The technology of cryogenic air separation unit has become increasingly mature, mainly reflected in the fact that the cryogenic air separation process has not undergone fundamental changes since the full distillation argon process appeared nearly 30 years ago. With the development of the global economy, energy crisis and environmental degradation have come along. In order to control the global temperature rise target set by the Paris Agreement, the global CO2 emission intensity should be reduced by more than 30% by 2030. Air separation units are large energy consumers. By calculating the energy consumption of typical coal chemical enterprises, the energy consumption of air separation units can account for ~40% of the total energy consumption of the plant. Reducing the energy consumption of air separation units has become an urgent need for sustainable social and economic development, driving the development of air separation units towards the following characteristics:
1) Large-scale. The compression of steel industry capacity and the launch of large-scale coal chemical projects have driven air separation units to develop in the direction of large-scale. At the same time, with the expansion of the oxygen production scale of air separation units, the unit oxygen production energy consumption has been significantly reduced. In terms of related parts and machines, MAN Turbo, Siemens and Shenyang Blower have developed and produced large compressors that meet the requirements of 100,000-level air separation units; the successful development of high-efficiency structured packing has enabled the size of the distillation tower equipment supporting large air separation equipment to meet the requirements of transportation conditions; the various types of air separation units in actual operation have provided rich data, and the calculation of air separation processes has become more and more accurate, so that the size of the device is no longer unnecessarily enlarged.
2) The degree of automation is getting higher and higher. With the development and popularization of technologies such as distributed control systems (DCS) and advanced control technologies (APC), it has become easier and easier to improve the automation of industrial processes. Improving the automation of the device and realizing automatic variable load control of the air separation device will greatly improve the operating efficiency of the air separation device and effectively reduce the failure rate of the device.
3) Low energy consumption. The efficiency of the compressor unit has been improved, and the energy consumption of the compressor unit has been continuously reduced; the successful development of new structured packing has continuously improved the distillation efficiency of the distillation tower; the successful development of new molecular sieve adsorbents can effectively extend the adsorption cycle of molecular sieve purifiers; the successful development of new energy-saving steam heaters; the efficient main cooling structure effectively reduces the heat exchange temperature difference of oxygen and nitrogen in the main cooling.
4) Investors. They hope that the invested funds can be recovered as soon as possible and the benefits can be seen as soon as possible. This requires that the economic potential of the device be explored as much as possible in the process selection and design, and the operation stability and reliability of the device be improved.
5) The development trend of Cryogenic equipment is closely related to the design of air separation processes. The selection and calculation of air separation processes determine the investment, operating energy consumption, and safety and stability of the device during operation from the source. Whether the process selection is appropriate, whether the process calculation is accurate, and whether the parameter selection is appropriate directly affect the design parameters, operating efficiency and operating stability of each unit (such as whether the air compressor has a wide stable operating range, whether the liquid volume of the expander is within the allowable range, whether the unit efficiency is optimal, and the selection of the cross-sectional temperature difference of the heat exchanger affects its long-term stable operation), the size of each unit (such as the diameter and height of the distillation tower, the heat exchange area and number of the main heat exchanger) and the selection of related unit equipment (such as the booster Whether to add a first-stage impeller), which in turn affects the investment of the device; the improvement of automation requires process calculation to provide relevant parameters (such as medium concentration) for the selection of various instrument equipment, and the realization of automatic variable load technology requires process calculation to provide control indicators under different working conditions (such as logistics flow, temperature, pressure, etc.); the organization of each material flow path of the distillation tower involves the convenience of operation and the safety of the distillation system on the one hand, and the reasonable design of the flow path organization can improve the distillation efficiency of the tower (thereby improving the extraction rate of the device) and reduce the operating height of the tower on the other hand;
Air separation process design promotes the continuous development of Cryogenic equipment technology and is the soul of the air separation system. The diversification of air separation product demand leads to the great differences in the configuration of air separation devices and the ever-changing forms of air separation processes. Diversified process forms make process selection work inevitable. Summarizing the basic characteristics, basic types and guiding principles of air separation process selection will be of great significance for achieving safe, stable and reliable operation of air separation units, meeting diversified product demands, meeting different needs of users and resolving users' concerns, saving time and manpower and material costs spent by system integrators on determining processes, reducing costs for equipment and component manufacturers and improving work efficiency, increasing returns to investors and bringing greater economic benefits to investors, and even improving the competitiveness of all stakeholders in air separation units.
Hot Tags: cryogenic equipment, China cryogenic equipment manufacturers, suppliers, Carbon Dioxide Manufacturing Plant, Co2 Factory, Cryogenic Oxygen Generator, air products air separation unit, Liquid Co2 Plant, Liquid Nitrogen Gas Plant
