GreatPoint Energy is developing a gasification process for converting coal into high value clean natural gas which they call BluegasTM. The gas is 98% methane (1000 BTU/ft3), meeting all natural gas purity requirements and can be transported using the existing natural gas pipeline infrastructure. The company plans on building, owning and operating the production facilities and to sell the gas. Because domestic natural gas has passed peak production rates, the US has the world's largest coal reserves and because natural gas is the fuel of choice for many uses; given a low cost source of gas, the company believes there is a huge potential market for their gas.
GreatPoint Energy’s technology uses the same basic technique as is used in petroleum refining to “refine” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into clean burning methane (natural gas). This single stage process is called catalytic coal methanation and forms the basis of their process. By adding a catalyst to the coal gasification system, they are able to reduce the operating temperature in the gasifier and at the same time directly promote the reactions that yield methane (CH4). Very low cost carbon sources (such as lignites, sub-bituminous coals, tar sands, petroleum coke and petroleum resid) can be used as feedstocks.
The process produces methane in a single step and in a single reactor. In the process, (shown at left, click to enlarge) coal and catalyst are fed to a fuidized bed methanation reactor. Steam is added to "fluidize" the mixture and ensure constant contact between the catalyst and the carbon particles, generating a gas of predominately methane and CO2. The water gas shift occurs within the methanation reactor eliminating the need for a separate reactor. The catalyst allows the reaction to take place at a lower temperature than typical gasification processes, lowering the cost of materials of construction, lowers the maintenance costs and eliminates high temperature cooling. The use of steam eliminates a costly air separation plant that typically runs at 20% of the total capital costs. The process has an overall efficiency of about 65%.
After methanation the gas is sent to a gas cleaning system where CO2 and other contaminants are removed. In addition, the catalyst is recovered from the bottom of the gasifier and recycled back into the methanation reactor. The byproducts (such as sulfur, nitrogen and CO2) are captured and sold to the chemicals and petroleum industries, resulting in near zero hazardous air or water pollution.
Half of the carbon, in the form of CO2, can be captured and sequestered in local oil wells or coal bed methane mines. In addition, the other harmful contaminants contained in coal are removed including sulfur, nitrogen, arsenic, mercury, and particulates. Once captured, most of these materials are sold to the chemicals industry and the remainder is disposed of in a safe non-leachable manner.
Their technology has been shown to work in the laboratory. The company is building a pilot plant (shown at begining of post) in Des Plains, IL which will start-up this summer to prove that the process works on a larger scale.
The company envisions that production facilities would be sited in regions of the country where CO2 can be sold and safely sequestered using currently available commercial technologies for enhanced oil recovery (EOR) and coal bed methane production.