Creating OH radical is best done by leveraging existing processes. The radical is too short-lived to be effectively distributed when produced industrially, and energy costs are also too high.
The NOx recycling reaction series was chosen by L Zhou et al in their recent paper, as (in dry air) NOx is persistent and recycles. For the paper, see http://www.atm.helsinki.fi/FAAR/reportseries/rs-109/abstracts/Luxi%20Zhou.pdf Biological processes are able to indirectly create NOx by nitrogen fixation using symbiotic bacteria in root nodules. The plants can then be burned to liberate NOx into the atmosphere. The Lupin is one potential candidate, but other N2 fixers such as clover may also work. This could additionally perhaps be used as a source of biochar. The slight complexity is that NOx rains out in wet air, but the plants need to be grown in wet soil. Haul costs are likely to be a significant issue, therefore. One slightly 'far out' approach is to press ahead with the attempts to make non-legumes capable of fixing N2 through GM. This would revolutionize global agriculture, as well as giving a feedstock for geoengineering - as the N2 fixation process is the chemical underpinning of protein creation in crops. This isn't fanciful, and lots of work is already being done. An alternative technique with a much more limited scope of application is the addition of Br2 to create Br radical. This would need to be done in clean, damp air overlying the oceans. There is an existing 'hole' in the global OH shield east of Papua New Guinea, where this technique could be applied. http://eprints.ifm-geomar.de/10069/ It is one of the authors of this paper who suggested the Br technique to me. The downsides of creating NOx, as Zhou et al note, is that the both NOx itself, and the trop O3, are both toxic and also GHGs in their own right. It's not a pleasant solution to have to be considering. Readers should note the Kyoto controls on NOx, which have a beneficial effect by potentially reducing forcing, but a negative indirect effect by reducing OH radical production, which will become more significant in a low OH, high CH4 atmos. However, it should also be noted that locally high NOx concentrations are associated with different chemistry which does not lead to the production of OH and the consequential breakdown of methane. Therefore, industrial OH controls, particularly in smoggy cities, are generally beneficial, whereas in rural areas those same controls may have a positive RF outcome. This is a very interesting field, and one that more assistance and input is welcomed in. A On 26 July 2011 10:54, Sam Carana <sam.car...@gmail.com> wrote: > Oliver Tickell wrote: >> Another approach would be to enhance HO hydroxyl in the atmosphere - the >> main destroyer of methane. I have no idea how to set about doing this. It >> could be helpful to reduce emissions that utilise existing hydroxyl, such as >> miscellaneous hydrocarbons. But the chemistry is complex and it is hard to >> strictly follow through any intervention to its end results! > > There are a number of methods that seek to reduce methane whilst still > in the water (microbes, bubbles, covering the water surface with white > plastic to capture the methane, etc). > > One problem is that, in many places (including in ESAS), waters are > shallow and there's little time for microbes to do their work, > especially when hydrates suddenly start releasing huge amounts of > methane. > > Therefore, it's crucial to also look at hydroxyl and I advocate two > types of feebates to help reduce emissions that compete for hydroxyl: > 1. Energy feebates (seeking to reduce emissions from power plants and > help electrify transport); and > 2. Fees on livestock products to fund biochar, which will reduce > methane, while encouraging pyrolysis and thus also reduce BC, VOC and > the like. > http://knol.google.com/k/sam-carana/the-way-back-to-280-ppm/7y50rvz9924j/78 > > As to enhancing hydroxyl in the arctic, here are some suggestions: > > - Tri-Air Developments has developed a technology that combines UV > light with extremely low levels of ozone and mixes it with volatile > hydrocarbons, to produce hydroxyls. This technology is used in Cirrus3 > devices that emit hydroxyls in rooms of less than 25m3 up to rooms in > excess of 500m3 (image below). Perhaps such technology could be used > at large scale in the Arctic to combat the methane menace. > > - Another method may be to use UV light for photolysis of hydrogen peroxide. > > - Using UV light to break down methane in the Arctic could possibly be > achieved by model airplanes, equipped with LiPo batteries and with > solar thin film mounted both on top of and underneath the wings. > Numerous such planes could navigate the Arctic by autopilot in summer, > when there are high concentrations of hydrogen peroxide and when the > sun shines 24-hours a day. Flying figure-8 patterns with the wings > under an angle could optimize capture of sunlight, keeping the planes > in the air, while using surplus energy to power UV lights. At the end > of summer, the planes could return home for a check-up and possible > upgrade of the technology, to be launched again early summer the next > year. > > http://knol.google.com/k/the-threat-of-methane-release-from-permafrost-and-clathrates > > Cheers! > Sam Carana > > > > On Tue, Jul 26, 2011 at 1:44 PM, John Nissen <j...@cloudworld.co.uk> wrote: >> >> Thanks Oliver. >> >> I'm posting your comments to the geoengineering group with the questions you >> raise: >> >> 1. Could the CDM be used to fund, or help fund, our pilot project to trial >> various techniques for tackling the Arctic methane problem? Could it >> subsequently fund deployment of selected techniques? >> >> 2. Is there any way to enhance HO hydroxyl in the atmosphere? >> >> Cheers, >> >> John >> >> --- >> >> On 25/07/2011 17:52, Oliver Tickell wrote: >> >> Certainly it makes sense to do something about large, concentrated methane >> emissions where it is realistic to capture the gas and burn it off, or use >> it for heat / power. >> >> Does the CDM currently provide credits for methane projects of this type? I >> believe it does for methane from pig farms etc so there is no obvious reason >> why it should not. >> >> Another approach would be to enhance HO hydroxyl in the atmosphere - the >> main destroyer of methane. I have no idea how to set about doing this. It >> could be helpful to reduce emissions that utilise existing hydroxyl, such as >> miscellaneous hydrocarbons. But the chemistry is complex and it is hard to >> strictly follow through any intervention to its end results! >> >> Oliver. >> >> -- >> Oliver Tickell >> >> On 25/07/2011 15:09, Veli Albert Kallio wrote: >> >> I think definitely that we can prevent on-shore methane explosions, and >> saturated methane laden water pockets that are approaching nucleating point. >> >> There are 3 types of methane leaking: >> >> 1) generic leaking of methane from melting permafrost over large areas that >> provide widespread methane haze >> 2) spot type ongoing methane leaking from permaforst or onshore gas fields >> that are losing their subterranean gas compression due to ruptures. >> 3) explosive methane eruptions (methane clatrates, Lake Cheko's conical >> basin gas field failure in Tunguska 1908 as river fell into gas field and >> drove methane out). >> >> No. 1 you cannot control. No. 2 depends on how big and focused the leaking >> is, there are vast bubbling spots, in Azerbaijan there are flaming mountains >> where gas comes out of rocks. These you can control. No. 3 can be controlled >> by method of Professor Michel Halbwachs. Often methane can be spotted as a >> very focused leak on sea floor which might be possible to cap. So, I think >> the idea is valid in certain cases, in other cases it may not be workable. >> >> >> ________________________________ >> Date: Mon, 25 Jul 2011 11:28:12 +0100 >> From: oli...@its.me.uk >> Subject: Re: Arctic methane workshop, London, 15-16th October CONFIRMED >> To: crisis-fo...@jiscmail.ac.uk >> >> John, I think you are on a hiding to nothing trying to trap or destroy the >> methane. >> >> The reason is simple - the emissions are spread over such a vast area of >> many millions of sq.km. Even to trap and destroy the methane emissions from >> 1sq.km would be a fantastically difficult and expensive task. >> >> So you can simplify things by just ruling this one out at the start! >> >> Oliver. >> >> -- >> Oliver Tickell >> >> On 22/07/2011 18:29, John Nissen wrote: >> >> Dear all, >> >> In case you were not aware, the workshop, which was to have been 3-4th >> September, is now going to be on 15-16th October. Here is the background >> and purpose of the workshop... >> >> A group of scientists and engineers (including myself) is deeply concerned >> about the potential of methane from thawing permafrost in the Arctic to >> cause irreversible, catastrophic and unsurvivable global warming. Major >> factors are the unexpectedly rapid retreat of sea ice [1] and the >> unexpectedly large quantities of carbon which might be emitted as methane >> [2]. In June 2010 we wrote an open letter to Obama's scientific adviser, Dr >> John Holdren, suggesting action was urgently needed to address the methane >> issue [3]. Some sea ice experts, including Professor Peter Wadhams in our >> group, now reckon the Arctic Ocean will very likely become seasonably ice >> free this decade if there is no action to cool the Arctic. >> >> Recently Peter Wadhams has drawn my attention to work of Natalia Shakhova >> with Igor Semiletov on East Siberian Arctic Shelf (ESAS) - particularly >> concerning the present large emissions of methane and the possibility of >> release of much larger quantities "at any time". So we have been wondering >> whether anything can be done quickly to reduce this methane threat. We >> have been discussing possible action, and plan further brainstorming at a >> workshop in October in London. >> >> We are hoping this workshop will lead on to a pilot project to trial the >> most promising techniques. Here is an extract from the proposal, concerning >> management of the methane environment at the local level (e.g. in ESAS): >> >> [begin quote] >> >> Approaches can be categorised according to where the intervention action >> takes place. Where the methane is from lake or sea bed, the action could >> be: >> >> >> below the permafrost, where there may already be methane or methane hydrate; >> in the permafrost, or to plug gaps in the permafrost where methane is >> rising; >> in the bed of the sea or lake, above the permafrost layer; >> in the water at the bottom of the sea or lake; >> at the surface of the sea or lake, and below any ice; >> at the point of emergence of methane into the atmosphere. >> >> In the case of methane from wetlands, some of the above actions would be >> relevant to ponds, commonly forming above permafrost and emitting most of >> the wetlands methane. There is also the possibility of pond drainage as a >> means to reduce methane emissions. >> >> Returning to the case of lakes and deeper water, the problem with trying to >> deal with methane below the permafrost is that any disturbance is liable to >> trigger an eruption of methane through gaps in permafrost known as taliks. >> Commercial methods of extraction of natural gas can be used when there is in >> impermeable layer above the gas, but cannot be applied in our situation >> because of the danger either from puncture of the permafrost or from >> enlarging existing taliks. >> >> In the bed of the sea or lake there may be aerobic microbes, capable of >> ‘digesting’ the methane and converting it into less harmful products. >> Supply of oxygen and nutrients to such microbes could be helpful. Microbes >> may also congregate in a ‘biotic layer’ at the bottom of the sea or lake. >> These could be boosted or encouraged to proliferate. >> >> Methane can dissolve in the water. At atmospheric pressure and freezing >> point, 0.04 grams of methane will dissolve in a litre of water. Therefore >> one approach could be to extract the water when it is nearly saturated with >> methane. A more commercial approach would be to use a specific methane >> solvent in a relatively heavy layer, resting on the seabed (or lake bed). >> From time to time the solvent would be extracted, scrubbed to remove the >> methane, and replaced. A major issue could be containing the solvent and >> making sure there was no long-term harm to the marine habitat. >> >> A general problem with emissions of soluble gas from the beds of lakes and >> shallow seas is that the water column can become unstable – with the >> dissolved gases coming out of solution, leading to a sometime violent >> upwelling. Because of the low density of the rising column of bubble-filled >> water, ships on the surface can sink! Furthermore any turnover of the >> water allows warmer surface water to be transported towards the bottom, >> which can lead to permafrost melt and enhanced methane production. Thus any >> underwater approach to methane must take into account the stability of the >> water column. >> >> However if the methane is already bubbling to the surface, then one could >> consider capturing it before it escapes into the atmosphere. One way would >> be to use ice, which will anyway be present in winter. The methane collects >> under the ice, and boring through the ice, one could collect the methane >> that emerges. The problem would be keeping an intact layer of ice >> throughout the year. Therefore one might consider strengthening the ice to >> produce ‘pykrete’ [3]. However a more promising approach would be to have >> mats, preferably of methane-absorbing substance (biological or chemical) >> which could be harvested to collect the methane. But care would be needed >> not to deplete oxygen from water underneath the mats, since oxygen is >> required from the important methane-digesting microbes in any biotic layer >> that has formed above the sea or lake bed. >> >> If and when some methane bursts into the atmosphere, it could be burnt or >> ‘flared’. In remote areas, and in open water, this could be problematic. >> Furthermore, methane only burns in air at between 5% and 15% concentration >> by volume. As it disperses quickly, one would need to torch the methane >> within a few seconds of eruption. It is almost impossible to imagine how >> this could be done in a remote location, unless the methane is laser-zapped >> from a monitoring satellite! >> >> [end quote] >> >> The pilot project will promote a three-prong attack, though trials will >> focus on local action (particular item 2): >> >> 1. cooling the Arctic, regionally or locally, using SRM geoengineering; >> 2. management of the methane environment at the local level (see quoted text >> above); >> 3. capture or destruction of methane, already in the atmosphere. >> >> The capture or destruction of methane in the atmosphere is a last resort, if >> other approaches fail. It would also be vital if there were a sudden large >> emission of methane with serious warming potential. Such "air capture" or >> destruction could be local or not. The advantage of local air capture is >> that efficiency may be improved through having the methane at higher >> concentration (as the efficiency is for CO2 air capture). >> >> The workshop is intended as a brainstorming session to establish the most >> promising techniques which might be trialled in the pilot project. If you >> have already expressed an interest in attending the workshop, please confirm >> that the new date is OK. If you have not yet expressed an interest, and >> would like to attend, let me know. >> >> John Nissen >> >> Chiswick, London W4 >> >> [1] Copenhagen Diagnosis, 2009 >> http://www.ccrc.unsw.edu.au/Copenhagen/Copenhagen_Diagnosis_LOW.pdf >> see figure 13 page 30. >> >> [2] Ibid, see page 21 - referring to Shuur et al 2008. >> >> [3] >> http://geo-engineering.blogspot.com/2010/06/sea-ice-loss-stuns-scientists.html >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To post to this group, send email to geoengineering@googlegroups.com. >> To unsubscribe from this group, send email to >> geoengineering+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/geoengineering?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to geoengineering@googlegroups.com. > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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