1. Energy ConsumptionEnergy consumption is an important source of GHG emissions in the industrial park. As defined in this study, energy consumption processes involved mainly includes fossil fuel combustion, electricity and heat energy next production, and transportation vehicles. The estimation of the GHG emission from above processes refers to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories [22].For the fossil fuel combustion, (1) is given asEGHG,ic=Qic��EFGHG,ic,(1)whereE(GHG,i)c is the emissions of a given GHG by type of fuel (kg), Qic is the amount of fuel combusted (TJ), andEFGHG,ic is the emission factor of a given GHG by type of fuel (kg GHG/TJ).For the electricity and heat energy productionprocesses,if the power comes from the sectors outside the industrial park, the concerned GHG emission can be calculated according to the average energy consumption level of the local sector.
If the power is produced by the enterprise just in the industrial park, the concerned GHG emission can be estimated as zero to avoid the repeated calculation based on the fossil fuelofcombustion process. Equation (2) is presented to calculate the GHG emission from electricity and heat energy productionprocesses asEGHGe=Qe��EFGHGe,(2)where EGHGe is the emissions of a given GHG by electricity or heat (kg), Qe is the amount of electricity or heat produced (kWh or TJ), and EFGHGe is the emission factor of a given GHG by electricity or heat (kg GHG/kwh or kg GHG/TJ).As for the transportation process, it refers to the transportation of the energy resources, raw materials, instruments and equipment from the origin to the industrial park.
The GHG emissions from the transportation process can be estimated from the fuel consumed:ECO2t=��i(Qit��EFCO2,it),(3)whereECO2t is the emissions of CO2 (kg),Qit the fuel consumed (TJ), and EFCO2,it is the emission factors (kg CO2/TJ), or calculated by the distance covered by the vehicles asENH4,N2Ot=��a,b,c,d(La,b,c,d��EFa,b,c,dt)+��a,b,c,dCa,b,c,d,(4)where ENH4,N2Ot is the emissions of CH4 or N2O (kg),La,b,c,d is the distance travelled during thermally stabilized engine operation phase for a given mobile source activity (km), EFa,b,c,dt is the emission factor (kg/km), Ca,b,c,d is the emissions during warm-up phase (cold start)(kg), a is the fuel type (e.g., diesel, gasoline, natural gas, and LPG), Batimastat b is the vehicle type, c is the emission control technology (such as uncontrolled, catalytic converter, etc.), and d is the operating conditions (e.g., urban or rural road type, climate, or other environmental factors).In general, the first approach (fuel sold) is appropriate for CO2 while the second (distance travelled by vehicle type and road type) is suitable for CH4 and N2O.2.2.