[Gasification] SVO emissions (was Re: Torrified woodchipsas a gasifier fuel)

[doug.williams]

Hi Daniel, Rolf, and Harmon,

> STOP!  (sorry for shouting, but I think it is appropriate here)

I could not agree more, and to discuss this sensibly, all the issues need to
 separated, then bought back together to understand the answers as applied
to Harmon's interest in using exhaust gas into his greenhouse.

> I would be extremely cautious about any scheme that involved sending
> engine exhaust into a greenhouse.  To do it safely would require a very
> well-engineered system that made sure that you don't end up poisoning
> the greenhouse's occupants (people or plants).

I have had a couple of projects that investigated this option, plus the fact
that I have an ongoing interest in using the CO2 as a control for white fly
that infests some glass house crops. Plants don't like more than 10% CO2,
and less in many situations.

> Carbon monoxide comes
> immediately to mind, but you'd also have to be assured that everything
> else was properly taken care of (what else in exhaust would you care to
> not breathe - unburned tars? NOx?)

If we are taking engine exhaust, then a catalytic converter will be 
necessary,
but this does no more than to burn the un-burnt CO, as the H2 will more
than likely combust as a priority in the cylinder. Alternative fuel oils are
less understood when applied to producer gas, and might produce an ash
particle rather than soot from diesel, which the catalytic converter would
reduce to CO2. So, particulates become a problem for plants, in a contained
environment. NOx has not been an issue with producer gas in spark engines
that I am aware of in practice. Dual fuel could be, if the system is not set 
up
to control the variations that occur across changing loads, and fluctuation
of gas quality.

>But real engines also produce the typical
> pollutants/emissions we associate with engine exhaust - CO, unburned
> hydrocarbons, NOx, SOx, etc.

We can forget the CO, if we fit the CV, and as SOx is more associated with
fossil fuel in discussing Producer gas engine emissions. Alternative fuel 
oils
might create SOx, but that needs to be clarified by someone who is working
specifically in this field. Can any one point to a research that can through
some light on this?

> Safely piping engine exhaust from a woodgas-powered engine into a place
> where plants live and humans work will be roughly the same undertaking
> (difficulty-wise) as using a fossil-fueled engine exhaust for the same
> purpose.  Not impossible of course, but in most cases probably
> uneconomic.

You cannot pump hot exhaust gas into plants, and it has to be cooled, 
possibly
 with water that can then be used to heat the plant beds or air. This then 
would
allow you to use plastic piping, and a very good non corrosive answer to use
wet CO2.

If the interest is to use the exhaust for plant application, The advise I 
give to all,
is to first start with plastic tunnel houses, then risk to human health is 
avoided.

Must leave this discussion now, with still only limited time to participate, 
but
this is a safety issue and could not it go by ignored. Hope it offers some 
insight
to your interest.
Doug Williams,
Fluidyne Gasification.