The Disadvantages of Bio Diesel

A lot of people who are involved in the bio-diesel industry would like us to think that biodiesel is the be all and end all of alternative fuel.

The Disadvantages of Bio Diesel

The Disadvantages of Bio Diesel

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The Disadvantages of Bio Diesel

The Disadvantages of Bio Diesel

Bio diesel in its rightful place has a meaningful contribution to make in the alternative fuel arena. Make no mistake, I am an advocate for bio diesel, and I use it everyday in my vehicles.

There are however are a number of issues that bio diesel can cause that people must be aware of before they use it. Not knowing what these pitfalls are can lead to people being permanently disillusioned with biofuels.

Cold weather.

The first disadvanTAGe of bio diesel is that its cold weather properties are not as good as that of petroleum diesel. This means that thosepeople who live in cold countries will need to take precautions during winter if using bio diesel.

When discussing bio diesel people refer to the Cloud Point. The cloud point is that point at which the bio diesel starts to solidify. I know a cloud point of 10° C means that if cannot be used below this temperature.

Bio diesel takes on the characteristics of the material from which it is made. If you make bio diesel from soybean oil, then it will have a cloud point less than -2° c. If you make bio diesel from palm oil, then this cloud point could be more than 10° c.

It is thus vital that the infeed material that is used for the manufacturing of bio diesel is suitable for the country in which it is going to be consumed. This is one reason why the major nationalbio diesel fuel standards like ASTM D6751 and EN 14214, specify what the maximum point cloud should be. Highly saturated fats like palm oil will not make bio diesel that is suitable for use in North America or Europe during winter.

When making bio diesel from used Cooking oil (which is the major source of bio-diesel in many countries) it is very difficult to determine exactly what kind of oil is being used. The oil may be sourced from hundreds of different restaurants and mixed together before use. This means that in many cases, the cloud point is difficult to determine. Each batch will need to be tested to ensure that it complies with national standards before it is sold.

Material incompatibilities.

The second disadvanTAGe of usingbio diesel is that bio-diesel tends to dissolve nitrile rubbers. Prior to the introduction of ultra-low sulfur diesel, nitrite and other natural rubbers were widely used in fuel systems. This makes these older systems incompatible with bio diesel. After 1994, in many countries, motor manufacturers started using more bio diesel compatible materials.

If you drive a later model vehicle, this will not be an issue for you. Many people who drive older vehicles adopt a wait-and-see attitude. Nitrile and other incompatible rubber will break down, but the process takes an extended period of time. It can take up to a year for these issues to show. This leaves plenty of time for these materials to be identified and replaced.

Fuel system flushing.

One of the characteristics of bio diesel is that it is an extremely good solvent. Petroleum diesel on the other hand, tends to leave deposits in the fuel system. These deposits take the form of sludge in the fuel tank, as well as a varnish on the inside of the fuel pipes. Using bio-diesel will flush these deposits out.

This will block up the fuel Filters and will cause the engine to stall. When using bio-diesel for the first time. It is wise to carry a spare fuel Filter with you.

This really is only an issue on vehicles which have been run on petroleum diesel for a long period of time. New vehicles that have only been running on diesel for a few years will not have a problem.

It is possible tohave the fuel tanks steam cleaned which will remove the deposits and minimize the problem.

Power Loss

When running bio diesel you will experience a loss of anywhere from 1-10%. Typically the power loss is about 5%.

This may be an issue if the engine is running close to full load, under heavy acceleration or you are a street racer, but it is not usually a significant issue. Most vehicles today have plenty of spare power available.

However when hauling goods or in other situations where engines are run at load, the fuel consumption will increase accordingly. Fuel consumption can increase from 5-10%.

The Disadvantages of Bio Diesel