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Calculation Method for Basic Energy Consumption of Catalytic Cracking Units 1 Scope of Application This benchmark energy consumption applies to medium and large-scale catalytic cracking units (≥50×104 t/a) of various types in China, which process different types of feedstocks and operate under any production scheme (including ARGG, MGD, MIP, FDFCC, etc.). The baseline energy consumption calculated by this method includes components such as reaction, regeneration, distillation, absorption stabilization, the main fan and flue gas turbine, waste heat boilers, compressors, and waste heat recovery units, but it does not include water treatment and product purification. 2 Main revisions to the baseline energy consumption: (1) Given that heating furnaces are hardly used in the normal operation of catalytic cracking units, the energy consumption item related to heating furnaces in the original baseline energy consumption has been removed. (2) Since heavy oil catalytic cracking accounts for the vast majority in current catalytic cracking units, using only the slag blending ratio to measure the lightness or heaviness of catalytic cracking feedstocks is not accurate. Therefore, when calculating the chemical enthalpy difference energy (i.e., reaction heat) under the new baseline energy consumption, the slag mixing ratio is not used to distinguish between different types of raw materials; instead, the main properties of the raw materials (specific gravity, residual carbon, average boiling point, molecular weight) are utilized to determine their relative importance. The reaction heat is calculated using the molecular expansion method. (3) In the original baseline energy consumption, the flue gas temperature of the waste heat boiler was assumed to be 250°C. Given that the flue gas temperature from the waste heat boilers of some existing units has been reduced to 180°C, the energy consumption for regenerating flue gas at the new baseline energy consumption level is taken as 180°C. (4) In the original baseline energy consumption, the heat dissipation energy consumption is correlated with the device’s coke yield and the reprocessing ratio. Given that the cooling energy consumption is only related to the dimensions of the equipment as designed initially, and has little to do with changes in actual operating conditions or processing volumes, the new baseline energy consumption and cooling energy consumption are linked to the processing volume and coke yield specified at the time of the device’s initial design, independent of other factors. (5) Statistical analysis of multiple sets of data shows that it is difficult to identify parameters associated with the energy consumption of the booster, making it the most uncertain component in the calculation of the device’s energy consumption. In light of this, the new benchmark energy consumption for the booster pump is determined based on actual consumption. (6) In the new baseline energy consumption, the energy consumption for discharging recycled flue gas is calculated based on the difference between the flue gas temperature and the atmospheric temperature; whereas in the energy consumption category related to the main fan, the temperature rise of the main air flow is considered as the useful work generated by the main fan. (7) Considering that many current devices use injection terminators or reprocessed gasoline, a new energy consumption item for terminators or reprocessed gasoline has been added to the new baseline energy consumption. (8) The energy consumption for process discharge and cooling medium was revised based on the different impacts of various schemes such as ARGG, MGD, MIP, and FDFCC on energy consumption. (9) In the steam energy consumption item, in addition to considering the impact of the proportion of atomized steam on steam consumption, the effect of different reprocessing ratios on the amount of atomized steam is also taken into account. 3 Basic conditions for baseline energy consumption In the calculation of baseline energy consumption, the main basic conditions are set as follows: (1) CO2/CO in the recycled flue gas = ∞, with an excess oxygen content of 2% (on a dry basis, in molecular ratio). (2) The H/C ratio in coke is 7/93. (3) No heating furnace is provided; the heating of raw materials is entirely based on heat exchange. (4) The pressure drop from the main fan outlet to the flue gas fan inlet is taken as 0.09 MPa, and the pressure drop from the top of the settler to the compressor inlet is taken as 0.08 MPa. (5) The conditions for product inlet and outlet devices are shown in Table 1. Table 1: Conditions of product inlet and outlet devices – Phase, Temperature, Phase, Temperature. Dry gas: gaseous state, 40°C; Light diesel: liquid state, 60°C; Liquefied gas: liquid state, 40°C; Heavy diesel: liquid state, 90°C; Gasoline: liquid state, 40°C; Oil slurry: liquid state, 90°C. (6) The exhaust temperature of the waste heat boiler is set at 180°C. (7) The main fan unit is configured as three units: the main fan, the exhaust fan, and the motor, with the main fan being an axial flow fan. If the power recovered from the smoke extractor is insufficient to drive the main fan, electricity is used to make up for it ； If the recovery rate is greater than 1, electricity is also included in the baseline energy consumption. (8) The process steam pressure is 1.0 MPa; steam used for line cleaning, heat tracing, evacuation, heating, and other intermittent purposes is not included in the baseline energy consumption. (9) The distillation column uses top-loop reflux instead of cold reflux. Three separate circulation return heat extraction systems are provided: one for medium oil, one for light oil, and one for circulating slurry. (10) The portion of the vapor and oil at the top of the fractionation tower with a temperature of ≥90°C is considered for low-temperature heat recovery