Phone: +86 15951568878
The significance of developing coal chemical industry
2017-03-22895
Coal chemical industry is a process in which coal is used as raw material and transformed into gas-liquid solid and other chemical components through processing, including coal gasification, liquefaction and other processing processes. China is a country with more coal, less oil and gas. In the past two decades, with the development of China's economy and the improvement of people's living standards, the demand for oil has increased greatly, and oil mainly depends on imports. Coal chemical industry includes three basic units: coal gasification, coal liquefaction and coal carbonization.
2.1 coal gasification
Coal gasification technology is a common technology of coal chemical products, coal liquid fuel, IGCC power generation, filtration system, hydrogen production and other technological processes. It is also the leading technology of methanol plant, synthetic ammonia plant and coal to oil plant, that is, it is applied to the fields of five major products of ammonia, hydrogen, alcohol, oil and gas
2.2 liquefaction of coal to oil
Coal liquefaction can be divided into indirect liquefaction and direct liquefaction
The indirect liquefaction of coal to produce oil refers to the gasification of gas with oxygen and water vapor to produce synthetic gas. Under the action of certain temperature, pressure and catalyst, synthetic oil is produced. Shanxi Institute of coal gasification, Chinese Academy of Sciences, has the technology of indirect coal liquefaction. Direct coal liquefaction to produce oil is through solvent extraction or hydrogenation of coal slurry under the condition of high temperature and high pressure catalyst to improve the C / H ratio and directly convert to oil. Shenhua Group's 1 million T / a coal to oil project is a demonstration project of direct coal liquefaction to oil, which has been put into operation
3.1 large capacity of supporting air separation for coal gasification
The gasification reaction of coal briquette in gasifier is the reaction of carbon, oxygen and water vapor in coal to produce CO and H2. The amount of oxygen blowing directly affects the conversion rate of coal. On the premise of determining the coal type, the oxygen demand of coal gasification technology depends on the oxygen coal ratio (oxygen and coal) or specific oxygen consumption (oxygen and synthetic gas ratio). At present, the mature coal gasification technology is represented by Texaco process, Lurgi process and shell process. Texaco process is a coal water slurry gasification technology, which was introduced into China in 1980s. Its conversion rate is relatively high, and the effective component CO + H2 of gas can reach 78-80%. Shell technology was introduced into China in 1990s, its conversion rate is higher, and the effective component of gas can reach 90-92%. In recent years, advanced ash fusion fluidized bed coal gasification technology has been developed by Shanxi Institute of coal gasification, Chinese Academy of Sciences
At present, coal gasification is developing towards large-scale. The maximum coal handling capacity of Texaco furnace is 1000 tons / day, and that of shell furnace is 2500 tons / day. Through calculation, the annual output of 1 million tons / year methanol is 120000m3 / h using GE coal water slurry gasification technology, 1 million tons / year coal to oil using shell coal gasification technology, 250000m3 / h hourly oxygen consumption, 600000 tons / year methanol to olefin using Shell gasification technology, 230000m3 / h hourly oxygen consumption. The annual output of natural gas is 2 billion m3 / year, and BGL powder coal gasification is adopted, with oxygen consumption of 160000 m3 / h. Obviously, the supporting air separation units are all super large air separation units larger than 30000m3 / h, and even need 100000 levels of air separation.
Large scale air separation is not a simple amplification of supporting equipment and units, but to solve many key technical problems. First of all, the static equipment such as tower should solve the transportation problem, (1) limit the diameter, and the tower height should not be too high, so it is necessary to strengthen the heat and mass transfer on the unit section, such as the use of new structured packing for the upper and lower tower, the increase of the opening rate of sieve plate tower, etc.; (2) gas and liquid filtration device, the urgent need for new tower internals development and application; (3) piping problems, etc. In the aspect of heat exchanger, high efficiency heat exchanger needs to be developed. In the aspect of the development of 120000 grade air separation, hang Yang has done a lot of work and solved the key technical problems. In the development of 80000 air separation units, Kaikong has also made a breakthrough.
The development and selection of large-scale high-efficiency units, such as high-efficiency medium pressure expander, liquid expander, large flow filter, large-scale air compressor, supercharger and large-scale centrifugal liquid pump, are the core issues of dynamic equipment. At present, almost all of them choose foreign imports. If they want to reduce investment, the only way is to try to localize.
3.2 diversification of air separation unit
The diversification of air separation unit is reflected in the diversification of process and product.
(1) process diversification.
Because the pressure of oxygen required by coal chemical industry is usually 4.0 ~ 8.0MPa, the internal compression process is adopted for coal chemical air separation However, due to the different coal gasification technology, different oxygen pressure levels, different nitrogen product demand and specifications, the formation of air separation process diversification must be targeted design.
(2) product diversification
The air separation of coal chemical industry usually requires to provide high-pressure oxygen, high-pressure nitrogen, medium pressure nitrogen, low-pressure nitrogen, instrument air, plant air, liquid oxygen, liquid nitrogen and liquid argon. Especially for the demand of nitrogen products, there are as many as six specifications. Moreover, the oxygen consumption also changes in a large range. Even when the subsequent process is shut down, the nitrogen consumption increases several times in a short time, which is a challenge to the design and operation.
3.3 integration of large units
The matching air compressor of super large air separation unit and the matching air compressor of air separation unit above 80000m3 / h are not single centrifugal type, but axial flow plus centrifugal type. In order to save energy, simplify the process and reduce investment, one steam turbine is usually used, that is, one driven by two. Even need to drag nitrogen compressor that is, one drag three. Some exhaust expansion air in the middle of the supercharger, which will make these units highly integrated
Products center
Contact Us
In the oil, Sinopec, CNOOC, Sinochem Group, a non-standard equipment suppliers.
Brand-name products in Jiangsu," "National Customer Satisfaction Brand" and the honorary title of the winner.
Brand-name products in Jiangsu," "National Customer Satisfaction Brand" and the honorary title of the winner.
- E-mail：unite@unitefilter.com
- Address：No. 24 all the way,industrial park,new area,Wuxi
Copyright © 2018 Jiangsu Unite Filtration Equipment Co., Ltd. All rights reserved. 苏ICP备16037675号