Powering a sugarhouse with used vegetable oil

Report Summary:

Our project's purpose was to power our sugarhouse using UVO. We found a source for UVO, built the infrastructure needed to receive and store the UVO and then converted our evaporator and a generator to run on UVO. Once we installed a day tank for the evaporator, everything worked very well with very little hassle. We added around $7,000 to our bottom line from increased production during power outages and by saving $1.00/gallon on the 3,700 gallons of fuel we burned. In the future, we may want to collect and refine our own vegetable oil. This project has met and exceeded all our expectations.

Goals:

Our goal was to produce maple syrup using used vegetable oil (UVO). Our main objective was to successfully convert our evaporator and a diesel generator to both run on UVO.

Farm Profile:

Sidelands Sugarbush is a large 23,000 tap modern maple sugaring operation, which was started in 1982. We produce between 5,000 and 7,000 gallons of maple syrup annually. This year (2007) we produced 6,100 gallons.

Participants:

As project leader, I overaw all aspects of the conversion project and did almost all the plumbing and electrical work. Harry Atkinson of Thunderbolt Technologies in Burlington, Vermont was the engineer in charge of converting our 5x16 Thunderbolt Evaporator (Harry's design). Oliver Piluski, an engineering graduate of Vermont Technical College, who has had lots of experience converting diesel motors to UVO, was in charge of converting the 100kw used (400 hour) diesel generator we purchased.

Joe Merceer, my neighbor and wizard of everything mechanical, helped with all aspects of the project and answered most of my questions involving the project. Bill Harlow of Harlow and Son's did all the infrastructure/excavating work to make it possible to bring in taker loads of UVO. Brian Irish helped with running the electric wires and UVO pipelines. Finally, Al Powers and his crew from Powers Generator Service hooked up the diesel generator and installed the transfer switches.

Project Activities:

First, we located a source of UVO, Smarter Fuels of Bethlehem, Pennsylvania. As we had to buy the fuel by the tanker load, we needed a 7,000-10,000 gallon oil tank. I found a used, clean 10,000 gallon oil tank locally, which I had Bill Harlow haul to my site. We prepared a hole with containment for the tank, which we half buried so the bottom of the tank was five feet above the evaporator. We also built a road to the tank, made a concrete pad next to the tank for the generator, and made a gravel road above the tank, so the tanker truck could park while unloading the oil.

To feed the UVO to the evaporator, we buried four inch PVC pipe with two runs (feed and return) of 3/4" PEX pipe inside the PVC pipe. The PEX pipe was sandwiched between a line of heat "tracer" tape and insulated. The tracer tape was set up on a thermostat so that the PEX pipe could be kept at any constant temperature between 60 F and 180 F. The UVO feeds through the PEX pipe 140 feet to the front of the evaporator and then through a 10kw electric heater, which heats the oil from 60 F to 200 F, where it is then pumped into the oil nozzles and ignited.

To make the generator work and to heat the oil in the 10,000 gallon tank, we ran a loop of engine collant down into the big oil tank. We ran the diesel generator on regular diesel fuel for 20 minutes and then could switch it over to UVO once the UVO was heated up to 160 F. Converting the generator was a matter of installing a lot of valves, tees, a special oil filter purchased from Grease Car, Inc. of Northampton, MA, and a 12 volt electric pump to get the oil up out of the big tank to feed the engine. The diesel generator conversion went perfectly as planned. We used it three times as back up when the power went out and one full day when we converted it. The evaporator conversion wasn't so smooth. We had trouble because of the line friction created by being 140 feet from the oil tank. The fuel pump at the evaporator was cavitating because it had to pull too hard on the oil to get it through the pipe. We solved this by installing a gear pump at the oil tank which pushed the oil through the lines to the inline heater and into an insulated "day tank." For the day tank, I insulated my old 1,000 gallon back-up fuel tank. The UVO entered the day tank at 130 F. We then would be able to boil for several days before having to refill the day tank. After we set up the day tank the system operated trouble free for the remainder of the season.

Results:

Once we switched to the day tank, everything worked perfectly. The only unexpected result was that the evaporator increased its boiling capacity by 10-15%. I think this was due to heating the oil above 200 F before firing. My evaporator never worked better or faster and the pans stayed cleaner on their bottoms.

Conditions:

Because my sugarhouse is old, uninsulated, and we plan to tear it down in the near future we had to site things farther away than we wanted. The whole system would be easier to set up in a new heater sugarhouse.

Economics:

The UVO cost $1.47/gallon delivered. I paid $2,47 for regular fuel oil, which I had to use for the first 500 gallons of syrup made until we got the day tank working. I used about 3,700 gallons of UVO to make my 6,100 gallons of syrup, saving me $3,700.

Our power went out three times this year. The first two were 2 hours an 1 hour, respectively. As they were both days during vacuum runs, the sap would have stopped flowing without power. I estimated that I made about $1,500 more in syrup than I would have had without power from these two outages. The third outage lasted 5 hours during our biggest run of the year. I would have lost about $2,500-$3,500 had I not had the generator during this outage. For this year, 2007, my expenses decreased by $3,700 and net income will be up by around $7,000-$8,000.

Assessment:

In assessing the project, I would say the next step might be to collect and process UVO myslef. This is a project which would have benefits for any sugarmaker using fuel oil.

Adoption:

As long as I can obtain UVO at a reasonable price, I plan to use it as a fuel.

Outreach:

I have had articles written about my project in the Brattleboro Reformer and the New York Times. I have written the UVM maple extension agency and offered myself as a speaker at their annual maple schools next January (January 2008). I have also written Bascom Maple Farms and offered myself to speak at their equipment open house. I have sent a letter to Dave Folino, director of the Addison County Sugar Makers Assocation and offered myself as a speaker. They are one of the more progressive groups in the state and would probably be very interested in hearing about my project. Finally, "The Maple News," one of our industry publications, has asked to do an article on my UVO conversion.