# Has pyrolysis been proven for removing wire insulation? **URL:** \ **Category:** Factual Questions\ **Created:** [February 9, 2020, 4:42am UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664 "2020-02-09T04:42:02Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Yakamaniac](https://avatars.discourse-cdn.com/v4/letter/y/a5b964/32.png) [@Yakamaniac](https://boards.straightdope.com/u/Yakamaniac)\ **Post date:** [February 9, 2020, 4:42am UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/1 "2020-02-09T04:42:02Z")
There are very large amounts of copper tied up in wiring which is not in use or surplus, but this copper is sheathed in plastic and/or rubber, which is very difficult to remove manually. Burning generates hazardous gases, so I was wondering if an effective and efficient pyrolysis process has ever been developed for removing wire insulation? I live near a site that was proposed for the pyrolytic processing of old tires, and the backers assured the locals that the process would not be environmentally hazardous. Given the value of copper, the energy costs of pyrolysis might be acceptable. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [February 9, 2020, 1:58pm UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/2 "2020-02-09T13:58:27Z")
There are two common methods for stripping insulation for recycling. One is a chipper-type [machine](https://youtu.be/qgyrTbWzX7M) that chops it all up into small pieces and automatically sorts out the copper. For really long pieces, there are stripper [machines](https://youtu.be/3EQJl1iH5Tc) that can handle a variety of gauges. Burning would be a waste of fuel compared to those, not to mention cleaning the waste fumes. If you browse around YouTube for lessons on recycling copper, some will tell you to _not_ try burning off the insulation as some scrap dealers refuse to take that. (Dealers grade wire based on the thickness of the copper, relative proportion of insulation, etc. The better the grade the more you get per pound.) ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [February 9, 2020, 2:37pm UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/3 "2020-02-09T14:37:28Z")
I’m not aware of anything, chemically, to prevent a pyrolytic or combustion (not the same thing) process. It just comes down to economics. This was the first journal article I stumbled on: > **[Low Temperature Pyrolysis for Valuable Resources Recovery from Waste Wire...](http://www.koreascience.or.kr/article/JAKO200910103432575.page)** > > 본 연구에서는 기존 소각방법의 단점을 보완할 수 있는 열분해를 통해 폐전선을 처리하고 부가적으로 생성되는 구리 및 합성연료유의 회수를 그 목적으로 하고 있다. 폐전선의 열분해 공정을 거쳐 구리를 회수하고 쉽게 오일로 분해될 뿐 아니라 오일의 유용성이 매우 크기 때문에 아주 고가의 유효자원을 회수할 수 있다. 폐전선 열분해를 위한 최적 온도를 결정하기 위하여 350, 450, \$550^{\\circ}C$\에서 열분해를 실행하였다.... ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [February 9, 2020, 3:02pm UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/4 "2020-02-09T15:02:50Z")
Pyrolysis of most carbon based things produces compounds that are very environmentally unfriendly. Compounds like Benzene, phenols, and in the case of PVC (wire insulation) will have chlorinated compounds. So apart from using all the energy for pyrolysis, there is the added capital investment and operating costs of gas cleanup. It wouldn’t be economically feasible in the US, but countries with lax environmental laws may allow it. Combustion again will require investment in flue gas treatment because like most plastics, you will get dioxin in the combustion products. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [February 9, 2020, 6:10pm UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/5 "2020-02-09T18:10:47Z")
> [@ftg](#): > > (Dealers grade wire based on the thickness of the copper, relative proportion of insulation, etc. The better the grade the more you get per pound.) At the top of the pricing charts is what’s called ‘bare bright.’ Not surprisingly, that’s clean, unoxidized, shiny Cu. ---
**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\ **Post date:** [February 9, 2020, 6:31pm UTC](https://boards.straightdope.com/t/has-pyrolysis-been-proven-for-removing-wire-insulation/847664/6 "2020-02-09T18:31:20Z")
I used to strip wires with a formic acid goo which worked a treat, but I don’t know if this would be economical or safe for large amounts of wire.