Difference between internal compression and external compression in air separation
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What are the differences between internal compression and external compression in air separation? Is the initial investment higher for internal compression, while the energy consumption during operation is lower and safety levels are higher? Can small-scale air separation units be designed with internal compression?
The poster is probably a newcomer to air separation; the questions they asked are things that can generally be found in FAQs for oxygen production workers. Additionally, if you are an operator, it is recommended that you first become familiar with the operations, combining theory with practice
Difference: 1. Product parameters, the decisive factor. If the product pressure is high, above 30 kilograms, it is essentially internal compression, as the maximum pressure at the oxygen and nitrogen permeation outlets can only reach 30 kilograms ； If the liquid volume is very large, exceeding 10% of the oxygen production amount, internal compression should be considered as it results in lower energy consumption. If the liquid volume is 5% or less, the external compression energy consumption is basically low. Specifically, it’s better to calculate both options and compare them. 2. In terms of configuration, external compression systems include a product compressor, while internal compression systems do not have such a compressor; they instead have a booster pump and a product pump. Moreover, both the main heat exchanger and the expander are designed for medium to high pressures, which means that the investment required is usually higher than that for external compression systems. 3. From a safety perspective, external compression users generally consider oxygen permeation to be dangerous. However, there have also been cases of explosion within liquid pumps due to the accumulation of liquid oxygen under internal compression. Therefore, I personally think there is no difference. 4. In terms of operation, externally compressed products offer greater flexibility in adjustment, making them suitable for metallurgical processes with large fluctuations in gas demand. 5. User preferences.
There is more internal compression now, which makes it relatively safe. Because external compression processes generally involve oxygen compressors, which is extremely dangerous
It can be determined according to process requirements; P:L
What you said makes sense! I also perform compression externally