[Gasification] Making char vs producer gas

[Doug]

Hi Peter and Colleagues.

Sorry for the delay in this reply:


On Sat, 15 Mar 2014 02:02:38 +1100
Peter Davies <idgasifier at gmail.com> wrote:

> Hi Doug,
> 
> Thanks, yes we do have it sorted out and during our development years 
> playing with early packed beds have experienced most of the things you 
> observed.  I recall an awful lot of bed profiling work looking at 
> particle distribution at different time and output changes to see what 
> was going on. However our mature system is not low temperature and no we 
> do not get torrefied chip out but rather a very high fixed carbon 
> charcoal (>85%) with little if any remaining volatiles.

I obviously wrote in a way that wasn't understood,so I will have to another explain in another way. I have no doubt you have a high carbon char with the volatiles normally released by oxidation, and you do not have torrified char as an output. Possibly you do not have an integrated gas making and char producing process, but if you have high temperatures created in an oxidation bed, all the volatiles are out of the chip in the form of pyrolysis gases at a temperature of about 475C. Once out of the char, it leaves completely and cannot be internally baked to improve the carbon content. These are oxidized in this situation. In saying that, the high temperature at the point of blast into the bed will only torrify the raw chip outside the reach of the free oxygen. Given that I only know what I have seen on the video of your system working, and it might not be the same type of design principles, this would fit the two opposing air blasts being set wider apart, and torrified chip d!
 rops down into a high temperature baking phenomena to result in the higher grade char. As for the remaining volatiles, this is determined by the speed of extraction so can be nicely controlled to suit the type of wood etc.

>Tested gas 
> outputs show  up to 55% combustible gas high H2, slightly lower but 
> roughly equivalent CO and less than 1% total CH4 and higher molecules. 
> Nowadays the systems are normally started on the char bed from the 
> previous run and  on larger models if this is within twelve hours of 
> shutdown then engine grade gas is achieved within 2 minutes without need 
> for external re-ignition of the hearth. We have proven the design 
> parameters from 20kg/hr models through to 500kg/hr so far.

As I always say, photos are cheap and easy to show the World your process, but talking about it is even cheaper, which unfortunately restricts opportunity to enter the market with really appropriate people and projects. Otherwise, it's buyer beware without "due diligence".
 
> RE: Sydney; Yes the supplier was from Vermont. Our understanding is that 
> what was installed has never run on site and is being removed. We were 
> asked to come and "fix" it but we declined as we have already lost IP to 
> the people involved in the past and had no desire to be further 
> compromised, quite apart from the false assumption that our own systems 
> were sufficiently similar that we could just "tweak It". They lurk on 
> this list so given the saga is far from over and investigation 
> continuing it would be unwise to say anything further other than for 
> those contemplating a purchase please do your due diligence! And if 
> anyone claims to be the "originator' of our tech you can safely assume 
> they are lying.

Thanks for your comments and am aware of the conflict between yourself and B.K. but now being manufacturers, I think there is a saying something like "no honour between gasifier manufactures" (:-).

 I can only encourage you to stand up and be seen, but if you prefer to stay at some level of anonymous activity, especially on this forum, then you relegate the true value of your work to a lower level of acceptance.

We need winners which are sadly all to few, but hope the above might help others still learning the ropes.

Doug Williams,
Fluidyne.