Fire and explosion protection design for CO2 gas compression plants
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Dear experts, I would like to ask: For the gases in question, water condenses and is discharged after compression by a compressor, and alcohols are present in this water. Can the compression facility be designed with Class V fire protection measures rather than explosion-proof features? (1) Gas composition: CO2 97%, N2 2.8%, saturated water, methanol 200 ppm, ethanol 300 ppm. (2) Pressure: 0.003 Mpa. (3) Temperature: room temperature. (4) Flow rate: 10,000 Nm³/h. The main component of the gas is a non-flammable gas, and the amount of water discharged during compression is also very small. Many colleagues believe that a design that is not explosion-proof would suffice, but I think an explosion-proof design is necessary for the following reasons: (1) As the alcohols in the gas are discharged along with the water, their concentration increases significantly, reaching around 0.1–5% (or at least 100 times higher). This increases the danger associated with such aqueous solutions ； (2) Compressor rooms are generally enclosed; if ventilation is poor, alcohol-based substances tend to evaporate and accumulate inside the room. In the presence of static electricity or sparks generated by motors, fire or explosion can occur. Please share as many suggestions as possible; specific guidelines would be ideal. Thank you!
Whether the compressor building is enclosed depends on the local climate conditions; in areas with low winter temperatures, it must be enclosed. In other cases, it is mostly an open design, with side walls only on the two-story unit platform. It’s not enough, and this is also related to the *habits of various design institutes. Additionally, it is also crucial to ensure that the surrounding safety distance is sufficient.
First, figure out what they’re asking before answering
We have a CO2 recovery system here; I wonder how it was designed
It should be designed as a non-explosion-proof system, with an explosion-proof zone designated; GB3836 can be used as a reference. If funds permit, it can also be designed to be explosion-proof. There are many experts in China, and it would be troublesome if the design fails to meet the standards; it’s best to let experts make the decisions
GB3836 is a standard that specifies design requirements after classifying explosion areas; currently, the discussion is about whether a particular area qualifies as an explosion area.
The explosion protection classification for decarbonization processes is also a matter of concern; I hope everyone will engage in lively discussions on this topic. In my opinion, aqueous solutions with low concentrations of flammable substances should be treated as non-flammable materials since they are not within the flammable range. However, during normal drainage operations, such substances can be released into the surrounding area, so they should be considered as Class 1 emission sources. The explosion protection measures need to be determined by taking into account both explosion protection requirements and the structure of the compressor plant； Communicate more with the process piping team; if the process layout is economical and reasonable, it may be possible to avoid using explosion-proof motors for the compressors
Call the experts at the design institute or visit colleagues to learn from their experience.
There are many experts from design institutes and peers in the group; the best talents can be found among the ordinary people