Method for preparing methyl tertiary butyl ether (MTBE)

Abstract

The invention discloses a method for preparing methyl tertiary butyl ether (MTBE). The method is characterized in that: an external circular heat-removing fixed bed reactor is connected in series in front of an original mixed-phase fixed bed reactor. The method comprises the following steps of: (1) inputting mixed C4 serving as a raw material into the external circular heat-removing fixed bed reactor for reacting till the content of isobutene in the mixed C4 serving as the raw material is lowered below 30 percent by weight; (2) introducing the reacted material into the mixed-phase fixed bed reactor for reacting; and (3) introducing the reacted material discharged out of the mixed-phase fixed bed reactor into a catalytic distilling tower for performing deep etherification and separating. The method can adapt to the raw material change of an upstream device, so that the equilibrium conversion rate of the MTBE is increased, the temperature of the catalytic distilling tower is prevented from surpassing a temperature limit, the raw material purity of a downstream device is ensured, and an MTBE device does not to halt during replacement of a catalyst.

Description

technical field [0001] The invention relates to a method for preparing methyl tert-butyl ether MTBE, in particular to a method for preparing methyl tert-butyl ether in a mixed-phase bed reactor. Background technique [0002] Methyl tert-butyl ether MTBE is a colorless, transparent liquid with an ether-like odor. It is an ideal blending component for the production of unleaded, high-octane, and oxygenated gasoline. As a gasoline additive, it has been used worldwide commonly used. MTBE and gasoline can be miscible in any proportion without stratification. When blended with gasoline components, it has a good blending effect, and the blended octane number is higher than its net octane number. MTBE has a relatively high oxygen content. It can not only effectively increase the octane number of gasoline, but also improve vehicle performance, reduce CO content in exhaust gas, and reduce gasoline production costs. In addition, MTBE is also an important chemical raw material, such a...

AI Technical Summary

Problems solved by technology

[0007] Yet, all can not fully satisfy this for above two kinds of processes, when the isobutene content in the mixed C4 raw material fluctuates in the upstream unit, the etherification reaction of MTBE unit can not be carried out completely; The equilibrium conversion rate of MTBE has also dropped significantly, and the above two situations directly lead to the content of isobutene in C4 after ether is often greater than 0.1%

[0008] Therefore, the two technological routes of adopting external circulation heat extraction fixed-bed reactor or mixed-phase fixed-bed reactor alone have the following disadvantages: 1. Can not adapt to the reaction with high concentration of isobutylene in the raw material at the same time; 2. The device must be shut down when changing the catalyst ; 3. When the downstream device is more sensitive to isobutene, the etherification reaction fluctuates greatly and the isobutene cannot fully react, which will affect the downstream device; 4. The concentration of isobutene in the raw material mixing C4 is relatively high, and the incomplete reaction will cause the follow-up catalytic distillation tower over temperature