CN103435442A - Waste methanol recycling method - Google Patents

Abstract

The invention discloses a waste methanol recycling method and relates to the technical field of chemical engineering. The waste methanol recycling method comprises the following steps of: collecting the waste methanol and putting the collected waste methanol in an evaporator in distillation equipment, and suppling steam to the steam heating coil of the container, wherein the evaporation temperature is lower than or equal to 68 DEG C and the distillation amount is 80 kg/h; heating the waste methanol in the evaporator so that the waste methanol is evaporated to form a gaseous-phase material, feeding the gaseous-phase material into a condenser and condensing the gaseous-phase material in the condenser to separating out clean liquid methanol; finally, evaporating the residues and feeding the clean liquid methanol into a collecting barrel. The waste methanol recycling method is capable of solving the problems of the reduction of the raw material conversion rate and the product quality and the increase of raw material consumption caused by the reduction of catalyst activity in methanol production due to high impurity content of the methanol.

Description

Useless Methanol Recovery is utilized method

Technical field

The present invention relates to chemical technology field, especially a kind of for recycle the method for the useless methyl alcohol produced when producing formaldehyde.

Background technology

As shown in Figure 1, the Formaldehyde Production raw material comprises methyl alcohol and air, in the raw material preparatory stage of Formaldehyde Production, it is the ratio preparation of methyl alcohol and air, this process is carried out in evaporating pan 11, liquid methanol enters evaporating pan 11 with certain flow by methanol pump 13 from methyl alcohol groove 12, controls certain liquid level and temperature; It is methanol gas that methyl alcohol is heated pipe 16 heating and gasifyings in evaporating pan 11; Air is blasted after pipeline 15 enters evaporating pan and is passed through methanol liquid and mix with methanol vapor in the bubbling mode by blower fan 14, from outlet, draw, complete the preparation of raw material, in the process for preparation of methyl alcohol and air, the entrained impurity of air, methyl alcohol and transport pipe can gather gradually in the methyl alcohol of vaporizer, simultaneously because air flow quantity is larger, and pass methanol solution in the bubbling mode, methanol solution is acutely seethed, air-methanol mixed gas is when leaving methanol solution and make progress away, after the partial impurities in methanol solution can being brought in the reactor of an operation.In vaporizer, the foreign matter content of methyl alcohol is higher, and the impurity that air-the methanol mixed band of gas goes out is just more, after these impurity enter oxidizer, can cover catalyst surface, and the activity of catalyzer is reduced gradually until lose activity.For the work-ing life of extending catalyst, when the methanol contaminant content in evaporating pan reaches a certain amount of, just need its sewage draining exit from evaporating pan 11 bottoms 17 is discharged, putting temporarily need not, but because methyl alcohol is poisonous, inflammable and explosive hazardous substance, and the methanol feedstock expense accounts for 90% of production cost, therefore putting no useless methyl alcohol temporarily, these are stored into certain amount, after the precipitation certain hour or directly used when raw material.Because these useless methyl alcohol are impure more, just through precipitating without other processing, after using so each, the activity of catalyzer all can descend rapidly, causes feed stock conversion and quality product to descend, and raw material consumption also increases.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of useless Methanol Recovery and utilizes method, it can solve affects catalyst activity reduction in Formaldehyde Production because methanol contaminant content is higher, cause feed stock conversion and quality product to descend, the problem that raw material consumption also increases.

In order to address the above problem, technical scheme of the present invention is: this useless Methanol Recovery utilizes method the steps include:

(1) the useless methyl alcohol that will produce in producing the formaldehyde process is collected the vaporizer of putting into distillation plant;

(2) input steam to the steam heating coil of described vaporizer, vaporization temperature≤6 8 ℃, the distillation amount is 80kg/h, useless methyl alcohol is heated evaporation and forms gaseous phase materials in described vaporizer;

(3) the useless methyl alcohol of the gasification of step (2) gained is sent in condenser, useless methyl alcohol condensation in condenser, can isolate clean liquid methanol, and residual quarrel is evaporated, and clean liquid methanol is sent in gathering barrel.

Owing to adopting technique scheme, the present invention has following beneficial effect:

1, the present invention can solve because methanol contaminant content is higher and cause catalyst activity reduction in Formaldehyde Production, causes the problem that feed stock conversion and quality product descend and raw material consumption increases;

2, but the use of the present invention's extending catalyst is received the order.

The accompanying drawing explanation

Fig. 1 is the schematic diagram that existing useless formaldehyde produces.

Fig. 2 is the water distilling apparatus schematic diagram of the useless methyl alcohol of the embodiment of the present invention 1.

Fig. 3 is the water distilling apparatus schematic diagram of the useless methyl alcohol of the embodiment of the present invention 2.

Embodiment

Below by concrete accompanying drawing example, the present invention is described in further detail:

Embodiment 1 as shown in Figure 2:

During each the shutdown, the useless methyl alcohol in evaporating pan is entered in the methyl alcohol storage tank, then inject the vaporizer 1 of distillation plant; To the heating coil 2 input steam of vaporizer, vaporization temperature is controlled in 68 ℃, and the distillation amount is 80kg/h, and useless methyl alcohol is heated evaporation and forms clean methanol steam in vaporizer 1; Methanol steam enters in condenser 3 by transfer lime 5, and clean liquid methanol is isolated in condensation in condenser 3, and residual quarrel is evaporated, and clean liquid methanol sends in the methyl alcohol gathering barrel 4 by transfer lime 5.

Embodiment 2 as shown in Figure 3:

With pipeline, the useless methyl alcohol injection tube of distillation plant and evaporating pan bottom blow-down pipe are coupled together, open the evaporating pan wash water valve, utilize pressure in the production process evaporating pan methyl alcohol that will give up on a small quantity to be depressed in the vaporizer 1 of distillation plant, flow control is 80kg/h; To the heating coil 2 input steam of vaporizer 1, vaporization temperature is controlled in 68 ℃, and useless methyl alcohol is heated evaporation and forms clean methanol steam in vaporizer 1, and the distillation amount is 80kg/h; Methanol steam enters in condenser 3 by transfer lime 5, condensation in condenser 3, and the clean liquid methanol of gained flows in material benzenemethanol groove 12 by pipeline 6, makes the Formaldehyde Production raw material and uses.

Claims (1)

1. a useless Methanol Recovery is utilized method, it is characterized in that: include following making step:

(1) the useless methyl alcohol that will produce in producing the formaldehyde process is collected the vaporizer of putting into distillation plant;

(2) input steam to the steam heating coil of described vaporizer, vaporization temperature≤6 8 ℃, the distillation amount is 80kg/h, useless methyl alcohol is heated evaporation and forms gaseous phase materials in described vaporizer;

(3) the useless methyl alcohol of the gasification of step (2) gained is sent in condenser, useless methyl alcohol condensation in condenser, can isolate clean liquid methanol, and residual quarrel is evaporated, and clean liquid methanol is sent in gathering barrel.

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