From: "David B. Benson" <[EMAIL PROTECTED]> Newsgroups: gmane.science.general.global-change To: "globalchange" <[email protected]> Sent: Monday, March 31, 2008 7:55 PM Subject: [Global Change: 2514] Re: nding Global Warming via Biocoal Sequestration
> > On Mar 31, 4:58 pm, "Michael Tobis" <[EMAIL PROTECTED]> wrote: >> Wouldn't the best way to end up with a given amount of buried coal be to >>refrain from digging that amount up in the first place? > > Yup. But it is a done deal, about 500 GtC worth. Much of that needs > putting back, one way or the other. <...> > But the point was that for quite a modest tax, it would be possible to > start 'putting it back' today, safely and 'forever' secure. Diamonds are forever. I suppose graphite is too, for present purposes. Both can be synthesized, for a price: is it worth it? Pressure-cooked bio-anthracite may be stable enough, indeed ordinary charcoal may be stable enough, but further research is required to measure biodegradability. Seems like a good idea. I suspect the excellent article you posted (http://orgprints.org/13268/01/Biochar_as_a_soil_amendment_-_a_review.pdf), or something very similar will find its way into the next IPCC assessment report on "mitigation strategies". Certainly worth a closer look, but the closer I look at the ointment I see a multiplying myriad of flies. On economic grounds, one estimate says torrefied wood transported 80 miles or less is competitive with coal at $80/ton for electricity production in South Carolina ( http://terrapreta.bioenergylists.org/files/TorrefiedWoodPresentation_2-08.pdf ) . Central Appalachian coal is currently selling at about that price (Powder River Basin coal goes for about $15/ton). Annual torrefied wood production from logging slash would amount to 10% of annual coal use for South Carolina. This suggests that even with the biofuel carbon offset, the coal plants should be fitted with carbon capture and storage technology if a radical reduction in carbon emissions is desired. That analysis assumes that forestry slash can be utilized for torrefaction, which is by no means certain. Looking at biomass removal as an alternative to prescribed burns in US forests, no less than 34 technical, economic, environmental, and socio-political barriers have been identified ( http://www.wrapair.org/forums/fejf/documents/task4/WRAP_Non-Burning.ZIP). In Wisconsin, with abundant forestry residues, two wood-burning electric power plants (Xcel Energy 100 MW units at French Island and Bay Front), and greater demand than available supply of waste-wood, market research has shown fuel-wood plantations to be more viable than forest residue harvest. Woody biomass energy plantations compete for land with food crops, and have a long investment recovery period: there are no woody biomass energy plantations in Wisconsin despite favorable conditions ( http://www.rs-inc.com/downloads/FOE%20Bioenergy%20Final%20Report_091707.pdf ). In February 2008 the NRC docketed Duke Energy's application to build two AP1000 power plants at the site of the existing Lee nuclear generating station in South Carolina, which amounts to about 33% of existing coal-fired generating capacity in that state. Doubling that state's nuclear capacity would eliminate coal from its generating mix - probably the most direct path toward "leaving coal in the ground", rather than fussing around in the forest. Doubling nuclear capacity would leave many smaller gas and oil-fired plants to experiment with carbon capture and storage along with bio-gas and bio-oil combustion, and would leave bio-char to be marketed primarily for soil improvement rather than energy production. If carbon emission taxes (or caps) and tradable carbon offset/sequestration credits can be secured by bio-char/gas/oil (and nuclear power) producers, so much the better for a "carbon negative" energy mix. -dl --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. 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/globalchange -~----------~----~----~----~------~----~------~--~---
