The real problem is not with the carbon dioxide emissions from the fuel. It's
with how much fuel has to be used and its cost. That is the argument for
starting with residue as close to deep water as possible, e.g. as previously
mentioned, eastern Japan and the Bay of Biscay off the west coast of France.
There are probably other locations as well that meet these criteria. If a
pipeline could be run from the coastal area to the deep water, there would be
no need for barging. Experience in the handling of bagasse by sluicing can
probably be applied to the CROPs strategy.
----- Original Message -----
From: Stuart Strand
To: David Schnare
Cc: [email protected] ; [email protected]
Sent: Monday, February 02, 2009 4:34 PM
Subject: [geo] Re: Crop residue ocean permanent sequestration
David,
You are wrong about the carbon that would be emitted during transportation of
residues to the sea. Our calculation of 92% carbon sequestration efficiency
for CROPS is based on truck transport to the upper Mississippi and barging to
deep water in the Gulf. If you want a reprint please ask and I will send.
Nothing against no-till; it seems a good way to improve soil fertility and not
waste root carbon, but it is still a lossy way to sequester above ground crop
residue carbon.
= Stuart =
Stuart E. Strand
167 Wilcox Hall, Box 352700, Univ. Washington, Seattle, WA 98195
voice 206-543-5350, fax 206-685-3836
http://faculty.washington.edu/sstrand/
From: David Schnare [mailto:[email protected]]
Sent: Monday, February 02, 2009 9:04 AM
To: Stuart Strand
Cc: [email protected]; [email protected]
Subject: Re: [geo] Re: Crop residue ocean permanent sequestration
Stuart:
I've been studying notill agriculture that relies, in major part, on building
soil carbon to hold nutrients in the soil (reducing application requirements
and keeping it out of streams). While a 14% sequestration (limited to only
about 20 years before maxing out on sequestration potential) seems small
compared to 100% if dumped into the ocean deeps, it seems to me that when used
in places more than 150 miles from the ocean, it is carbon reduction efficient
(based on fuels needed for transport).
As such, shouldn't we be narrowing the crop waste discussion to coastal
agriculture only, and give credit for soil sequestration where that's as good
as is available?
David Schnare
On Mon, Feb 2, 2009 at 11:54 AM, Stuart Strand <[email protected]>
wrote:
By straw we are referring to the stalks of agricultural plants, wheat stalks
and corn stover. The water and nutrients were expended to grow the grain.
Straw has a low nutrient content (C/N = ca 50/1). Presently straw is wasted by
allowing it to decay on the soil surface (only 14% or less of the straw carbon
is incorporated into the soil).
A variety of processes are available to get energy out of crop residues, but
they are limited by the poor specific energy of biomass. Our focus is how to
efficiently remove Pg amounts of carbon from the atmosphere and permanently
sequester it in the least environmentally harmful manner.
= Stuart =
Stuart E. Strand
167 Wilcox Hall, Box 352700, Univ. Washington, Seattle, WA 98195
voice 206-543-5350, fax 206-685-3836
skype: stuartestrand
http://faculty.washington.edu/sstrand/
Using only muscle power, who is the fastest person in the world?
Flying start, 200 m 82.3 mph! http://en.wikipedia.org/wiki/Sam_Whittingham
Hour http://en.wikipedia.org/wiki/Hour_record
55 miles, upside down, backwards, and head first!
From: [email protected]
[mailto:[email protected]] On Behalf Of [email protected]
Sent: Wednesday, January 28, 2009 7:16 PM
To: [email protected]
Subject: [geo] Re: Crop residue ocean permanent sequestration
Stuart,
Why bundle and stash terrestrial straw. Growing straw requires substantial
fresh water and nutrients. You could bundle and stash algae instead. How
about sargassum or kelp? A macro-algae can be bundled in large mesh "tea bags"
with much of the water being squeezed out during the bundling process.
Then, as long as you've got bundles of biomass, why not separate the
nutrients from the carbon before you stash the carbon? That way, you can
recycle the nutrients back to the ocean surface for growing more biomass.
High-pressure anaerobic digestion will release the carbon in two separate
streams; one gaseous CH4, one dissolved CO2, which easily converts to liquid
CO2 at typical ocean temperatures and pressures.
Would you or others be interested in a California Energy Commission grant to
run a few bench experiments on high-pressure anaerobic digestion? I can send a
draft abstract.
Mark E. Capron, PE
Oxnard, California
www.PODenergy.org
--
David W. Schnare
Center for Environmental Stewardship
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"geoengineering" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/geoengineering?hl=en
-~----------~----~----~----~------~----~------~--~---
