Propylene purification for arsenic removal
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A hydrogen pipeline has been connected online to the nitrogen regeneration unit in the propylene refining process. What is the purpose of adding hydrogen here? The catalyst is copper oxide
We don’t have it; we only have nitrogen lines
Yes, I see that many of them contain only nitrogen.
Are you sure that’s hydrogen? Isn’t it IA? Perhaps hydrogen goes to the IA by switching to a pipeline that leads to the nitrogen line; it should enter the deoxidation bed. Did you not read the process carefully?
That hydrogen line is intended to react with arsenic-containing compounds and is considered a reactive gas. Use hydrogen to reduce arsenic-containing organic compounds into hydrocarbons and arsine. Hydrogen arsenide, under the action of a nickel catalyst, produces nickel arsenide and hydrogen.
R3As+3H → 3RH + AsH3; 2AsH3 + 3Ni → Ni3As + 3H2
They didn’t make any mistakes; it’s you who is wrong. There are several types of catalysts used for arsenic removal, and the one mentioned by the original poster is likely one of these catalysts. The principle behind this process is illustrated by the following reaction equations: R3As + 3H → 3RH + AsH3; 2As + 3Ni → Ni3As + 3H2
It mainly depends on what form arsenic is in propylene, and then different catalysts are used to remove it
8# 297212909 Didn’t you also look up relevant information before saying that? Would you know if you didn’t look it up? I checked the information on one facility; their arsenic removal beds don’t use hydrogen, and a friend of mine also said the same thing. So I think the original poster might have misread it. But you can see that your catalyst is nickel, while theirs is copper oxide; when hydrogen arsenide reacts with copper oxide, copper arsenide and water are produced. Stop misleading people
Those up there who haven’t done proper research don’t have the right to speak~ Please don’t mislead others; I at least made an effort to look up information~~~~~~~ The moderator should deduct points from them
Thank you all for your remarks. I’m describing the propylene purification arsenic removal bed layer again. During normal operation, propylene passes directly through this bed to remove arsenic contained in it, with copper oxide as the catalyst. During bed regeneration (deactivation), a mixture of hydrogen and regenerated nitrogen is introduced first, followed by a mixture of IA and regenerated nitrogen. Many processes skip the previous step and go straight to the next one. What I want to ask is what the purpose of the previous step is. Is it to react the arsenic in the bed layer to form AsH3, which is then carried away? Introducing IA is a passivation of CUO that has been reduced to CU.