CN104058924A - Method for preparing chloromethane by utilizing alcohol-containing hydrochloric acid - Google Patents
Method for preparing chloromethane by utilizing alcohol-containing hydrochloric acid Download PDFInfo
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- CN104058924A CN104058924A CN201410294534.XA CN201410294534A CN104058924A CN 104058924 A CN104058924 A CN 104058924A CN 201410294534 A CN201410294534 A CN 201410294534A CN 104058924 A CN104058924 A CN 104058924A
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Abstract
The invention discloses a method for preparing chloromethane by utilizing alcohol-containing hydrochloric acid. The method comprises the following steps: continuously adding alcohol-containing hydrochloric acid and methanol into a tower reactor according to a mass ratio of 1:(1-2), carrying out a two-stage reaction, and extracting mixed gas containing methane chloride from the tower reactor, wherein the mixed gas contains a small amount of hydrogen chloride, unreacted methanol, water, dimethyl ether and other substances; introducing the mixed gas into a rectifying tower, extracting pure chloromethane on the tower top, performing condensation return on the methanol, and adding the methanol into the reactor for reutilization; allowing a small amount of hydrogen chloride and water to form low-concentration hydrochloric acid wastewater at the tower bottom, and performing neutralizing treatment. The invention also discloses a device for preparing chloromethane by adopting the method. The method has the advantages that waste alcohol-containing acids which are difficultly treated can be changed into valuable materials to produce the chloromethane, so that the hydrogen chloride and methanol which are not completely reacted can be recycled, the raw material utilization efficiency is improved, and the waste acid treatment cost is reduced, so that the production cost is reduced.
Description
Technical field
The present invention relates to a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride, belong to chemical technology field.
Background technology
Present methyl chloride synthesis technique is to utilize methyl alcohol and hydrogenchloride solution-air two phase reaction in liquor zinci chloridi, because reaction is not thorough and air foam is carried secretly, a large amount of hydrogenchloride and methyl alcohol are distilled out of, after condensation, collect in sour water tank, form alcoholic hydrochloric acid, this part is difficult to process containing alkyd, and especially hydrogenchloride and water form azeotrope, are difficult to pass through rectifying separation.Existing processing mode is to reclaim methyl alcohol by methanol distillation column, but need to consume a large amount of steam, and produce spent acid be difficult to process, cause a large amount of wastes of raw material and the processing costs that has strengthened waste acid water.
Summary of the invention
For the deficiencies in the prior art, the object of this invention is to provide a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride, recycle the halfway hydrogenchloride of reaction and methyl alcohol, improved the utilising efficiency of raw material, reduce spent acid processing costs, thereby reduced production cost.
For achieving the above object, the present invention adopts following technical scheme:
Utilize alcoholic hydrochloric acid to prepare a method for methyl chloride, comprise the following steps:
(1) alcoholic hydrochloric acid is joined in reactor; Methyl alcohol is vaporized, also join in reactor, the control 80-90% of gasified methanol and the alcoholic hydrochloric acid of liquid phase carry out the first step and react; The 10-20% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 115-170 DEG C, and pressure is 240-500KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 110-125 DEG C, and pressure is 210-450KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and the dme extraction from reactor generating in step (3), pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower;
Wherein, in step (1), the mass ratio of alcoholic hydrochloric acid and methyl alcohol add-on is 1:(1~2).
In step (2), preferred temperature of reaction is 130-160 DEG C, and pressure is 300-450KPa;
In step (1), (2), described reactor is tower staged reactor;
In step (4), the methyl alcohol in mixed gas enters into return tank through condensation, further joins in reactor and participates in and react through gasification;
In step (4), a small amount of hydrogenchloride in mixed gas and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging after neutralizing treatment.
Adopt method of the present invention to prepare the device of methyl chloride, comprise staged reactor and rectifying tower, described staged reactor is connected with vaporizer with heat exchanger respectively, and the top of staged reactor is connected with condenser, and the other end of condenser is connected with rectifying tower; The top of described rectifying tower is connected with condenser, and the other end of condenser is connected with return tank, and described return tank is connected with vaporizer with rectifying tower respectively; The bottom of described rectifying tower is connected with reboiler.
The present invention has following beneficial effect with respect to prior art:
The present invention can be by unmanageable containing the alkyd production methyl chloride of turning waste into wealth, and makes to react halfway hydrogenchloride, methyl alcohol is recycled, and has improved the utilising efficiency of raw material, has reduced spent acid processing costs, thereby has reduced production cost.Year output is the methyl chloride device of 50,000 tons, can on average save every year 800 tons of methyl alcohol, and 2700 tons, hydrogenchloride, has good economic benefit.
Brief description of the drawings
Fig. 1 is process flow sheet of the present invention.
Embodiment
The present invention is further illustrated in conjunction with the embodiments, should be noted that following explanation is only in order to explain the present invention, does not limit its content.
Embodiment 1
Technical process as shown in Figure 1, a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride, comprises the following steps:
(1) 50kg alcoholic hydrochloric acid is joined in reactor, 50kg methyl alcohol is vaporized, also join in reactor, 80% of control gasified methanol carries out the first step with the alcoholic hydrochloric acid of liquid phase and reacts; 20% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 115 DEG C, and pressure is 240KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 110 DEG C, and pressure is 210KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and dme extraction from reactor, pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower; Methyl alcohol enters into return tank through condensation, further joins in reactor and participates in and react through gasification; A small amount of hydrogenchloride and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging as factory effluent after neutralizing treatment.
After testing, the purity that makes monochloro methane is 99.95%, is 99.2% containing hydrogenchloride transformation efficiency in alkyd.
As shown in Figure 1, adopt the method to prepare the device of methyl chloride, comprise staged reactor and rectifying tower, described staged reactor is connected with vaporizer with heat exchanger respectively, and the top of staged reactor is connected with condenser, and the other end of condenser is connected with rectifying tower; The top of described rectifying tower is connected with condenser, and the other end of condenser is connected with return tank, and described return tank is connected with vaporizer with rectifying tower respectively; The bottom of described rectifying tower is connected with reboiler, and reboiler is for providing heat to rectifier bottoms material, methyl alcohol in separation of material.
Embodiment 2
Utilize alcoholic hydrochloric acid to prepare a method for methyl chloride, comprise the following steps:
(1) 50kg alcoholic hydrochloric acid is joined in reactor, 100kg methyl alcohol is vaporized, also join in reactor, 90% of control gasified methanol carries out the first step with the alcoholic hydrochloric acid of liquid phase and reacts; 10% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 170 DEG C, and pressure is 500KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 125 DEG C, and pressure is 450KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and dme extraction from reactor, pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower; Methyl alcohol enters into return tank through condensation, further joins in reactor and participates in and react through gasification; A small amount of hydrogenchloride and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging as factory effluent after neutralizing treatment.
After testing, the purity that makes monochloro methane is 99.96%, is 99.4% containing hydrogenchloride transformation efficiency in alkyd.
Embodiment 3
Utilize alcoholic hydrochloric acid to prepare a method for methyl chloride, comprise the following steps:
(1) 50kg alcoholic hydrochloric acid is joined in reactor, 70kg methyl alcohol is vaporized, also join in reactor, 85% of control gasified methanol carries out the first step with the alcoholic hydrochloric acid of liquid phase and reacts; 15% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 130 DEG C, and pressure is 300KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 115 DEG C, and pressure is 300KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and dme extraction from reactor, pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower; Methyl alcohol enters into return tank through condensation, further joins in reactor and participates in and react through gasification; A small amount of hydrogenchloride and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging as factory effluent after neutralizing treatment.
After testing, the purity that makes monochloro methane is 99.95%, is 99.3% containing hydrogenchloride transformation efficiency in alkyd.
Embodiment 4
Utilize alcoholic hydrochloric acid to prepare a method for methyl chloride, comprise the following steps:
(1) 50kg alcoholic hydrochloric acid is joined in reactor, 50kg methyl alcohol is vaporized, also join in reactor, 90% of control gasified methanol carries out the first step with the alcoholic hydrochloric acid of liquid phase and reacts; 10% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 160 DEG C, and pressure is 400KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 110 DEG C, and pressure is 350KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and dme extraction from reactor, pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower; Methyl alcohol enters into return tank through condensation, further joins in reactor and participates in and react through gasification; A small amount of hydrogenchloride and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging as factory effluent after neutralizing treatment.
In step (1), the mass ratio of alcoholic hydrochloric acid and methyl alcohol add-on is 1:1.
After testing, the purity that makes monochloro methane is 99.95%, is 99.2% containing hydrogenchloride transformation efficiency in alkyd.
Claims (6)
1. utilize alcoholic hydrochloric acid to prepare a method for methyl chloride, it is characterized in that, comprise the following steps:
(1) alcoholic hydrochloric acid is joined in reactor; Methyl alcohol is vaporized, also join in reactor, the control 80-90% of gasified methanol and the alcoholic hydrochloric acid of liquid phase carry out the first step and react; The 10-20% of gasified methanol enters the upper strata of reactor, forms reaction zone, the second stage;
(2) reactor is heated, the temperature of controlling first step reaction is 115-170 DEG C, and pressure is 240-500KPa, keeps liquid composition and level stability in reactor, continues charging, and the hcl reaction in methyl alcohol and liquid phase generates monochloro methane;
(3) monochloro methane generating in step (2), and unreacted hydrogenchloride, methyl alcohol are constantly distilled out of, the gaseous mixture steaming enters into reaction zone, the second stage, unreacted hydrogenchloride further reacts with methanol mixed, the temperature of controlling second stage reaction is 110-125 DEG C, and pressure is 210-450KPa;
(4) by the mixed gas that contains monochloro methane, hydrogenchloride, methyl alcohol, water and the dme extraction from reactor generating in step (3), pass into rectifying tower, through separation and purification, from the pure monochloro methane of the top extraction of rectifying tower;
Wherein, in step (1), the mass ratio of alcoholic hydrochloric acid and methyl alcohol add-on is 1:(1~2).
2. a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride as claimed in claim 1, is characterized in that, in step (2), temperature of reaction is 130-160 DEG C, and pressure is 300-450KPa.
3. a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride as claimed in claim 1, is characterized in that, in step (1), (2), described reactor is tower staged reactor.
4. a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride as claimed in claim 1, is characterized in that, in step (4), the methyl alcohol in mixed gas enters into return tank through condensation, further joins in reactor and participates in and react through gasification.
5. a kind of method of utilizing alcoholic hydrochloric acid to prepare methyl chloride as claimed in claim 1, it is characterized in that, in step (4), a small amount of hydrogenchloride in mixed gas and water form the hydrochloric acid waste water of lower concentration at the bottom of rectifying tower, carry out discharging after neutralizing treatment.
6. a device that utilizes alcoholic hydrochloric acid to prepare methyl chloride, it is characterized in that, comprise staged reactor and rectifying tower, described staged reactor is connected with vaporizer with heat exchanger respectively, the top of staged reactor is connected with condenser, and the other end of condenser is connected with rectifying tower; The top of described rectifying tower is connected with condenser, and the other end of condenser is connected with return tank, and described return tank is connected with vaporizer with rectifying tower respectively; The bottom of described rectifying tower is connected with reboiler.
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Cited By (8)
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CN106748632A (en) * | 2017-01-10 | 2017-05-31 | 南通科恩化工技术有限公司 | A kind of clean preparation method for synthesizing chloromethanes |
CN106748631A (en) * | 2016-12-15 | 2017-05-31 | 湖北兴瑞化工有限公司 | A kind of monochloro methane energy-saving processing technique and device |
CN108409526A (en) * | 2018-03-09 | 2018-08-17 | 中国化学赛鼎宁波工程有限公司 | A kind of monochloro methane production energy-saving system and method |
CN105985217B (en) * | 2015-02-04 | 2018-11-02 | 山东东岳有机硅材料股份有限公司 | Reaction system and its application of reactant utilization rate are improved in a kind of production of chloromethanes |
CN110862296A (en) * | 2019-11-05 | 2020-03-06 | 天津大学 | Method for separating reaction product in chloromethane production process |
CN111606776A (en) * | 2019-02-26 | 2020-09-01 | 四川晨光工程设计院有限公司 | Clean production process for synthesizing methane chloride by liquid-phase catalyst-free synthesis |
CN113582811A (en) * | 2020-04-30 | 2021-11-02 | 蓝星(北京)技术中心有限公司 | Deacidification method of methane chloride |
CN113828001A (en) * | 2021-10-29 | 2021-12-24 | 新疆晶硕新材料有限公司 | Separation system and separation method of chloromethane |
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Cited By (12)
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CN105985217B (en) * | 2015-02-04 | 2018-11-02 | 山东东岳有机硅材料股份有限公司 | Reaction system and its application of reactant utilization rate are improved in a kind of production of chloromethanes |
CN106748631A (en) * | 2016-12-15 | 2017-05-31 | 湖北兴瑞化工有限公司 | A kind of monochloro methane energy-saving processing technique and device |
CN106748632A (en) * | 2017-01-10 | 2017-05-31 | 南通科恩化工技术有限公司 | A kind of clean preparation method for synthesizing chloromethanes |
CN106748632B (en) * | 2017-01-10 | 2019-05-10 | 南通科恩化工技术有限公司 | A kind of clean preparation method synthesizing chloromethanes |
CN108409526A (en) * | 2018-03-09 | 2018-08-17 | 中国化学赛鼎宁波工程有限公司 | A kind of monochloro methane production energy-saving system and method |
CN108409526B (en) * | 2018-03-09 | 2020-11-20 | 中国化学赛鼎宁波工程有限公司 | Methane chloride energy-saving production system and method |
CN111606776A (en) * | 2019-02-26 | 2020-09-01 | 四川晨光工程设计院有限公司 | Clean production process for synthesizing methane chloride by liquid-phase catalyst-free synthesis |
CN110862296A (en) * | 2019-11-05 | 2020-03-06 | 天津大学 | Method for separating reaction product in chloromethane production process |
CN110862296B (en) * | 2019-11-05 | 2022-05-10 | 天津大学 | Method for separating reaction product in chloromethane production process |
CN113582811A (en) * | 2020-04-30 | 2021-11-02 | 蓝星(北京)技术中心有限公司 | Deacidification method of methane chloride |
CN113828001A (en) * | 2021-10-29 | 2021-12-24 | 新疆晶硕新材料有限公司 | Separation system and separation method of chloromethane |
CN113828001B (en) * | 2021-10-29 | 2022-10-11 | 新疆晶硕新材料有限公司 | Separation system and separation method of chloromethane |
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