Design and equipment selection for hydrogen dehydration.
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This post was last edited by sunjl1981 on 2013-1-6 at 22:55. Hello everyone, our company’s original hydrogen system did not include a dehumidification unit; it was designed solely for producing hydrochloric acid in synthesis furnaces. Now, since we need to supply hydrogen chloride gas to polysilicon manufacturers, it is necessary to cool and dehumidify the hydrogen. May I ask how to choose the type of heat exchanger, as well as the chiller unit and mist collector? ， ， -
I’m not sure what the specific process requirements downstream are? Writing it down can give you a dehydration plan tailored to your situation!
First, thank you. The purity of hydrogen chloride is required to be above 93%, with water content below 200PPM. The pressure should be greater than 0.1MPa.
When the water content is less than 200PPM, it’s a bit difficult to achieve dehydration solely through physical methods!
Molecular sieve dehydration can be considered; it can achieve levels below 50 ppm, and its capital investment and energy consumption are lower compared to freeze dehydration.
We plan to use a hydrochloric acid synthesis furnace to produce hydrogen chloride gas for the production of trichlorosilane; no dehydration of hydrogen is carried out. Can the water content in the resulting hydrogen chloride be kept below 400PPM? This post was last edited by shizhiyong001 on 2008-9-2 at 15:29.]
For the dehydration of hydrogen and hydrogen chloride, low-temperature condensation dehydration combined with Memmert demisting can be employed.
Hydrogen does not require special equipment for dehydration; air cooling is used for this purpose, and this poses no problem for the synthesis of hydrogen chloride. However, if it is used in the trichlorosilane production process, the hydrogen chloride produced must be dehydrated, and deep cold water cooling is employed for this purpose, followed by filtration using an acid mist filter! ! In this way, the moisture level should be able to be kept below 400 ppm!
Upon investigation, it was found that for hydrogen chloride gas used in the production of PVC or trichlorosilane, etc., a 7-degree cold water mist catcher is employed to dehydrate the hydrogen gas.
Molecular sieves are generally used when good results are desired. We have used it; it’s good.
Our company is also considering the issue of recycling hydrogen and trichlorosilane in recent times; as long as 10% trichlorosilane is present in it. We are currently thinking about recovering hydrogen and trichlorosilane, and we would like to discuss which type of dehydration equipment should be used. Everyone is welcome to share their opinions.