Biodegradable Lubricants

 

Bio oils are an important part of the Forestry Commission's objective of reducing the use of chemicals on its estate.  The Forestry Commission used 72,000 litres of bio hydraulic oils in financial year 2007/08, which represents a significant reduction in the usage of potentially damaging mineral oils.  Mechanical Engineering Services workshops sell biodegradable lubricants in areas where they are not readily available. Contact details of your nearest MES workshop. 

Biodegradability is the most important environmental quality of lubricants that have to be disposed of. A product that can degrade into safe gaseous or liquid products under the biological action of air, water and bacteria can be termed as biodegradable. A common test method for biodegradability of hydraulic oils is the Co-ordinating European Council (CEC) standard. To qualify as biodegradable the product must degrade by at least 80% in 21 days. The relative biodegradability of base fluids to the CEC standards are:

Mineral oils 20-30%
Synthetic esters 50-100%
Rapeseed Oil 90-100%

The biodegradable hydraulic oil currently used by the Forestry Commission is BP Biohyd SE-S, which is a synthetic ester and it degrades at over 85% as measured by the CEC-L-33-A-93 standard. The chain oil is BP Bioforst 2000, which is based on vegetable (rapeseed) oil, which degrades at over 99% as measured by the CEC-L-33-T-82 standard.

In addition to this it is important that the dissolved material does not harm plant, animal or aquatic life when disposed. Biodegradable substances pose a lower water pollution risk than mineral oils.

When a lubricant evaporates, it pollutes the atmosphere. A lubricant that shows a lower evaporation loss as compared to conventional products is safer. Evaporation losses of environment friendly base oils are generally lower, resulting in a significant reduction in emission levels. The evaporation loss, per cent by weight of the base substances of different hydraulic oils is as follows.

Mineral oils 16%
Synthetic Esters 2%
Rapeseed Oil 1%

Information on the biodegradable lubricants used by the Forestry Commission is available on the BP link in the right collumn.