Recovering process of solvent tertiary butanol in production process of ammoximation

Abstract

The invention discloses a recovering process of a solvent tertiary butanol in a production process of ammoximation. The process comprises the following steps of: combining a rectifying system by a plurality of rectifying towers and configuring corresponding re-boiler, cooling system, reverse-flow system and compressing system; recovering ammonia and tertiary butanol in a reaction liquid of a reactor by a double-effect or multi-effect rectifying tower; using the overhead gas phase of the previous rectifying tower as a heat source of the re-boiler of the next rectifying tower by setting different operating pressures of the rectifying towers so as to utilize the previous gas phase condensing heat energy, wherein the operating pressure of one rectifying tower is 0.08-0.6MPa (absolute pressure) while the operating pressure of the last rectifying tower is 0.001-0.1MPa (absolute pressure), the overhead temperature of one rectifying tower is 60-140 DEG C, while the overhead temperature of the previous rectifying tower is 10-40 DEG C higher than that of the next rectifying tower; condensing the overhead gas phases by the cooling system, controlling the discharge temperature at 10-80 DEG C, the condensate enters into the reverse-flow system, and is pressurized by a pump, and part of the condensate is fed to the rectifying tower to reverse-flow, while the other condensate is fed outside the rectifying system; and feeding noncondensable gases in the cooling system to the compressing system to be compressed and feeding outside the rectifying system. According to the tertiary butanol recovering process flow, steam consumed is just 45-65% of that consumed by a single rectifying tower.

Description

technical field [0001] The invention relates to a process for recovering tert-butanol, in particular to a process for recovering solvent tert-butanol in ammoximation production by means of multi-effect rectification. Background technique [0002] In order to make the ammoximation reaction proceed in a uniform solution, tert-butanol is introduced into the reaction solution as a solvent, so that the reactants, catalysts and reaction products are evenly distributed in the reactor. After the oximation reaction solution is filtered, the catalyst is separated from oxime, water, and tert-butanol. Since tert-butanol acts as a solvent in the reaction system, it does not participate in the reaction itself. In order to improve the utilization rate of tert-butanol, it is recovered and recycle. [0003] Since the boiling point and relative volatility of tert-butanol and oxime and water are quite different, a distillation column can be used to separate tert-butanol. The current conventi...

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Problems solved by technology

[0005] In order to overcome the above problems and reduce energy consumption, a combination of high and low pressure towers is used to separate tert-butanol by multi-effect distillation; the operating pressure of the high-pressure tower and low-pressure tower in the separation process determines the performance of the multi-effect separation. If the tower pressure is too high, the temperature of the high-pressure tower will increase, which will adversely affect the performance of the product at the bottom of the tower. Increases vacuum compression costs, or causes other operational problems, making multi-effect distillation impossible

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