Research and development of large-scale cryogenic air separation in China

Abstract

Abstract:With the rapid growth in demand for industrial gas in steel and chemical industries, there has been significant emphasis placed on the development of China's large-scale air separation technology. Currently, the maximum capacity of a single unit has been able to attain 120 000 Nm 3 /h (oxygen), and the specific power consumption of 0.38 kWh/m 3 . This paper reviews the current state-of-the-art for large-scale cryogenic air separation systems being deployed in China. A brief introduction to the history and establishment of the large-scale cryogenic air separation industry is presented. Taking the present mainstream large-scale air separation unit operating at 60 000 Nm 3 /h (oxygen) as an example, the technological parameters and features of the involved key equipment, including a molecular sieve adsorber, air compressor unit, plate-fin heat exchanger, turbo-expander and distillation column are described in detail. The developing 80 000-120 000 Nm 3 /h air separation processes and equipment are also introduced. A summary of the existing problems and future developments of these systems in China are discussed.

Air Separation by Catechol-Ligated Transition Metals: A Quantum Chemical Screening

“…1 Oxygen is used by the steel industry in massive quantities, but it is also an important reactant in the manufacturing of a wide variety of chemicals. 2,3 Moreover, oxygen is a key component of oxy-fuel combustion, which improves efficiency and greatly reduces the NO x pollutants in flue gas. 4,5 Oxy-fuel combustion is also an approach to carbon capture.…”

Efficient Method To Obtain the Force Field for CO2 Adsorption on Zeolite 13X: Understanding the Host–Guest Interaction Mechanisms of Low-Pressure Adsorption

“…Industrial gases, such as nitrogen, oxygen, and helium, play a crucial role in steel, metallurgical, coal chemical, and other modern industries . The air separation unit (ASU), which produces these industrial gases from atmospheric air by cryogenic distillation, is extensively adopted as the most economical and reliable method to obtain these gases in large-scale gas production . In an ASU, the compressed air (at approximately 0.6 MPa) is fed into an air prepurification system to remove impurities such as CO 2 and H 2 O by temperature swing adsorption (TSA) with zeolite 13X and active aluminum, to prevent the interior of the distillation column from being obstructed by frozen impurities .…”

“…1 The air separation unit (ASU), which produces these industrial gases from atmospheric air by cryogenic distillation, is extensively adopted as the most economical and reliable method to obtain these gases in largescale gas production. 2 In an ASU, the compressed air (at approximately 0.6 MPa) is fed into an air prepurification system to remove impurities such as CO 2 and H 2 O by temperature swing adsorption (TSA) with zeolite 13X and active aluminum, to prevent the interior of the distillation column from being obstructed by frozen impurities. 3 Since the volume fraction of CO 2 is 400−1500 ppm in the atmosphere, the partial pressure of CO 2 is lower than 1 kPa in the prepurification system.…”

Temperature inhomogeneity in high capacity pulse tube cryocoolers

“…Stirling type pulse tube cryocoolers (SPTC), having the benefit of no moving parts at the cold end, could be more reliable and require lower maintenance than Gifford-McMahon (GM) and Stirling cryocoolers (Li et al, 2014;Zhang et al, 2014). However, there are still serious unsolved problems in large scale SPTC.…”