There is a significant difference in energy consumption among petroleum refining and chemical enterprises

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There is a significant difference in energy consumption among oil refining and chemical enterprises. (1) Oil refining enterprises: Over the past decade, although China’s oil refining technology has developed rapidly, there is still a considerable gap in terms of energy and material consumption compared to advanced levels abroad. In 1999, the comprehensive energy consumption per ton of refined oil produced by Sinopec’s refining enterprises was 92.64 kilograms of standard oil per ton, while that of Sinopec was 85.55 kilograms of standard oil per ton; the best levels abroad have reached 53.2 kilograms of standard oil per ton. In 1999, the average energy consumption per unit of energy factor for the refining enterprises under Sinopec was 14.97 kilograms of standard oil per ton·factor, while that of Sinopec’s subsidiaries was 14.28 kilograms of standard oil per ton·factor. In Japan, the energy consumption per unit of energy factor in refineries in 1991 was already as low as 13.99 kilograms of standard oil per ton·factor. 　　Based on an analysis of the energy consumption levels in refining facilities, in 1998 the average advanced level for energy consumption in atmospheric and vacuum distillation units in China was 11.54 kilograms of standard oil per ton, while the advanced level abroad was 10 kilograms of standard oil per ton ； The average advanced level of energy consumption in catalytic cracking units is 65.21 kilograms of standard oil per ton, while the advanced level abroad is 42.5 kilograms of standard oil per ton ； The average energy consumption level for hydrocracking units is 49.3 kilograms of standard oil per ton, while the advanced level abroad is around 40 kilograms of standard oil per ton. 　　Data analysis shows that the high energy consumption is mainly due to the high overall oil refining energy consumption of the refining enterprises affiliated with the oil fields. To reduce the energy consumption of these refining enterprises, it is necessary to focus first on efforts to save energy and reduce consumption in those enterprises. 　　(2) Chemical enterprises Ethylene: Over the past decade, China’s production technology for ethylene has made significant progress, and the energy consumption of related facilities has also decreased considerably. However, our country’s technical and economic indicators (especially energy consumption indicators) still fall far short of the world’s advanced levels. In 1999, the average ethylene energy consumption of Sinopec was 867.16 kilograms of standard oil per ton, while that of CNPC was 746.5 kilograms of standard oil per ton. In some developed countries such as Japan and South Korea, the ethylene energy consumption is around 500 kilograms of standard oil per ton when naphtha is used as the raw material, and about 550 kilograms of standard oil per ton when light diesel is used as the raw material. This shows a significant gap compared to the levels achieved by CNPC and other advanced foreign companies. 　　Synthetic resins: In China, the average energy consumption for producing high-pressure polyethylene in 1997 was 329 kilograms of standard oil per ton, while the advanced level abroad is 283 kilograms of standard oil per ton. In China, the average specific fuel consumption for HDPE plants in 1997 was 249 kilograms of standard oil per ton, while the advanced levels abroad ranged from 138 (Mitsui) to 148 (Phillip) kilograms of standard oil per ton. 　　(3) Fertilizer companies Synthetic ammonia: The production of synthetic ammonia consumes a large amount of energy, and its output is high; therefore, its energy consumption level has a significant impact on the entire petrochemical industry. Currently, the comprehensive energy consumption of large ammonia plants in China is 957 kilograms of standard oil per ton of ammonia, while the average energy consumption after renovation is 876 kilograms of standard oil per ton of ammonia. The comprehensive energy consumption of small and medium-sized ammonia plants ranges from 1430 to 1444 kilograms of standard oil per ton of ammonia. In 1999, the comprehensive energy consumption for synthetic ammonia production in Sinopec was 1,029.2 kilograms of standard oil per ton of ammonia, while that in CNPC was 1,001.24 kilograms of standard oil per ton of ammonia. The advanced energy consumption levels in large ammonia plants abroad range from 679 to 698 kilograms of standard oil per ton of ammonia. 　　The above analysis and comparison show that there is a significant gap between China’s energy consumption levels in the oil refining and chemical industries and those of advanced countries. The gap between domestic and international levels is caused by factors such as the low management level of China’s petrochemical industry, small scale of production facilities, low operating rates, relatively backward process technologies, suboptimal quality of raw materials, long processing sequences, and high processing loss rates. 　　Furthermore, the difference between the best and worst energy consumption levels among the various units within the joint stock company is also significant, and at present, the energy consumption of some equipment still does not meet the design requirements. Compared with advanced international standards, especially in terms of energy consumption for petrochemical products, the gap is quite significant, which indicates that there is still considerable potential for energy savings in the refining and petrochemical operations of this joint-stock company. 　　(4) Problems in the storage and transportation systems of refining enterprises In terms of the storage and transportation of crude oil and heavy oil in refineries, steam and electricity are primarily used, with steam being the main energy source. Abroad, great attention is paid to controlling the temperature of heavy oil, and various methods are employed to achieve heating and insulation with minimal energy consumption ； Since the 1970s, oil refining plants built abroad have mostly adopted thermal integration or deep integration, striving to minimize the use of intermediate tanks and employing direct or thermal feeding. Pipeline blending is commonly used for oil blending in order to reduce fuel and power consumption. At present, domestic manufacturing enterprises have a considerable number of small-scale independent unit installations; water supply, power supply, heating, and air supply should be approached from a systems engineering perspective. When carrying out renovations, emphasis should also be placed on economies of scale, as well as on the rational utilization of low-temperature waste heat. 　　In terms of the storage and transportation systems for refined oil, the type of oil tank has a significant impact on energy savings. Investigations show that refineries currently use floating roof tanks on a widespread basis; however, in the sales systems (especially those of petroleum companies at the county level and below), a considerable number of tanks used for storing refined oil (transfer tanks) are still steel-roofed tanks. Steel-roofed tanks suffer from 80-90% higher evaporation losses compared to floating roof tanks, so it is necessary to carry out reforms and improvements in this regard. Furthermore, in terms of the loading and unloading of finished oil, manufacturing enterprises and transfer stations generally do not employ sealed loading methods or oil vapor recovery systems ； In terms of the transportation of refined oil, the proportion of various transport methods currently in use is unreasonable; compared to foreign countries, the amount transported via pipelines is too low, resulting in high losses during transportation. These are all areas where energy savings can be achieved in future storage and transportation systems.