Coal Gasification and Environment
Gasification, in fact, may be one of the most flexible technologies to produce clean-burning hydrogen for tomorrow’s automobiles and power-generating fuel cells. Hydrogen and other coal gases can also be used to fuel power-generating turbines, or as the chemical “building blocks” for a wide range of commercial products.
The syngas which the gasifier produces undergoes a significant amount of processing. The pollutants, such as sulfur, are stripped out of the gas, and in some cases the carbon dioxide is also removed on site. The carbon dioxide may also be removed offsite in hydrogen, ammonia, or fuel production facilities. The remaining hydrogen and byproducts are used for a variety of purposes. Hydrogen can be converted for both transportation and non-transportation fuels. It is can be used for the production of commercial chemicals. Byproduct methanol can also be used in the commercial chemical production process. Hydrogen is used as a feedstock for fertilizer production and it can be utilized for fuel cells.
The environmental benefits of gasification stem from the capability to achieve extremely low SOx, NOx and particulate emissions from burning coal-derived gases. Sulfur in coal, for example, is converted to hydrogen sulfide and can be captured by processes presently used in the chemical industry. In some methods, the sulfur can be extracted in either a liquid or solid form that can be sold commercially. In an Integrated Gasification Combined-Cycle (IGCC) plant, the syngas produced is virtually free of fuel-bound nitrogen. NOx from the gas turbine is limited to thermal NOx. Diluting the syngas allows for NOx emissions as low as 15 parts per million. Selective Catalytic Reduction (SCR) can be used to reach levels comparable to firing with natural gas if required to meet more stringent emission levels. Other advanced emission control processes are being developed that could reduce NOx from hydrogen fired turbines to as low as 2 parts per million.
Coal gasification may offer a further environmental advantage in addressing concerns over the atmospheric buildup of greenhouse gases, such as carbon dioxide. If oxygen is used in a coal gasifier instead of air, carbon dioxide is emitted as a concentrated gas stream in syngas at high pressure. In this form, it can be captured and sequestered more easily and at lower costs. By contrast, when coal burns or is reacted in air, 79 percent of which is nitrogen, the resulting carbon dioxide is diluted and more costly to separate.
Coal Crushing Machine
In nature, coal is the important energy resource, has played an important role in modern industry. In order to use coal highly, we ususlly crush coal into powder to increase the efficiency and protect environment.
In coal crushing process, we use coal crushing machine such as coal crusher and coal mill to crush coal. Generally, we choose the right coal crusher according to the size of coal you need. The hardness of coal is usually 1-4. After coarse crushing by jaw crusher , fine crushing by impactor crusher, and sieved by vibrating screen , coal can be processed and crushed into different sizes of the requirements. NFLG jaw crusher, impact crusher for coal crushing have been widely used in the coal mining industry. They can crush coal at large quantity and high efficiency. In addition, NFLG vertical shaft impact crusher can crush coal into much smaller sizes to meet specific requirements.
In order to use coal more rationally, efficiently and effectively, the coal need to be processed and crushed into different sizes, 0 ~ 25 mm particle size for coal gas stove, 25 ~ 8 mm for steam locomotive, 25 ~ 6 mm for the industrial furnace, and coal power plant requires grain coal of 0 ~ 25mm. So coal processing in coal preparation plant includes coal crushing and coal milling.
Coal crushing plant consist of many types of crushers and grinding mills. Coal crushers including jaw crusher, impact crusher, cone crusher etc. Coal mill include ball mill , vertical mill , Raymond mill etc.
NFLG is a coal mining machine manufacturer in China, located in Shanghai. It supplies all kinds crushing machines and design stone crushing production line according to the requirements of customers, such as aggregate rock crushing plant, iron ore crushing plant, coal crushing ang grinding plant for sale with best price.