Novel technology of electric combustion of pulverized coal and prospects of its use with small additions of hydrogen to ensure ignition of low-grade fuels

Abstract

Coal-fired generation has long been, and still is, one of the leaders in global power generation. According to the International Energy Agency at the moment the share of coal-fired generation is about 39%.Despite the global trend of decarbonization, global coal-fired power generation is steadily growing. In 2019, coal-fired generation grew by about 1.5%. As of 2019, the world's proven coal reserves are concentrated in the United States (23%), the Russian Federation (15%), Australia (14%), and China (13%), amounting to about 1070 billion tons. In 2020, due to the pandemic of a new coronavirus infection, coal-fired power generation has been slightly reduced. Low-grade coals such as brown coals or lignite make up more than 40% of the world's reserves [4–6]. Which suggests the need to switch to burning these types of coals. Consumption of high-sulfur viscous fuel oils as starting, reserve or main fuel leads to emissions of such harmful substances as benz(a)pyrene and vanadium pentoxide in addition to toxic sulfur oxides, nitrogen and carbon. When sulfur oxides are formed, the dew point temperature of flue gases increases, which leads to the formation of sulfuric acid and, as a consequence, to frequent repairs of tail parts of boiler units due to their corrosion. Composition of flue gases at oil combustion also depends on its quality: its content of sulfur, nitrogen, metals, polycycloarenes, etc. The same replacement of liquid fuel at start-ups of pulverized coal-fired boiler units and maintenance of pulverized coal flare combustion will reduce the fire hazard of the production process, the operating costs of TPP, the environmental hazards of gaseous products of co-combustion of liquid and solid fuels. The article presents a review of modern technologies for firing up pulverized coal-fired boiler units, as well as presents the original technology of electric ignition and the results of tests on the laboratory bench.