----- Original Message ----- From: "Dana Linscott" <[EMAIL PROTECTED]> > Can anyone tell me what the pH of BD is prior to > washing and what the lowest temperature at which the > reaction will take place is?
Dana pH of BD prior to washing can be 9 or 10 or even higher if an excess of NaOH is used. Clean lightly used tallow-free wvo can be processed at 20 deg C, the reaction just takes a bit longer. Unfortunately WVO in Aust contains beef tallow leached from the part-cooked frozen chips used by fish&chip shops. This mixture will not process cold (at least the tallow portion won't). The use of excess NaOH mentioned above, in conjunction with 250ml of Methanol per litre and temp of 55 deg C processes the oil and tallow giving a uniform BD which shows no sign of tallow/ tallow ester dropout on standing or freezing. This is usually a big problem with oil containing tallow. The WVO deacidificaton/filtration unit which you are developing sounds just the thing for problem WVO. Would it also be suitable for waste animal fat ( a favourite chip cooker in Oz fish & chip shops)? > Is anyone using a plastic reaction vessel? Yes and sometimes. For 1L test batches I use the "Patented Dr.Pepper Method by Tilly". PET bottles withstand the reaction, heat, initial presurisation and final depresurisation. Some of the larger batches I have made involved mixing/settling the reactants in 25L plastic buckets and polythene(?) drums. Neither has caused problems. Some plastics are more resiliant than others, the worst seem to be plastic appliance cases and general consumer plastic items. For your BD production add on vessel you may be interested in utilising an idea myself and others have tried. Mechanically mixing the NaOH into the methanol is a dangerous and time consuming process. A much simpler method is to substitute a concentrated aqueous solution of NaOH for the solid NaOH. The small ammount of water in the solution appears to make no difference to the reaction. Perhaps it is chemicaly bound. Mixing is instantaneous, easy and safe. The method lends itself to automation if an alkali resintant pump can be used. Possibly a peristaltic pump would be suitable. More details supplied if interested. One scenario I have considered to get around the EPA/Local Council lisencing restictions on transporting WVO was to part process the WVO at pick up. Two engine oil pumps would be coupled to an electric motor, one running at 1/5 the speed of the other. The faster pump would draw the WVO from its container, circulate it through a coil of pipe heated by propane. The slower pump would be for the methoxide (could be corosion and seal problems here). Both pumps would deliver into one end of a mixing chamber consisting of a length of pipe packed with ball bearings. The chamber is unpressurised and discharges by overflow, ie in at the bottom and out at the top. The mixture is then fed into lidded bins. Now I am no longer transporting waste but fuel with a much higher flashpoint than the diesel that used to be carried in the fuel tank of the vehicle. Settling, decanting, washing and filtering is all that remains to be done. Regards, Paul Gobert. www.ozimages.com.au/profile.asp?MemberID=517 Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
