I have some questions regarding the initial steps for learning MTBE operation; feel free to discuss.

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This post was last edited by Ding Erxi on 2020.1.8, and further edited on 2020-2-17 at 15:34. 1. The catalyst has been loaded, and nitrogen has been used for purging. 2. The water wash tower and methanol unit are already in operation, with full reflux in the methanol purification tower. 2.1 Question 1: At this point, the methanol reflux tank is filled with water; will the incoming methanol-containing material gradually be replaced by qualified material? 3. Alcohol washing of the fixed-bed reactor 4. Nitrogen purging of the fixed-bed reactor 5. Alcohol washing of the catalytic distillation column 4.1 Option 1: Alcohol washing of the catalytic distillation column is carried out through a methanol feed line, allowing operation with a single column. (During full reflux operation of the reactive distillation column, the material at the bottom of Reactive Distillation Column B is sampled and analyzed every 2 hours.) When the methanol content in the bottom material of reaction distillation column B shows no significant decrease (remains stable), it can be determined that the catalyst has passed the alcohol washing test. ) 4.2 Option 2: The catalytic distillation column is subjected to alcohol washing via a methanol feed line; it is analyzed that the methanol content at the bottom of the column remains unchanged or no washing is performed. Is that plan good? 6. Methanol recovery, 6.1 Question: Should we wait until the methanol recovery by alcohol washing is complete before proceeding? 7. Initial startup of the reactor 7.1 Option 1: For the first start-up, since the catalyst is fresh, methanol is fed in first to further displace methanol from the catalyst bed; the output from the reactor is then sent directly to V301. At this time, the temperature of the reactor is relatively low, the reaction rate is slow, the heat release is small, and the temperature of the catalyst bed does not exceed 80°C. Then for the heat source, control the inlet temperature at 30°C, with a maximum of no more than 40°C. To control the temperature of the catalyst bed, the operating pressure can be controlled at 0.60 MPa. After performing such operations continuously for a period of time, the composition at the outlet of the reaction reactor is analyzed; if the methanol level is high, carbon tetrafluoride can be added to V301 ； If the methanol content is low, the P302A/B methanol feed pumps can be started to feed it into the reactor ； If V301 is full and contains a high level of methanol, some of its contents can be fed into the azeotropic distillation column T301, with efforts being made to maintain an alcohol-to-olefin ratio of 1.0–1.05 (on a molar basis); the material in this state can then be used as feed for column T301. 7.2 Option 2: Methanol and isobutylene are fed simultaneously, with an alcohol-to-olefin ratio maintained at 0.9. That plan is good. Additionally, the conditions for feeding into the catalytic distillation tower are described differently as well; one approach is to prepare to feed into the separation tower when the MTBE concentration at the outlet, as measured by sampling and analysis, reaches 18%. One option is to feed the catalytic distillation column once the reactor’s isobutylene conversion rate meets the required standards; that would be good. 8. Start up the catalytic distillation column. 8.1 When and how much ethanol should be added to the catalytic distillation tower? Is it appropriate to estimate the amount of methanol to be added based on the approximate methanol content in the C4 fraction after ether separation, with a methanol content of 1%–2% in that fraction being suitable? 9. There are no objections to the other driving steps, so they need not be repeated here.