Because it's better for the atmosphere. If I hand you a lump of coal, which is better for the atmosphere and global warming? For you to burn it or to throw it into the sea?
You can burn it and sequester the liquid carbon dioxide in deep saline aquifers, as we must do to continue to burn coal, and that will bring you nearly up to the carbon sequestration efficiency of CROPS. But now you have two complicated technologies to develop and we don't have time. Why not at least start with the easy crop residues and sequester them on land or at sea? Every year that we waste another Keeling curve cycle looses many megatons of carbon that could've been removed permanently from the surface biosphere. We need to start the research to allow us to tap into this carbon flow. Your points about biochar are fine, but you are still focused on energy production, and making energy from biomass, wasting the carbon back to the atmosphere. Biomass is a crummy energy source and photosynthesis a lousy solar collector in terms of efficiency. I do not believe for a minute that we get the energy to run civilization or even just transport in 2050 from biomass even if we are much more efficient in its use. There are other more efficient alternatives for the energy we need. But terrestrial biomass represents a huge part of the carbon cycle. The question is how to best use it. = Stuart = -----Original Message----- From: Andrew Lockley [mailto:[email protected]] Sent: Monday, February 02, 2009 5:51 PM To: [email protected] Cc: Stuart Strand; David Schnare; [email protected]; [email protected] Subject: Re: [geo] Re: Crop residue ocean permanent sequestration Could someone please explain why you would want to throw fuel into the sea? Surely it's better to: a) Burn it, then use CCS b) Pyrolise it to recover energy and to reduce mass/bulk and then throw the char in the sea. Just to question the 'safety factor' of terra preta as opposed to ocean burial: As I understand it there's actually a net benefit to biochar, as it helps 'bulk' the soil and cause it to sequester yet more carbon from organic residues. A 2009/2/3 Alvia Gaskill <[email protected]>: > 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 -~----------~----~----~----~------~----~------~--~---
