Chlorinated paraffin production tail gas absorption treatment device

Abstract

The utility model relates to a chlorinated paraffin production tail gas absorption treatment device in the field of chemical tail gas treatment. The chlorinated paraffin production tail gas absorption treatment device comprises a chlorination reaction main kettle, an auxiliary kettle I and an auxiliary kettle II, a first-stage graphite absorption tower, a dichlorine kettle, a second-stage graphite absorption tower, a monochlorine kettle and a third-stage graphite absorption tower are sequentially connected in series at the downstream of the secondary kettle II, and a diluted hydrochloric acid circulating tank for supplying circulating spray liquid is arranged outside the graphite absorption towers and is also used for receiving a hydrochloric acid solution generated by absorbing hydrogen chloride in tail gas; the downstream of the graphite absorption tower is sequentially connected with a packing absorption tower and an alkali absorption tower, an alkali circulating tank for supplying sodium hydroxide circulating spray liquid is arranged outside the alkali absorption tower, an emptying port is formed in the top of the alkali absorption tower, a liquid outlet of a sodium hypochlorite solution is formed in the bottom of the alkali circulating tank, a dilute acid tank is arranged on the outer side of the acid circulating tank, and a circulating water replenishing port is formed in the dilute acid tank. The device can recycle chlorine and hydrogen chloride in the tail gas, and the tail gas absorption treatment and purification effect is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical tail gas treatment, and in particular relates to a tail gas absorption treatment device for chlorinated paraffin production. Background Art

[0002] Chlorinated paraffin is a chlorinated derivative of paraffin hydrocarbons. It has the advantages of low volatility, flame retardancy, good electrical insulation, and low price. It can be used as a flame retardant and auxiliary plasticizer for polyvinyl chloride, and is widely used in the production of cable materials, flooring materials, hoses, artificial leather, rubber and other products. Chlorinated paraffin is mainly produced by the chlorination reaction of liquid paraffin and chlorine in a reactor. The exhaust gas discharged from the chlorination reactor still contains unreacted chlorine and hydrogen chloride gas produced by the reaction. Due to safety and environmental protection requirements, this exhaust gas is not allowed to be discharged directly into the atmosphere. It must undergo exhaust gas absorption treatment until it meets emission standards before it can be emptied. At the same time, chlorine and hydrogen chloride gases are also valuable chemical raw materials. If they are not properly recycled and utilized, it will cause certain economic losses. The absorption efficiency of existing chlorinated paraffin exhaust gas treatment equipment is relatively low, which in turn has a certain impact on the production efficiency of chlorinated paraffin. Efficiency upgrades and technical transformations are urgently needed. Utility Model Content

[0003] In view of the above situation, the utility model provides a chlorinated paraffin production tail gas absorption treatment device, which can better recycle the chlorine and hydrogen chloride gases in the tail gas through technical upgrading and transformation.

[0004] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0005] A chlorinated paraffin production tail gas absorption and treatment device includes a main kettle for performing a chlorination reaction between liquid paraffin and chlorine, and a secondary kettle 1 and a secondary kettle 2 for recycling the chlorine in the tail gas discharged from the main kettle for further chlorination reaction. The top of the main kettle is provided with an exhaust port for discharging the tail gas in the kettle. The secondary kettle 1 and the secondary kettle 2 are sequentially connected in series downstream of the exhaust port of the main kettle. The exhaust port of the main kettle is connected to the air inlet of the secondary kettle 1, and the air outlet of the secondary kettle 1 is connected to the air inlet of the secondary kettle 2. A first-stage graphite absorption tower, a dichlorine kettle, a second-stage graphite absorption tower, a chlorine kettle, and a third-stage graphite absorption tower are sequentially connected in series downstream of the air outlet of the secondary kettle 2. The outside of the three-stage graphite absorption tower is equipped with an acid circulation tank for providing circulating spray liquid for the three-stage graphite absorption tower, and is also used to receive the hydrochloric acid solution generated by the three-stage graphite absorption tower absorbing hydrogen chloride in the tail gas. The monochlorine kettle is used to re-chlorinate and absorb the second and third-stage graphite absorption towers. The dichlorine kettle is used to re-chlorinate and absorb the chlorine in the middle tail gas of the first and second-stage graphite absorption towers. The downstream of the gas outlet of the third-stage graphite absorption tower is connected in sequence with a packed absorption tower and an alkali absorption tower. The top of the alkali absorption tower is provided with an exhaust port for finally discharging the purified tail gas that meets the standards after absorption treatment into the outside air.

[0006] Furthermore, in order to improve the production efficiency of chlorinated paraffin, the main kettle can be a plurality of main kettles connected in parallel, and the exhaust port of each main kettle is connected to the air inlet of the auxiliary kettle.

[0007] Furthermore, in order to ensure that the final exhaust gas is purified to meet the standards, the packed absorption tower may also be a plurality of packed absorption towers connected in series.

[0008] Furthermore, an alkali circulation tank containing sodium hydroxide solution is provided on the outside of the alkali absorption tower to provide circulating spray liquid for the alkali absorption tower. A drain port is provided at the bottom of the alkali circulation tank to discharge sodium hypochlorite solution generated after the sodium hydroxide solution circulates and absorbs chlorine.

[0009] Furthermore, a dilute acid tank is provided outside the acid circulation tank for providing circulating spray liquid for the packed absorption tower, and is also used to provide hydrochloric acid dilution water for the acid circulation tank. A circulating water replenishment port is provided on the dilute acid tank. The hydrochloric acid solution formed by absorbing hydrogen chloride will become higher and higher, and finally form concentrated hydrochloric acid.

[0010] The present invention also includes other components that enable it to be used normally, which are all conventional means in the field. In addition, the devices or components not limited in the present invention, such as: graphite absorption tower, filler absorption tower, alkali absorption tower, etc., all adopt the existing technology in the field.

[0011] The beneficial effects of the utility model are as follows:

[0012] The utility model provides a chlorinated paraffin production tail gas absorption and treatment device, which, through technical upgrading and transformation, better recycles chlorine and hydrogen chloride gases in the tail gas, improves the absorption and treatment effect of the chlorinated paraffin production tail gas, can better meet safety and environmental protection requirements, and at the same time saves chlorine raw material consumption and generates hydrochloric acid by-product income, which is conducive to improving the overall economic benefits of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of the chlorinated paraffin production tail gas absorption treatment device in the embodiment. DETAILED DESCRIPTION

[0014] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0015] Example

[0016] like Figure 1 As shown, a chlorinated paraffin production tail gas absorption and treatment device includes a main kettle 1 for chlorination reaction of liquid paraffin and chlorine, and a sub-kettle 1 2 and a sub-kettle 2 3 for recycling chlorine in the tail gas discharged from the main kettle for chlorination reaction. An exhaust port for discharging the tail gas in the kettle is provided on the top of the main kettle, and the sub-kettle 1 and the sub-kettle 2 are connected in series downstream of the exhaust port of the main kettle. The exhaust port of the main kettle is connected to the air inlet of the sub-kettle 1, and the air outlet of the sub-kettle 1 is connected to the air inlet of the sub-kettle 2.

[0017] Downstream of the gas outlet of the secondary still, a first-stage graphite absorption tower 4, a dichloro reactor 5, a second-stage graphite absorption tower 6, a monochloro reactor 7, and a third-stage graphite absorption tower 8 are connected in series in sequence. An acid circulation tank 9 is provided on the outside of the third-stage graphite absorption tower for providing circulating spray liquid for the third-stage graphite absorption tower and for receiving the hydrochloric acid solution generated by the third-stage graphite absorption tower absorbing hydrogen chloride in the tail gas. An acid circulation pump (not shown) is provided on the circulating spray liquid supply pipeline connected to the acid circulation tank to each graphite absorption tower. Because hydrogen chloride gas is highly soluble in water, after three cycles of spray absorption in the third-stage graphite absorption tower, the hydrogen chloride gas in the tail gas is basically completely absorbed. The monochloro reactor and the dichloro reactor contain liquid paraffin. The monochloro reactor is used for re-chlorination reaction absorption of the second and third-stage graphite absorption towers, and the dichloro reactor is used for re-chlorination reaction absorption of chlorine gas in the tail gas between the first and second-stage graphite absorption towers.

[0018] The gas outlet of the third-stage graphite absorption tower is connected to the packing absorption tower 10 and the alkali absorption tower 11 in sequence downstream. The top of the alkali absorption tower is provided with an exhaust port for finally discharging the purified exhaust gas that meets the standards after absorption treatment into the outside air.

[0019] In order to improve the production efficiency of chlorinated paraffin, the main kettle adopts 1#-7# main kettles connected in parallel, and the exhaust port of each main kettle is connected to the air inlet of the auxiliary kettle.

[0020] In order to ensure that the final exhaust gas is purified to meet the standards, the packed absorption tower adopts a two-stage packed absorption tower connected in series.

[0021] The outer side of the alkali absorption tower is equipped with an alkali circulation tank 12 containing sodium hydroxide solution, which is used to provide circulating spray liquid for the alkali absorption tower. The alkali circulation tank pumps the circulating spray liquid to the alkali absorption tower through an alkali circulation pump (not shown in the figure). A drain port is provided at the bottom of the alkali circulation tank for discharging sodium hypochlorite solution generated after the sodium hydroxide solution absorbs chlorine gas in a circulating manner, and transporting it to a sodium hypochlorite storage tank as a by-product of chlorinated paraffin production.

[0022] A dilute acid tank 13 is also provided outside the acid circulation tank for providing circulating spray liquid for the packed absorption tower, and is also used to provide hydrochloric acid dilution water for the acid circulation tank. A circulating water replenishment port is provided on the dilute acid tank. The hydrochloric acid solution formed by the circulating absorption of hydrogen chloride by the three-stage graphite circulation tower will become higher and higher. The concentrated hydrochloric acid finally generated can be transported to the hydrochloric acid storage tank as a by-product of chlorinated paraffin production.

[0023] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to ordinary technicians in this technical field. Any technical deformation made within the spirit and principles of the present invention falls within the scope of protection of the present invention.

Claims

1. A chlorinated paraffin production tail gas absorption and treatment device, comprising a main kettle for chlorination of liquid paraffin and chlorine, with an exhaust port provided on the top of the main kettle for discharging the tail gas in the kettle, characterized in that: The invention also includes a sub-reactor 1 and a sub-reactor 2 for recycling the chlorine in the tail gas discharged from the main reactor for chlorination reaction. The sub-reactor 1 and the sub-reactor 2 are connected in series downstream of the exhaust port of the main reactor. The first-stage graphite absorption tower, the dichlorine reactor, the second-stage graphite absorption tower, the monochlorine reactor and the third-stage graphite absorption tower are connected in sequence downstream of the gas outlet of the sub-reactor 2. The outer side of the third-stage graphite absorption tower is provided with an acid circulation tank for providing circulating spray liquid for the third-stage graphite absorption tower, and is also used to receive the hydrochloric acid solution generated by the third-stage graphite absorption tower absorbing hydrogen chloride in the tail gas. The packing absorption tower and the alkali absorption tower are connected in sequence downstream of the gas outlet of the third-stage graphite absorption tower, and an emptying port is provided on the top of the alkali absorption tower.

2. A chlorinated paraffin production tail gas absorption treatment device according to claim 1, characterized in that: The outer side of the alkali absorption tower is equipped with an alkali circulation tank containing sodium hydroxide solution, which is used to provide circulating spray liquid for the alkali absorption tower. The bottom of the alkali circulation tank is provided with a drain port, which is used to discharge the sodium hypochlorite solution generated after the sodium hydroxide solution circulates and absorbs chlorine.

3. A chlorinated paraffin production tail gas absorption treatment device according to claim 1, characterized in that: A dilute acid tank is also provided outside the acid circulation tank for providing circulating spray liquid for the packed absorption tower and also for providing hydrochloric acid dilution water for the acid circulation tank. A circulating water replenishment port is provided on the dilute acid tank.

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