# Tar Cracking device

**URL:** http://forum.driveonwood.com/t/tar-cracking-device/4296
**Category:** Projects
**Created:** [January 4, 2019, 10:45am UTC](http://forum.driveonwood.com/t/tar-cracking-device/4296 "2019-01-04T10:45:22Z")
**Posts on this page:** 1
**Showing post:** 19

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### Author: ![Grimm](https://avatars.discourse-cdn.com/v2/letter/g/f4b2a3/32.png) [@Grimm](http://forum.driveonwood.com/u/Grimm)
#### Post date: [October 7, 2019, 4:26am UTC](http://forum.driveonwood.com/t/tar-cracking-device/4296/19 "2019-10-07T04:26:48Z")

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Apparently. It’s an actual documented gasifier. Hundreds of them were built less than 120 years ago.

I started a thread under charcoal. I’ll post all the info I have about it there in a couple of days.

> [@The Riche' Retort](http://forum.driveonwood.com/t/the-riche-retort/4820):
>
> So, anyone who has made charcoal knows, there is a lot of wasted potential in the process. Especially if you’re making it by destructive distillation in a sealed retort, you’re probably thinking “there’s just gotta be a way to harness those gasses.” There may be a way. The Riche’ Retort gasifier was developed about 120 years ago, and according to books about gasifiers from that time, seems to have been able to clean up the gasses from the destructive distillation process. In a very small nutsh…

I’m sorry you have to wait. I know you are eager to know more. It’ll probably just drive you crazy if I told you that there’s a second design he made. 😁

Though you may have seen a smaller more “modern” version of it. Besides the retort gasifier, there was the Riche’ Combustion gasifier.

> [@cogénération](http://forum.driveonwood.com/t/cogeneration/378):
>
> hello, I am very happy to find your site in people as crazy as us Europeans, but it is we who in the sum Veritee, enclosed a picture of a generator fonçonnant a gas generator and at the same time factory heat (cogeneration) cordially. pal françois

Check out post 20 and 21. Not specifically a Riche’ Combustion gasifier, but it embodies the main idea behind it. The charcoal reduction filter. Heat from the burning wood gets the charcoal hot enough to crack the tars.

And if you pause and think about it, any gasifier that puts out low tar/tar free gas pretty much has to have glowing char in it, unless you have pure carbon fuel, or an extensive filtration system.

In a standard combustion based gasifier the products in the pyrolysis zone really aren’t any different than the distillation gasses. It only takes them a moment to pass through the hot coals. Granted there is oxygen present to support partial combustion to supply the heat needed. With the retort, the same heat is being supplied by an external source instead of an internal one.

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