Torrification of Pellets

I've been doing some research on torrification and it seems like the ideal solution for producing quality pellets with higher energy content and alleviating the sawdust problem because torrified pellets are said to be hydrophobic. Torrified pellets are not only ideal for gasifiers, but for coal fired power plants too.

A gasifier's waste heat is more than enough to create torrification, plus there is the exhaust heat from engine operations.

If anyone can dig up some reports on torrification and attach them that would be much appreciated.

Tags: torrification, torrified wood

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Permalink Reply by randy ury on April 2, 2009 at 5:12am: found this http://bioenergylists.org/ardrwanda030808; ▶ Reply to This

Permalink Reply by JSGolightly on September 2, 2009 at 7:40pm: http://www.techtp.com/recent%20papers/ECN-Torrefaction%20for%20biom...

judging from this, it seems like it might be a process that could be performed within a gasifier its self.

From Page 4:

Torrefaction is a thermo-chemical
treatment method that is earmarked by an
operating temperature ranging from 200 °C
to 300 °C. It is carried out at near
atmospheric pressure in the absence of
oxygen and characterised by low particle
heating rates (< 50 °C/min). The biomass
partly decomposes during the process
giving off various types of volatiles, which
results in a loss of mass and chemical
energy to the gas phase.

however, some of the stuff through out this document makes me think that torrefaction must take place before the material is briquette'd/pellet'd.

another good link might be found here:

http://terrapreta.bioenergylists.org/taxonomy/term/663; ▶ Reply to This

Permalink Reply by JSGolightly on September 12, 2009 at 9:41am: After a little bit of research, i've discovered the "torbed reactor" (Tor-Bed is my guess at pronunciation).

A little bit of media describing the unit:

http://www.torbed.org/video.php?PHPSESSID=20e87e9d40f647cac6977efe8...
http://www.torftech.com/tech1c.php
http://www.torftech.com/tech2c.php

http://www.oceta.on.ca/profiles/torftech/torftech_tech.html lists the following applications:

* roasting
* calcination
* dry gas scrubbing
* pasteurization
* combustion
* minerals
* foods
* chemicals
* metals
* waste
* hazardous wastes
* desorption
* catalysis
* fine powders
* reacting
* gasification
* pyrolysis

now the bad news is i have no idea how to make the torrefaction work with this "reactor".

i have found that "roasting coffee beans" is a form of torrefaction, so there may be some interesting information in "custom coffee" circles. I'll keep looking.

In the mean time, hope this helps.; ▶ Reply to This

Permalink Reply by JSGolightly on September 13, 2009 at 11:47am: i tried to post it as a link and a pic, but for some reason i couldn't get it to work.

http://1.bp.blogspot.com/_-S7OmspNfHU/Sf5Ip3i9CiI/AAAAAAAAAMI/EpEJ9...

at any rate its a pic describing the temp range for torrefaction vs carbonization; ▶ Reply to This

Permalink Reply by JSGolightly on September 13, 2009 at 1:16pm: Torrefaction Machine Conceptual Schematic:

http://3.bp.blogspot.com/_-S7OmspNfHU/SDlofLqTHFI/AAAAAAAAAE8/zx9xL...; ▶ Reply to This

Permalink Reply by Renewablejohn on April 11, 2010 at 2:27pm: I have looked at the Torbed system for torrefication but received a very negative response from the company as they have licensed the worldwide use of their Torbed reactor for torrefication of wood to a company called Toppoll in the Netherlands. I am therefore developing my own reactor using a vibrating spiral elevator enclosed in a thermal oil tank heated by thermal solar tubes. It has been designed for torrefication of Arb waste and forest brash produced by standard chipping machines. The Torrefied wood will then be processed into Briquettes and Pellets.; ▶ Reply to This

Permalink Reply by Renewablejohn on June 9, 2010 at 4:10am: Renewablejohn said:
I have looked at the Torbed system for torrefication but received a very negative response from the company as they have licensed the worldwide use of their Torbed reactor for torrefication of wood to a company called Toppoll in the Netherlands. I am therefore developing my own reactor using a vibrating spiral elevator enclosed in a thermal oil tank heated by thermal solar tubes. It has been designed for torrefication of Arb waste and forest brash produced by standard chipping machines. The Torrefied wood will then be processed into Briquettes and Pellets.

Just to update we have now found a Krauss Maffei plate dryer which we can heat with thermal oil to a temperature which should make torrefied wood. The spiral elevator was finally rejected due to the high amplitude needed to move the woodchip up the spiral which would have resulted in a larger diameter machine to obtain the necessary residence roasting time.; ▶ Reply to This