Showing papers on "Carbochemistry published in 2013"

Hydrothermal Treatment of a Sub-bituminous Coal and Its Use in Coking Blends

Abstract: The demand for metallurgical coke for blast furnaces is forcing the coke-making industry to look for new sources of coking coals. Noncoking coals are attractive for use in the coke-making coal blen...

Study on Model Test of Underground Gasification of Coking Coal

Abstract: In order to examine the applicability of underground coal gasification technology for coking coal,the pyrolysis test and model test of underground gasification were carried out.The results shows in the oxygen-enriched air gasification of coking coal,the optimal oxygen concentration was 60%,the gasification efficiency on this condition was about 80%,the heat value of the coal gas was about 8.36 MJ/Nm3(2 000 kcal/Nm3).The adhesion and expansion make the liquid plastic mass and melting ash attach on the coal well in the underground coal gasification process,which inhibit the reaction between gasifying agent and coal body,it was difficult to obtain good gasification effect.The contents of H2S,HCN,ammonia nitrogen,benzenes,COD,volatile phenols in the crude gas and gas condensate are exceed the national emission standards dozens or even hundreds of times,must be treated before discharge.

Coal Characterisation and Design for Fossil Fuel Fired Boiler in Thermal Power Plants

Abstract: Coal is a highly heterogeneous in nature and requires several analytical techniques for its characterization so as to accurately predict its behavior during conversion processes such as combustion, gasification or liquefaction. The goal of utilizing the available large quantities of indigenous coal alone with reducing emissions is increasing the efficiency of power plants by utilizing steam conditions. The performance correlations based on bulk property analysis of coal adequately impact coal quality on conversion efficiencies and plant performance. Thermo mechanical analysis , an advanced bulk analytical technique provides detailed thermal behavior of ash relevant to power plant operations. The decrease in easily worked deposits , together with the decline in the availability of the better quality coals has resulted in a need for the development of blending techniques. Blending is now extensively practiced in the preparation of coals which involve blending of several different classes and / or grades of coals to produce blends which on carbonization will yield coke. Coal petrology is the study of organic materials which make up coal .The object of study is to identify in terms of reactive capabilities , each of the organic materials making up coal and an attempt to relate the reactive capabilities with the industrial applications of coal. Various tests are being designed to investigate the feasibility of Indian Coals in pulverized coal boilers.

Energy-technological method for utilization of coal of the Kansko-Achinskii basin

Abstract: The state of the market segments connected with coal fuel consumption is estimated. As a whole it is characterized by the shortage of high-calorific coals for special purposes and the excess of offerings of low-rank coals. The classic method for firing coal has substantially exhausted its potential and is not in the condition to meet the ever increasing needs of power efficiency and environmental safety. For resolution of the existing situation the author proposes to use the technology of internal partial coal gasification with the parallel production of heat energy and brown-coal coke. Scopes of new products are briefly described with the prevailing orientation on the replacement of classic coke in metallurgy.

Chemistry of Fossil Fuels and Biofuels: Carbonization and coking of coal

Abstract: Thermal decomposition of coals Often the terms carbonization and pyrolysis are used almost interchangeably. Pyrolysis has the broader meaning: breaking apart of molecules by application of heat or thermal energy. As discussed in Chapters 19 and 22, pyrolysis processes could be run to make gases or liquids rather than solids as the primary product. Carbonization, more narrowly defined, refers to conversion of a starting material into carbon, or a carbon-rich solid. It is entirely possible, and indeed often done, to pyrolyze a hydrocarbon feedstock for the purpose of carbonization, but carbonization is not simply pyrolysis by another name. Carbonization can be effected without using heat as the primary driving force, a good example being carbonization of sucrose (ordinary table sugar) by pouring concentrated sulfuric acid on it; carbonization occurs very promptly and very effectively. Carbonization driven by thermal energy usually requires temperatures >500 °C. A carbonaceous solid that appears to have passed through an intermediate fluid state when being produced is called a coke . Carbonaceous solids that do not pass through such a fluid state during formation are chars . These definitions apply to carbonization processes using any feedstock, including biomass, petroleum, and polymers. All coals, regardless of whether they are caking or coking coals, leave a solid carbonaceous residue at the end of the carbonization process. Chars, if heat-treated to extreme temperatures, e.g. ≥2500 °C, do not form graphite, while cokes do. That is, chars are non-graphitizable, while cokes are graphitizable [A].