Many biodiesels have a viscosity that is slightly higher than mineral diesel, which is generally too high. The atomization qualities of a fuel with a high viscosity are poor, and the spray angle is narrow.
Is diesel or biodiesel more viscous?
At 40°C, the viscosity of biodiesel was insignificantly higher than that of normal diesel fuel. Biodiesel viscosity tends to be substantially higher at lower temperatures, especially below 25°C.
Is biodiesel more viscous?
At lower temperatures, biodiesel has a lower viscosity than vegetable oils. The viscosities increase closer at higher temperatures. When the temperature rises, the viscosity of biodiesel in the liquid phase changes less than that of vegetable oil.
What is the viscosity of biodiesel?
Biodiesel has a kinematic viscosity of 3.6 to 5.0 cSt at 313 K, whereas diesel has a kinematic viscosity of 1.9 to 3.8 cSt), lower energy content (biodiesel has a higher heating value (HHV) of 39.3 to 39.8 MJ/kg, whereas diesel has an HHV of 45.3 to 46.7 MJ/kg), higher cloud point (2622
Why is biodiesel more viscous?
The molecules in biodiesel create dipole-dipole bonds. Biodiesel has a higher viscosity due to the presence of larger interparticle forces, specifically dipole-dipole interactions, due to the polar nature of the molecule. This pushes biodiesel chains closer together, thickening or viscosifying the liquid.
Is diesel more viscous than gasoline?
This arranges the fractions in ascending order from lowest to highest boiling point. Petroleum gas, naphtha, gasoline, kerosene, diesel, lubricating oil, fuel oil, and tar are the complete names of the fractions. As a result, gasoline has a lower viscosity than kerosene. Furthermore, kerosene has a lower viscosity than diesel.
Why does biodiesel have a higher viscosity than petrodiesel?
– Because petrodiesel is non-polar, only dispersion forces occur between molecules. – Biodiesel has a power component due to its ester functional group. – In biodiesel molecules, modest dipole-dipole interactions between ester functional groups contribute to overall intermolecular forces. As a result, the intermolecular forces between molecules in biodiesel will be stronger than in petrodiesel- biodiesel is more viscous than petrodiesel due to larger intermolecular forces between molecules. The flow rate of biodiesel is slower than that of petrodiesel.
Why does biodiesel burn cleaner than diesel?
Biodiesel produces less sulfur and carbon monoxide in emissions than petroleum-based diesel. Not only would the emissions be cleaner than petroleum-based diesel, but they would also be less expensive, allowing for the use of less expensive car catalysts to further cut hazardous emissions.
What kind of fuel is diesel?
The distillate fuel oil sold for use in motor vehicles that use the compression ignition engine named after its inventor, German engineer Rudolf Diesel, is known as diesel fuel. In 1892, he received a patent for his original design. Diesel fuel is made from a combination of crude oil and biomass resources.
Is biodiesel cheaper than regular diesel?
How does biodiesel compare to ordinary petroleum diesel as its use grows in the marketplace? What are the advantages and disadvantages? Here are four factors to consider while assessing the potential impact on fleet.
1. Cost Analysis
When comparing biodiesel prices, the National Biodiesel Board recommends using the following formula: For each percent of biodiesel blended with petrodiesel, add one penny per gallon. B-5, for example, would cost about five cents per gallon more than petrodiesel. B-20 would cost an extra 20 cents, and so on.
The Department of Energy’s handbook provides another option “Alternative Fuel Price Report for Clean Cities,” available at www.eere.energy.gov/afdc. Biodiesel pricing for low-level blends (B-2 to B-5) are nearly the same as conventional diesel, according to the September 2005 edition, $2.81 per gallon biodiesel against $2.81 regular diesel. Blends with B-20 are around ten cents extra at $2.91. Pure biodiesel (B-100), at $3.40 per gallon, is about 59 cents more expensive than conventional diesel.
2. Pollution Impact
According to the report, “In “Clean Alternative Fuels: Biodiesel,” the US Environmental Protection Agency (EPA) shows how biodiesel compares to normal diesel in terms of emissions.
The rise in nitrogen oxide (NOx) emissions is alarming because NOx is a major contributor to ozone formation. Fuel suppliers for fleets, such as Eastman Chemical, blend appropriate additives with biodiesel to counteract and reduce NOx emissions. For example, according to NREL-sponsored research, adding cetane enhancers such di-tert-butyl peroxide at 1% or 2-ethylhexl nitrate at 5% can lower NOx emissions. The study also claims that combining biodiesel with kerosene or Fischer-Tropsch diesel can lower NOx emissions.
“Biodiesel is a superior alternative for fleets interested in decreasing petroleum usage, greenhouse gas emissions, and regulatory pollutants,” adds NREL’s McCormick.
3. Gasoline Quality
“The only drawback we faced in transitioning to biodiesel was a gasoline quality issue with our prior supplier,” explains Curtis of Eastman Chemical. Biodiesel that does not satisfy high quality standards can reduce engine performance, clog filters and injectors, and result in a slew of other expensive repairs.
Eastman Chemical changed suppliers within the first two months of their biodiesel program and hasn’t had any fuel problems since. Curtis strongly advises fleet managers who are considering using biodiesel to double-check that their fuel supply follows ASTM D6751 criteria. The American Society of Testing and Materials International (ASTM) is one of several international standard-setting organizations that have approved biodiesel requirements.
In the United States, ASTM D6751 is the most commonly cited standard. The goal of this guideline is to safeguard customers from subpar products, lower the cost of buying and selling biodiesel, and simplify the procurement process.
“The benefits can only be obtained if high-quality biodiesel that meets ASTM D6751 requirements is utilized for mixing,” warns McCormick. “Biodiesel that isn’t up to grade can create engine difficulties and increased emissions.”
What effect does biodiesel have on engine performance when compared to normal diesel? The Engine Manufacturers Association (EMA) estimates that using pure biodiesel results in a 5-7 percent reduction in maximum power output. That’s with biodiesel that’s 100 percent biodiesel. Lower ratio blends, such as B-2, B-5, or even B-20, appear to have little, if any, impact on perceived performance as long as fuel quality meets ASTM criteria. The greater lubricity of biodiesel is one performance problem. On the one hand, high lubricity helps to reduce early wear and tear in the fuel system. H
However, when switching from conventional diesel to biodiesel, the enhanced lubricity may pose issues. It can, for example, operate as a solvent for some fuel system components and concrete-lined tanks, releasing deposits built up on tank walls and pipes from diesel fuel storage, causing fuel filter blockages at first. The EPA recommended that car owners replace their fuel filters after the first tank of gas.
Another point of worry is how well it performs in cold conditions. In his analytical paper “Biodiesel Performance, Costs, and Use,” Anthony Radich of the Department of Energy writes, “The performance of biodiesel in cold temperatures is considerably inferior than that of petroleum diesel.”
He claims that the temperature at which wax crystals can develop in a vehicle’s fuel system and potentially clog fuel lines and filters is higher than that of petroleum diesel.
Is biodiesel better than petrodiesel?
Biodiesel vs. Petrodiesel Although petrodiesel produces 10% more energy than biodiesel, biodiesel burns cleaner and more effectively. Biodiesel has a higher viscosity, making it more difficult to flow through gasoline lines.