Assessment of the Potential for Decreasing Greenhouse Gas Emission in Burning Fuels in Boilers at Thermal-Power Plants (TPP) and Boiler Houses

Many countries around the world, including Russia, are performing extensive work towards meeting the Paris Agreement goals to reduce greenhouse gas emissions. One of the main industries that is an anthropogenic source of greenhouse gases is the coal-fired heat and power industry. A change-over from coal to natural gas becomes a promising measure for reducing carbon dioxide emission in the power industry. In the process, special attention is given to the combustion of natural gas mixed with hydrogen. This work examined engineering capabilities for burning hydrogen-containing gases (HCG) in conventional and condensing power facilities. Increasing the content of hydrogen in a mixture with natural gas when burning it in boilers has been demonstrated to affect the heat absorption of all heating surfaces in the boiler gas path, the gas temperature, and, ultimately, the boiler efficiency of the boiler, thereby requiring in-depth redesign of conventional gas-fired and pulverized coal-fired boilers. At the same time, the addition of hydrogen to natural gas extends the concentration range of stable combustion of such a mixture and increases the normal flame propagation velocity, which not only plays a positive role but also makes more intricate the practical implementation of the combustion of a hydrogen–natural gas mixture in burners and power facilities. Measures should be taken to prevent self-ignition of hydrogen-containing gases due to their higher fire and explosion hazard, including issues related to the location of process equipment and hydrogen transportation. A simultaneous decrease in atmospheric emissions of both water vapor and carbon dioxide during combustion of natural gas or hydrogen-containing gases in steam- and hot-water boilers can be attained by means of condensing heat recovery units that will improve the efficiency of fuel utilization and increase the thermal capacity of the power facility.