[Gasification] Food meets energy, butanol catalysis anyone?

[AJH]

On Mon, 7 May 2007 09:14:32 +0200, Pels, J.R. (Jan) wrote:


>
>> 40% of a harvested corn plant is the ear.

25% in the root system below ground?

Farmers in UK seem to get a yield of around 8tonnes/ha, this is
relatively intensive and with artificial fertiliser. The straw yield
would be around 1.5 tonnes, I've no idea what the chaff would be as
this isn't currently collected. Just 60 years ago the whole crop was
collected as sheaves and then processed in a barn over the winter
period.

>> The balance stays 
>> in the field. Is there a process for harvesting and baling 
>> the grain and stalks, leaves and the like at the same time? I 
>> read some work being done on this but never saw any conclusion of it. 

I'm fairly confident a mower incorporating a rotobaler would gather
the whole crop without losing much grain from the ear, especially if
harvested around 20% mc, though this means you would always need some
further frying to store the grain once threshed. The problem would be
one of timeliness, a modern combine harvester harvests the grain at,
say 50 tonnes/hour and all the associated transport is geared to this.
If you remove the whole crop you increase the mass harvested by a
modest 30% but the bulk will go up by a much larger multiple. You
would have the luxury of a much lower capital cost threshing device
and the bales could be stacked outside prior to threshing, vermin
problems would increase.

>LINVENT at aol.com>The balance stays there for a reason. Harvesting (and gasification) of
>100% of crops will rapidly deplete the carbon in the soils. Faster than
>other nutrients. Perhaps some of the 'balance' can be used,

There is some synchronicity with the [terrapreta] discussion here.
Once you have harvested the whole crop off, for example, a modest
600ha arable cereal acreage then you may sell 4800 tonnes of wheat and
have 900tonnes of straw plus chaff, say 1000tonnes total, pyrolise
this in a simple continuous cross draught gasifier running at low
temperature, ~500C. Much of the minerals will then remain in the char,
the heat can be used locally, perhaps to run the dryer and heat the
farmhouse and with a char yield of 40% of the straw dry matter you'd
have 300tonnes of biochar. Incorporate this back into the soil with
some verification and not only to you replace minerals but you can
claim some carbon credits. So the net position is not a lot different
from returning the straw and chaff to the soil with a straw chopper,
so that it can decompose back to water and CO2 plus minerals but you
have derived some heat from it and fixed a couple of hundred tonnes of
carbon so that it is sequestrated for a long period, plus you have the
much vaunted benefits of terra preta soils on the holding.

AJH