The R-value per inch on rice hulls was 3. And unlike cellulose insulation, if properly installed, they do not settle over time. https://dl.dropboxusercontent.com/u/22013094/Rice%20Hull%20House/ASTM/114941Report.pdf https://dl.dropboxusercontent.com/u/22013094/Rice%20Hull%20House/ASTM/astm1.pdf I even built what was called a Rice Hull House: https://dl.dropboxusercontent.com/u/22013094/Rice%20Hull%20House/The-Rice-Hull-House2.pdf
Thanks. Paul On Fri, Jun 14, 2013 at 9:31 AM, Kevin <[email protected]> wrote: > ** > Dear Paul > > Very interesting!! > > Sawdust has an "R-Factor" of about 2 BTU-hr/ft^2- degF-inch. Would you > recall the R-Factor for Rice Hulls? > > Best wishes, > > Kevin > > ----- Original Message ----- > *From:* Paul Olivier <[email protected]> > *To:* Discussion of biomass cooking stoves<[email protected]> > *Sent:* Thursday, June 13, 2013 11:22 PM > *Subject:* Re: [Stoves] Meat grinder fuels for TLUDs was Re: wheat husk > pellets > > Tom, > > Ten years ago I had worked a Carl Simpson of Riceland in Arkansas on the > idea of using rice hulls as insulation. We found out that untreated rice > hulls make an excellent insulation, and unlike cellulose insulation, > chemicals do not have to be added to rice hulls to make them fire and fungi > resistant. Untreated rice hulls passed all ASTM tests for insulation > materials. Carl told me of piles of rice hulls that had been in place > outdoors for over 20 years. Rice hulls do not decompose very easily. I do > not know much about wheat hulls. > > Paul Olivier > > > On Fri, Jun 14, 2013 at 4:39 AM, Tom Miles <[email protected]> wrote: > >> Fair enough. Wheat byproducts that I have worked with are usually >> either a granular or powdery meal. I don’t know how much hulls would break >> down biologically. Proabbly not much since they are used as a bulking agent >> for compost. **** >> >> **** >> >> Tom**** >> >> **** >> >> *From:* Stoves [mailto:[email protected]] *On >> Behalf Of *Legacy Mail >> *Sent:* Thursday, June 13, 2013 2:18 PM >> >> *To:* Discussion of biomass cooking stoves >> *Cc:* Discussion of biomass cooking stoves >> >> *Subject:* Re: [Stoves] Meat grinder fuels for TLUDs was Re: wheat husk >> pellets**** >> >> **** >> >> Tom, Paul,**** >> >> the problem with running a fiberbound residue through, especially, an >> augur driven meat mincer type die, is that the process itself tends to >> shear the very fibers that do the binding. 1" dia x 1 long sausages are >> about as small as you can go from our experience .**** >> >> Richard**** >> >> >> Sent from my iPhone**** >> >> >> On Jun 12, 2013, at 21:07, "Tom Miles" <[email protected]> wrote:**** >> >> Paul,**** >> >> **** >> >> The hulls would have to be incorporated into a meal that when dried would >> form into a ball or pellet shape by using something like a meat grinder. It >> might be possible to “ret” them with the coffee skins a la Bryant/Legacy. >> Then you would have something to form. I have always experienced a large >> quantity of fines with rice husks and straw. You could tie those up by >> combining them in a meal but you need something fibrous to hold them >> together. **** >> >> **** >> >> Think of other uses for composted rice husks. I know someone who has made >> thousands of cubic yards of peat substitute by composting rice husks. So it >> is clearly possible to biologically “process” the husks to a beneficial >> form. Once you have composted the hulls why use them as fuel? They could be >> better as a soil amendment. The composting should generate biological >> binders that would give you a choice of densification methods. Pressing >> hulls through a metal die will just wear out the die. Probably not the >> first choice. I think there is a form of fuel or soil amendment that could >> be created. Meanwhile keep the day job and perfect your rice husk TLUD ** >> ** >> >> **** >> >> Tom **** >> >> **** >> >> **** >> >> *From:* Stoves >> [mailto:[email protected]<[email protected]>] >> *On Behalf Of *Paul Olivier >> *Sent:* Wednesday, June 12, 2013 7:38 PM >> *To:* Discussion of biomass cooking stoves >> *Subject:* Re: [Stoves] Meat grinder fuels for TLUDs was Re: wheat husk >> pellets**** >> >> **** >> >> Tom's explanation still leaves me with a few questions.**** >> >> Would the rice hull have to be ground into a powder to go through a meat >> grinder?**** >> >> It takes a lot of energy and maintenance to grind up rice hulls.**** >> >> With a conventional pellet machine, rice hulls do not have to be ground >> up.**** >> >> What binder would be used with rice hulls?**** >> >> **** >> >> Paul**** >> >> **** >> >> On Thu, Jun 13, 2013 at 9:08 AM, Paul Anderson <[email protected]> >> wrote:**** >> >> Stovers, >> >> Tom gave a good explanation. His message is now in the Listserv >> Archives. But how can such content be made more available for future >> readers?**** >> >> >> >> Paul >> >> Paul S. Anderson, PhD aka "Dr TLUD" >> Email: [email protected] Skype: paultlud Phone: +1-309-452-7072 >> Website: www.drtlud.com**** >> >> On 6/12/2013 4:24 AM, Tom Miles wrote:**** >> >> Andrew, >> >> Good explanation. >> >> Think of two methods of forming fuels. One requires high heat and >> pressure. >> The other requires water and biological or chemical degradation. >> >> Heat, pressure and some moisture (10% MC) are required for densification >> to >> pellets, briquettes or fire logs. A dry biomass is finely ground and >> pressed >> through a metal die. There are two principal binding mechanisms. In one, >> cellulose fibers pressed together with heat removes excess water and the >> fibers are bonded to each other through what is called paper bonding, or >> hydrogen bonding. It is like wetting two pieces of paper and letting them >> dry out. They are difficult to pull apart. This is a chemical bond that >> is a >> major bonding mechanism for most densification. When you break the pellet >> or >> briquette it falls apart rather than snaps. >> A second mechanism is lignin plastic flow, as Andrew describes below. >> The >> lignin and part of the celluloses actually plasticize and flow. Under high >> power magnification with a scanning electron microscope a portion of the >> wood looks like solid plastic with no identifiable fibers. These pellets >> snap when you break them. >> >> Both mechanisms are at play in a densifier. Together these mechanisms >> make a >> durable pellet or briquette. As Andrew points out they require power and >> an >> extrusion process like a pellet mill. >> >> A third mechanism that is used with mechanical densifiers is adding >> chemical >> binders, starches, or even expanding clays. These were employed in the >> older, low power cubers and briquetters to make animal feed. Molasses >> based >> binders were added to help stick hay together in cubes and to add nitrogen >> (protein) etc. They often added 30% to the cost of the feed. We used >> sodium >> hydroxide to hydrolyze straw to make it pliable for making cubes. It had >> the >> advantage of making the straw more digestable for the animals. This was >> fine >> for using low quality feeds like straw in times of feed shortage but too >> expensive when feed prices fell. >> >> Wet methods of forming fuels are like the method described by Richard >> Stanley. Using water, chemicals, or biological degradation the biomass is >> softened and the surface become sticky. You make a pulp, meal, or dough. >> You >> can then use a press, like a piston press (a la Bryant), a meat grinder, a >> roller mill, or a cement mixer (Davis) to form the fuel into balls or >> bricks. Then you dry it out. The sticking mechanisms include the paper >> bonding, as described above, and adhesion by any number of sugars, >> starches, >> etc. that are activated or released by the process. The dried fuel is not >> as >> dense as a pellet or briquette but it is uniform, it stays together, and >> It >> burns very well because for the form of the fuel. >> >> When we worked with Ben Bryant in the 1970s and 1980s we tried a number of >> simple wet pulping processes to make building products for both developed >> and developing countries and fibers for erosion control. Some of his >> products from this period are still made commercially. In the 1990s Ben >> introduced me to Richard and how he was applying some of the same wet >> forming principles to make bricks for fuel (and for growing seedlings). >> The >> lesson is to learn and understand how natural fibers and fiber chemistry >> can >> be used to an advantage. Sometimes a small percentage of long wet fibers >> can >> be used to bind together dry fine particles. >> >> Torrefaction. Think of torrefaction as roasting biomass fuel in the >> absence >> of air. Biomass is heated first to dry it, then in the absence of air to >> 280C. At this temperature it is completely dry and some of the cellulose >> has >> converted to gas. You lose about 30% of the weight and 10% of the heating >> value. The fuel is in the same form that you started with but it is dry >> and >> brittle. If you have a densifier then it takes less energy to pelletize >> it. >> The pellets store well because they resist moisture. Torrefaction is used >> primarily for preparing wood fuel for burning with coal in very large >> utility boilers. There are several torrefaction projects in Europe and a >> few >> in North America. A plant in Mississippi has shipped a couple of large >> barge >> loads of torrefied wood to customers in Europe. >> >> There was a project in Rwanda some years ago that used partial >> torrefaction >> to prepare fuel bricks for domestic use. A professor from the US >> designed a >> small torrefier and installed it in a refuse fuel operation run by a >> women's >> coop. The torrefied biomass was formed into a brick using a fire log maker >> like the Shimada machine. A USAID employee we contacted knew of the >> project >> but did not know if it was still in operation. I haven't heard of any >> similar projects at the small scale. >> >> I hope that this long-winded explanation helps make these processes clear. >> >> Tom >> >> >> >> >> -----Original Message----- >> From: Stoves [mailto:[email protected]] On Behalf >> Of >> [email protected] >> Sent: Wednesday, June 12, 2013 1:01 AM >> To: Discussion of biomass cooking stoves >> Subject: Re: [Stoves] Meat grinder fuels for TLUDs was Re: wheat husk >> pellets >> >> [Default] On Wed, 12 Jun 2013 12:53:02 +0700,Paul Olivier >> <[email protected]> wrote:**** >> >> How does lignin soften to become a binding agent using a meat grinder? >> This would be truly wonderful, if it were true.**** >> >> It won't with a meat grinder, you will need some sort of binder, like >> boiled starch or clay. >> >> Lignin plastisises under high pressure and heat, the heat is normally >> derived from the friction of the material passing through the die. At >> these pressures the cell walls collapse and then the lignin re sets to >> form a pellet that is denser than the wood it was made from. All these >> systems use a lot of power and the expensive dies wear. >> >> The Shimada press is the one that produces a hexagonal log with a hole >> down the middle, often blackened on the outside from the heat from the >> press walls. >> >> Similarly rotary die extruders use pinch rollers to punch small >> amounts of feed through the holes. >> >> >> Have a look at: >> >> http://www.fao.org/docrep/x5738e/x5738e0j.htm >> >> >> 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/**** >> >> >> >> _______________________________________________ >> 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/**** >> >> >> _______________________________________________ >> 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/ > > > _______________________________________________ > 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/
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