CN109724368A - The recovery method of chlorinated exhaust in a kind of production of Sucralose - Google Patents

Abstract

The present invention relates to the recovery methods of chlorinated exhaust in a kind of production of Sucralose, the steps included are as follows: low temperature chlorination liquid is put into high-temperature kettle, chlorination temperature reaction generates sulfur dioxide and hydrogen chloride tail gas, tail gas is by preliminary cooling and isolates high boiling substance, roots blower outlet enters compressor after cooling and carries out being forced into 0.6MPa, subsequently into three-level cooler, outlet temperature is controlled at -35 DEG C or so, it is condensed into liquid after sulfur dioxide is cooling, hydrogen chloride gas enters storage tank after separation.Technical process of the invention is simple, sulfur dioxide and HCl separation are more thoroughly, sulfur dioxide and hydrogen chloride can be used as stand-alone product after separation and carries out using or sell, it avoids traditional handicraft and generates largely neutralization salt water with sulfur dioxide and hydrogen chloride in a large amount of lye in the process, reduce pollution, while generating economic benefit.

Description

The recovery method of chlorinated exhaust in a kind of production of Sucralose

Technical field

The invention belongs to chemical technology fields, and in particular to the recovery method of chlorinated exhaust in Sucralose production.

Background technique

Sucralose is fresh sweetener, and sugariness is 600-800 times of sucrose, and sweet taste is pure similar to sucrose, trichlorine Sucrose is not absorbed by the human body, and has no bioaccumulation, highly-safe, therefore Sucralose industry in this year rapidly develops, production Enterprise is stepped up, and yield is continuously improved.Largely thionyl chloride is used to use as chlorinating agent in sucrose trichloride production process, with The raising of yield, the usage amount of thionyl chloride be consequently increased, and at present production chloridization process in necessarily lead to titanium dioxide Sulphur and hydrogen chloride, the prior art are to be neutralized after absorbing above-mentioned tail gas with water with a large amount of lye, while generating and largely being difficult to locate The solid salt slag of reason.

Summary of the invention

It is high and low the purpose of the present invention is overcoming the deficiencies of the prior art and provide one kind easy to operate, high efficiency, the rate of recovery The method of tail gas recycle in the Sucralose production of cost.

To realize that above-mentioned goal of the invention, the process step of the invention are as follows:

The recovery method of chlorinated exhaust in a kind of production of Sucralose, it is characterised in that include the following steps:

A. the chlorated liquid comprising thionyl chloride, dimethylformamide, sucrose ester and trichloroethanes is put into high-temp chlorination kettle, is added Heat simultaneously controls high-temp chlorination kettle temperature at tiny structure -5KPa and is raised to 105 DEG C -115 DEG C, chlorination reaction generate sulfur dioxide and Hydrogen chloride tail gas；

B. sulfur dioxide and hydrogen chloride tail gas are drawn by tentatively cooling and isolating high boiling substance, are then evacuated with roots blower It pressurizes into compressor, outlet pressure control is in 0.6MPa after compressor pressurizes for tail gas, subsequently into three-level chilled water Cooler is cooled to -35 DEG C, and liquid is condensed into after sulfur dioxide in tail gas gas cooling into sulfur dioxide storage tank, hydrogen chloride gas Enter storage tank after separation.

Further technical solution, the tail-gas quality score are 10-40%.

In above-mentioned technical proposal, the chlorination reaction generates time 6-12 hours of tail gas, after reaction in chlorination tank Mixture includes dimethylformamide, Sucralose 6 ester, trichloroethanes.

It is handled by method of the invention, finally obtains mass percent >=99.%, the moisture content < of sulfur dioxide 0.5%, hydrogen chloride gas mass percent >=99.%.

Compared with prior art, advantage of the invention is that using sulfur dioxide and hydrogen chloride boiling point and vapour pressure not Together, sulfur dioxide gas is pressurized liquefied while further reducing saturated vapor pressure, hydrogen chloride gas is more than its boiling point, shape At gas-liquid separation, sulfur dioxide liquid and hydrogen chloride gas have preferably been obtained,.Method process proposed by the present invention is simple, Product purity meets the requirements, and is a kind of process for separating and recovering method with preferable application prospect.

Detailed description of the invention

Attached drawing Fig. 1 is the process flow chart of the method for the present invention.

Specific embodiment

Technology contents, construction feature, the objects and the effects for detailed description technical solution, below in conjunction with specific reality It applies case and attached drawing is cooperated to be explained in detail.

Embodiment 1

As shown in Figure 1, will include thionyl chloride, the chlorated liquid of dimethylformamide, sucrose ester and trichloroethanes be put into high-temperature chlorine Change in kettle, then slowly opens heating steam, interim heating, chlorination temperature reaction are carried out according to high-temp chlorination temperature program Sulfur dioxide and hydrogen chloride tail gas are generated, temperature is raised to 105 DEG C at tiny structure (- 5KPa), and tail gas is preliminary by recirculated water Cool and isolate high boiling substance, with roots blower pumping and and high-temp chlorination kettle pressure it is mutually chain (high-temperature kettle pressure control- 10--+10KPa, roots blower frequency control revolving speed, signal feedback increases to roots blower motor speed when pressure is high, increases Sucking rate, roots blower motor speed slows down when pressure is low, reduces sucking rate, the pressure of high-temperature kettle is made to remain at tiny structure State), make holding -5KPa negative pressure in chlorination tank.Tail gas is exported through roots blower enters compressor progress after 30 DEG C cooling Pressurization, makes outlet pressure control in 0.6MPa, freezes water cooler (- 5 DEG C of level-one, -25 DEG C of second level, three-level subsequently into three-level - 35 DEG C of outlet temperature), liquid is condensed into sulfur dioxide storage tank after sulfur dioxide is cooling, and hydrogen chloride gas enters after separation Storage tank.

Mass percent >=99.%, the moisture content < 0.5% of sulfur dioxide sulfur dioxide.Hydrogen chloride gas weight percentage Number >=99.%.

Embodiment 2

It will include thionyl chloride, the chlorated liquid of dimethylformamide, sucrose ester and trichloroethanes is put into high-temp chlorination kettle, then Heating steam is slowly opened, interim heating is carried out according to high-temp chlorination temperature program, chlorination temperature reaction generates titanium dioxide Sulphur and hydrogen chloride tail gas, temperature is raised to 115 DEG C under tiny structure, tail gas is by preliminary cooling and isolates high boiling substance, With roots blower pumping and, chlorination tank in -3KPa negative pressure mutually chain with high-temperature kettle pressure.Roots blower outlet enters after cooling Compressor pressurizes, and makes outlet pressure control in 0.6MPa, freezes water cooler subsequently into three-level, and -30 DEG C of outlet temperature, It is condensed into liquid after sulfur dioxide is cooling, hydrogen chloride gas enters storage tank after separation.

Mass percent >=99.%, the moisture content < 0.5% of sulfur dioxide sulfur dioxide.Hydrogen chloride gas weight percentage Number >=99.%.

It should be noted that being not intended to limit although the various embodiments described above have been described herein Scope of patent protection of the invention.Therefore, it based on innovative idea of the invention, change that embodiment described herein is carried out and is repaired Change, or using equivalent structure or equivalent flow shift made by description of the invention and accompanying drawing content, it directly or indirectly will be with Upper technical solution is used in other related technical areas, is included within scope of patent protection of the invention.

Claims (2)

1. the recovery method of chlorinated exhaust in a kind of Sucralose production, it is characterised in that include the following steps:

A. the chlorated liquid comprising thionyl chloride, dimethylformamide, sucrose ester and trichloroethanes is put into high-temp chlorination kettle, is added Heat simultaneously controls high-temp chlorination kettle temperature at tiny structure -5KPa and is raised to 105 DEG C -115 DEG C, chlorination reaction generate sulfur dioxide and Hydrogen chloride tail gas；

B. sulfur dioxide and hydrogen chloride tail gas are drawn by tentatively cooling and isolating high boiling substance, are then evacuated with roots blower It pressurizes into compressor, outlet pressure control is in 0.6MPa after compressor pressurizes for tail gas, subsequently into three-level chilled water Cooler is cooled to -35 DEG C, and liquid is condensed into after sulfur dioxide in tail gas gas cooling into sulfur dioxide storage tank, hydrogen chloride gas Enter storage tank after separation.

2. the method for chlorinated exhaust recycling in a kind of Sucralose production according to claim 1, which is characterized in that described Tail-gas quality score is 10-40%.