Research On Contaminants’ Emissions And Applicability Of Heating Modes Concerning The Conversion Of Coal To Gas

In the northern part of China,coal is the main source of heating in winter.This kind of heating not only has low energy utilization efficiency,but also causes a lot of air pollution.As a kind of clean renewable energy,natural gas has many advantages,such as high calorific value,clean and so on.It has been popularized by the state in recent years,and it has become the first choice for clean heating in winter.Compared with coal heating,gas heating has a natural advantage in pollutant discharge,simple operation,clean and so on.However,there was no specific research on the specific reduction of pollutants and the overall economic benefits after the conversion of coal to gas.Therefore,this paper mainly studied the specific emission reduction and environmental benefits of the pollutants after coal modification,as well as the calculation and analysis of the overall economic benefit of coal to gas,which was of practical reference significance for the country to carry out some projects.The article first analyzed several ways of coal gas change from the angle of heating,including the initial investment,operation cost,pollutant discharge and so on,and chose the most suitable heating mode according to the users’heating characteristics.Then the formula of pollutants（such as CO₂、SO₂ and NOx）emission from coal and gas heating was derived and calculated.The distributions of two kinds of heating modes in distributed and centralized heating systems were fitted and analyzed.The results showed that the emission of coal-fired pollutants in centralized heating was higher than that of gas-fired pollutants.The CO₂ emission of coal was 2.88 times as high as that of the gas.The NOx emission of coal was 6.31 times as high as that of the gas.In the type of the distributed heating,The CO₂emission of coal was 3.73 times as high as that of the gas.The NOx emission of coal was 415times as high as that of the gas.There were no SO₂ in the two ways of heating.Secondly,through the investigation of Shandong Jianzhu University,five kinds of heating schemes were given,and the five schemes were compared and analyzed from the initial investment,the annual operation cost and the system operation.Finally,the scheme five（The gas boiler was the main heat source,and the rest equipment was used as peak load regulation.）was the best heating scheme.Compared with coal-fired boiler heating,this scheme had significant environmental benefits.The annual CO₂ pollutant emissions of the fifth schemes decreased by7.56×10⁶ kg（down row 59%）;the annual SO₂ pollutant emissions of the fifth schemes decreased by 8.67×10⁴ kg;the annual NOx pollutant emissions of the fifth schemes decreased by 1.933×10⁴kg（down row 93%）.Considering the cinder treatment and environmental protection,the annual operation cost of gas heating was slightly higher than that of coal heating.Finally,based on the current hidden dangers of coal-to-gas conversion and the problems encountered during the implementation process are discussed in this paper,and aimed at the problems from the policy level,the choice of the ways of coal to gas,construction,installation,operation and management,economic benefits and safety improvement measures are proposed.