Understanding Biodiesel

What is Biodiesel?

Biodiesel comes as a clean-burning alternative fuel produced from renewable inputs. Procured from edible and nonedible plant oils, it can completely replace diesel or can be blended with the same in any desirable percentage. The green fuel can be efficiently utilized in compression ignition diesel engines without any vehicle modifications. It is simple, effective and free from toxic sulphur and aromatics. The fuel is completely eco-friendly, as its exhaust emissions are significantly low and it biodegrades as rapidly as sugar.

How is Biodiesel produced?

Biodiesel is produced from palm stearin, used cooking oils, waste oils and other non-edible feedstock. It is mass-produced through a chemical process called transesterification. Under the process, the fatty acid portion of oils is reacted with a small percentage of methanol in the presence of a catalyst to form biodiesel.

As a by-product, glycerine is also released in small percentages. Biodiesel is chemically a fatty acid methyl ester while glycerine is a valuable by-product utilized in the manufacturing of soaps, paints, pharmaceuticals, cosmetics etc.

Biodiesel quality and health effect standards

The quality of fuel-grade biodiesel has been standardised globally. For instance, the standards in the USA are guided by ASTMD 6751 while European standards are established as EN-4214 and Indian standards as BIS 15607.

All three standards require minimum ester content of 96.5 percent. Biodiesel is the only alternative fuel to have fully complied with the health effects testing requirements of the USA 1990 Clean Air Act amendments, the most stringent emissions testing protocols ever required by the EPA for certification of fuels in the USA.

Biodiesel is a legally registered fuel with the US Environmental Protection Agency (EPA). The blends of the fuel are denoted as BXX with XX representing the percentage of Biodiesel. For instance, B100 is 100 percent Biodiesel while B20 is 20:80 Biodiesel.

Biodiesel power and mileage at par with diesel

The energy content of conventional diesel can vary upto 15 percent depending on weather conditions. The variability in convention diesel is due to changes in its composition, which are determined by refining and blending practices. The efficiency of diesel engines remains the same whether using biodiesel or diesel. Biodiesel has an edge over convention diesel in this regard as its energy content is much less variable than that of diesel.

Its energy content is more dependent upon the feedstocks used than the extraction process. Also the blends of biodiesel and diesel fuel fall between the parent fuels.

Advantages & Benefits of using Biodiesel

Biodiesel is an excellent fuel in the operation of diesel engines, steam rollers, thermic fluid heaters and vaporisers.

  • It requires no engine modifications
  • The exhaust emissions are much cleaner with the reduction in black smoke, NOx, CO and absence of SO2
  • There is no abnormal wear-and-tear in engine components
  • There are no nozzle deposits
  • Features enhanced safety characteristics due to higher flashpoint
  • Offers higher Cetane Number(CN) indicating better combustion quality as compared to petroleum and diesel
  • Eliminates the requirement of steam tracer for maintaining the fluidity of the fuel

More benefits of Biodiesel

Biodiesel furnishes a significant increase in combustion smoothness (anti-knock) due to its high Cetane content. This also results in significantly less engine noise. The fuel’s high lubricity keeps moving parts from wearing prematurely thus prolonging the life of the engine.

The production and use of biodiesel produce approximately 90 percent less carbon dioxide and 100 percent less sulphur dioxide emissions.