Recycling system for low-boiling point substance in furfural production

Abstract

The invention discloses a recycling system for a low-boiling-point substance in furfural production. The recycling system comprises a stock solution condenser, a stock solution tank, a primary tower, an overhead condenser, an aldehyde separation device, a crude aldehyde measuring tank, a waste gas mixing box, a tower bottom heater, a tail gas semi-condenser and a gas-liquid separator. In the invention, the low-boiling point substance is separated from aldehyde gas before the aldehyde gas enters into a fractionator to be used as combustion-supporting gas of a boiler, thereby avoiding the pollution of the low-boiling point substance on the environment and the influence on separative efficiency of the fractionator, improving the distillation efficiency and simultaneously improving the yield of furfural.

Description

technical field [0001] The invention relates to a recovery and utilization system of low boilers, in particular to a recovery and utilization system of low boilers in furfural production. Background technique [0002] In the hydrolysis section of furfural production, the furfural mixed gas extracted from the hydrolysis kettle is condensed for the first time and becomes liquid, which is called raw liquid in the industry. In order to ensure the normal and balanced evaporation of the initial distillation tower, the temperature of the original liquid is controlled by the process conditions, so the temperature cannot be reduced to the lowest limit, so a part of the non-condensable gas must be discharged before the original liquid enters the initial distillation tower, and this part of the non-condensable gas is called For exhaust. The main components of the discharged non-condensable gas are low boilers, mainly composed of acetone (boiling point 56.5°C), methanol (boiling point ...

AI Technical Summary

Problems solved by technology

Aldehyde and water can not be separated well, so that the yield is reduced, so the tail gas has a great influence on the initial distillation tower

[0004] At present, most factories in my country use the form of unorganized discharge to discharge non-condensable gases. Due to the low-boiler acetone, methanol and other harmful substances contained in non-condensable gases, they cause great pollution to the environment. The smell of the factory is pungent, which is harmful to the operation. varying degrees of bodily injury

Chinese patent 200720093140.3 discloses an oxygen degassing device for removing low boiling substances. The device of this application can only remove low boiling substances in wastewater, which solves the problem of serious pollution of wastewater discharge, but cannot fundamentally eliminate the impact of low boiling substances on whole system impact

Images