I'm not yelling, nor am I resorting to some kind of quasi-religious argument. I'm pointing out a systematic series of shortcomings with the technique. These have now been brought up numerous times on this list, but never satisfactorily addressed IMO. Quite frankly, I think the technique is mildly interesting but far from appealing in it's current form. A number of respondents have pointed out alternatives, such as biochar, which address some/most of the problems. I am feeling like we're going round in circles on this particular technique, with the shortcomings never properly addressed. For example, I never even received a (public, printable) reply to my point that it was probably illegal.
A 2009/2/6 Stuart Strand <[email protected]> > Thank you for your creed, Andrew. > > > > I am trying to have a rational debate. Yelling does not win scientific > debate. > > > > > > = Stuart = > > > > *From:* Andrew Lockley [mailto:[email protected]] > *Sent:* Thursday, February 05, 2009 5:36 PM > *To:* Stuart Strand > *Cc:* Alvia Gaskill; [email protected]; geoengineering > > *Subject:* Re: [geo] Re: Crop residue ocean permanent sequestration > > > > I don't think that the 'permanence' of CROPS sequestration has been > demonstrated to a satisfactory extent. > > I don't think it's been shown to be legal. > > I don't think it's been shown to be practical or cost effective for inland > crops. > > I don't think that it's been shown to sequester carbon from biodegradable > material. > > I don't think it has been demonstrated to be superior to charring > > I don't think it has been demonstrated to be superior to AD for methane. > > > > A > > 2009/2/5 Stuart Strand <[email protected]> > > OK, we are in agreement that most of the surface sequestration schemes are > "kicking the can down the road", they are temporary. But CROPS is one kick > and you have _permanent sequestration_. That is the goal of geoengineering > of greenhouse gases, right? > > There is an element of danger in keeping the fossil fuel carbon on the > surface in contact with the atmosphere, no matter what form it is in. > > = Stuart = > > > -----Original Message----- > From: Alvia Gaskill [mailto:[email protected]] > Sent: Thursday, February 05, 2009 10:58 AM > To: Stuart Strand; [email protected]; geoengineering > Subject: Re: [geo] Re: Crop residue ocean permanent sequestration > > 100 years may be enough if technological advances allow us to remove > atmospheric CO2. Remember also that if it is 100 years for complete > oxidation of the biomass, that would be 2109 for crop residue sequestered > today and 2150 for crop residue sequestered in 2050. Just as we would only > be able to remove carbon via crop residue sequestration one year at a time, > nature will also have to operate on the same schedule, unless you can show > that oxidation rates will increase in the coming decades. Admittedly, this > is kicking the can down the road, but that's the whole point of > geoengineering, buying time. > > The way nuclear waste is being handled is instructive. High level waste > will remain radioactive for up to 250,000 years. There is no way we can > guarantee removal of this from the biosphere for that long. Future > civilizations may unwittingly dig it up, irrespective of where and how it > is > stored. Keeping it out of the environment for as long as practical is the > best we can hope for. By 2100 or 2200 or sometime in the next millenium, > it > is likely that solutions other than burying it in caves or salt mines will > have been found. > > By storing crop waste aboveground, it is also still available for use as a > soil amendment if that is necessary. Very likely, crop residue > sequestration will wind up being done in various ways, from aboveground > storage in dry areas to landfilling to produce methane to some ocean > disposal. A one-size fits all strategy probably won't work. > > In looking at the landfill option, I noticed that in several states, MI and > MO, efforts were underway to get approval to let yard waste be sent to > municipal landfills instead of separate ones as is now mostly the case. > Part of the reason may be financial as waste haulers could get higher fees > if the grass clippings and tree limbs were back in the mix. The stated > reason is to generate more methane for energy recovery. The reason to keep > yard waste out of landfills is to extend the life of the facility. The > fire > issue is a legitimate one. Durham County maintains a yard waste landfill, > but hired a bankrupt contractor who failed to keep it aerated and allowed > waste to accumulate until it spontaneously combusted during a major > drought. > The ensuing fire burned for several weeks, sending local residents to > hospitals with respiratory problems and was finally extinguished by another > outside contractor at a cost of nearly $100,000. > > Adding crop waste to existing landfills may be the most expedient way to > capitalize on the methane option, while avoiding the problems with gas > pockets Andrew mentioned. However, biocells could also be utilized. About > 50% of landfill gas is methane and the rest CO2 with leakage rates varying > considerably. Whatever strategy or combination of strategies are employed, > complete life cycle comparisons need to be developed with respect to energy > costs and GHG emissions. Stuart attempted to do this for biomass burning > for energy recovery vs. cellulosic ethanol vs. CROPS. A follow on study > should include all other realistic scenarios including tree planting and > sequestration and consider impacts on surface albedo from the darker tree > canopies vs. the barren ground that may exist there now. > > > ----- Original Message ----- > From: "Stuart Strand" <[email protected]> > To: <[email protected]>; "geoengineering" > <[email protected]> > Sent: Thursday, February 05, 2009 12:59 PM > Subject: [geo] Re: Crop residue ocean permanent sequestration > > > > 30-40% of the crop residue must be left on the land to prevent erosion. > > So removal for biochar could reach 60-70%, not 100%. > > > > Decadal sequestration is not enough, 100 years is not enough. 1000 years > > is barely enough. > > > > I am not seeing much discussion of numbers here. Can you please refer me > > to peer reviewed literature that in your opinion does the best estimate > of > > carbon flows in biochar/biomass pyrolysis? > > > > > > = 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! > > > > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of Sam Carana > > Sent: Thursday, February 05, 2009 5:23 AM > > To: geoengineering > > Subject: [geo] Re: Crop residue ocean permanent sequestration > > > > > > Stuart, > > > > If we only looked at the percentage of carbon was kept out of the > > atmosphere, then we should look at methods such as using crop residue > > and other organic material to produce bricks, pavement, tiles and > > similar building components. I wrote about Timbercrete in an article > > on carbon-negative building at: > > http://gather.com/viewArticle.jsp?articleId=281474977316789 > > Timbercrete is used to build houses, garden walls, for pavement and > > the like. It is made from sand and recycled timber waste, such as > > sawdust or other cellulose material. It is designed to last for > > generations, so for its lifetime it will store 100% of the carbon that > > was removed from the atmosphere by vegetation. I suppose that, if the > > building is taken down, the material could be recycled into new > > Timbercrete, but by that time we may have developed even better > > methods to reduce greenhouse gases. > > > > Anyway, my point is that this figure of 90% efficiency in keeping > > carbon out of the atmosphere should not be taken as the sole measure > > to assess methods. If we took such a narrow view, then the above > > Timbercrete would seem superior to ocean sequestration. But again, my > > point is that we should instead look at the wider picture. If we can > > pyrolyze three times as much material and bury it in the form of > > biochar, then that method would store a greater net amount of carbon. > > > > In conclusion, we should get communities to grow more vegetation and > > keep as much of the carbon contained in the vegetation out of the > > atmosphere for a long time, at least for decades to come. We can only > > suggest methods, but what works best locally depends on the benefits > > that communities each see in the various methods. Part of that bigger > > picture is illustrated by the image of my article Four Cycles of a > > Sustainable Economy, at: > > http://gather.com/viewArticle.jsp?articleId=281474977561808 > > > > Don't just look at the figures for two specific methods in isolation. > > We need to give it all we've got and many methods can work together > > and, by complementing each other, increasing the result in terms of > > reducing greenhouse gases. > > > > Cheers! > > Sam Carana > > > > > > > > On Thu, Feb 5, 2009 at 4:06 AM, Stuart Strand <[email protected]> > > wrote: > >> Sam, > >> > >> In your first point you touch on one problem: pyrolysis is about 50% > >> efficient use of crop residue carbon for sequestration. CROPS is about > >> 90% efficient. Perhaps a combination of the two would be synergistic. > >> > >> = 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! > >> > >> > >> -----Original Message----- > >> From: [email protected] > >> [mailto:[email protected]] On Behalf Of Sam Carana > >> Sent: Wednesday, February 04, 2009 6:21 AM > >> To: geoengineering > >> Subject: [geo] Re: Crop residue ocean permanent sequestration > >> > >> > >> Stuart, you conclude that ocean burial was more efficient in reducing > >> greenhouse gases than biochar, but you draw that conclusion by looking > >> at only one small part of what is a much bigger picture. > >> > >> 1. As we get better in pyrolysis, it should be no problem capturing > >> half of the carbon in the form of biochar. It depends partly on what > >> material is pyrolyzed, but that's also the beauty of this method, i.e. > >> many things can be treated this way, such as agricultural waste, > >> animal manure, sawdust, etc. > >> > >> 2. Apart from this, biochar enriches soil, allowing more vegetation to > >> grow and draw carbon dioxide from the atmosphere. This will raise the > >> net effect of this method well beyond the 50%. This also goes hand in > >> hand with afforestation, prevention of erosion, less emissions of > >> nitrous oxide (N2O) by fertilisers, the ability to feed a growing > >> world population and preservation of rainforest and water resources. > >> > >> 3. Thirdly, pyrolysis also produces biofuel and hydrogen. Quite > >> frankly, I cannot imagine a cleaner way to power shipping than by > >> means of hydrogen. If you take into account the carbon that would > >> otherwise result from ships burning (a typically very polluting type > >> of) oil, this alone could very well make the pyrolysis method > >> worthwhile as a method to reduce greenhouse gases. > >> > >> Combine the above three, and the combined net effect of pyrolysis, > >> biochar and hydrogen seems more efficient than ocean sequestration, > >> which requires substantial transport and logistics. Similarly, the > >> biofuel produced by pyrolysis could be used in transport, and perhaps > >> we can even capture some of the carbon that is released in the > >> process. > >> > >> If you look at each of these three points in isolation, there may seem > >> to be better alternatives than biochar, in the sense that each such > >> alternative may either seem to sequester more carbon, act as a better > >> fertiliser or produce energy cheaper. But if you look at the bigger > >> picture of what difference biochar could make, it is superior in all > >> respects, i.e. in its capacity to reduce greenhouse gases from the > >> atmosphere, as a way to enrich soil and as a way to produce energy, > >> e.g. for the transport sector. > >> > >> For a local community there may be many reasons to welcome pyrolysis > >> and biochar burial. It can deliver many local benefits, such as: > >> - thinning forests, removing crop residue and getting rid of waste, > >> thus reducing the risk of wildfires, pests and diseases, > >> - providing renewable energy on demand, > >> - enriching soil, which allows farmers to stay on their land and > >> reduces slash-and-burn of further forest; > >> - preventing long diseases (people can stop practices like burning cow > >> dung and wood in open fires, for cooking and heating). > >> People will welcome solar cookers together with pyrolysis and biochar, > >> and start to plant more vegetation, rather than to breed more > >> livestock (and the associated nomadic lifestyle). The fact that this > >> new lifestyle also reduces greenhouse gases in many ways may not be an > >> argument for them, but all the other benefits do weigh heavily. > >> > >> Try convincing a local community to carry their agricultural waste and > >> surplus wood to the sea, for dumping into the ocean, and they will see > >> no benefit in doing that. > >> > >> By contrast, local communities will see the benefits of less need for > >> fertilisers, as this saves money and also because this means less dead > >> zones in the sea and thus results in better yield of fish. So, local > >> communities will welcome biochar, even if they are unaware of > >> greenhouse gases. And of course, biochar and the associated change in > >> lifestyle as pictured above will also reduce global warming in many > >> ways, such as by: > >> - reducing the use of cow dung as fuel, meaning less methane due to > >> less livestock; > >> - reducing the use of fossil fuel such as oil, e.g. to power ships or > >> for heating; > >> - reducing the use of wood and conventional charcoal for heating and > >> cooking; > >> - increasing vegetation growth, thus drawing larger amounts of carbon > >> dioxide out of the atmosphere; > >> - reducing soot, which acts as a greenhouse gas and settles on top of > >> glaciers and polar ice, causing albedo change; > >> - reducing CO2 and methane emissions, compared to the alternative of > >> leaving much organic material to rot away; > >> - reducing emissions of nitrous oxide (N2O), due to less use of > >> fertilisers; > >> > >> Cheers! > >> Sam Carana > >> > >> > >> > >> On Tue, Feb 3, 2009 at 8:28 AM, Stuart Strand <[email protected] > > > >> wrote: > >>> > >>> I am reading the biochar literature now and it is fascinating stuff. > >>> But first glance reveals that pyrolysis schemes return 20-50% of the > >>> total carbon originally in the biomass back to sequestration in the > soil > >>> (ES&T Sept 1 2007, p 5932). So already there is an efficiency problem > >>> compared to CROPS which is 90% efficient. Also I am concerned about > how > >>> often biochar can be done on a given soil without undesirable effects > on > >>> agricultural soil ecology. And how permanent is charcoal in soil? > >>> Amazonian terra preta still contains charcoal, but how much was lost > >>> over the intervening 500 years? We would be storing biochar in soil in > >>> direct contact with the atmosphere. If it decays there is no safety > >>> factor as there would be in deep sediments. Safety factors and > >>> redundancy are important in engineering; although geoengineering > doesn't > >>> seem much like any other engineering I am familiar with... > >>> > >>> = 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/ > >>> > >>> -----Original Message----- > >>> From: [email protected] > >>> [mailto:[email protected]] On Behalf Of Andrew Lockley > >>> Sent: Monday, February 02, 2009 12:46 PM > >>> To: [email protected] > >>> Cc: Stuart Strand; [email protected]; > >>> [email protected] > >>> Subject: [geo] Re: Crop residue ocean permanent sequestration > >>> > >>> > >>> Isn't it more efficient to pyrolyse the waste first, recovering energy > >>> and reducing transport carbon? > >>> > >>> A > >>> > >>> 2009/2/2 David Schnare <[email protected]>: > >>>> 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 > >> > >> > > >> > > > > > > > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
