[Bioconversion] biogas yield of switchgrass

[Roger Samson]

Hi Jeff

Thanks, what is the source? The Finnish study I posted yesterday on the
bioenergy list gives a value of about 140 m3 (400 m3 /ODT) for reed
canarygrass silage. So I am basing my baseline case at 140 m3/tonne of warm
season grass silage at 35% dry matter (equivalent to 400 m3/oven dry tonne).

Assuming a biogas energy content of 0.232 GJ/m3 it yields 3.3 GJ/tonne of
silage (9.3 GJ/ODT equivalent) .
This is about half the energy of switchgrass pellets at 18-19 Gj/tonne but
is arguably a higher quality fuel form. 

A field should produce about 28.5 tonnes of silage per ha (equivalent to 10
ODT) or 93 GJ/ha of biogas. You can then compress this gas and use it for
transport or in a CHP plant and have a much better energy balance than corn
ethanol. I don't thinks it is as economically viable as SG pellets but is an
option in areas where the delayed harvesting of SG is not possible. 

We would like to test various warm season grasses especially eastern
gamagrass, big bluestem and high forage digestibility switchgrass varieties
as well as processing treatments to make this economically viable in
locations with green power agreements or emission reduction programs. 

Roger Samson
www.reap-canada.com
   

-----Original Message-----
From: bioconversion-bounces at listserv.repp.org
[mailto:bioconversion-bounces at listserv.repp.org] On Behalf Of Jeff Davis
Sent: Thursday, September 14, 2006 1:53 AM
To: bioconversion at listserv.repp.org
Subject: Re: [Bioconversion] biogas yield of switchgrass

On Tuesday 12 September 2006 03:58 pm, Roger Samson wrote:
> Anyone aware of any biogas yields per tonne from warm season grasses such
> as switchgrass, big bluestem or eastern gamagrass.

Not sure if this will help:

m^3 biogas production/ton

fat & grease = 961
bakery waste = 714
food scraps = 265
corn silage = 190
grass silage = 185
green clippings = 175
brewery waste = 120
chicken manure = 80
potato waste = 39
pig manure = 30
cow manure = 25

No idea how accurate the above is.

Maybe it's around the 190 to 170 range?

Jeff



-- 
Jeff Davis
Somewhere 20 miles south of Lake Erie, USA
http://www.velocity.net/~jeff0124

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