in answer to : From: "Editor" <[EMAIL PROTECTED]> Subject: Oil crude
I'm new too. Can anyone tell me if is possible to make Bd using crude oil of sunflower i.e. the oil obteined from the first pressed without process with hexane. *jorge, i think we are confusing two procesing steps here. *hexane is used to extract oil that remanins in the cake after pressure extraction. it might contain less solids in suspension, but is otherwise pretty much the same as 'first press oil', also called 'crude' oil in the edible oil industry to diferentiate it from 'refined' oil. *first press, or crude oil, needs to be refined, mainly for commercial reasons. for biodiesel production it only needs adequate filtering, and very rarely some neutralizing, if excessive free fatty acids are present, which should not be the case if you're pressing fresh, dry, sunflower seed. *when refined for sale as edible oil, sunflower oil is usually processed as follows : -filtering, or clarification with diatomaceous earths. -neutralization if excesive free fatty acids are present. -color correction. -deodorizing. *for biodiesel production, only filtering is actually required (down to 25 microns, or less). if gums and excessive free fatty acids are present, water precipitation might be necessary to remove them, but again, this should not be necessary if you are pressing fresh, dry, sunflower seed. *it might be a good idea to heat the oil to 105 celsius for a few minutes, while stirring, to evaporate any excess water, but this will depend on the pressing process. *other than that and filtering, no other processing should be necessary. hexane processing just increases the oil yield, it does nothing to the oil's chemical composition per se. hope this helps, i will be contacting you off list in spanish. cheers, dick. done any <snipping> lately ? saves heaps of bandwidth !! this is a public service message. 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/
