Claims
- 1. A method of pyrolytically decomposing a plastic material, comprising the steps of:heating the plastic material at approximately 270 to 350° C., whereby a plasticizer contained in the plastic material is decomposed into a decomposition matter which is vaporized, and a chlorine-containing polymer contained in the plastic material is dechlorinated to produce a dechlorinated matter and hydrogen chloride; removing the vaporized decomposition matter and the hydrogen chloride, from the plastic material heated at the heating step; separating the vaporized decomposition matter from the hydrogen chloride by cooling the vaporized decomposition matter with a cooling oil which absorbs the decomposition matter and condensing the vaporized decomposition matter; and pyrolytrically decomposing the plastic material after the removing step, by heating the plastic material at approximately 450° C. or a temperature higher than 450° C. to produce a pyrolysis product.
- 2. The pyrolytic decomposition method of claim 1, wherein the plasticizer includes a phthalic ester which is selected from the group consisting of di(2-ethylhexyl) phthalate, dibutyl phthalate, diheptyl phthalate, di(isodecyl) phthalate and di(isononyl) phthalate.
- 3. The pyrolytic decomposition method of claim 1, wherein the plasticizer includes a phthalic ester which is selected from the group consisting of di(2-ethylhexyl) isophthalate, di(n-octyl) phthalate, dinonyl phthalate, dilauryl phthalate, butyl lauryl phthalate, butyl benzyl phthalate, dihydroabietyl phthalate, di(butoxyethyl) phthalate, di(2-methoxyethyl) phthalate, dicapryl phthalate, di(ethoxyethyl) phthalate, di(2-ethylbutyl) phthalate, diethyl phthalate, di(isoamyl) phthalate, di(isobutyl) phthalate, di(isooctyl) phthalate, di(isooctyl) isophthalate, di(methylcyclohexyl) phthalate, dimethylisobutylcarbinyl phthalate, dimethyl isophthalate, n-octyl, n-decyl phthalate, diphenyl phthalate, dipropyl phthalate and ditetrahydrofurfuryl phthalate.
- 4. The pyrolytic decomposition method of claim 1, wherein the chlorine-containing polymer includes a polymer selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, polyvinylidene chloride-polyvinyl chloride copolymer, chlorinated polyether, chlorinated polyvinyl chloride and chlorinated polyolefin which includes chlorinated polyethylene and chlorinated polypropylene.
- 5. The pyrolytic decomposition method of claim 1, wherein the removing step comprises:reducing the pressure of the atmosphere surrounding the plastic material so that the vaporized decomposition matter and the hydrogen chloride are biased to move out of the heated plastic material.
- 6. The pyrolytic decomposition method of claim 1, wherein the removing step comprises:carrying away the vaporized decomposition matter and the hydrogen chloride from the heated plastic material with a non-oxidizing carrier gas flow to the heated plastic material.
- 7. The pyrolytic decomposition method of claim 1, further comprising:contacting the hydrogen chloride separated at the separating step with water to recover the hydrogen chloride as hydrochloric acid.
- 8. A method of pyrolytically decomposing a plastic material, comprising the steps of:heating the plastic material at approximately 270 to 350° C. whereby a plasticizer, including an ester compound and contained in the plastic material, is decomposed into a decomposition matter which is vaporized, and a chlorine-containing polymer contained in the plastic material is dechlorinated to produce a dechlorinated matter and hydrogen chloride; removing the vaporized decomposition matter and the hydrogen chloride, from the heated plastic material; separating the vaporized decomposition matter and the hydrogen chloride by cooling the vaporized decomposition matter with a cooling oil which absorbs the decomposition matter, and condensing the vaporized decomposition matter; and pyrolytically decomposing the plastic material after removal of the vaporized decomposition matter and the hydrogen chloride, by heating the plastic material at approximately 450° C. or a temperature higher than 450° C. to produce a pyrolysis product.
Priority Claims (10)
Number |
Date |
Country |
Kind |
P03-338183 |
Dec 1991 |
JP |
|
P04-033814 |
Feb 1992 |
JP |
|
P04-035334 |
Feb 1992 |
JP |
|
P04-275763 |
Oct 1992 |
JP |
|
P05-227589 |
Sep 1993 |
JP |
|
P05-227596 |
Sep 1993 |
JP |
|
P05-229311 |
Sep 1993 |
JP |
|
P05-336905 |
Dec 1993 |
JP |
|
P08-59680 |
Mar 1996 |
JP |
|
P08-59682 |
Mar 1996 |
JP |
|
Parent Case Info
This application is a continuation-in-part application from U.S. patent application No. 08/725,926 filed on Oct. 4, 1996, which is now abandoned and which is a continuation application of U.S. patent application No. 08/282,185 filed on Jun. 20, 1994, which is now U.S. Pat. No. 5,605,136, which is a continuation-in-part application of U.S. patent application No. 07/992,761 filed on Dec. 18, 1992, which is now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (4)
Number |
Date |
Country |
48-43482 |
Jun 1973 |
JP |
49-21479 |
Feb 1974 |
JP |
58-209998 |
Dec 1982 |
JP |
58-172322 |
Oct 1983 |
JP |
Continuations (1)
|
Number |
Date |
Country |
Parent |
08/262185 |
Jun 1994 |
US |
Child |
08/725926 |
|
US |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
08/725926 |
Oct 1996 |
US |
Child |
09/033921 |
|
US |
Parent |
07/992761 |
Dec 1992 |
US |
Child |
08/262185 |
|
US |