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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Crispin,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks. The pellets they have selected for carbonizing are 8-12 mm. We have done a lot of densification and we understand the issues related to densifying crop residues. We’ll see how long the dies last. The pellets I saw had corn stover blended in with the rice straw. The corn stalks could act as a binder and lubricant. If I recall the intended working radius for each pellet plant is about 50 km. Delivered cost of the pellets to the biochar plant is USD$70/ton.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It’s interesting to learn about the Hebei project. The handling and processing infrastructure for one project should help another. Some successful biochar producers are supplying different fiber and char products to different markets. <o:p></o:p></p><p class=MsoNormal><a name="_MailEndCompose"><o:p> </o:p></a></p><p class=MsoNormal><span style='mso-bookmark:_MailEndCompose'>Tom<o:p></o:p></span></p><span style='mso-bookmark:_MailEndCompose'></span><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Crispin Pemberton-Pigott<br><b>Sent:</b> Wednesday, November 22, 2017 1:01 PM<br><b>To:</b> Discussion of biomass cooking stoves <stoves@lists.bioenergylists.org><br><b>Cc:</b> 'Biochar' <biochar@yahoogroups.com><br><b>Subject:</b> Re: [Stoves] Air pollution in cities<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-CA>Thanks Tom<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>I know my posts don’t go to the biochar list so you can post it on if it is relevant.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>The pelleting of agriwastes is mechanically difficult because of the ash in the material and contamination from dirt. The trend is to make relatively large pellets that are square in cross-section. The energy input is really high even at low density so the ‘moving parts’ are difficult to keep together. The subsidy <i>was</i> about $50 per ton and the limitation of the system is that the transport radius is defined by the subsidy, if you boil it down. It is something like 150 km. When the distribution radius is small, the factories can’t be too large.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Perhaps a dual approach would yield the best overall system performance when agriwastes are digested before being pelleted. Who tries, wins.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>The Hebei Clean Air Project ($500m) is implementing 51 measures with a large ($80m) component of improved stoves. I have yet to see a really improved ‘wood briquette’ stove, only coal stoves. Some basic research is needed to fill that gap.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>At least some of the H-CAP items attempt to ‘do something’ with the agriwastes from fields because it is a major contributor to poor air quality in Beijing in October. The smoke is similar in content and concentration to the illegal Indonesian peat burning to create biodiesel plantations that affects Singapore air. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>At this time, it seems likely that some form of crossdraft stove, perhaps similar to the Fyro-stove layout, will be able to burn these large ‘pellets’ (briquettes). The heat applied to the pyrolysation has to be greatly reduced compared with the successful coal gasifiers.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Regards<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>Crispin<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal>Crispin,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks for your comments. The agricultural science that we have seen is done at a high level. It is also done in collaboration with expert institutions around the world. In just our limited view we are interacting with a large department of soil and crop scientists at a “key university” for biochar. They are collaborating with some large corporations. They have really been innovative compared to how others around the world are thinking about the conversion and use of biochar. The people we are working with have been at it for at least 10 years, so it hasn’t happened overnight.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The business model is unique and there clearly are subsidies. There are multiple objectives, but a main driver is to reduce the open field burning. Improving soil health, reducing effects of pollution, increasing yield and sequestering carbon are other targets. There are many local challenges to deal with, like arsenic and cadmium. National, county, and local governments are involved organizing supporting policy and funding businesses. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>They are moving very quickly to scale. The scale is not surprising. You can get to the current stated capacities with only 25 plants each processing 30,000 tons of residue per year at about 4 tons per hour. They have engineered one processing scheme and have cloned it. Meanwhile they are working on incremental improvements. Whether each plant is actually producing 8,000 hours per year may be debatable but that’s also true of our small North American biomass plants. Field testing in300 locations is impressive. There is a whole educational program at each level. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I haven’t seen their pelleting operations, but I have seen other stationary systems with Chinese equipment and know their typical limitations. The pellets are not very dense which should offset some of the wear issues associated with crop residues. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This is still evolving. It will be interesting to see where they are in a year’s time. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Tom <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>