Dear Jonathan
You are in for a journey of discovery which I hope you will share because I think you are on the cutting edge of this J-fuels curve. >The plan is to take J seedcake produced by an electric screw expeller, If it is a modestly priced Indian press you will have something like 10% oil in the cake. It is not totally important to know (yet) but others trying to reproduce the process will want to know. Setting the press correctly is going to make a big difference to the oil yield. I hope you don't get talked into running it through several times. If you need to, you have the wrong press or are using it improperly. along with rice hulls that have been chopped up by an electric hammer mill, I presume you are using something like a Hippo Mill (South Africa - really well made) or an equivalent. It should have a 'full screen' and tripper bars (which will wear out) because you are using a pretty small initial size. It is quite possible that it should NOT be run to flour. That means a large hole size in the screen. Richard should hopefully have an insight on this score - about the fibre length and how to mill rice hull. What you want is binding, not problems, and to pay extra money for milling it from a solution into a problem. mix them together thoroughly and run this mixture through an electric pelletizer to produce fuel for use in a TLUD stove for household cooking. Keep the pellets small (not 50mm) in that case, and no smaller than 7mm. Probably an 8 to 10mm size would be ideal. Paul A may like to comment. There is inevitable breaking of the pellets so the final mix in the stove will actually be smaller than the nominal size. The economic logic is that by first expelling the J oil, you get two fuels: pellets based on the J seedcake plus the free waste produced by rice dehulling, and J oil itself, which seems to have a ready market as a biodiesel, for research, etc. Well, I presume you will have explored the possibility that the best economics are achieved that way. In other words that the oil is worth as much more than seeds compared with what you are paying to remove it. Never assume anything. It might be a better business case to use the whole seed and use the rice hull in a rice hull stove. My request for now concerns any advice you can offer concerning: A) the mixing of J seedcake and chopped-up rice hulls as pelletized fuel It can all burn. Ash can be an issue: what is the Cl and K content? They are fluxes and lower the melting temperature of the ash. B) combustion of these pellets in a TLUD or other stove for household cooking Make no assumption, no holds barred - you are on a quest which has multiple answers. Downdraft, sidedraft, updraft, whole seeds, pellets, fuel blends, the whole scene. For example, you might press the seeds in a low pressure manual press, expelling whole seeds with a lot of oil still in it. That oil may have much better characteristics for fuel than oil pressed really hard. And the resulting 'natural pellet' may outperform anything you can make with an (expensive) pelletizer. Pelletizing is really finicky with close control of moisture being probably the main challenge. You should have a back-up plan for what to do 'in the meantime' as the pelleting operation is worked out. C) whatever else we haven't thought about in designing this process that we need to consider I think you should not be sucked into any 'vortex of the moment' regarding any particular stove design. TLUD's are a good way to burn some fuels but most have issues: they are hard or impossible to reload, and they can (not all) make a great deal of smoke near the end of the burn. Both have solutions on offer but they are really not a fully developed system. There are large working examples of TLUD combustion of coal which can be refuelled continuously but this has not been copied into the current stove offers. Burning oily seeds in a downdraft stove has a big advantage which is that 'yielded oil' falls directly into the fire instead of away from it so it can be burned as it comes out of the seeds. That may interest you. If the best business cases all involve getting the oil out first, you are forced to make a plan to deal with the cake, not seeds. Where the seeds are not oily (marginal land) you are probably best burning the seeds whole instead of processing them. You may have to consider mixing dry and oily seeds to get what you want. This operation has yet to begin, so we have no performance data to present; but it's certainly a good moment to seek advice of those who have dealt with seedcake and/or pelletized fuels. If you can, get an ultimate analysis of the fuels you will be blending and a chemical analysis. You will be able to make projections in future. Actually Frank at Compost lab will probably be a good source of advice on how to characterise the materials before putting them into the pelletizer. As you keep notes, you will observe certain characteristics that always give a good result. That will be valuable to future generations of equipment and producers still to come. Good luck! Crispin
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