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Introduction to the gas deep cooling separation process

Release date:2022-10-24    author: Suzhou XITE

[Suzhou XITE Gas] Introduction to the gas deep cooling separation process

With the continuous improvement of the application level of gas deep-cooling separation technology in China, the current process of process technology application involves the separation and processing of gases as a means to meet the standardized requirements of process technology. The article first analyses the technical characteristics of the gas deep-cooling separation process, followed by an elaboration of the scheme and selection strategy of the gas deep-cooling separation process technology, and at the end discusses the technical measures of the gas separation process, hoping to effectively enhance the technical development strategy of the gas deep-cooling separation process and promote the stable and healthy development of the industry.

Gas deep cooling separation technology can effectively improve the quality of gas separation and obtain purer oxygen. Through the method of temperature control, the various components of the air can be distilled and separated to obtain products of higher purity, which is the technical characteristic of the deep cooling separation process. In the process of optimising the gas deep-cooling separation process technology, in order to further meet the development needs of gas production enterprises and obtain higher quality gas, it is necessary to do a good job of technical improvement and upgrading, the basic features of the gas deep-cooling separation process technology are shared as follows.

I. Overview of the gas deep-cooling separation process

Gas deep-cooling separation process is a kind of technology to obtain pure gas products through a series of physical and chemical separation means to achieve precise separation of multi-component mixed gases. The technology in the application process will go through compression, cooling, liquefaction, expansion and other links, while the internal components of their own physical properties are different, can be separated using temperature control - gasification, which is one of the technical core of the gas deep cooling separation process. In the use of deep-cooling separation process technology, it is necessary to take into account the process of high-pressure low-temperature physical separation process, including throttling refrigeration, pressure reduction process and throttling control process, etc. Through a variety of process coordination, in order to achieve energy control efficiency specialisation and enhance the economic and social benefits of process applications. In the whole process of technology application, also need to take into account environmental protection and other aspects of the problem, to ensure that the technology can be applied and promoted.

Second, the gas deep-cooling separation process technology program selection

1. Deep-cooling separation process scheme selection

The choice of deep-cooling separation process scheme is very crucial to enhance the implementation effect of gas deep-cooling separation process. Generally speaking, according to the depth of recovery and different requirements, can be divided into deep cooling, shallow cooling and other technical types. Shallow cooling refers to a refrigeration temperature of around -25 to 40°C, while deep cooling is at around -90 to 100°C. Comparing these temperatures, we can see that the application of deep cooling technology can yield purer gases, especially for special types of gas such as ethane. In the recovery of natural gas, there are various technical options such as oil absorption, direct freezing and expansion. When choosing a process, a number of components and requirements need to be taken into account, including cost, the current state of technology and the adaptability of the enterprise, etc. Focusing on good planning can effectively improve the effectiveness of the application of technology.

2. Deep-cooling separation process selection

Process selection, in general, manufacturers in the flow rate of raw gas, into the plant pressure and other aspects of a certain difference, especially in the internal components of raw gas is a significant difference, coupled with the actual concentration of users, purity requirements vary, so in the process selection should be combined with a variety of factors for a reasonable, scientific choice. Generally speaking, the main factors that can affect the production of processing plants include the internal components of the raw gas, the requirements of recovery C and the requirements of temperature and calorific value, etc. In the pretreatment of raw gas, it is also necessary to give priority to the above options and make the most reasonable and scientific choice to improve the technical application of the product equipment, which is also in line with the basic expectations of the deep cooling separation process technology process selection mode.

The choice of a reasonable expander load is of some value in enhancing the economics of production. Combined with the current production reality, most of the expander shaft power is used for booster, generator and other equipment. In practice, these devices have a wider range of applications and are more adaptable than load pumps, so they are generally not used to provide load. When the admission pressure is low, pre-pressurisation is required by means of expansion refrigeration, a process which requires the selection of a suitable expander to act as a pressurisation device. According to the case analysis situation, the entry pressure is below 5Mpa when the expander needs to be selected to cooperate with the realization of deep cooling separation process technology, the technology can meet the actual requirements of production during normal operation, while its power consumption is not too high, the overall application efficiency is above 70%, which can meet the needs of actual production.

Three, gas separation process technology measures

Gas deep-cooling separation process technology is professionally characterized by the use of the boiling point of each component is different to obtain a higher purity of gas products, which is also the main task objective of technology development. According to the characteristics of the gas deep-cooling process, the following technical optimisation strategies are analysed.

1. Core technology of gas deep-cooling separation technology

With the help of the difference in boiling points between the different components of the gas mixture, the components can be separated precisely, which is also the basic point of the gas deep cooling separation technology. In the entire separation process, in order to prevent the emergence of impurity components affecting the equipment, the daily management of the equipment needs to be done, the impurity components should be pre-treated, and the solidification of the components should also be prevented in low temperature production to ensure the application level of the technology. It is worth noting that the use of deep cooling separation process technology often requires the use of lower temperatures and certain pressure, in such an environment to achieve a certain degree of difficulty in the control of equipment. Therefore, the application of deep cooling separation technology for gases also needs to be combined with the control of the separation and purification process to ensure that the whole technology can be realised in a relatively stable environment. During the application of deep cooling process technology, in order to obtain more cold volume, it is necessary to do a good job of sealing management, to intervene through recycling, heat exchangers and other equipment, to effectively improve the level of temperature control in the separation process and to enhance process safety. In the process of designing the application of deep-cooling separation technology for gases, priority needs to be given to selecting out the best production tools and equipment to ensure that the process design requirements and target parameters are met as soon as possible by improving the operational efficiency of the system, thus avoiding the annual occurrence of over-pressure operation and avoiding a bad impact on the production process.

2. Deep-cooling separation process technology for oxygen and nitrogen

The separation of oxygen and nitrogen using the deep cooling separation process is the most basic separation technology, which is also the basic link for the purification of raw gas impurities. In the removal of impurity gases, cooling with the aid of a heat exchanger is required, followed by a pre-separation process in the tower, after which oxygen-rich liquid air can be obtained at the top of the tower. In the lower part of the tower, a part of the nitrogen gas enters the heat exchanger and is sent out, while the rest is formed into liquid nitrogen in the main condensing section, thus allowing heating and evaporation to form upward liquid oxygen. The first part is the reflux; the second part is cooled and stored in the liquid nitrogen separator; and the last part is extracted and sent back to the top of the tower as reflux. In the whole process, the upper tower undergoes distillation and the bottom obtains high purity liquid oxygen, which is pressurised and sent to the reheat section of the main heat exchanger and finally to the boundary zone.

3. Gas deep cooling separation process equipment management

The deep-cooling separation process cannot be separated from the application and management of equipment, in this link, the selection of suitable deep-cooling separation equipment has an important role in better improving the gas separation effect. Under conventional conditions, the choice of self-cleaning air filters can effectively remove impurities and dust from the mixed gas. By sending the mixed gas to the fractionation tower, the separation and treatment of the mixed gas can also be achieved, and the purified gas can be obtained as soon as possible, and it is easier to achieve the target in terms of purity requirements. In the application of centrifugal gas compression tower process, the export of high-pressure gas, and distillation tower equipment can also be largely to meet the requirements of the separation of mixed gases, to better meet the objective needs of gas separation.

Summing up

In summary, gas deep cooling separation technology has an important role and value in strengthening the effect of gas deep cooling separation and enhancing the production conversion rate. With the refrigeration control strategy of the compressor, the pressure and temperature control level can be effectively enhanced, so as to achieve the precise separation of the mixer and obtain the target product while a variety of pure by-products can be obtained. In the process of applying deep-cooling separation processing technology, the safety of gas separation also needs to be given sufficient attention. By avoiding gas leaks, environmental pollution can be effectively prevented, the safety of the gas separation process can be improved, and production costs can be reduced and the efficiency of gas well separation improved, so as to achieve the production goals and requirements of industrial modernisation.

 Translated with www.DeepL.com/Translator (free version) 


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