The United States emits nearly 5.8 million metric tons of CO2 into the atmosphere annually, which is 24 percent of the world's total. China has the next highest of 3.3 mt/year which is 15 percent of world emissions.
China is projected to exceed United States CO2 emissions by 2020. China has already passed the United States as the world's largest consumer of coal, which fuels 90 percent of the country's electricity demand.
China's rapidly increasing demand is expected to cause the expansion of generation capacity by 300,000 MW over the next 30 years. This expansion alone equals half of the United States present generating capacity.
If old pulverized coal technology is used in new power plants in the United States, China and India, the impact of CO2 emissions on climate change will be frighteningly disastrous.
Clean electricity generation with coal gasification .....
If coal generation is unavoidable, then coal gasification could be its' savior to provide clean generation.
Gasification of coal does not involve burning coal. Coal is heated to 2000°F in a sealed chamber, to which small quantities of steam and oxygen are added. Instead of combustion, dozens of chemical reactions break down coal in the gasifier into its' basic components. The gas that is produced, principally consisting of carbon monoxide, hydrogen, sulphur and nitrogen, is cleaned to become synthetic gas.
Coal gasification has been used for some time. It provided fuel for German Luftwaffe aircraft during World War II. Syngas is produced at the Great Plains Synfuels Plant in North Dakota which was developed in 1980 to provide an alternative to natural gas.
Syngas can fuel an Integrated Gasification Combined Cycle (IGCC) power plant. Two IGCC plants are operating in Europe, and two are operating in the United States in Wabash, Indiana and near Tampa, Florida.
During 10 years of operation, Tampa Electric's IGCC plant is the most reliable coal-fired plant on the grid, producing the cheapest electricity on its' system. This stops the defenders of traditional coal generation, who say IGCC will be less reliable.
The National Commission on Energy Policy has recommended the deployment of 10,000 to 20,000 MW of IGCC plants throughout the United States during the next ten years.
The capture of CO2 from a conventional coal power plant is technically possible, however, it is impracticably expensive The separation of CO2 from the synthetic gas stream of a gasification plant is a simple chemical process that incurs little additional cost.
Sequestration is tried and tested by the oil industry which uses a technique known as "enhanced oil recovery" to force oil and extend the life marginal wells. Gas is pumped into the aquifer to force the oil out.
Enhanced oil recovery at PanCanadian Petroleum's Weyburn oil field in Saskatchewan, Canada will sequester 20 miilion tons of CO2 during the life of its' injection project. The gas is pumped through a 200-mile pipeline after it is captured from the Basin Electric coal gasification plant in North Dakota.
CO2 mitigation technology .....
The organic process of algae bioreaction provides great potential for CO2 mitigation.
GreenFuel Technologies Corporation based in Cambridge, Massachusetts announced in November 2006 that CO2 has been successfully recycled from stack gases of the 1,040 MW Redhawk power plant in Arlington, Arizona, into transportation grade biofuel.
GreenFuel’s Emissions-to-Biofuels™ algae bioreactor system creates a carbon-rich algal biomass with sufficient quality and concentration of oils and starch to be converted into biodiesel and ethanol.
The technology uses safe, naturally occurring algae to recycle CO2 from the stack gases of power plants and other commercial sources of emissions. Algae are unicellular plants and, like all plants, they divide and grow in sunlight by photosynthesis, and consume CO2.
“We estimate that this process can absorb 80 percent of CO2 emissions during the daytime at a natural gas fired power plant,” said GreenFuel CEO Cary Bullock.
The GreenFuel field assessment program will now move into the next phase with construction of an engineering scale unit that will be completed in first quarter of 2007.
The New Zealand company Aquaflow Bionomic Corporation based in Marlborough, announced in May 2006 that it produced its first sample of bio-diesel fuel with algae from sewage ponds.
“We believe this is the world’s first commercial production of bio-diesel from algae outside the laboratory, in ‘wild’ conditions", said Aquaflow spokesperson Barrie Leay.
By taking the waste product, Aquaflow can create bio-diesel and produce clean water, a process known as bioremediation. Dairy farmers, and many food processors could also benefit from recycling their waste streams that algae thrive in.
Aquaflow is increasing production and testing its product in a range of diesel engines. “The market potential for this product is almost unlimited in the ‘Peak Oil’ environment we are in". “We expect to produce at least 1,000,000 litres of bio-diesel per year from Blenheim,” says Leay.