At a time when oil supplies are running low, the need for alternative or renewable fuel sources is beginning to affect the types of cars that are offered for sale to the public. There are very few in today’s public who have not heard the terms “biodiesel fuel” or “waste vegetable oil” when it comes to renewable energy sources that are currently being investigated to try to find answers to declining emissions. supplies of petroleum fuels.
Technically speaking, waste vegetable oil is a biodiesel fuel because biodiesel fuels are any fuel derived from vegetable oils or animal fats that are powered by a “diesel” or compression ignition engine. The term Biodiesel is currently used almost exclusively for the product made by combining lipids that react chemically such as vegetable oil or animal tallow and alcohol.
An important difference between biodiesel and waste vegetable oil is that biodiesel is formulated to be used alone or with petrodiesal blends in “standard” diesel engines and is different from the new vegetable and waste oils used to power diesel engines that must be specifically converted to do so.
To produce biodiesel fuels, the oils must undergo a process known as “alcoholysis” (sometimes called “transesterification”). In this process, vegetable oils have the fatty acids separated from the glycerol components using ethanol (and sometimes methanol) to replace the glycerol with specific types of alcohols known as short linear alcohols. In its purest form, biodiesel is designated (B100) or can be mixed with petroleum diesel in any concentration for use in most modern diesel engines.
Due to the different solvent properties that biodiesel has versus petrodiesel, biodiesel will damage the natural rubber gaskets and hoses of vehicles manufactured before 1992. For this reason, these older automobile parts must be replaced with a non-reactive one. to biodiesel.
An unexpected advantage is that biodiesel is known to break down and remove residual deposits left in fuel lines where petroleum diesel has been used before. As a result, engine fuel filters can become clogged with particles, especially if you quickly switch to pure biodiesel. Mechanical experts recommend that engine fuel filters and glow plugs be changed shortly after switching to a biodiesel fuel blend for the first time.
Additional advantages of using biodiesel include the fact that water does not mix with it; Biodiesel has a higher boiling point and flash point of (less than 266 ° F for biodiesel compared to 147 ° F for petroleum-based diesel or -52 ° F for gasoline. Virtually no content sulfur and is often used as an ultra-low sulfur diesel fuel additive (ULSD).
Waste vegetable oil (WVO), unlike pure vegetable oil (PPO) or pure vegetable oil (SVO), is a by-product of other industries, such as fryers used in industrial potato processing plants, factories that They produce sandwiches and fast food restaurants. Most enthusiasts who use it prefer to call the vegetable oil used for fuel as waste vegetable oil (WVO), particularly if it is recycled waste oil from a restaurant to better distinguish it from pure vegetable oil (PPO) or pure vegetable oil. oil (SVO) commonly regarded as standard biodiesel
In 2000, industry experts estimate that the United States was producing more than 11 billion liters, or 2.9 billion US gallons. If this total amount could be collected and used, it could be used to replace the equivalent amount of fossil-based oil, which totals almost 1% of oil consumption in the US The only theoretical drawback here is that vegetable oil production Waste is limited by the amount that industries can produce as a by-product versus pure or pure vegetable oil, which is limited only by the agricultural production capacity of any given national economy.
Like pure vegetable oil used as an alternative fuel for diesel engines, the viscosity of residual vegetable oil must be lowered for proper atomization of the fuel to prevent incomplete combustion of the oil and carbon build-up that can ultimately damage the fuel. motor. . Also, the free fatty acids (FFA) found in WVO can have an adverse effect on metals. Copper and alloys derived from it, such as brass, are affected. Zinc and metals like zinc, or galvanized by galvanizing, are stripped by FFA. Additionally, tin, lead, iron, and steel are also susceptible. Stainless steel and aluminum are the only metals that appear to be immune to the effects of FFAs.
Ideally, a car engine should be transformed before using vegetable oil as fuel. Most diesel car engines can use WVO, if they are tuned with the proper modifications. A common solution is to reduce the viscosity and surface tension of the oil by preheating, by adding a heat exchanger and an additional fuel tank for “normal” diesel fuel (petrodiesel or biodiesel). It will contain valves to switch between this additional tank and the main tank that contains the vegetable oil. This tank and valve system is an aftermarket modification that costs around $ 1200 USD.
The engine is initially started on diesel, switched to vegetable oil when it warms up, and switched back to diesel fuel shortly before shutting down to make sure no vegetable oil is left in the engine or in the fuel lines to read you start when it’s cold again. For longer term durability, it has been found best to increase the frequency of oil changes and pay more attention to engine maintenance, particularly when it comes to fuel injectors, cooling system, and glow plugs.
Although initially a bit more expensive, as you can see, using biodiesel or waste vegetable oil has several advantages as a vehicle fuel. In addition to being a renewable resource, unlike fossil-based oil, these fuels also release fewer pollutants into the atmosphere that can worsen global warming.
