REDUCING THE СО2 ATMOSPHERIC EMISSION BY NATURAL GAS “OXY-FUEL COMBUSTION”, AS A MEANS OF PREVENTION THE GREENHOUSE IMPACT

Abstract

At present, the relation to the fuel-energy complex as the main source of climatic changes of a planetary scale (global warming) has been formed. In view of the corresponding forecasts related to the greenhouse effect, mostly associated with emissions of carbon-containing combustion products (carbonization of the environment), the following ways of countering the climate threat are considered the last time: a — rejection of use of the organic fuel with a gradual transfer to using (burning) of carbon-free fuels (primarily hydrogen and hydrogen-containing mixtures); b — increasing an efficiency of use the organic fuel, first of all is the natural gas, which can provide a 2-times (sometimes more) reduction of total CO2 emissions in the industry; c — reducing the consumption of C-containing technological substances in the treatment of thermal and chemical-thermal processing of metallic materials (steel); d — ferrous recycling and maximum scrap using by iron and steel production. In the paper under consideration the methodology, based upon application the specific greenhouse (CʺСO2) and harmful (CʺNOx) substances issue per unit of useful energy as the determinative parameters, has been advanced for the first time from the standpoint of environment’s decarbonization and pollution. The proper solution for lowering СО2 issue is especially suitable by provision the high temperature processes with utilization the systems of gently oxygen-enriched combustion air. In contrast to traditional assessment of harmful (primarily NOx) and greenhouse (СО2) emissions per unit of generated or supplied energy (the corresponding indicators are C'NOx and C'СO2), application of more adequate values have been proposed by performing the relevant calculations per unit of useful energy Quse. The proper values of relevant indicators CʺNOx and CʺСO2 are objective characteristics by option the most suitable composition of fuel-oxidant mixture. This is approach makes the decisive solution by conditions of mutual substitution the fuels with purpose of account the energy utilization of exhaust gases. Thermodynamic principles and a methodology for calculation the relevant indicators of pollution the exhaust gases CʺNOx and CʺСO2 have been developed. Numerical calculations have been performed and the values of specific emissions of CʺNOx and CʺСO2 have been and determined in dependence on degree of enrichment an oxidizing air-oxidant with oxygen [O2], % (vol.), by account the operating temperature of the process. The possibility of reducing the CʺСO2 emissions by 2 to 3 times or more compared to natural gas with atmospheric air burning has been established even by the cases of a slight (till 30 % vol.) enrichment of the air with oxygen. Bibl. 33, Fig. 11, Tab. 1.