Tom, I found this news report: http://www.ipsnews.net/2009/10/thailand-renewable-energy-not-so-clean-and-green-after-all/ Not such a nice story. I do not think it's a good idea to burn rice hulls or rice straw in either power plants, brick kilns or household stoves.
Paul On Sat, Jun 15, 2013 at 1:10 PM, Paul Olivier <[email protected]>wrote: > Tom, > > I have read in many articles that cristobalite can form at temperatures of > about 900 C. > http://www.jicosh.gr.jp/old/niih/en/indu_hel/2004/pdf/42-2-24.pdf > In burning rice hulls, temperatures can easily exceed 900 C. > If cristobalite forms and is breathed in, human health is severely > impacted: silicosis, tuberculosis, cancer and so forth. > > *Silica (SiO2) is a constituent of the ash produced by the combustion > process. Different > types of biomass fuels contain different quantities of silica. The > International Agency for > Research on Cancer has classified silica as a human carcinogen. Long term > inhalation > of airborne silica particulates can cause lung cancer or other related > health problems. > As rice hull ash contains high levels of silica (~15%), its use as a > biomass fuel > presumably increases the risk of developing silicosis-related illnesses, > and care should > be used in handling the ash.* > > http://www.reap-canada.com/online_library/IntDev/id_eco_sugarcane/7%20Strategies%20for.pdf > > *Silica (SiO2) is the main mineral component of rice husk ash (RHA) > (85-90 per cent). It carries serious health risks, particularly to the > respiratory system.* > http://www.dhf.uu.se/pdffiler/cc7/cc7_web_art4.pdf > > Cristobalite can be present in both the ash and fly ash. If someone > designs a stove to burn rice hulls or rice straw, he has to be sure that > temperatures remain below the point of cristobalite formation. > > Paul > > > On Sat, Jun 15, 2013 at 11:18 AM, Tom Miles <[email protected]> wrote: > >> Paul,**** >> >> ** ** >> >> After discussing rice hull combustion and gasification at some length you >> are now saying this is dangerous. Why, specifically? You have discussed the >> potential to emit cristobalite but there is no evidence of the hazard it >> presents. What evidence do you have that burning rice husks or rice straw >> is a health hazard?**** >> >> ** ** >> >> Tom **** >> >> ** ** >> >> *From:* Stoves [mailto:[email protected]] *On >> Behalf Of *Paul Olivier >> *Sent:* Friday, June 14, 2013 8:56 PM >> *To:* JJ Claire; Discussion of biomass cooking stoves >> *Subject:* Re: [Stoves] Chimneys, rice husks [Ovens]**** >> >> ** ** >> >> JJ,**** >> >> I would not recommend that you burn rice hulls ir rice straw.**** >> >> In many cases this is quite dangerous.**** >> >> Paul**** >> >> ** ** >> >> On Sat, Jun 15, 2013 at 9:40 AM, JJ Claire <[email protected]> wrote:* >> *** >> >> Greetings one and all,**** >> >> I visit the Philippines often and usually stay about six months a year. >> **** >> >> I often use a rice hull stove. I would like to get a plan to build a *** >> * >> >> concrete stove. I am also wondering if there is such a thing as building >> **** >> >> an 'oven' using cement and/or concrete? I would like to build one, **** >> >> a white model if possible, [vice a black model], if such a plan is **** >> >> available and if the technology would be practical. We have a **** >> >> lot of rice hulls and not all that much firewood. **** >> >> I would be open to heating the oven with firewood and then **** >> >> maintaining the heat level with or by burning rice hulls. I have**** >> >> a lot of rice hulls and want to make the best use of the hulls.**** >> >> I currently use the wood ashes to make lye so I can make soap, **** >> >> but I have not used any ashes from rice hulls to make lye. I**** >> >> wonder if making lye with rice hulls is possible.**** >> >> The rice hull stoves we use are sort of a metal pail with a wire rack. * >> *** >> >> I am looking for a stove, hopefully one that is hot, medium and cool, *** >> * >> >> for cooking with rice hulls over a long number or years. **** >> >> On our island, rice hulls are still burned to 'get rid of them', and **** >> >> believe it or not, rice straw is still burned. I often ask neighboring*** >> * >> >> farmers to bring me their straw and provide them a small bit of **** >> >> cash for doing so. We use the rice straw for making compost.**** >> >> We add some rice hulls to the compost. Most of the rice hulls**** >> >> are burned for fuel to cook with. We add the char from the cooking**** >> >> process to the garden. I am wondering if we are making the best**** >> >> use of the rice hulls and if the plans I am speaking of by post **** >> >> are available. **** >> >> Please inform, I am open to suggestions and direction.**** >> >> Blessings,**** >> >> JJ**** >> >> **** >> >> *From:* "[email protected]" <[email protected]> >> *To:* Discussion of biomass cooking stoves < >> [email protected]> >> *Sent:* Friday, June 14, 2013 5:02 PM >> *Subject:* Re: [Stoves] Chimneys, rice husks**** >> >> >> [Default] On Fri, 14 Jun 2013 17:37:30 -0400,"Crispin >> Pemberton-Pigott" <[email protected]> wrote: >> >> >We are experimenting in Indonesia with draft-operated buoyancy balancers >> to limit the pull to the ideal even when combustion conditions change in >> the large wood stoves. They are easy and cheap to make. They are mounted on >> the side of the stack of all oil furnaces. >> >> We have used them on pellet stoves (which have their own id fans) to >> limit draught on an insulated ss chimney that rose through 4 floors. I >> wasn't entirely happy with the idea as it raised the possibility of >> the boiler room getting combustion products if the seal wasn't good, I >> would have been happier if the air was sucked from outside. In fact >> there was subsequently a problem but this was down to poor >> maintenance. >> >> AJH >> >> _______________________________________________ >> Stoves mailing list >> >> to Send a Message to the list, use the email address >> [email protected] >> >> to UNSUBSCRIBE or Change your List Settings use the web page >> >> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org >> >> for more Biomass Cooking Stoves, News and Information see our web site: >> http://stoves.bioenergylists.org/ >> >> >> **** >> >> >> _______________________________________________ >> Stoves mailing list >> >> to Send a Message to the list, use the email address >> [email protected] >> >> to UNSUBSCRIBE or Change your List Settings use the web page >> >> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org >> >> for more Biomass Cooking Stoves, News and Information see our web site: >> http://stoves.bioenergylists.org/ >> >> **** >> >> >> >> >> -- >> Paul A. Olivier PhD >> 26/5 Phu Dong Thien Vuong >> Dalat >> Vietnam >> >> Louisiana telephone: 1-337-447-4124 (rings Vietnam) >> Mobile: 090-694-1573 (in Vietnam) >> Skype address: Xpolivier >> http://www.esrla.com/ **** >> >> _______________________________________________ >> Stoves mailing list >> >> to Send a Message to the list, use the email address >> [email protected] >> >> to UNSUBSCRIBE or Change your List Settings use the web page >> >> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org >> >> for more Biomass Cooking Stoves, News and Information see our web site: >> http://stoves.bioenergylists.org/ >> >> >> > > > -- > Paul A. Olivier PhD > 26/5 Phu Dong Thien Vuong > Dalat > Vietnam > > Louisiana telephone: 1-337-447-4124 (rings Vietnam) > Mobile: 090-694-1573 (in Vietnam) > Skype address: Xpolivier > http://www.esrla.com/ > -- Paul A. Olivier PhD 26/5 Phu Dong Thien Vuong Dalat Vietnam Louisiana telephone: 1-337-447-4124 (rings Vietnam) Mobile: 090-694-1573 (in Vietnam) Skype address: Xpolivier http://www.esrla.com/
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