[Gasification] Fluidyne Update

[Doug Williams]

On Thu, 26 Feb 2015 14:49:36 +0100
"Energies Naturals C.B." <energiesnaturals at gmx.de> wrote:

Hi Rolf and Gasification Colleagues,

Sorry about the brief reply:
 
> congratulation! It seems that you and your co-workers have done more than your homework.

The CalForest team have done a fantastic job under difficult operating
conditions and in between running a busy tree Nursery. What you see now
is the accumulated knowledge obtained from testing procedures that work
or destroy. The back yard junk pile is now considerable in size(:-)
> 
> The failures you report seem to be located and solvable at a reasonable cost, I guess.

We found that you still need to make your own specifically designed
components as off the shelf products cannot cope with pyrolytic
condensates, especially seals.
> 
> What I would like to know is your estimation on replacement periods and cost of the main wear parts, the "hot spots", I presume.

I assume you mean the Shasta Mk2 gasifier. Nothing has been replaced
internally for the 2,000 hrs, but the grate is gradually eroding from
the gas exit temperature of around 900C. The only obvious hot spot is
the ends of the lower char chamber which are not insulated with
refractory, but this would need another Mk3 model to be built, which of
course would improve again due to the experience gained regarding key
points. Replacement spare parts would not be unreasonably expensive,
and could be made any where using the correct material.
> 
> Today I have a guest here who has developed a novel system to convert granite sawing sludge into good and hard tiles and other objects. For this, she needs baking the pressed "cake" at 1200 °C .Sometimes oxidizing, sometimes reducing, she says.

Updraft pyrolysis gas will give you the 1200C, and we know from glass
furnace experience, that by adjusting the air ratio to your burner, you
can have both reducing and oxidizing atmospheres in the furnace as the
process requires.
> 
> Do you have any experience/reference on how to do this with e.g. pine chips or almond shells?

As you know we only built downdraft gasifiers for engines, but in the
early days (1977/8) when we just sold the hearth modules, DIY artists
blew them both up and down. Any workable updraft design will do the job
for you, but it will depend on fuel feeding and waste clean-outs
working continuously for stability using both chip and shell.

 > It could be an interesting use of biomass and reduce cost of
eliminating what is considered a hazardous waste.

All I can say at this stage of our charmaking project, is that we now
have very useful experience in the controlling mechanisms that will
help overcome all the issues of using difficult ash forming fuels that
we have available as biomass. From my own perspective, I can see
considerable change to how gasifiers might be built for toxic
applications at some future date. In the mean time, we do the best we 
can(:-) Hope this might be of assistance.

Doug Williams,
Fluidyne.