Academician Osimi Tajik Technical University, Dushanbe, Tajikistan:

Z. Kh. Gaibullaeva, Associate Professor, Candidate of Chemical Sciences, zumratihabib@rambler.ru
B. I. Asrorov, Office-seeker
Sh. Bakhridinzoda, Office-seeker

Dangara State University, Dangara, Tajikistan:
A. Sharifov, Professor, Doctor of Engineering Sciences

Coal is a conventional source of energy, but its use has recently been restricted because of the environmental standards. Coal is a high-value source for the production of chemicals such as hydrogen, ammonia, methanol, carbamide, etc. The chemicals are produced from synthesis gas in the course of coal gasification. The value of coal as a source for the chemical production also lies in the ampleness of its reserves worldwide while oil and gas reservoirs are available not in all countries. Accordingly, the effective use of coal can contribute to the development of many branches of the chemical industry. The wasteless technologies of coal gasification for the production of heat, synthesis gas, reducing gas for the metallurgy needs and pure hydrogen are described. In these technologies, prior to gasification, thermal decomposition of coal is carried out in a reactor under temperatures up to 700 °C, and the volatile and resinous matters separated from carbon under temperatures of 300–550 °C, after cooling, are used in conformity with their material constitution. The coal gasification flowcharts function in a closed mode, where flows of heated gases first heat coal for the recovery of the associate components of carbon, some heat of the heated gases goes to the production of vapor for the steam gasification of carbon, and the residual heat of gases, up to absorption of СО₂ by solutions of alkalis, is used to produce hot water, which reduces external consumption of heat in coal gasification. The proposed methods of coal gasification are low-cost as the by-produced substances and heat of different heated materials are utilized. Moreover, air emissions are absent, thus, the production is ecofriendly and green.

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