Catalytic dry gas utilization
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We are planning to set up a catalytic cracking unit with a capacity of 1.8 million tons per year, which will produce around 72,000 tons of dry gas per year. There are no facilities for producing ethylene, styrene, etc. We intend to recover the ethylene (31.9% w) and hydrogen (4% w) present in the dry gas – are there any new technologies that can be utilized for this purpose? How much investment is needed? Can it be achieved through organic membrane purification? This post was last edited by psw1420 on 2009-4-14 16:54.]
It’s fine to work with polyethylene or polyvinyl chloride
Pressure swing adsorption technology can. For specific investment details, please consult the design institute. I heard that Sichuan Tianyi Design Institute is good at this.
Several technologies for recovering ethylene from dry gas are introduced: the technology for producing ethylbenzene from dry gas, which has a relatively simple process and allows for the direct production of ethylbenzene. However, due to the low concentration of ethylene in the catalytic dry gas, the equipment investment required is relatively high compared to that needed for obtaining ethylene of higher purity； Deep cryogenic separation technology has high energy consumption and large equipment investment ； The main drawback of pressure swing adsorption is the difficulty in obtaining polymeric-grade ethylene in a single separation step; under normal conditions, the purity of the ethylene produced is 80% (by volume). To produce high-purity ethylene using a combined process, higher investment is required ； The intercooling oil absorption technology can only produce 84% (by volume) of crude ethylene ； Advanced recycling system technology. It has low energy consumption – saving 15%–25% compared to conventional cryogenic separation techniques – with a hydrocarbon recovery rate of 96%. It exhibits strong adaptability to various feedstocks and yields products of high purity; however, this technology is foreign-originated, and the associated patent costs are high
Hydrogen can be concentrated and utilized, but this is not possible for ethylene; the styrene route is the only option.
PSA for hydrogen concentration; Luoyang Institute for producing ethylbenzene from dry gas
This amount is too small; it doesn’t even reach the threshold for acceptance. A more practical and reasonable approach is to use dry gas to produce styrene