hi all thought i would start a discussion on winter additives for biodiesel.would be very interested to hear different approaches to making biodiesel for winter temperatures of -15 or so.i used hiberna last year and it worked well but did have a bit of waxing when temp got down to about -14.would greatly appreciate your recipes!!!!!!
I'm thinking of trying JetA1, aircraft fuel for those who don't know, not an option for everyone I know but it is for me. It's a type of kerosene so I'll have to be careful how much I add but I think I recall someone saying you are allowed add up to 10% without falling foul of customs.
sounds good how much would it work out costing you.i get hiberna from trinity chemicals,i pay £50 for 5litres which will treat around 1000litres of biodiesel.
I work in aviation so should be able to get my hands on some very cheap but ordinary kerosene will work as a winter additive too.
This graph shows the cloud point temperature of clear canola biodiesel mixed with kerosene, jetA, or stove oil. The fat based biodiesel which will clog filters and screens at temperatures below 40°F was removed before mixing.
canolaBD.gif (44 Kb, 279 downloads)
This has been discussed extensively before; use the 'find' function to learn more. Here's just one example of many.
my bio would cloud using hiberna at around -5 but would not start producing wax crystals till -14,might just increase the dosage this year just in case.
what is 'hiberna' ?
Wax is a petroleum product [except beeswax of course]. How is it getting into your biodiesel?
read up on biodiesel waxing,it is very common in winter,this is what blocks your fuel filter and causes all the problems.once wax has formed in biodiesel it never goes
Quite simply, diesel engines do not run as well at cold temperatures. Modern diesel engines are being created to remedy this problem, but it is still difficult to start a diesel engine in cold weather. According to the Biodiesel Encyclopedia, both diesel and biodiesel begin to form wax crystals when temperatures are low, which can eventually turn the fuel into gel that cannot be pumped. These crystals can clog fuel lines and filters, which will obviously affect the performance of the engine. Biodiesel begins to form wax crystals even sooner than regular petroleum diesel.
Read more: The Disadvantages of Diesel & Biodiesel Fuel | eHow.com http://www.ehow.com/list_60720...l.html#ixzz1Vvo3Gh9N
just found this to explain
Wax forms plate like structures (flat) and AMSOIL Cold Flow breaks those up, more like strings, so fuel can flow through. It modifies the wax crystals to allow the fuel to pass through filters, and prevent premature plugging due to gel. It also works well with biodiesel blends as well. Biodiesel has horrible cold temperature properties in general, and the use of a biodiesel-compatible product will help lower the point at which the fuel clouds, or begins to gel. Biodiesel or B100 does not contain paraffin since it is not petroleum based. When B100 gets cold crystals do appear and they act like wax in that they stick together and are large enough to plug filters. These crystals form sooner or at higher temperatures and are larger in size in B100 than in regular diesel fuel. Biodiesel is defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats which conform to ASTM D6751 specifications for use in diesel engines. The saturated compounds in the Biodiesel form the crystals that plug filters. When they form they are larger than diesel wax crystals. Most anti-gels, including AMSOIL's, work best on biodiesel fuels B20 and less.
The key to messing with paraffin wax gel is to disrupt it from agglomerating together into a “glob” that is big enough to plug a filter and or fuel line. A copolymer chemical with molecular chains similar in size and distribution to paraffin co-crystalize with the wax and disrupt the crystal formation, thereby allowing your fuel to continue to flow through your fuel filter and keep you on the road.
As diesel fuel cools you will notice a white haze or cloud in the fuel. This usually happens around +10 degrees F. but can happen at higher or lower temperatures depending on fuel characteristics. The white cloud or haze is caused by wax crystals precipitating (coming out of solution) out of the fuel and becomes visible. When fuel warms above the Cloud Point of the fuel, the white appearance will disappear as wax crystals dissolve back into the fuel. The use of an anti-gel usually does not change the Cloud Point of a fuel, and if it does it is usually only by a few degrees. There are however some Cloud Point depressants that can significantly reduce the Cloud Point of a fuel. Cloud Point depressants will adversely affect anti-gels or Pour Point Depressants, however. Anti-gels typically affect the CFPP (cold filter plugging point) and Pour Points of a fuel. Anti-gels work on the wax crystals in the fuel. As the wax crystals form or come out of solution, the anti-gel will modify the wax crystals so they are smaller, will not stick together and will continue to flow through the filter in much lower temperatures than untreated fuel.
You're describing wax formation in petro diesel fuel. Biodiesel does not contain wax, it can however contain fats, calling them 'wax' is a misnomer and only adds to confusion because they do not act like wax in petroleum diesel.
I live where it routinely gets extremely cold every winter. Our diesel engines start and run just fine in cold winter temperatures, it's not a problem here in Northern Canada and Alaska. Our winter grade diesel fuel does not 'wax' or gel til -37°C; I've confirmed this with actual samples at that temperature. I have four winters experience with VO and biodiesel blends in sub zero F temperatures. I have seen what happens in both biodiesel blends and diesel fuel when it gets very cold. It's not the same. The antigel additives for petro diesel fuel do not work with biodiesel. To successfully use biodiesel in cold temperatures it must be mixed with winter grade diesel fuel [or kerosene], and the blend must be chilled to the operating temperature then cold filtered, additives are ineffective.
I appreciate what you've posted, but until you've experienced cold temperature operation firsthand it's just recounting what someone else believes.
very interesting,i used hiberna last winter and as i said got it down to -14 withno wax like deposits.i use a 1000 litre processor and dont se how i can freeze this down to -20.but hiberna does work but probably not down to -30,and you do not have to add kerosene or similar.what percentage of biodiesel is your mix for -37 temps and do you mix it first then chill it
Waxes are insoluble in water but soluble in organic, nonpolar solvents. All waxes are organic compounds, both synthetic and naturally occurring.
Waxes are organic compounds that characteristically consist of long alkyl chains. Natural waxes are typically esters of fatty acids and long chain alcohols. Synthetic waxes are long-chain hydrocarbons lacking functional groups.
Plant and animal waxes
Waxes are biosynthesized by many plants and animals. They typically consist of several components, including wax esters, wax acids, wax alcohols, and hydrocarbons. Wax esters are typically derived from a variety of carboxylic acids and a variety of fatty alcohols. The composition depends not only on species, but also on geographic location of the organism. Because they are mixtures, naturally produced waxes are softer and melt at lower temperatures than the pure components.
The best known animal wax is beeswax, but other insects secrete waxes. A major component of beeswax is the ester myricyl palmitate substance which is used in constructing their honeycombs. Its melting point is 62-65 °C. Spermaceti occurs in large amounts in the head oil of the sperm whale. One of its main constituents is cetyl palmitate, another ester of a fatty acid and a fatty alcohol. Lanolin is a wax obtained from wool, consisting of esters of sterols.
Especially in warm climates, plants secrete waxes as a way to control evaporation and hydration. From the commercial perspective, the most important wax is Carnauba wax, a hard wax obtained from the Brazilian palm. Containing the ester myricyl cerotate, it has many applications. Other more specialized vegetable waxes include candelilla wax, ouricury wax, sugarcane wax, retamo wax, jojoba oil. The epicuticular waxes of plants are mixtures of substituted long-chain aliphatic hydrocarbons, containing alkanes, fatty acids, primary and secondary alcohols, diols, ketones, aldehydes.
Are you implying that those plant waxes are found in biodiesel? The comments I've made are in the context of biodiesel; that's what this forum is about.
If there is wax in your fuel mix then the source is petroleum diesel, not biodiesel.
Flowability: A Complex Issue
"One of the biggest issues for FAME is its tendency to form wax crystals at low temperatures because of the degree of saturated fatty acids in the feedstock used to make the biodiesel. This wax can block vehicle filters and settle in storage and vehicle fuel tanks. As more highly saturated feedstocks are introduced, biodiesel and its blends with diesel are more likely to exhibit cold weather operability issues because of the additional saturated esters increases the total wax level in the fuels. Field issues observed in buses indicate that problems tend to occur on start-up in the morning in vehicles that have been refuelled the previous evening, suggesting that the wax had settled out in the fuel tank overnight. Unfortunately, the obvious solution on refuelling in the morning is not always practical as fleets often need to move off quickly at the start of the day. Appropriate additive solutions could help to provide consistent FAME product quality throughout the distribution system and ensure vehicle operability."
If it makes you feel better to call the material that drops out of biodiesel "wax" then go for it.
The important point is not what we call it but what we do to prevent it clogging screens and filters in the vehicle fuel system when it's cold. The vehicle fuel system doesn't care if it's wax, fat, or snot. It's a problem.
Additives can depress the temperature that 'stuff' starts falling out of the otherwise clear fuel by a few degrees. A variety of fuel additives for diesel and biodiesel are commercially available to improve the cold flow properties. Dunn et al. (1996) studied the effects of 12 cold flow additives for petroleum diesel on the cold flow behavior of biodiesel. They concluded that the additives significantly improved the PourPoint of diesel/biodiesel blends but did not affect the CloudPoint greatly. In some climates this might be adequate.
Cold filtering is more effective and less expensive. Cold filtering works best with a B75 to B50 mix diluted with kerosene, stove oil, jet fuel or arctic winter diesel. This achieves the greatest CloudPoint depression by a combination of petroleum dilution with removing saturated methyl esters by cooling the fuel to cause crystallization and then separating the high melting components by settling and filtration. A simple way to do this is leaving the fuel mix storage barrel outside in the cold, let the 'stuff' settle out in the cold, and pump from the clear top layer thorough a 5µ filter and into the vehicle.
Simple, easy, effective, and economical.
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