Feasibility Study Of Fuel-Switching Projects From Coal-Fired To Gas-Fired For District Heating System In The Northern Of China

With the development of society and economy, people’s requirement for higher living standards grows day by day. With the growth of urbanization rate in China, the construction area of building will be growing, and then building heating demand will be enlarged. The result is increasingly serious environmental problems be happened. It is imperative to seek an efficient district heating method to accords with energy conservation and environmental protection.Through the on-site survey research of coal-fired district heating stations in Tianjin, this paper selects 20 typical heating stations to analyze the heating situation. The selected heating stations are responsible for heating area of 15.87 million square meters; the standard coal consumption of per unit area for each heating season is 24kg/m2, and power consumption is 2.94kWh/m2; the heating efficiency is only about 65% on average, but the greenhouse emission is reached up to 67kgCO2/m2. The research results indicate that the traditional coal-fired heating way has a widespread defect of low efficiency and high pollution, a new heating way is in urgent need to solve this problem. In order to solve the financial barrier of such renovation projects, a carbon market mechanism is introduced. A new CDM (Clean Development Mechanism) methodology is developed based on such heat renovation projects in China. After confirming the project boundary, baseline scenario and emission sources, the calculations of greenhouse gas baseline emission, project emission as well as leakage emission are formulized, and then the calculation method of greenhouse gas emission reduction has been gotten. Apart from that, the project additionality has also be defined and analyzed. At last, the project monitoring procedures and monitoring parameters are developed and regulated to make assurance of the accuracy and verification of the methodology. In order to verify the feasibility of the CDM methodology for heating renovation projects,43 small coal-fired boilers renovation project in Tianjin is as a case study to analyze the emission reduction ability of greenhouse gas, air pollutants and particulate matters with two different renovation types (heating with efficient large social Denerits ana economic Denerits unaer two-type stations.With the case study in the paper, if the traditional coal-fired boilers are replaced with efficient coal-fired boilers, the heating energy efficiency is expected to reach 82%, the annual CO2 emission reduction of unit heating area will be 11.5kg/m2, the NOx emission reduction of per unit area will be 0.054kg/m2; If the traditional coal-fired boilers are replaced with gas-fired boilers, heat energy efficiency is expected to reach 93%, the annual CO2 emission reduction will be 31.6kg/m2, the emission reduction of NOx can reach 0.263kg/m2. In other pollutants emissions, gas-fired boilers are better than efficient coal-fired boilers. Relatively, a gas-fired boiler serves better to environment benefits. In economic benefits, the profitability and capital recovery speed of the efficient coal-fired boiler both surpass the gas-fired boiler. The gas-fired boiler renovation station needs to gain the support from CDM project or other carbon markets, then the internal return rate can rise from 7.54% to 11.37%, otherwise it will be have no attractive to enterprises economically.In conclusion, in the economic developed areas eapecially in the northern of China, the district heating stations which are replacing traditional inefficient coal-fired boilers with gas-fired boilers are more conforming to the requirement of energy conservation and emissions reduction of China’s 12th five-year national plan, so it should be implemented vigorously. In order to overcome the capital obstacles and make the enterprises joining in such projects actively, China should introduce such projects to carbon market mechanism.