Bio Liquid Fuels :

Oil & Bio-Liquid Boilers
Conversion of existing oil boilers

The article below is taken from OFTEC ‘Going Green’ information sheet

What is a bio-liquid?

Bio-liquids suitable for use in the home heating market are commonly FattyAcidMethyl Esters (FAME) derived from either used cooking oil or virgin plant sources such as Rapeseed and Soya, etc. grown specifically for this purpose.

The use of FAME in liquid fuels creates overall carbon reductions in lifecycle analysis of emissions when compared to the use of traditional mineral (fossil) fuels such as kerosene or gas oil. This is as a result of the

carbon absorbed by the plant during its lifecycle offsetting carbon emissions from the combustion process.

Producing FAME from used cooking oils gives a higher carbon saving than that of virgin plant stock*.

FAME for heating purposes should meet the requirements of EN 14213 (EN 14214 for automotive use can be considered to be a higher standard but some additional tests requirements fromEN 14213 will be required to

be satisfied before use) and be produced under strict quality assurance systems to achieve consistent quality and properties of the fuel.

FAME to EN 14213 can either be used as part of a blend with mineral fuels such as kerosene or gas oil or even in its pure form as a 100% bioliquid fuel with bespoke equipment

What are the implicationsof usingbio-liquids incurrent appliances?

The properties of bio-liquids and bio-liquid blends in comparison to mineral fuels such as kerosene are different. This is an important factor to bear in mind as this means that to change from 100%mineral fuel (even to a kerosene or gas oil bio-liquid blend) will require formal conversion and re-commissioning of

installations and equipment. Literally speaking the bio-liquid is thicker and heavier and has a different energy content. The properties of bioliquids being different to mineral fuels, react differently to different materials. Materials such as rubber – as found in fuel pump and filter seals – which are commonly encountered in mineral fuel installations are not compatible with bio-liquids. Bio-liquid compatible components should be in place before use of a bio-liquid as a heating fuel and are available from OFTEC Manufacturing Members. Pressure jet appliances and installations can be converted to run on bio-liquids with relative ease but only where the actual properties of the fuel are known. Conversion would commonly require at least the replacement of:

• Atomising nozzles

• Fuel pumps

• Flexible oil lines

• Filters and/or filter seals

Bio-liquids are hydroscopic (they absorb water) and should never be introduced to oil storage and supply systems which are contaminated. Contaminated systems should be cleaned before application of bio-liquids as the consequences will inevitably result in blocked filters and inoperative systems. Bio-liquids should never be introduced to existing oil storage installations which do not have secondary containment as the cleaning effect of the fuel may well find weaknesses in existing tanks which could lead to leaks. It is recommended that wherever possible and practicable new integrally bunded oil storage tanks suitable for bio-liquids are installed.

To help prevent long term storage stagnation it is recommended that smaller tanks are utilised based upon half yearly usage. For bespoke installations where a 100%FAME is being considered as the fuel to be used in a specific application then consideration will have to be made to the use of heated and insulated (and possibly agitated) fuel storage tanks as well as trace heated and insulated supply lines.

Vaporising burners and appliance installations should not have bio-liquid fuels introduced to them. It has been proven that bio-liquids in kerosene can immediately adversely affect vaporising burner combustion and manifest in the rapid onset of premature carboning in vaporising sleeve burner bases – even within hours. It is recommended that vaporising appliances such as range cookers are converted with appliance manufacturer’s (or appliance manufacturer’s approved) bio-liquid conversion burners.

Please contact us to find out more about conversion