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Saving the Planet, v2.0 by Planet Physicians

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Tom Mallard

Jan 29, 2013


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A strategy to have low carbon liquid fuels for transportation and heating. Studied wastewater treatment since college and visited the full-recycle plant at North Lake Tahoe a couple of times ... wastewater effluent is algae food but making biodiesel isn't especially low carbon-footprint because the water isn't recycled. If you don't recycle the water you'll have to truck the slurry/slime/sludge to some fields for dispersal regardless of method used at the treatment plant or biodiesel plant, this a heavy blow to carbon-footprint because of the weight, overhead is high on scheduling, many times contains pathogens and so on. The other issue is harvesting, centrifuges are used at about 100% of biodiesel plants using algae, this requires a lot of electrical power so the low carbon-footprint is gone but still way better than a fossil fuel so this is relative but significant for costs not just carbon. When you recycle the water what's left are de-watered, pressed algae cakes that are lightweight, all the pathogens are consumed by bacteria then algae in the end, and importantly it's a good fertilizer & soil enhancer & can be stored dry & applied on-demand making it a far better agricultural product over slurries & sludges. Finally my favorite algae Spirogyra jumped wheat yields 25% tests ongoing but there ya' go. So we don't need gasoline or fossil-diesel, using algae to purify a city's wastewater can return 7L/2gal per person per day on the system, the USA burns 6L/1.6gal per day per person in all types of transportation fuels. This can be miniaturized to family-farm-ranch scale so that anyone can make the fuel they need by living in a home. Then we need a low cabon-footprint fuel that runs in any IC-engine on the planet or it won't scale, from leaf-blowers to aircraft, and biodiesel can be tweaked to run in the gamut of engines with 3-grades at the pump, 2 for gasket & seal types in engines & the third to deal with 2-stroke/4-stroke. Biodiesel from algae consumes CO2 and emits O2, so when scaled this technique will seriously drop global CO2 values from world transportation running on wastewater locally so costs are low on distribution, distances trivial from biodiesel producer to pump, the water is recycled, the pressed cakes are a good agricultural product and this in high-volume so a large resource for local food production.

Jonathan Sheppard

Jun 15, 2013


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Love the planet physicians' proposal . Absolutely wholeheartedly agree that the key to mitigating ocean acidification and moderating atmospheric carbon lies in mobilising silicate minerals . Being ignorant of these interesting electrolysis results , I'd signed in here to make a last minute proposal for hydraulic ram driven rock cutting equipment , or pan-American high speed rail at around 1700m above m.s.l. , thinking that maturing humid watersheds with feldspar probably the most promising geo-engineering approach . Imagine my delight when a whole new vista of possibilities opens up ! Thanks guys . Looking forward to following developments here and a really sustainable future . Using nature as a teacher

2013geoengineeringjudges 2013geoengineeringjudges

Jul 5, 2013


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Thank you for the proposal. Please find below an integrated set of comments and some additional comments from two reviewers on your proposal. Integrated Comments The scheme presented here relies on proven electrochemistry, and its approach is established in the references that are cited. What the scheme does is attempt a large scale acceleration of weathering. It would be helpful to have context for non-experts who read this proposal on the kinetics of weathering reactions, and describing what the key innovation in this proposed scheme is for accelerating the process As you will see below, the main themes of the comments are the following. A set of questions has to do with whether the process can be scaled up to make a significant impact on atmospheric CO2, how large these electrolysis cells would generally be, on the order of how many of these would be required, and whether the required scale up of deployment (for it to constitute the major part of a geoengineering solution) can be achieved. Second, what are the energy costs of the process? The proposal mentions using renewable energy. But might the effort required to generate sufficient renewable energy to deploy this scheme, at the scale where it can make a large difference to atmospheric CO2, be better used to substitute fossil-fuel CO2 emissions? Can you estimate some relevant quantities that speak to this issue, in order to help others understand your thinking on this? Third, what are the engineering challenges that would have to be solved? Can seawater be used directly as input for the electrochemical cells? Can the brine be discharged directly back into the oceans? If some of these steps have to be resolved before the scheme can be deployed, how would they affect the scalability of the process? Fourth, could you please elaborate on the economic cost of the scheme, and how this compares with alternate methods of mitigating CO2 emissions or capturing CO2 from the air? The reviewer comments are below. Reviewer 1 The proposal is based on large scale electrochemistry that in itself will require excess carbon neutral electrical energy production, such as hydro or photovoltaic (neither truly carbon negative in production). However, the energy calculation indicates an energy savings versus current industrial scale electrolytic processes. The scale of the operation would seem to be unrealistically enormous in volumes of processed sea water or alternate electrolyte. The brines themselves will need to be pH neutral when discharged to the sea. Bicarbonate discharges really only become biologically useful if introduced to optimal cultures and then achieve a double benefit. Novel aspect is co-generation of hydrogen gas (note fuel cell market reactant) and chlorine (in itself industrially useful). Reviewer 2 This sounds like perhaps a variant of an idea of Kurt House's, to use essentially the electrochemical production of NaOH and HCl by hydrolysis of NaCl in water.  The strong acid can be used to dissolve the rock more effectively than can a direct reaction of CO2 (H2CO3) with the rock, because increasing temperature pushes the equilibrium for the CO2 /rock reaction toward CO2, whereas HCl isn't a gas so it's not so favored by high temperatures. It's a clever idea; it sounds expensive relative to other options but that shouldn't preclude further work on it. Seawater is probably chemically too messy to serve as a primary input to such an electrochemical system, would be my guess, which would limit its scalability. The proposed work, however, to get a team of scientists to evaluate it, kind of leaves me cool. The proposer(s) should clear out a place in the garage and play with this themselves.

2013geoengineeringjudges 2013geoengineeringjudges

Jul 31, 2013


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To remove CO2 from the air as well as limit the effects of acidification of the ocean on the marine biosphere, this proposal envisions accelerating the natural weathering process. As a result of natural weathering, the Earth system limited extreme ocean acidification during past periods of Earth history that had a very high CO2 concentration. This proposal envisions accelerating this process by a large factor by subjecting rocks to acid produced in an engineered electrochemical reaction. The process produces hydrogen as a by-product, which is intended as a fuel. While the chemistry is relatively straightforward, implementing such a strategy over the large global ocean area would require very large amounts of energy and materials and a very extensive engineering effort, and it is not clear that this is feasible. It appears more likely any practical application would, if the approach worked as described in the scheme, necessarily be limited to reasonably small but ecologically important areas. While this is important, this alone would not have the large effect on the atmospheric CO2 concentration needed for this proposal to become a major part of a geoengineering approach to limiting climate change. Members of the Climate CoLab community are also invited to read a more comprehensive set of “Comments by Expert Reviewers on the Geoengineering Proposals” at

Wyatt Wadsworth

Aug 23, 2013


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William Haaf

Sep 21, 2013


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i like the concept but an avg (of the top 100) coal burning utility emits 12 million metric tons of CO2 / yr. so to neutralize one site would require 30 million tons. is this really doable ? practical? where would that limestone come from and how crushed to present large surface area?

Wei Shyy

Oct 2, 2013


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This is a sensible proposal integrating numerous aspects, based on known principles and creative thinking, to help meet the challenges. There are many unknowns but the issues seem treatable. The team deserves to be supported.

Wolfgang Sanz

Oct 30, 2013


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The proposal is very innovative, but also very ambitious. I like it :-) I am especially interested in the energy needed for this process. You claim about 400kJe/mol CO2, that is about 9 GJ/ton CO2 (if I am right). This needs an enormous amount of energy, which should not be provided by fossil fuels. What would be the ratio of CO2 captured to emitted if the needed energy is provided by a coal plant? If we use renewable energy I would like to know how much CO2 can be removed from atmosphere by existing plants. I think the percentage is relatively small. Therefore the authors propose an energy concept which should provide plenty of renewable energy in the form of hydrogen. Could the authors provide more details on the energy ship concept? Can this concept provide remarkable amounts of renewable energy? And if yes, how much CO2 can be removed from atmosphere if this concept is realized?