[Gasification] Biodiesel by product.

[jim mason]

Discussion we had was; Can this stuff be processed through a gasification or
> pyrolysis system to produce energy instead of dumping in a landfill,
> something no likes to do. I'm aware that Glycerin can be used to make some
> products but IF it can be used for energy, this would be better.



there are many heat straight and use scenarios.  peter will like those, of
course.

there is also an interesting option for this "waste" oil, or really any
"waste" oil in gasifcation.  i don't know any way to convert it so that it
will properly pyrolysis to solid char, which is what we need to run the
reduction reactions, but we can use this fuel as is to amend the combustion
step in a gasifier.  namely, in the same way that a downdraft is burning
lots of tar to produce its combustion heat and co2 and h2 to run the
reduction bed, we can also introduce other waste hydrocarbons to the
combustion zone that would otherwise be too difficult to burn on their own
(dirty, low energy, etc).  they will will take the place of any char that is
being burned in the combustion zone, which is good.

the degree to which a waste oil can supplement combustion in a downdraft
depends on the degree of tar the above pyrolysis is producing.  i'm not sure
of the range of variation here.  you likely know john.

an updraft will be able to take much more waste oil, as an updraft is mostly
burning char in the combustion zone.  all this can be replaced with waste
oil.

i often use such "waste" oil to get my open top gasifiers going.  let some
dirty gas or diesel soak into the wood and everything starts faster.  the
heat also just vaporizes the fuel so you are really running
gasoline/diesel/paint thinner vapors on start up.  somewhat like the old
style vapor carburetors on old ic engines.  heat engines are very flexible
beasts.


i'm surprised that this easy use of waste oils has not been more engaged in
gasification.  as long as you are introducing enough solid biomass or char
to support the incadescent char bed, nearly anything else that burns is fine
to support the combustion zone.  if it produces heat and co2 and h2, amend
away and save on biomass feed.

of course this will require some sensing and control equipment to keep
things in balance, or an operator to tweak as effects are seen.  but such is
not difficult.  and the benefits of "anything" amendment seem rather large.

and of course "anything" needs to be reckoned according to how the material
responds to combustion at gasfier temps so as to produce exhaust components
that are acceptable.

i have found fuel mixing like this, even fuel mixing between different types
of solid fuels, to greatly increase the flexibility of what gasfiers will
do.  tom pointed this out to peter in suggesting that it will be easier to
gasify shredded bagasse if he is mixing it with cohune nut shells.  the
shells will make much better char than bagasse.  mixing good char making
with not so good char making fuels seems a good way to make not so good
fuels work pretty good.

again, gasifiers do not really like to respect many rules (except the
thermodynamic ones).  and in my experience they greatly reward all attempts
at thoughtfully breaking the rules.  even in failure, the diagnosis of what
went wrong is always more educational and interesting than it just working.


in my experience, it seems that almost every good innovation starts with
diagnosing an interesting failure.  those who invent the most interesting
things are usually those who make the most interesting mistakes.

j



I would appreciate feedback on this issue. Thanks in Advance.
>
> John Flottvik
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