[Gasification] questions

[Doug Williams]

Hi Kermit,

As I have just spent the last few months with your issues in my focus,
I can share a few pointers from the commercial perspective. There are
many researching gasification and biochar of crop residues, and it is
clear their being linked into soils enhancement and growing, that
results can be skewed, not surprisingly by the quality of the chars
they work with. As you can see from the information offered so far,
there is a lot of expertise out there, but not coordinated to make a
fig of difference to the national need of any country. There are needs
to burn or gasify many types of crop residues to prevent the increase
of soil pests like nematodes, but if made into biochars are a better
option than just returning raw crop to the soil.

> One major question that I have about gasification is why corn cobs
> are not mentioned more as a major fuel source. There must be a lot of them
> and as combined heat and power they could keep farm houses, schools, and
> apartments warm. 

It takes a brave company to develop any sort of biomass energy
gasification system, and nobody wants the first units even for free if
it isn't fully automated. The heating part is easy enough, but engine
quality gas making is still a black art, as is the reliability of the
CHP equipment to achieve it.

>I know that some of them are returned to the soil and some
> are probably used to distill ethanol. Wouldn’t it be better to distill the
> ethanol with solar energy or with combined heat and manufacturing
> (comanufacturing)? Is cellulosic ethanol likely to become important?

All things are possible for a price, but not many people work for
nothing to realise idealistic potentials.

> Another question is, can we gasify the cobs and then return the ashes to
> the soil or must we put carbon back to the soil to fertilize it?

When you gasify biomass to make gas not biochar, your clean out waste
is usually a slightly activated charcoal containing some ash dust. As
mentioned, cobs can create clinkers, but ash is normally the result of
a fuel being combusted completely to create heat. Ash is helpful as a
fertilizer, but the char or carbon only fills the role as a bacteria
habitat and moisture retainer. Both are needed to convert the
fertilizer into plant food.

> Would powdered coal stay indefinitely in the soil and do the same thing? On this
> list I have seen opinions on both side of this but I hope someone knows the
> truth.

This question crosses the boundary of two types of work going on that I
am aware of, one to enhance soil  conditions, and the second to bury
high carbon content chars as carbon sinks. Soil enhancement needs high
porosity chars without the retention of pyrolysis volatile carbon,
while carbon sinks need the more traditionally baked dense retort type
chars. Soils in South America contain large amounts of historically old
carbons, but nobody has answered my own questions as to what type of
char remains today. The same can be said for the char found in cooking
hearths of cave dwelling people.           

>Since fertilizer is all important to gasification and it will be
> scarce, we should consider the use of sewage for fertilizer. One of the
> reasons that sewage is said to be unfit is that medicines and other
> impurities would poison us. Wouldn’t gasification destroy many of these
> organic compounds and thus purify the ashes so they could be used as
> fertilizer for food crops? 

Sewage sludge is a minefield of toxic material especially heavy metals,
with Mercury being top of the list as an atmospheric pollutant if not
thermally disposed of correctly. High temperature down-draft
gasification can make a useful clean gas, but as a technology it is
difficult to obtain permits to access the wet sludge for those who want
to develop new disposal systems, especially engine driven generation.

>Inorganic compounds probably would not be
> destroyed and in recycling fertilizer, salt might be the ultimate pollutant.

In Northern Ireland, sewage sludge are used directly to feed coppice
willow which take up a lot of the nasties. The willow is then used as
boiler fuel without any emission problems. Nature can help a lot if we
work with it's cooperation! Some types of Australian eucalyptus can be
used to take up salt, and this was proposed for a power gasification
project to reduce salination of old irrigated soils. In that scenario,
the trees were to be delimbed in a rotational programme of harvesting
the wood.
> 
>Tom Reed’s gasification driven tractor seemed to me to be one of
> the best gasification projects. I did think that the sheet metal would rust
> pretty quickly and that it needed cast iron. I wonder if it ever worked
> enough to plow with. I believe that some farm made ethanol used as a
> starting and power increasing fuel might make it more practical. Making
> farming self supporting in terms of energy seems like a good idea.

All things are possible, but the cost of labour to maintain a reliable
system at this time might put it into the too hard basket.
> 
> There are many corn fields surrounding Ann Arbor yet the best energy
> project the city has came up with is a large array of solar panels. Why not
> use those corn cobs? Where is the propaganda machine for biomass energy?

The City is the best market available for commercially made solar
panels which were at one time in the main, part of oil company
portfolios. Laying in the Sun and creating electricity is slightly
easier than trying to stuff a forest through a funnel, difficult to
convince city officials other wise. 

>I believe that available biomass energy is greater than either solar or wind
> but the environmentalists ignore and deplore it. One way to advertise the
> virtue of biomass energy would be to create a large farm with an apartment
> on it. Gasification, can combine heat and power for the building and also
> create enough fuel for plowing from farm biomass. This would create a huge
> advertising of the need for gasification.

I cannot fault you belief as it mirrors my own, but doors of
opportunity open and close for biomass energy across the World. In the
USA and New Zealand, there is a need for forest fuel reduction as wild
fire devastate our forests. Chipped forest residues are great for
boilers, but even that industry struggles to have any momentum as the
generation is undervalued by controlling grid interests. Yes we can
generate gasified power, but economic scale and location to the fuel
resource remains an issue for every one working to release the
potentials of biomass energy.

While our own development work in California at CalForest has centred
around gasified power generation, it would not have much impact on
forest fuel reduction programmes. To convert this huge resource is a
new project at CalForests which brings together the combined experience
of gasification, commercial growing practice, and the use of biochars
as a growing medium. As a privately funded project, this is no free
ride on the tax payer. The activity will be linked into the Pacific
Northwest Biochar Initiative Programme of information dissemination.

I am in the process of assembling a new file of this project with
photos taken during my commissioning visit to California in the last
week of January 2015 for the Fluidyne Archive.
www.fluidynenz.250x.com  It will probably be next week before you can
see this work and I will advise when it becomes available.

Hope you can see get something out of my explanation Kermit, but a lot
of dedicated people are doing their best to make it happen in each area
of need. I applaud their tenacity and diversity of interests.

Doug Williams,
Fluidyne.