USE IN REGULATED FLEETS

WHAT IS B100?
B100 is a diesel fuel substitute produced from renewable sources. B100 has been registered with the WorkSafe Australia by MBM as a pure fuel or as a fuel additive and is a legal fuel for commerce. B100 is an alternative fuel that can be used in neat form, or blended with petroleum diesel for use in compression ignition (diesel) engines. Its physical and chemical properties as it relates to operation of diesel engines are similar to petroleum based diesel fuel. The specification for pure (100%) B100 is described in Table 1.

Table 1. B100 Specifications (as of July 2000).

EPACT and REGULATED Fleets
The U.S. Congress enacted the Environmental Protection Act (EPACT) in 1992. The intent of this statute was to strengthen U.S.'s energy security by displacing imported petroleum. To help accomplish this goal, EPACT required that by the year 2000, 75% of all affected vehicle purchases for state fleets must be alternative fuelled vehicles. The U.S. Department of Energy (DOE) was authorised to implement this legislation and, on February 28, 1995, proposed the Alternative Fuel Transportation Program regulations. This rule was finalised on March 14, 1996.

State fleet requirements will began in the model year 1997 (MY97) and affected centrally fuelled fleets with 20 or more light-duty vehicles that operate in major urban areas. Acquisition schedules were revised to begin in MY97, starting on September 1, 1996, and be met by August 31, 1997. Currently, state government fleets will only be required to purchase AFV's. There was no requirement that these fleets actually used alternative fuel in those vehicles.

The U.S. Department of Energy revised the definition of "alternative fuel" to include B100. The DOE concluded that an additional rulemaking proceeding was required to develop the information needed to reach a conclusion on which, mixture or blends of B100 should be included in the definition of "alternative fuel". DOE defined an alternative fuelled vehicle as a dedicated vehicle or a dual fuelled vehicle (including flexible fuelled vehicles). A flexible fuelled vehicle (FFV) means any motor vehicle engineered and designed to be operated on any mixture of two or more different fuels. Since neat B100 has been classified as an "alternative fuel", a bi-fuel vehicle that is authorised to be operated on 100% B100 or diesel would meet the definition of a dual fuelled vehicle.

Table 2. EPACT Acquisition Requirements for State Fleets.

The acquisition of AFV's exceeding 8,500 pounds GVWR (gross vehicle weight rating) generated credits for this program. The final rule provided for the allocation of one credit for each AFV a fleet or covered person acquires that exceeds the number of alternative fuelled vehicles that fleet or person is required to acquire. These credits can be banked, traded, or applied to the State fleet light duty requirements.

Fleet Economic and Performance Implications of B100 Use
Fleet Economics
B100 in Australia will be marketed at a premium compared to petroleum diesel. Therefore, fuel costs will be greater than petroleum diesel for fleet managers that use a B100 blend. Although B100 is more expensive in Australia on a per litre basis, there are no significant infrastructure changes or incremental maintenance costs associated with its use. This contrasts to the significant capital investments that must be made in vehicle modifications and fuelling infrastructure for other alternative fuels. Three independent studies have confirmed that B100 blends (ie. B20) are cost competitive with other alternative fuel options when compared on a vehicle life cycle basis.

A study completed by Booz-Allen & Hamilton found that the cost of converting to B100 is very competitive with converting to any of the alternative fuels because no additional capital or maintenance costs are incurred. Under the scenarios analysed in a 1994 report, a truck or bus fleet using B20 would experience lower total annual costs than using compressed natural gas or ethanol.

Table 3: Medium Duty Truck Fleet Economics

Similar conclusions have been reached in the Urban Transit Bus Industry. Bi-State Development Agency is the transit authority in the City of St. Louis, MO that operates over 700 buses that consume over 22.7 million litres of diesel fuel annually. Lyle Howard, Quality Assurance Manager for Bi-State, has documented the advantages and disadvantages of various alternative fuels. Bi-State has used B20 for two years in a documented research program. Conclusions from that work include:

• B100 is a viable motor fuel
• performance and fuel economy were unchanged with B20
• exhaust emission improved dramatically
• the fuel was fully compatible with vehicle and fuel dispensing equipment

Mr. Howard compared alternative fuels on the following evaluation criteria; vehicle cost, infrastructure cost, safety, operating cost, reliability, customer acceptance, funding assistance, training costs, fuel availability, fuel quality, and fuel price stability. Fuels were evaluated on a scale of 1 to 10 with 10 being most desirable. The following table compares B20 with diesel fuel, compressed natural gas, liquefied natural gas, methanol, and ethanol.

Table 4.

Vehicle Performance
Emissions and performance data on several medium and heavy duty engine families fuelled with B20, including the Detroit Diesel Series 60, 6V-71, 6V-92, 8V-71, Cummins L10, Cummins 5.9 B, and the Navistar 7.3 HEUI. Emissions data from these tests demonstrate that particulate matter, opacity, carbon monoxide and hydrocarbons are reduced. Oxides of nitrogen are slightly increased with some engines. Operating performance parameters, such as fuel consumption, power, and torque were similar to diesel fuel for these tests.

CONSIDERATIONS FOR B100 USE
Infrastructure
In general, the standard storage and handling procedures used for petroleum diesel should be used for B100. The fuel should be stored in a clean, dry, dark environment. Temperature extremes should be avoided. Acceptable storage tank materials include mild steel, stainless steel, fluorinated polyethylene, and fluorinated polypropylene. B100 has a solvent effect which releases the deposits accumulated on tank walls and pipes, which previously have been used for diesel. These deposits can be expected to clog filters initially and precautions should be taken to allow for this.

Materials Compatibility
B100 over time will soften and degrade certain types of elastomers and natural rubber compounds. Precautions are needed when using high percent blends to ensure that the existing fuelling system, primarily fuel hoses and fuel pump seals, does not contain elastomer compounds incompatible with B100. Manufacturers recommend that natural or butyl rubbers not be allowed to come in contact with neat B100. B100 will lead to degradation of these materials. If a vehicle's fuel system does contain these materials, replacement with B100 compatible elastomers such as Viton B is recommended. The recent switch to low sulphur diesel fuel has caused most original equipment manufacturers (OEMs) to switch to components suitable for use with B100, but users should contact their OEM for specific information.

Cold Flow Properties
As with any diesel fuel, cold flow properties are important. A 20% blend of B100 will increase the cold flow properties (cold filter plugging point, cloud point, pour point) of petrodiesel approximately 1 to 3 degrees Celsius. Thus far, no precautions have been needed for fuelling with 20% blends. Operation of neat (100%) B100 in cold weather, however, will experience gelling faster than petrodiesel. The solutions for this potential issue are much the same as that with low-sulfur diesel (ie. utilisation of fuel heaters and storage of the vehicle in or near a building). B100 appears to be largely unaffected by conventional pour point depressants.

Macroeconomic Impacts of B100 Utilisation
An important factor that is not usually considered when calculating the costs and benefits of industrial feedstock materials is the macroeconomic effect associated with domestically produced renewable energy sources. Economic benefits of a B100 industry would include

"value added to the feedstock, an increased number of jobs, an increased tax base from plant operations and income taxes, and investments in plant and equipment."

There are three possible benefits that would accrue to the state from a B100 industry;

• By expanding demand for vegetable oil, B100 allows vegetable processors to pay more for oilseed,
• oilseed farmers near the B100 plant would receive slightly higher prices for oilseed, and
• the presence of a facility that creates energy from oilseed would add value to the state's industrial and income base.

Previous economic work demonstrated that for each $1 generated in the state's oilseed processing industry an additional $1.50 is generated in the service sector. Of the total amount generated the state's treasury in the form of income, sales, and corporate taxes receives a portion of those revenues.

"If each State of Australia was to mandate the use of a 20% B100 blend in its state vehicle fleet where feasible, the total additional cost of this policy would be minimal. In this eventuality, the Government would using a B100 blend in about 1/6 of its fleet. If it could be shown that this policy would result at least one new B100 plant in each state of Australia, then the policy would create more new tax revenues than it would cost and would clearly be in the best interest of the state".

B100 plant production economics are highly dependent upon the cost associated with feedstock procurement. Feedstock costs represent approximately 75 to 80% of the overall costs of B100 production. Therefore, capital expenditures do not have a significant impact on the overall cost of producing B100. B100 production facilities tend to be more scale neutral than other technologies. Economic studies suggest plants can be sized according to regional conditions.

Market Issues: Manufacturers Warranty
General acceptance by the major US and European vehicle manufacturers is an essential step in the road to commercialisation for B100. A common misconception is that an engine manufacturer must warrantee B100 in order to use it in the Australia. The reality is that no engine manufacturer warrantees any fuel, including petrodiesel, because they do not produce fuel. If there is a problem caused by the fuel, it is the responsibility of the fuel supplier.

Engine manufacturers do, however, warrantee the materials and workmanship of their engines and have the ability to void their materials and workmanship warrantees if certain fuels are used in their engines. The question for B100 use is not whether an engine manufacturer ‘warrantees’ B100, it is whether the use of B100 will void their existing warrantee. Almost all the companies marketing diesel engines in the US and Europe have confirmed that the use of B20 will not void their parts and materials warrantees. This allows B20 to be used in most existing engines with no further approvals.

At present, 100% B100 has been declared and alternative fuel by the US Department of Energy and any vehicle certified to run on 100% vehicles are alternative fuelled vehicles under EPACT. Vehicles certified to lower blends, at the present time, do not classify as alternative fuelled vehicles for purposes of compliance with EPACT and similar European standards. At the present time, few engine manufacturers have certified B100 due to the added costs involved with certification and lack of data using B100, since almost all the research in the US and Europe has been on B20.

B20 is the most popular B100 blend tested so far with major diesel consumers and engine manufacturers. B20 provides many of the environmental and safety benefits of pure B100 at a fraction of the cost. B20 is also compatible with existing diesel engine maintenance and refuelling facilities. More than 40 million kilometres of actual in-service pilot programs have been conducted across the U.S. and Europe using B20. Several national trade associations representing major private diesel consumers including the American Trucking Association (ATA) and the American Bus Association (ABA) have endorsed including B20 as an alternative fuel.

For these reasons, B20 should be a popular compliance option for fleets that deploy diesel-powered vehicles.

B100 ATTRIBUTES
Emissions Reductions
The use of B100 in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle and testing methods. Particulate emissions from conventional diesel engines can be divided into three components. Each component is present in varying degrees depending on fuel properties, engine design and operating parameters.

The first component, and the one most closely related to the visible smoke often associated with diesel exhaust, is the carbonaceous material. This material is in the form of sub-micron sized carbon particles which are formed during the diesel combustion process and is especially prevalent under conditions when the fuel-air ratio is overly rich. This can occur as a result of insufficient combustion air, overfueling or poor in-cylinder fuel-air mixing. The second component is hydrocarbon material, which is absorbed on the carbon particles, commonly referred to as the soluble fraction. A portion of this material is the result of incomplete combustion of the fuel, and the remainder is derived from the engine lube oil. Finally, the third particulate component is comprised of sulfates and bound water. The amount of this material is directly related to the fuel sulfur content.

The use of B100 decreases the solid carbon fraction of particulate matter (since the oxygen in B100 enables more complete combustion to CO²), eliminates the sulfate fraction (as there is no sulfur in the fuel), while the soluble, or hydrocarbon, fraction stays the same or is increased. Therefore, B100 works well with new technologies such as catalysts (which reduces the soluble fraction of diesel particulate but not the solid carbon fraction), particulate traps, and exhaust gas recirculation (potentially longer engine life due to less carbon).

Health Effects
Evidence does exist which indicates that diesel particulate matter is a potential carcinogen. In 1988, the U.S. National Institute for Occupational Safety and Health (NIOSH) recommended that whole diesel exhaust be regarded as "a potential occupational carcinogen", as defined in the Cancer Policy of the Occupational Safety and Health Administration. The use of B100 does result in decreases in most regulated emissions. Relative to health effects, research results indicate that particulate matter, specifically the carbon or insoluble fraction, is significantly reduced. In addition to reducing the overall levels of pollutants and carbon, the compounds that are prevalent in B100 and diesel fuel exhaust are different. Preliminary research on the speciation of diesel and B100 particulate indicates that B100 exhaust has less harmful impacts on human health than petrodiesel.

The United States Bureau of Mines (USBOM) has completed Ames mutagenicity testing of the diesel particulate matter (DPM) and exhaust gases from engines fuelled with B100 to better understand how the use of B100 may impact the health of miners. Samples were taken from the exhaust of a Caterpillar 3304 PCNA equipped with an exhaust catalyst. Test results documented that the use of B100 reduced the Ames mutagenicity of DPM by 50% over conventional diesel fuel. In addition, the gas phase mutagenicity of B100 was negligible. USBOM researchers believed the strong reduction in mutagenicity may be due to the lack of aromatics or polycyclic aromatic hydrocarbons (PAH's) in the B100 fuel and, subsequently, in the exhaust gases. Tests from Europe confirm the reduction in DPM PAH using B100 blends as outlined below:

Table 5. Gaseous PAH levels of diesel fuel and a 50% B100 blend.

Lubricity
In the United States the sulfur level of diesel fuel that is used for on-road purposes is limited to 0.05% by weight. This limit was mandated in October 1993 as a method to decrease particulate matter emitted from diesel powered vehicles. With the mandated Environmental Protection Agency (EPA) low-sulfur diesel fuel as well as the CARB (California Air Resources Board) low-sulfur, low aromatic diesel fuel emerging on the market, fleet operators began to encounter premature wear and/or failure of injector pumps in increasing numbers.

Australia also currently has low sulphur diesel fuels.

Stanadyne Diesel Systems on October 15, 1993 and Bosch Diesel Fuel Injection Service on December 3, 1993 issued Service Letters to distributors and dealers concerning the lack of lubricity caused by hydroprocessing to reduce the sulfur content in the new low-sulfur diesel. The pump manufacturers recommended use of lubricity additives to alleviate the serious damage occurring to their injection pumps.

Testing at labs such as Southwest Research Institute, Stanadyne Automotive, and Engineering Testing Services has demonstrated that B100 shows significant lubricity improvement compared to diesel fuel. Two methods of analysis were utilised; the "Scuffing Load Ball On Cylinder Lubricity Evaluator" and the high frequency rotating rig (HFRR).

Table 6. Lubricity Results of B100 and Petroleum Diesel Using High Frequency Reciprocating Rig*

Flash Point and Sulfur Content
The flash point of a fuel is defined as the temperature to which the fuel must be heated to produce a mixture that will ignite when exposed to a spark or flame. If the flash point of a fuel is too low, the fuel is considered a fire hazard which is prone to flashing, possible ignition, and even explosion. The flash point of B100 has been tested and reported by various sources. Specific testing at Southwest Research Institute concluded that the flash point of B100 blends increases as the percentage of B100 increases. Therefore pure B100 or blends of B100 with petroleum diesel is safer to store, handle, and use than conventional diesel fuel. In addition, pure B100 is essentially sulfur free and results in a total reduction of SO² emissions as well sulfate aerosols in particulate matter. These reductions should assist in increasing both vehicle and catalyst life over time.

Neat B100 has a flash point over 148° C, well above the flash point of conventional diesel fuel. Detailed below are the results from research for the flash point of B100 and B100 blends:

Table 8.

The diesel fuel, B25, and B50 were testing using the ASTM D93 Pensky-Martens closed cup method. The B100 blend containing 75% and 100% B100 did not flash using D93, therefore ASTM D92, the Cleveland open cup method, was used. The flash point of B100 blends increase as the percentage of B100 added increases. Other tests have confirmed this data and suggest that most of the flash point benefits occur at blends levels of 85% and greater.

Biodegradability
B100 has desirable degradation attributes that make it the fuel of choice by environmentally conscious boaters. Studies at the University of Idaho have been conducted to determine the biodegradation of B100 in an aqueous solution compared to diesel fuel and dextrose (sugar). B100 samples degraded more rapidly than the dextrose control and were 95 percent degraded at the end of 28 days. The diesel fuel was approximately 40 percent degraded after 28 days.

It should also be noted that B100 blends accelerate the biodegradability of low sulphur diesel. For example a 20% B100 blend degrades twice as fast as low sulphur diesel. This illustrates that B100 use has demonstrated biodegradability benefits at levels lower than 100%. Simply stated, neat B100 degrades as fast as sugar and a B20 blend will degrade twice as fast as petroleum based diesel fuel.

Toxicity
Impacts on human health represent significant criteria as to the suitability of a fuel for commercial applications. Health effects can be measured in terms of fuel toxicity to the human body as well as health impacts due to exhaust emissions. Tests conducted by Wil Research Laboratories, Inc. investigated the acute oral toxicity of pure B100 fuel as well as B20 in a single-dose study on rats. The LD50 of pure B100, as well as B20, was found to be greater than 5000 mg/kg, although hair loss was noted on one sample in the B20 group. The acute dermal toxicity of neat B100 was evaluated in a single dose study involving rabbits. The LD50 of B100 was found to be greater than 2000 mg/kg and the 2000 mg/kg dose level was found to be a No Observable Effect Level (NOEL) for systemic toxicity.

Acute aquatic toxicity tests with Daphnia Magna have also been conducted. Table salt (NaCl), diesel, and B100 were compared to each other. The LC50 count (the concentration where 50 percent of the Daphnia Magna have died and 50 percent were still alive) for table salt was 3.7 parts per million (ppm). Fifty percent of the Daphnia Magna were dead at 1.43 ppm for diesel fuel. The LC50 number varied for B100 from 23 ppm to 332 ppm. Therefore, B100 is less toxic than diesel fuel.