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The Costs and Benefits of Heating with Vegetable Oil Fuels:

A Biodiesel Feasibility Study for Middlebury College.

The human economy requires extremely large amounts of energy and this energy comes almost exclusively from fossil sources. America alone used 94,192,000,000,000,000 BTU's of energy in 1997 which is about the equivalent of 724,553,846,154 gallons of diesel fuel.( www.eia.doe.gov ) Although humans have been using fossil fuels at a high rate since the industrial revolution the long term problems associated with burning fossil fuels are just beginning to enter into the public conscience. Fossil fuel extraction, transportation, refining, and consumption cause enormous amounts of environmental degradation. The Exxon Valdez oil tanker disaster in 1989 spilled approximately 11 million gallons of crude oil single handedly killing an estimated 250,000 sea birds, 2,800 otters, 300 harbor seals, 250 bald eagles, up to 22 killer whales and billions of salmon and herring eggs. The Exxon Valdez spill is just one example in thousands of the environmental problems with fossil fuels. (www.evostc.state.ak.us) The environmental impacts associated just with fossil fuel combustion include acid rain, global warming and increased cancer and asthma rates in humans just to name a few. (www.biodiesel.org)

            These impacts on the environment and the fear of global warming have led many to look for alternative energy sources. A search for alternatives has also developed because of the knowledge that fossil fuels are non-renewable and will eventually run out. The combination of negative environmental impacts and fossil fuel's finite amounts have driven a huge investment in alternatives in the last 30 years. The result has been viable wind turbines, photovoltaic cells, hydroelectric dams and biomass fuels. Some alternatives are clearly better suited for certain areas than others but alternative energy is becoming increasingly viable around the world.

            Because of the problems with combustion of fossil fuel Middlebury College has begun to examine the possibilities of switching away from fossil fuels to renewable sources. Middlebury College is located in Addison County Vermont, USA and the geographical location of the College necessitates large amounts of energy for heating buildings during the long winter.   Because approximately 70 percent of the college's energy usage goes into heating and cooling buildings this is an area that requires huge amounts of fossil fuels. (Moser, 1/14/03) This study will analysis the possibilities of switching from fossil to renewable fuels to heat campus buildings. Middlebury College's current heating infrastructure is capable of being adapted to burn liquid biomass fuels such as vegetable oil fuels. Vegetable oil fuels appear to be the most cost effective way to switch to an alternative fuel because of their compatibility with the current heating infrastructure and therefore vegetable oil fuels will be the focus of this study.

Fossil Fuel Consumption at Middlebury College

            This study will focus on the fossil fuel consumption that can be easily substituted by vegetable oil fuels. The fuel types that vegetable oil fuels can be used as a substitute for are diesel fuel, #2 and #6 fuel oil. The college also burns Liquid Propane Gas (LPG) and gasoline but these fuels cannot be substituted with vegetable oil fuels. There is the possibility of replacing engines and furnaces that use gasoline and LPG with equivalents capable of burning vegetable oil fuels but this would be an expensive process requiring a serious financial commitment. As of 2002 approximately 93% of Middlebury College's fossil fuel usage for heating purposes could be converted to burn vegetable oil fuels without purchasing new engines or furnaces. (Moser, 1/14/03)

In 2002 Middlebury College consumed 1,658,000 gallons of #6 fuel oil, 142,000 of #2 fuel oil and 7,815.2 gallons of diesel fuel. #6 fuel oil was purchased   for $0.69 a gallon and delivered from Rensselaer New York for $0.06 a gallon making the total delivered cost $0.75 per gallon. #2 oil was purchased for $0.90 a gallon from a local wholesaler including transportation. Diesel fuel was purchased for $0.98 a gallon from a local distributor. (Moser, 1/14/03) These three types of fuel can all be substituted with vegetable oil fuels. Although all three are similar #2 and #6 are different from diesel fuel in that #2 and #6 are used in furnaces and boilers to heat building while diesel fuel is used in internal combustion engines to power vehicles.

The pollutants released by the combustion of #2 and #6 are regulated by the State of Vermont Agency of Natural Resources Department of Environmental Conservation under the Air Pollution Control Division. Although the Air Pollution Control Division regulates air pollution from non-mobile sources it does not actually measure emissions, instead it estimates emissions of specific hazardous air contaminates. The emission estimate for the combustion of #2 and #6 oil are specified below.

Table 1

            This table shows the amount in tons of Particulate Matter, Sulfur dioxide, Nitrous Oxide, Volatile Organic Compounds and Carbon Monoxide emitted from the combustion of #2 and #6 heating oil at Middlebury college. (Middlebury College's Air Contamination Source Registration Fee Report from 2002.)

Middlebury College's use of 7,815.2 gallons of diesel fuel is not regulated by Vermont state because it is being burned in mobile internal combustion engines that are regulated by the Federal EPA. Even though the college is not required to pay a Air Contamination Source Registration Fee the emissions from diesel engines are still substantial. Emissions vary greatly with size and age of engine making it extremely hard to quantify the amount of pollutants released into the air. The difficulties in quantifying diesel engine emissions are beyond the scope of this study and therefore are not included in this inventory.

The Air Pollution Control Division requires that Middlebury College pay a fee of $32.00 per ton for emitting Particulate Matter (PM), Sulfur Dioxide (SOX), Nitrous Oxide (NOX), Volatile Organic Compounds (VOC) and Carbon Monoxide (CO). The fee also requires Middlebury College to pay $840.00 because it emits more than 10 tons of regulated pollutants. In addition to the fee for emissions the Air Pollution Control Division charges a combustion fee of $0.50 for every 1000 gallons of #6 oil and $0.20 for every 1000 gallons of #2 combusted. These combustion fees for Middlebury college's combustion of #2 and #6 fuel oil amount to $857.40. The emissions fees for #2 and #6 fuel oil amount to $4010.56. The total fees paid to the Air pollution Control Division by Middlebury College for #2 and #6 use in 2002 were $5707.96. (Middlebury College's Air Contamination Source Registration Fee Report from 2002 )

Although it is important   for PM, SOX, NOX, VOC and CO to be regulated one of the most significant pollutants, CO 2 is not regulated by any governmental organizations. The regulated pollutants are regulated because of the danger they pose to humans and all living organisms. Although CO 2 is not hazardous to living organisms in the quantities present in our atmosphere it is a greenhouse gas and is the largest single contributor to global warming. CO 2 is the primary gas released from the combustion of carbon based fuel such as fossil fuels and is the primary gas which needs to be controlled in order to avoid global warming.(Tickell, p17)

The   combustion of #2 and #6 releases 21.9 lbs and 24.7 lbs of CO 2 per gallon respectively. (Moser, 1/14/03) Middlebury College burned 142,000 gallons of #2   and 1,658,000 gallons of #6 fuel in 2002 resulting in 3,109,800 and 40,952,600 lbs of CO 2 released respectively. The total CO 2 released from the combustion of #2 and #6 in 2002 was 44,062,400 lbs. The incredible large amount of CO 2 released every year by Middlebury College just for heating building shows the need to find alternatives capable of reducing CO 2 emissions. (Moser, 1/14/03)

Switching to Vegetable Oil Fuels at Middlebury

            The main reason this study is focused on vegetable oil fuels is there ease of use in existing infrastructure thereby keeping implementation costs to a minimum as compared to the environmental benefits. Switching to vegetable oil fuels at Middlebury College can be grouped into two main categories, the initial investment and the increase in operating costs. Although the implementation costs are somewhat fixed there are options as to the type of vegetable oil fuel, making these fuels more economically feasible.

            The major initial investments required to switch to vegetable oil fuels is modification of the four main boilers in the central heating plant. The physical modifications required to convert these boilers is not expensive but the adjustments necessary to be able to burn a different type of fuel will require special technical   assistance from outside specialists. Another factor affecting the price of the conversion is that no one is currently using vegetable oil fuel on the scale of Middlebury College's needs so the conversion process is somewhat unknown. Although vegetable oils have not been used on a scale similar to Middlebury College's fuel needs vegetable oil fuels have been proven to work in smaller scale boilers with similar designs. Summing up all of these factors Michael Moser, the Heating Plant Manager at Middlebury College, believes the total costs to be approximately $100,000 per boiler converted. (Moser, 1/14/04)

            The other major cost associated with vegetable oil fuels is the increased cost of the fuel as compared to fossil fuels. This is an important aspect of the cost of switching to vegetable oil fuels because it is a recurring cost from year to year. The expected cost of biodiesel bought from World Energy and delivered to Middlebury College is $2.05 a gallon. Another important cost consideration is the BTU content of the fuel. Biodiesel contains between 119,967 and 128,613 BTUs per gallon depending on the type of oil or animal fats used to produce it while #2 fuel oil contains 135,000 BTUs per gallon and #6 contains 150,000 BTUs per gallon.(www.bioenergy.ornl.gov) (Moser, 1/14/04) The lower heat content of biodiesel means that it will take more gallons of biodiesel than #2 or #6 to produce the same amount of heat that #2 and #6 give of when burned. If Middlebury College switched from #2 to biodiesel it would require between 149,052 and 159,793 gallons of biodiesel to create the equivalent amount of heat that #2 produces. If #6 oil were to be replaced with biodiesel Middlebury College would require between 1,933,708 and 2,073,070 gallons to meet its heating needs.

            Clearly there is a substantial price difference between biodiesel and #2 and #6. This price discrepancy in increased because of greater number of gallons of biodiesel required to produce the same amount of heat. In 2002 Middlebury College spent $1,371,300 on #2 and #6 fuel oil. By replacing both #2 and #6 with biodiesel and assuming a price of $2.05 a gallon for biodiesel, Middlebury College would increase its fuel costs to between $4,269,685 and $4,409,586 depending on the BTU content of the biodiesel fuel.

            Although biodiesel emissions have been extensively tested in internal combustion engines the emission from furnaces and boilers burning biodiesel have not been as thoroughly tested. While some studies have compared diesel fuel and #2 fuel oil to biodiesel it is almost certain that no tests have been conducted to compare biodiesel and #6 fuel oil. (www.biodiesel.org) The emissions tests that have been conducted have determined that biodiesel lowers all pollutants as compared to #2 fuel oil but what is uncertain is the average emissions reduction across all types of furnaces and boilers. Because of the small number of studies comparing biodiesel emission to #2 fuel oil emissions this study will use emissions reduction data from internal combustion engines as a substitute. Although the emissions data from internal combustion engines compare diesel fuel to biodiesel the data should slightly underestimate the emissions reduction of biodiesel compared to #2 and #6 fuel oils. The reasoning behind this is that diesel fuel is known to burn cleaner, because of fewer impurities, than #2 and #6 fuel oil so any emissions reduction estimates between biodiesel and #2 and #6 should error on the low end. (Schmidt, p114)

            The emissions reductions when combusting biodiesel fuel in an internal combustion engine as compared to combustion of diesel fuel are shown below.

Table 2

This table shows the emissions reductions when 100% biodiesel is substituted for diesel fuel in an internal combustion engine. ( www.biodiesel.org )

Although NOX emissions increase when biodiesel is burned in most internal combustion engines it has been found that biodiesel combustion in furnaces decreases NOX emissions as compared to #2 fuel oil. (www.biodiesel.org) The emissions data shown above are averages for internal combustion engines but by applying it to Middlebury College's fuel use an estimate can be made as to the quantity of emissions reduction that can be expected if the college switches to biodiesel fuel.

Table 3

This table shows the estimated quantities of regulated pollutants that would be emitted if Middlebury College switched from burning #2 and #6 heating oils to biodiesel. The number of gallons of biodiesel is a range because of the uncertainty in the BTU content of the biodiesel.

  The total reduction in tons of emissions is unknown but it is clear that a substantial reduction in regulated pollutants can be expected by a switch to biodiesel. It appears that total reduction of regulated pollutants will be approximately 50% or 70 tons less. If one assumes that the reduction will be about 70 tons the cost saving to Middlebury College will be about $2240 per year in Air Pollution Control Division fees. (Vt State, Air Pollution Control Division)

More importantly than the reduction in regulated pollution is the reduction in non-regulated CO 2 emissions that is experienced with a switch to biodiesel. When burning biodiesel net CO 2 emissions can drop to 0 assuming that tractors and transportation equipment are using biodiesel. This is possible not because no CO 2 is released from biodiesel combustion but because biodiesel is a renewable carbon neutral biomass fuel. Another important environmental aspect of biodiesel use is its lack of toxicity. Biodiesel is non-toxic and biodegrades almost completely in three weeks. It has been shown that Biodiesel biodegrades as fast as sugar and is less toxic than common table salt. (Tickell, 37)

The environmental benefits of switching from #2 and #6 fuel oil to biodiesel are huge but the present costs make the switch economically prohibitive. Middlebury College's annual fuel bill would be increased by approximately $2,900,000 to $3,030,000 by switching entirely to biodiesel, an increase of over 300%. A possible way to achieve the environmental benefits of biodiesel without the high costs could be to burn straight vegetable oils. Although straight vegetable oils can cost more than biodiesel, waste vegetable oils are much less expensive. Soybean oil for example now costs $0.315 a pound, resulting in a price of about $2.50 a gallon while waste oil is free from most restaurants.(West central Soy, 1/29/04) Waste vegetable oils can be used as a fuel but there are some physical limitations. Normal residential and commercial furnaces will not burn waste vegetable oils. Although commercial furnaces that burn vegetable oils are available the college would have to purchase many new furnaces in order to be able to burn waste vegetable oils.

Residential furnaces are not capable of burning waste vegetable oil but the four main boilers in the heating plant probably would be able to. Waste vegetable oil has a viscosity similar to #6 fuel oil (Schmidt, p64) and the four main boilers have a similar fuel delivery system to commercial furnaces that are designed to burn waste vegetable oils. Although waste vegetable oils will not work in the furnaces that burn #2 fuel oil they would most likely work in the four main boilers that currently burn #6 fuel oil. The cost to convert the main boiler to burn waste vegetable oils would likely be similar to the cost of converting the boilers to burn biodiesel, namely $100,000 per boiler. (Moser,1/14/04)

The major draw back to burning waste vegetable oils is the supply of oil is limited and the filtering of the oil can be difficult. Although fast food restaurants in the U.S. produce over 3 billion gallons of waste vegetable oils each year the supply in Vermont might be somewhat limited as the population is relatively small and spread out. (Tickell, p40) Waste vegetable oils do pose a possibility but would require a substantial investment in filtering equipment and a system to deliver the oil to Middlebury College. The major benefit to burning waste vegetable oil is most restaurants must pay to have the waste oils disposed of so the costs of acquiring the oils would be very low if anything at all. Even thought the oil is free the transportation and filtering costs might make its costs use as a fuel prohibitive. Because waste oils have not been used as a heating fuel in large quantities the possibilities of using waste oils needs further investigation to determine the feasibility and costs.

Biodiesel is clearly an environmentally friendly alternative to Middlebury College's current fossil fuels but it potential is limited by costs. There have been enough studies conducted to determine that biodiesel lowers emissions of all regulated pollutants but the actual percentage reductions are still not well known. In addition to the reduction in regulated pollutants biodiesel's carbon neutral emissions are important to limiting the increase in atmospheric CO 2 levels. The environmental benefits of biodiesel are indisputable but the costs of its implementation and use are still a strong deterrent to its implementation here at Middlebury college. Although biodiesel use is constrained by price waste vegetable oils could provide the environmental benefits of biodiesel but at a manageable cost to Middlebury College.

• Schmidt, Paul F. Fuel Oil Manuel , Industrial Press Inc., copyright 1985
• Tickell, Joshua. From the Fryer to the Fuel Tank, Joshua Tickell Media Productions., Copyright 2003
• Moser, Michael. Heating Plant Manager at Middlebury College., Information gathered through his office and from an interview on January 14, 2004
• Vermont State Agency of Natural Resources Department of Environmental Conservation Air Pollution Control Division. Information taken from Middlebury College's Air Contamination Source Registration Fee Report from 2002 which was obtained through Michael Moser at Middlebury College.
• ( http://bioenergy.ornl.gov/papers/misc/energy_conv.html ) Emissions data for internal combustion engines obtained through a link from The National Biodiesel Board at www. Biodiesel.org
• ( http://www.biodiesel.org/resources/reportsdatabase/reports/hom/20011201_htg-001_spaceheating.pdf ). Information on biodiesel emissions for furnaces.
• ( http://www.biodiesel.org/pdf_files/emissions.PDF ) Information on emissions for 100% biodiesel burned in an internal combustion engine.
• ( http://www.eia.doe.gov/emeu/cabs/chapter3a.html ) Information on US energy use in 1997, obtained on 1/28/04.
• ( http://www.evostc.state.ak.us/facts/qanda.html ) Information on the Exxon Valdez Oil spill in 1989.
• Information obtained over the phone from a representative of West Central Soy.