| The environmental and cost benefits of biodiesel | | | | not pose any safety concerns, the presence of |
| fuel depend upon its properties. In turn, these | | | | these contaminant materials has undesirable |
| properties are largely determined by the way in | | | | mechanical implications. In particular, water and |
| which this new energy source is produced and | | | | sediment can clog filters, reduce ignition |
| stored. Thus, producers, distributors and retailers | | | | performance and have a negative impact upon |
| can ensure the quality of their product by | | | | the fuel pump. Specifications, set by the ASTM, |
| following the specifications presented by the | | | | refer to the amount of water dissolved and not |
| American Society for Testing and Materials | | | | to the water coexisting in bulk form alongside the |
| (ASTM). | | | | fuel within a tank. Nonetheless, the state of |
| The guidelines, within the ASTM specifications, | | | | Michigan also places constraints on the amount of |
| place limitations upon various properties. While | | | | such bulk water within a storage tank. |
| space constraints make an exhaustive discussion | | | | The presence of water may also stimulate the |
| of these properties impossible, this article will | | | | growth of microbes. This is especially true for |
| discuss the reasons why maximum and/or | | | | warmer temperatures. The microbes produce |
| minimum limits are placed on four of the | | | | deposits that can add to the clogging effects of |
| characteristics of the fuel. | | | | the water upon filters. This only further |
| One important characteristic is the flash point. The | | | | underscores the importance of testing for water. |
| flash point is the lowest temperature for which | | | | The final property that will be discussed is the |
| combustion may occur. If the flash point is too | | | | glycerin content. Glycerin is a natural byproduct of |
| low, then inadvertent combustion may occur | | | | the production process. A large glycerin |
| resulting in a safety hazard. According to some | | | | concentration in the final product may signal that |
| sources, one way of raising the flash point and | | | | the process used to transform oils and fats into |
| reducing the risk of accidental ignition is to | | | | fatty acid methyl esters (FAME) was not |
| increase the percentage of biodiesel within a blend. | | | | completed. A high glycerin concentration may |
| However, a low flash point can also result from | | | | result in the clogging of filters and pumps as well |
| small amounts of methanol left over from the | | | | as the contamination of injectors. |
| conversion process. Therefore, producers should | | | | Performing biodiesel fuel tests upon the four |
| always biodiesel fuel tests upon the flash point to | | | | characteristics discussed within this article, as well |
| ensure the safety of distributors, retailers and | | | | as other properties not discussed here, can help |
| consumers. | | | | to increase the safety of consumers and increase |
| While the amount of water and sediment does | | | | engine performance while reducing emissions. |