When should acid washing be initiated for LPG C4 sulfate alkylation?
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This post was last edited by Benpeng Guo Jibo45 on 2017-5-24 00:37. It provides an idea regarding when to start the acid washing process in LPG C4 sulfate alkylation, for everyone’s reference. If the alkylated oil sells well and the customer’s requirements can be met without acid washing, then no washing is necessary. Without acid washing, the content of sulfates is definitely higher than that after acid washing. There’s no need to worry that the acid will be difficult to remove after pickling. The acid that gets mixed in after pickling is mostly sulfuric acid, an inorganic acid that reacts immediately upon contact with alkali solutions. The hydrolysis of sulfates requires a certain temperature and hydrolysis time. Currently, the sulfur content in alkylated oils is generally 1–2 ppm, which means that 1 ton of alkylated oil contains 1–2 grams of sulfur; acid washing will not have a significant effect in such cases. If the sulfur content in the alkylated oil is high, acid washing should be carried out. Starting from January 1, 2018, phase V gasoline will be available nationwide, with a requirement that the sulfur content in gasoline not exceed 10 ppm; therefore, it is necessary to start seeking ways to improve the quality of alkylated oil right now.
Simply put, under the current process conditions, it is not recommended to carry out alkylated acid washing; the sediment resulting from this process does not settle properly and ends up in the alkali washing stage. Although alkali washing can effectively neutralize free acids, it results in waste of alkali solution, which represents an additional cost. For acid cleaning, the pump power should be around 35 KW, which also increases electricity consumption. In normal situations, without acid cleaning, I keep the sulfur content in the products at around 3 levels, which meets the requirements for improving gasoline standards.
Well, I have 1-2 here. Since we’re doing well, we should also pay attention to those with high sulfur content.
Dear everyone, the sulfur content in our alkylated gasoline is 10; it can be reduced to 3 after pickling. Could you help analyze the reasons for this? Thank you!