The method of the thick product purification of a kind of methane chloride
Technical field
The present invention relates to a kind of preparation method of methane chloride, the method for the thick product purification of particularly a kind of methane chloride.
Background technology
The thick product of traditional methane chloride is earlier through alkali cleaning deacidification part, again through dehydration, final refining goes out qualified methylene dichloride, chloroform and tetracol phenixin product or the first rectifying of thick product obtains the qualified methylene dichloride of purity, chloroform and tetracol phenixin product, and methylene dichloride, chloroform and tetracol phenixin product obtain qualified product through alkali cleaning deacidification and dehydration respectively again.The waste water that alkali cleaning produces is removed methane chloride through stripping tower, again waste water is carried out neutralizing treatment, this technology alkali cleaning, dewatering system running cost height, and equipment corrosion is serious, and the difficulty of environment protection standard is big, and wastewater flow rate is many, the energy consumption height.
The patent application CN1686980 of Meilan Chemical Co., Ltd., Jiangsu discloses the easier method for preparing methane chloride from methane chloride through heat chlorination of a kind of relative traditional technology.Raw material monochloro methane, carrier gas enter reactor with chlorine after mixing, under the high temperature about 380-440 ℃, react, the high-temperature gas that reflects is through Quench, condensation, separation, isolate hydrogenchloride and thick chlorated liquid, the hydrogenchloride circulation removes to produce methane chloride, and the thick chlorated liquid of collecting is sent to distillation workshop section and makes with extra care.The relative traditional technology of this technology, mainly be to need not to remove the acid that reaction member comes out and collect thick muriate by washing, caustic washing method, but adopt condensation method to collect thick muriate, remove the unitary washing of chlorination reaction, alkaline cleaning procedure, do not related to the deacidification technology of product stage of rectification.
Summary of the invention
The objective of the invention is at the deficiencies in the prior art, provide the thick product of a kind of methane chloride, directly the method for rectifying without alkali cleaning, dehydration.
The method of the thick product purification of a kind of methane chloride, it is characterized in that containing the thick product of methane chloride of small amount of acid part in treating process, the directly rectifying of thick product without alkali cleaning and dehydration, system's cumulative acid part is returned chlorination system by cat head in the rectifying, the product of rectifying extraction is handled by solid caustic soda, guarantees product quality.
The method of the thick product purification of described a kind of methane chloride, the methylene dichloride that it is characterized in that circulating is more than 10% of methylene dichloride product volume, the circulation chloroform is more than 5% of chloroform product volume.Prevent that acid part from accumulating at the methylene dichloride cat head, guarantee quality product and avoid equipment corrosion, when producing a high proportion of chloroform, need to add methylene chloride toward reactor, at this moment, the methylene dichloride of the extraction of methylene dichloride tower is back to reactor, helps improving the product ratio of chloroform, and do not increase the load and the energy consumption of distillation system, so this technology is particularly suitable on the methane chloride production equipment of high chloroform ratio.
The method of the thick product purification of described a kind of methane chloride is characterized in that said thick product rectifying, both can the rectifying of normal pressure temperature, also can compression rectification, and temperature is controlled at 40~130 ℃, and pressure-controlling is at 0~0.25MPaG.
The method of the thick product purification of described a kind of methane chloride is characterized in that a spot of acid part methylene dichloride that contains of rectifying tower top, and chloroform both can loop back chlorination reactor, also can be back to the monochloro methane recovery tower of chlorination system.
The method cancellation caustic washing system and the dewatering system of the thick product purification of a kind of methane chloride provided by the invention have reduced alkaline consumption, water consumption and power consumption; This method has also been cancelled waste water stripping system and Waste Water Treatment, has reduced discharge of wastewater.Not only simplify technological process, simple to operate, reduce investment and raw material consumption, and reduce equipment scaling and corrosion, product quality does not reduce yet.
Description of drawings
Accompanying drawing is the process flow diagram of the thick product purification method of methane chloride provided by the invention.
In the accompanying drawings,
1Be chlorination reactor,
2Be hydrogenchloride/monochloro methane recovery tower,
3Be thick product groove,
4Be the methylene dichloride tower,
5Be the solid caustic soda treater,
6Be the chloroform tower,
7Be the solid caustic soda treater.
Embodiment
Below in conjunction with description of drawings technical process of the present invention and embodiment:
As shown in drawings, chlorine, chlorination catalyst and monochloro methane enter chlorination reactor
1React.Chlorination reactor
1The crude product mixture that comes out is through hydrogenchloride/monochloro methane recovery tower
2, with hydrogenchloride/monochloro methane from hydrogenchloride/monochloro methane recovery tower
2Recovered overhead.Hydrogenchloride/monochloro methane tower
2Thick product discharging enters thick product groove at the bottom of the tower
3, thick product directly enters the methylene dichloride tower without alkali cleaning and washing
4, can atmospheric distillation, also can compression rectification, temperature is controlled at 40~130 ℃, pressure-controlling 0~0.25MPaG.The methylene dichloride tower
4The a spot of acid part methylene dichloride that contains of cat head both can loop back chlorination reactor
1, also can be back to the hydrogenchloride/monochloro methane recovery tower of chlorination system
2, the circulation methylene dichloride is more than 10% of methylene dichloride product volume, the methylene dichloride product is from the methylene dichloride tower simultaneously
4The side line extraction is again through the solid caustic soda treater
5After obtain the methylene dichloride product of excellent product quality.The methylene dichloride tower
4Discharging enters the chloroform tower at the bottom of the tower
6, similarly can the rectifying of normal pressure temperature, also can compression rectification, temperature is controlled at 40~130 ℃, pressure-controlling 0~0.25MPaG.The chloroform tower
6Cat head in a small amount contain hydrogenchloride/monochloro methane recovery tower that acid part chloroform is back to chlorination system
2, the circulation chloroform is more than 5% of chloroform product volume, the chloroform product is from the chloroform tower simultaneously
6The side line extraction is again through the solid caustic soda treater
7After obtain the chloroform product of excellent product quality.Last chloroform tower
6Discharging is the tetracol phenixin raffinate at the bottom of the tower.
Following embodiment further specifies of the present invention, but the present invention is not limited to this.
Embodiment:
Thick product is without alkali cleaning, directly rectifying, and 40~130 ℃ of temperature controls, pressure-controlling 0~0.25MPaG, the acid of system's cumulative part is returned the chlorination reaction unit by cat head and is taken away rectifying tower in the rectifying
4,
6The methylene dichloride of extraction, chloroform product are by the solid caustic soda treater
7, product quality does not reduce, and reduces waste water, energy efficient.
Detected result is as follows:
Thick product feed rate: 7.506 tons/hour.
Thick product feed composition: methylene dichloride: 43.06%, chloroform: 50.17%, tetracol phenixin etc.: 6.77%.
Methylene dichloride product: flow: 2.85 tons/hour, purity: 99.99%, acid part: do not detect.
Chloroform product: flow: 3.51 tons/hour, purity: 99.99%, acid part: do not detect.
Methylene dichloride cat head extraction (looping back the chlorination reaction unit): flow: 285 liters/hour, acid part: 53ppm.
Chloroform cat head extraction (looping back the chlorination reaction unit): flow: 170 liters/hour, acid part: 27ppm.