Method for recycling polyvinyl chloride or polyvinylidene chloride plastic

A polyvinyl chloride and plastic technology, applied in plastic recycling, recycling technology, production of bulk chemicals, etc., can solve the problems of solvent residue and high energy consumption, and achieve the effects of easy separation, low energy consumption and simple process

Inactive Publication Date: 2011-09-21
ZHEJIANG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this step is usually energy-intensive and does not necessarily result in the proper particle shape and size of the polymer particles, which often have significant solvent residues in them

Method used

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  • Method for recycling polyvinyl chloride or polyvinylidene chloride plastic

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] 1. Prepare 50kg of a solution containing 80% methyl ethyl ketone and 20% n-hexane (mass ratio), pour it into a stirred tank, and heat it to 110°C.

[0030] 2. Under the condition of pressure of 0.3Mpa and temperature of 110℃, add 5kg of PVC to make it dissolve within 10 minutes.

[0031] 3. Keep the temperature of the solution not lower than 75°C, filter to remove insoluble matter, and send the filtrate to the precipitation reactor.

[0032] 4. Use continuous operation mode for supercritical fluid extraction. The filtrate is sprayed down from the top of the reactor into the reactor through the nozzle, supercritical carbon dioxide is introduced from the bottom and then contacts the filtrate countercurrently, the solvent is quickly extracted and the entrained solvent leaves the reactor from the top, and solid PVC particles are enriched at the bottom of the reactor . The extraction process lasted 20 minutes. After the extraction is finished, continue to pass through sup...

Embodiment 2

[0036] 1. Prepare 100 kg of a solution comprising 85% methyl ethyl ketone and 15% n-hexane (mass ratio), pour it into a stirred tank, and heat it to 115° C.

[0037] 2. Under the conditions of pressure 10Mpa and temperature 115℃, add 10kg PVC to dissolve within 15 minutes.

[0038] 3. Keep the temperature of the solution not lower than 75°C, filter to remove insoluble matter, and send the filtrate to the precipitation reactor.

[0039] 4. Use batch operation mode for supercritical fluid extraction. All the filtrate is poured into the precipitation reactor, supercritical methane is introduced from the bottom and then contacts with the filtrate, the solvent is quickly extracted and the entrained solvent leaves the reactor from the top, and solid PVC particles are enriched at the bottom of the reactor. The extraction process lasted 40 minutes. After the extraction, continue to pass through supercritical methane to dry the organic solvent remaining on the deposited particles. T...

Embodiment 3

[0043] 1. Pour 10kg of tetrahydrofuran solution into a stirred tank and heat to 100°C.

[0044] 2. Under the conditions of pressure 0.5Mpa and temperature 100℃, add 1.5kg PVC to dissolve within 10 minutes.

[0045] 3. Keep the temperature of the solution not lower than 75°C, filter to remove insoluble matter, and send the filtrate to the precipitation reactor.

[0046] 4. Use batch operation mode for supercritical fluid extraction. All the filtrate is poured into the precipitation reactor, supercritical ethylene is introduced from the top and then contacts the filtrate, the solvent is quickly extracted and the entrained solvent leaves the reactor from the top, and solid PVC particles are enriched at the bottom of the reactor. The extraction process lasted 30 minutes. After the extraction is completed, continue to pass through supercritical ethylene to dry the organic solvent remaining on the deposited particles. This drying process lasted 40 minutes.

[0047] 5. Ethylene f...

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Abstract

The invention discloses a method for reclaiming polyvinyl chloride (PVC) or PVDC plastics. The supercritical anti-solvent technology is used to reclaim PVC or PVDC plastic products; the shivers of the plastic products are dissolved in the solvent and the undissolved substances are filtered and removed; then supercritical fluid is made to contact with the filtrate, and the polymer precipitation inthe solution is dissolved; the solvent is extracted, and the supercritical fluid and solvent are reclaimed separately and recycled; and finally, the polymer particles are reclaimed. The solvent and the supercritical fluid achieved by the method can be recycled, and are pollution-free and environment friendly; the polymers can be precipitated and dried in a same reactor, and the process is very simple; the supercritical fluid and the solvent can be separated easily, and the energy consumption is low.

Description

technical field [0001] The invention relates to a method for recycling plastics, in particular to a method for recycling polyvinyl chloride or polyvinylidene chloride plastics. Background technique [0002] Polyvinyl chloride (PVC) is widely used in the production of soft plastic products such as artificial leather, films, and wire sheaths, as well as hard plastic products such as plates, doors and windows, pipes, and valves. However, the recycling rate of PVC waste plastics is still very low, which has caused great pollution to the environment. The recycling methods of PVC include mechanical method, chemical method, solvent method, incineration method, direct burial method and so on. Pure PVC can be obtained by mechanical methods such as crushing, screening, electrostatic separation, and density separation. A variety of PVC products including pipes, cables, sheets, films, automotive components and bottles can be recycled mechanically. The chemical method is that PVC debr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J11/08C08L27/06C08L27/08
CPCY02P20/54Y02W30/62
Inventor 阳永荣黄正梁蒋斌波王靖岱
Owner ZHEJIANG UNIV
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