Keith etal I respond below in bold, with [RWL:
On Feb 22, 2014, at 7:23 PM, Keith Henson <[email protected]> wrote: > On Sat, Feb 22, 2014 at 1:35 PM, Ronal W. Larson > <[email protected]> wrote: >> Keith and ccs: >> >> Yesterday, you wrote: "PS. Biochar is a good idea in any case. It would >> be even better if the heat to make it came from a cheap renewable source and >> the off gas >> collected to make transport fuel." >> >> Both of your hopes are already standard (indeed mandatory if you want good >> economics) for biochar. The exothermic pyrolysis reactions necessary to >> convert biomass to ash yield about 18 GJ per tonne biomass. > > Coal runs around 24 GJ/ton. [RWL: and oil/gas higher still. But we are talking here of phasing out all fossil fuels. No fossil fuel is assumed in any CDR approach. > >> Obviously less >> if you convert biomass to charcoal. If you achieve 30% char, with a value >> of 30 GJ/kg char), then you have about a 50%-50% [or 9 GJ-9GJ} split, with 9 >> GJ/kg biomass of gas/liquid energy available for backing up wind and solar - >> in any of the usual energy forms (thermal, gas, liquid, electricity) or end >> uses (residential, industrial, commercial, transportation). > > I missed where the energy needed to process the biomass to char and > gas comes from. [RWL: Out of the roughly 9 GJ/tonne not ending up as char. Of course there will be some needed energy not from the biomass being pyrolyzes. But we are talking exothermicity here. > >> One other key word in your remark was "cheap". A typical cost for biomass >> these days is $50/tonne. If fully combusted, this is a cost of $50/18 or >> less than $3/GJ (similar in $/MMBtu terms). > > Coal at $30 a tonne and a higher heating value would be about half that cost. [RWL: Not permissible in any biochar scenario. > >> Low cost is the reason that >> there is now more global energy coming from biomass than nuclear, hydro, >> wind or solar. > > You must be counting firewood for cooking in 3rd world countries. [RWL: Yup - maybe for 3-4 billion people. > >> The cost of biomass energy of course roughy doubles if >> combustion is replaced by pyrolysis, but the char value when you consider >> long term out year soil improvement is on the verge of being enough. Carbon >> sequestration value of $15/tonne CO2 equates to about $50/tonne char (using >> the 44/12=3.67 ratio, and the fact that char is not pure carbon), There is >> not enough incentive being offered these days at $15/tonne CO2 - but some >> voluntary markets are in operation at about these levels for biochar. >> >> Some claim that biomass cannot be renewable - but there are plenty of >> counter examples. The production of biochar makes renewable/sustainable >> much more likely than other uses of biomass, given our big long-term need >> for biofuels and other forms of bioenergy to get us 100% off of fossils >> fuels. > > I fully agree with you that biomass is renewable. I disagree with you > that there is enough of it to support the kind of high energy life > which we have become used to. [RWL: Agreed - but I would say "...high fossil energy life..". We can certainly save money if we think in terms of reducing wasted energy and negative externalities associated with fossil fuels. Lots of energy efficiency and demand side management in every large biomass scenario. Plus much conversion to alternatives to biomass - especially needed if we are hoping to see any CDR. > David MacKay has a nice metric that a > typical road in the UK would need an 8 km wide strip of biomass to > support the traffic on the road. [RWL: I just spent a half-hour wandering around his fine book, but couldn't find this statistic. But the UK is one of the poorer places to grow biomass. And my biomass scenario, as stated above, uses much less biomass per road mile than he is probably assuming here. Britain will be an importer of biomass - but maybe less total imported energy than they now use. > I agree with you that in the long > run biomass *will* get the human race 100% off fossil fuels. [RWL: I am hoping for "long run" about 20% of the RE total from biomass (and a similar amount going for CDR). I have seen some 100% RE country scenarios with biomass at 40% (and zero "official" CDR scenarios at any level). > However, > it will be a _much_ smaller population in a somewhat radioactive world > since several billion people will starve or die in resource wars. [RWL: I disagree on that need - strongly. > > The reason humans switched from biomass (wood mostly) to coal and then > oil was partly lower cost, but also because there just wasn't enough > biomass for the size of the population. The problem is much worse > today. [RWL: Agreed. But, as said above, whereas not too many centuries ago, we were near 100% biomass and there was no shortage, I am sure we will struggle to find the amount we want for the combination of energy and CDR. Farmers and foresters will benefit from that presumed shortage. However, we have ruined a huge amount of land that biochar can help reclaim. I am not claiming it will be easy to sequester several wedges per year (to be followed by a similar annual amount from out-year CDR benefits that are mostly overlooked; soil carbon can increase as much or more than the standing biomass). I believe the necessary wedges can be done, even using some of the pessimistic numbers in the McKay book - which get much better as you move towards the equator. Ron > > Keith > >> You emphasized "transport fuel". See www.coolplanet.com. They use the term >> "fractionation" - their new advanced form of pyrolysis at high pressure and >> clever catalysts. Biochar is reported to be an important part of their >> corporate strategy for biofuel marketing. >> >> Ron >> >> >> On Feb 21, 2014, at 5:18 PM, Keith Henson <[email protected]> wrote: >> >> Olaf and I did some off list discussion. The result was that olivine >> mining looks to be at least ten times more expensive than the solar >> power from space option. >> >> That is if I have put the right numbers into the laser propulsion and >> power satellite economic model. And if Olaf has the right numbers for >> the cost of mining olivine. >> >> BTW, on the surface SRM front, PV or thermal solar power plants look >> much blacker from space than the desert they replace. How much this >> will affect warming depends on how many we deploy. It may or may not >> become a problem with extreme deployment. Arizona is hot enough as it >> is. >> >> Keith >> >> PS. Biochar is a good idea in any case. It would be even better if >> the heat to make it came from a cheap renewable source and the off gas >> collected to make transport fuel. >> >> On Fri, Feb 21, 2014 at 3:15 PM, Michael Hayes <[email protected]> wrote: >> >> Greg, Kieth, Olaf et.al., >> >> >> >> >> Ref: https://groups.google.com/d/msg/geoengineering/nncNYX7jS2U/AveEEzEMLuEJ >> >> >> >> The large basket strategy that Greg puts forth does seem to be the most >> sound approach. On the cost and carbon footprint of milling olivine; Olaf >> has done reliable work showing that this can be be inexpensively done using >> wave action. And, by using wave action in the reduction of the olivine, the >> synergistic effect is a localized pH adjustment of the water. Thus, the >> carbon footprint issue can be negated to a large degree. Olivine, in >> general, does offer multiple bird hits with one rather simple stone. >> >> >> >> >> The philosophy of "and investigate/employ a lot of other technologies, >> actions, and behaviors as well to help solve the problem." has been largely >> overshadowed by the understandable desire to develop means and methods which >> reduce everything down to a simplistic formula. As we know, Nature is not >> simplistic and global warming is far from simplistic. Expecting a simplistic >> solution which is flexible enough to meet Natures needs (and ours) may not >> be realistic. >> >> >> >> >> Looking for the most productive synergistic links between the >> technologies/socioeconomic needs/governance needs etc. and recognizing how >> the highest possible synergistic effect(s) can be achieved within a general >> working arena could prove out as being a productive first step in building a >> road-map for global warming mitigation and adaptation. Instead of working >> towards the reduction of technology to a minimum, it may be best to find >> ways to be as inclusive as possible. To date, I've found that the Large >> Scale Mariculture (LSM) concept can act as a nexus for multiple technologies >> that have been well covered within this group and elsewhere. The following >> list is not exhaustive: >> >> >> >> 1) Olivine for multiple roles >> 2) Biochar for multiple roles >> 3) Surface SRM (non-SSI) for multiple roles >> 4) MCB as an adjunct means for extending SRM coverage (ENSO buffering) >> 5) BECCS, a carbon negative replacement of FFs >> >> >> >> >> Kieth has a strong interest in low cost space launch (as I). Having access >> to multiple launch platforms within the subtropical convergence zones (STCZ) >> that, by and large, pay for themselves (and possibly help pay for launch >> services) could be a significant factor in getting to the advanced space >> based energy stage that Kieth has envisioned. The STCZs function well as >> regional launch sites and LSM platforms could be the nexus of the launch >> efforts. >> >> >> >> >> This post started out defending the use of a 'rock'. Yet, getting to LEO can >> be reasonably linked with that rock as olivine is actually, IMHO, important >> in the technology mix needed to make large scale multi-use ocean based >> systems profitable. >> >> >> >> >> Best, >> >> >> >> Michael Hayes >> 360-708-4976 >> The Large Scale Mariculture Option: Draft >> http://voglerlake.wix.com/vogler-lake-web-site -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
