of near 400 ppm.

This continuous increase in CO2 atmospheric content is not sustainable; whereby some of the ever-more intense weather around the globe has been attributed to climate change, and global warming. These changes include severe floods, drought, temperature ranges, hurricanes, and tsunamis to name some of the very expensive and harmful events as of late.

As for CO2 emissions at large, including power production, in 2011 some 84% of CO2 emissions were from all human-related activities. Further on the subject of CO2 emissions on a percentage basis, about 40% of all CO2 emissions are from the combustion of fossil fuels used to generate electricity.

One example surrounding fuel types which emit CO2 from combustion indicate nearly 78% of all CO2 emissions from the power sector are from coal fired power plants; and then to follow is natural gas at about 16%.

A changing landscape – projects underway

While many indications suggest the ever-growing severity of storms, droughts and weather patterns is a result of climate change, and while CO2 by volume is the leading gas being emitted from the power sector; positive changes can turn the tide. Carbon dioxide recovery and sequestration is gaining ground from various private and government-sponsored projects, when commercialised, will help the cause.

Some projects globally are joint ventures between major engineering firms and power producers, such as China’s Datang Corp. and Alstom. They are developing two carbon capture and storage (CCS) projects in China’s two largest oilfields, located in the Daqing, Heilongjiang province and Dongying, Shandong Province.

The 350 MW coal-fired plant of Daqing will use an oxy-firing technology for CO2 recovery; and the 1,000 MW Dongying coal-fired plant will use one of Alstom’s CO2 recovery technologies; which include chilled ammonia, amines, and oxy-firing. Oxy-firing involves using pure oxygen versus the approximate 20% found in the environment; where high combustion temperatures are achieved with concentrated oxygen.

Both of these Chinese CCS projects represent CO2 recovery and sequestration in excess of 1 million tons annually for each project; and more importantly, work in enhanced oil recovery (EOR).

The EOR aspects of these demo projects increase economic feasibility significantly; and for China, the vastly needed removal of carbon emissions from the atmosphere, and proof of viable technologies which will gain support throughout Asia in conjunction with proven success in China and the western world.

It is important to note the Chinese government has vowed to reduce CO2 emissions per unit of GDP by 40-45 percent by 2020, from 2005 levels, following its promise for a 20 percent cut by 2010.

These two demo projects will pave the way for much larger scale CCS projects, and will support the Chinese government’s promises.

Next is the Dongguan Taiyangzhou Power Corporation / Xinxing Group power project in Dongguan. This technology is integrating IGCC (integrated gasification combined cycle) technology, which gasifies coal to a syngas, and the CO2 is recovered.

The Dongguan, China coal-fired 800 MW power plant is a planned facility which will recover about 1 million tons of CO2 annually, and transport via pipeline for EOR use; at a distance of 101 – 150 km offshore. CO2 recovery is via pre-combustion technology, licensed by KBR and the Southern Company.

EOR will occur in the Shangdong Province; where planning of construction is underway now, and the project will be operational by 2015.

Another project is the Huaneng Green Gen IGCC project Phase 2, planned for China. This is pre-combustion, capture, gasification project. Plans are for onshore CO2 use for EOR, delivered via pipeline.

This is another power project which will recover CO2 for EOR.

Then, one specific project in Korea is the Korea CCS -1 project planned for recovery of CO2 from power generation, slated to send the CO2 via barge and tanker for geological storage in saline aquifers. This is non-EOR; however sequestration of CO2 will occur.

There are additional CCS projects associated with pre-combustion IGCC projects and oxy-firing in the power and coal gasification industries, which are being planned, evaluated, or in early stages of development. Other CCS projects are to recover CO2 from strictly natural gas processing facilities, for CCS / EOR projects.

Most Chinese and Korean CCS projects borne from power plant CO2 product, or chemical industry / natural gas processing facilities, are in early phases of development. However, in most cases, they are affiliated with EOR – so enhanced oil recovery benefits will aid the economics of a project which is the best form of carbon capture and storage.

Many of these projects are slated to be operational within the next 2-5 years out.

Viable future for cleaner fuels outside of coal

Then, of course cleaner fuels, such as biofuels and natural gas, when combusted, are much less harmful to the environment than coal. Such projects can include advanced biofuels such as cellulosic ethanol, which use non-edible agricultural materials as a feedstock; then biogas is gaining more traction as a fuel source which is a low carbon-emitting option.

Further, wind and solar energy options are part of the changing power and energy landscape, which represent no CO2 emissions.