Winter B100 Use – Hot Tank version
Many people, when faced with cold weather, wonder how to make it so that B100 ( 100% biodiesel) can be used in spite of below freezing temperatures, and use it without fear of the dreaded geling issues associated with cold weather biodiesel use. We have the answer.
Based upon the system commonly used by those using straight vegetable oil as their main fuel for diesel engines we have built a “light” version for B100 use. It consist of installing a second heated tank and fuel system to compliment the original fuel system, but where this system departs from the SVO one is that B100 does not require as much heat in order to flow as unprocessed vegetable oil does. The issue at hand here is the viscosity (thickness) of the fuel.
Our system also uses a seperate tank that is heated by means of coolant diversion, but the surface covered is not half that of the SVO (Straight Vegetable Oil) one, and our fuel is ready to burn much quicker as much less heat is required. In effect all we do is create a climactic environment that mimics Spring to Fall leaving winter out of the picture, and seeing as it is winter’s extreme colds that cause the difficulties encountered for those wanting to use this environmentally alternative fuel the solution is simple; complex without being complicated.
This Pollack 6 Port Selector Switch schematic tells you what hose to connect to what port for running a two tank system. These switches were commonly used by Ford for their two tank pick up trucks.
Getting started; we got a tank ( stainless steel, oh yeah baby ! ), and then we have secured it to a piece of thin metal sheeting for heat dispersement.
While building the convection box we have lined the inside with heat reflective paper in order to maximise heat retension. In this photo you can see how the black iron pipe has been laid out to form the heating radiator. (The Absolut is in case of methanol fumes 🙂 )
In this photo you can better see the rungs on which the tank will sit, one on either side and one down the middle for support. The plumbing runs under the floor and along the sides.
Here you can see the tank nestled into the box with the radiating pipes on either side. For this set up 1/2in black iron piping was used, although this can be changed to a larger diameter plumbing should your situation demand greater heat needs.
While building the convection box not just the bottom was lined with heat reflective paper, the sides and top were as well.
Here we can see the hot tank centered in the trunk of the car. The box has been secured to a piece of pressboard that covers the width of the trunk so that it will not move from side to side. On the left is a spare cubie of 20Lt’s B100. When parked in the cold overnight or for extended periods outside this cubie can be brought indoors to provide heat to the fuel before putting it in the tank. The three 4Lt jugs sit inside a cube made of 2×4’s that act as a block so the tank won’t move horizontally.
Here we can see the various lines going in and out of the tank; the inlet/oulet for the coolant and the feed and return ports for the fuel. The rectangular white thing nestled inbetween the tank and the box is a remote thermometer sender whose receiver is in the car’s glove box for easy access. This allows easy monitoring of the box’s heat levels.
A very important component is the tubing that will be used to transport not only the fuel but also the hot engine coolant back to the tank. Here we have used pressure rated braided PVC hose. It goes from the engine compartment,
through the firewall and along the inside of the vehicle on the passenger side,
under the back seat and through the rear wall and under the vertical fuel tank to come out in the trunk where it will be installed in the heated fuel tank.
Prior to running and bundeling all that hose through the car we colour coded the tubing so that we would know which hose went into which port. It saved quite a bit of confusion.
Then it’s time to hook it all together. In this close up of the Pollack selector switch you can see the two ports on the far side of the switch; the top one goes to the fuel feed and the bottom one to the return. On the near side of the switch you have 4 ports; two on the left and two on the right. The ones on the left are for the B100, top is fuel feed, bottom is return and on the right same for the main tank’s lines.
Once everything is connected and has been tried out to make sure there are no air leaks we insulated the lines inside the engine compartment. You will notice the fuel lines leading to the 6 port switch and also the coolant lines that have been tapped from the radiator cooling system. The one on the left is the return line and is protected by additional insulation and a pop can to safeguard it against heat from the rocker cover. The two coolant lines operate using ball valves to turn the heat on/off for the convection box back in the trunk. This does not negatively affect the use of the radiator heat and also allows for use of the rear fuel tank as an auxilary tank to extend range for summer use while keeping the heat turned off.
Here we see how we’ve used the fuse box to bring electricity to the switch. A ground wire is attached directly to the vehicle’s frame. Here the hot wire has been fitted with a flat connector and slid behind the fuse holder for one of the low use appliances.
And to finish it all off we’ve installed the on/on switch in the ashtray out of the way (the other switch on the right is a left over and no longer in use). By simply toggling the switch to one side or the other selects the tank from which the IP will draw fuel from. These selector switches only draw power to make their selection and then go dormant, no longer using power.
And that covers our pictorial of how we set up a heated fuel system for B100 winter use. As the weather gets colder the main tank will be filled with treated pump diesel and use of the auxiliary tank will become the primary fuel source. It is a 20Lt commuter tank, and has been kept small intentionally as this will make it all the easier to heat and keep warm. We have also opted to return biodiesel to the aux tank as this also will contribute in heating the tank as the returning fuel will be hot from the engine compartment and kept that way while riding hose on hose back to the trunk tank.
If the vehicle must sleep outside during cold temperatures then the selector must be flipped to choose the main tank’s fuel well before stopping to make sure the filters are evacuated of B100 or it may gel up and not start when you return to it, but if the vehicle sleeps indoors in a heated garage then no purge is necessary unless planning on stopping for extended periods of shopping, work or visiting friends ect.
One thing that must be mentioned here is another difference between this system and that of a full-on SVO system and that is the way the filters are used. Generally speaking, an SVO system will incorporate two separate sets of fuels filters to keep the blending of veggie and petroleum diesel to a bare minimum. This system however does not concern itself with that using one set of filters for both fuels. What this means however is that a partial filter full of fuel will divert to the opposing tank with every purge (switch over). For the most part this blending of a low percentage petro diesel and B100 will not significantly affect anything except perhaps in the case where a high temperature geling oil was used as the biodiesel feedstock, such as a fully hydrogenated oil or animal fat (tallow). Where high temp geling oils have been used for the biodiesel switching from one to the other should be kept at a bare minimum so as to not cause any gumming inside the main tank, where many are equipped with in-tank screen filters which can become clogged if a too high percentage of high temperature geling biodiesel gets mixed with cold petroleum diesel. Other than that restriction this system will handle all types of feedstock biodiesel with ease.
We hope this has been helpful to you in your search of a functional winter weather biodiesl use solution. We can be contacted should you have any questions at: fuelit at b100wh dot com.