CN106554247A - A kind of cold-producing medium R32 production technologies - Google Patents

Abstract

The present invention relates to chemical production field, especially cold-producing medium production field.The country is frequently with methods such as liquid-phase fluorination process and gaseous fluoridizing methods at present.Liquid-phase fluorination process has production capacity big, the low feature of energy consumption, has the disadvantage that corrosivity are strong, but ought strictly control reaction pressure for 0.1 ~ 1Mpa, when reaction temperature is 50 ~ 150 DEG C, substantially reduces can reactor material corrosivity, be nearly free from corrosion.Gaseous fluoridizing method have pollution it is little, the features such as be easy to continuous prodution, but reaction temperature is higher, and catalyst component is complicated and is difficult to prepare, easy carbon distribution in production process.

Description

A kind of cold-producing medium R32 production technologies

Technical field

The present invention relates to chemical production field, especially cold-producing medium production field.

Background technology

The country is frequently with methods such as liquid-phase fluorination process and gaseous fluoridizing methods at present.Liquid-phase fluorination process has production capacity big, The low feature of energy consumption, has the disadvantage that corrosivity are strong, but ought strictly control reaction pressure for 0.1 ~ 1Mpa, and reaction temperature is 50 ~ 150 DEG C When, substantially reduce can reactor material corrosivity, be nearly free from corrosion.Gaseous fluoridizing method have pollution it is little, be easy to continuous The features such as metaplasia is produced, but reaction temperature is higher, and catalyst component is complicated and is difficult to prepare, easy carbon distribution in production process.

The content of the invention

Technological process

Whole process units mainly includes fluorination reaction, washing alkali cleaning, a refined, fluorine monochloro methane（R31, CH₂FCl）Reclaim etc. Workshop section, detailed process are described as follows：

（1）Fluorination reaction workshop section

From the dichloromethane of basin（CH₂Cl₂）Reactor is entered Jing after metering preheating, with anhydrous hydrogen fluoride（AHF）Into fluorine Change reactor（Reaction pressure is 1.45 ~ 1.55MPa, and temperature is 85 ~ 95 DEG C）, in catalyst SbCl₅In the presence of react.

Reacted admixture of gas（R32, R31, HCl, unreacted CH₂Cl₂, AHF etc.）Into backflow knockout tower（Instead Pressure is answered to be 1.45 ~ 1.50MPa, temperature is -15 ~ 22 DEG C）, tower top light component material out（R32, HCl, a small amount of HF etc.）Enter Enter to wash alkali cleaning workshop section, bottom of towe heavy constituent material out（Unreacted R31, HF, CH₂Cl₂Deng）It is back to fluorination reaction kettle weight It is new to participate in reaction.

（2）Hydrogen chloride rectification and absorption by Hydrochloric Acid workshop section

From knockout tower light component material elder generation Jing HCl rectifying columns out（Reaction pressure is 1.4 ~ 1.65MPa, and temperature is -30 ~ -35 ℃）The HCl of light component is further separated out, this part HCl carries out absorption operation into film-falling absorption tower and spray absorber, is made Obtain about 34% hydrochloric acid of side-product.

（3）Washing alkali cleaning workshop section

Rough R32, a small amount of HF from detached remaining heavy constituent of hydrogen chloride rectifying column separates circulating and recovering with from finished product rectifying column Dichloroethanes mixing enter jointly water scrubber, absorb HF（And part HCl and a small amount of fluohydric acid gas difluoromethane）, then Jing point About 14% mixed acid is obtained after tower layering（It is back to ammonium acid fluoride and ammonium fluoride production）, after removing most of acidic materials Crude product enters back into caustic wash tower, with the acid impurities in 10%NaOH solution with remnants, enters back into R32 refined units afterwards.

（4）Refinement

Crude product enters R32 rectification drying towers（Reaction pressure is 1.43 ~ 1.5MPa, and temperature is 15 ~ 60 DEG C）Further purify, tower Top obtains final product product R32, packs into product groove, tower reactor substrate material（Main component is dichloroethanes, Shao Liangshui）Into two chloroethenes Alkane collecting tank Posterior circle is back to washing.

Reaction principle

This engineering is with dichloromethane（CH₂Cl₂）And anhydrous hydrogen fluoride（AHF）For raw material, beat according to strict proportioning after metering Entering reactor and the crude products such as difluoromethane being generated in 50 degree or so Jing liquid phase reactors, crude product is through cooling for reflux tower, returned cold Condenser, into hydrogen chloride rectifying column, rectification is isolated hydrogen chloride and enters hydrochloric acid tank into hydrochloric acid falling-film absorber generation hydrochloric acid, Hydrogen chloride rectifier bottoms material with after the dichloroethanes mixing of circulation with pump squeeze into washing alkali cleaning workshop section, it is layered separate it is laggard Enter R32 rectifying columns to be refined, after refinement process, obtain difluoromethane product, the primary chemical for occurring in the process is anti- Should be：

Primary response：CH₂Cl₂ + 2HF→CH₂F₂+ HCl

Side reaction：CH₂Cl₂ + HF→CH₂FCl+ HCl

Cold-producing medium R32 production process ton product material balance tables（Unit：kg/t）

Claims (2)

1. the present invention relates to material composition and proportioning.

2. the present invention relates to production procedure：（1）Fluorination reaction workshop section；（2）Hydrogen chloride rectification and absorption by Hydrochloric Acid workshop section；（3）Washing Alkali cleaning workshop section；（4）Refinement.