The government’s transport 2010 “Green Fuel Obligation” commits the UK to replacing 5% of transport fuel with biofuels by 2010, saving an estimated 1 million tonnes of carbon emissions per year.

Environmentally conscious motorists are now opting for biodiesel in preference to fossil fuels according to Department for Transport figures. Biodiesel consumption has shot up from just over 2 million litres a month during 2003 to an estimated 12 million litres a month by the end of 2005.

While biodiesel offers a simple way to cut transport carbon emissions, the only blend currently accepted universally by the auto-motive industry is a B5 biodiesel blend, (5% biodiesel and 95% mineral diesel), resulting in only modest carbon emission savings.

Research by Clean Energy Consultancy suggests higher carbon emissions savings are achievable by replacing conventional heating fuels with biofuels. Recent studies suggest biodiesel has similar properties to kerosene and could contribute significantly more to cutting UK carbon emissions than transport fuel. Importantly this means existing heating appliances in houses around the country are potentially compatible with the alternative biofuel, eliminating the need to replace boilers.

The research tested three variables of biodiesel; B20, B50 and B100, which refers to the concentrations of biodiesel mixed with kerosene i.e. B20 is 20% biodiesel with 80% kerosene and so on.

The research suggests boilers will need to pre-heat the fuel prior to combustion, a practice commonly used in mainland Europe. Some boiler models will simply require a preheat kit to be fitted to the existing boiler at a cost of around £100, other boiler models will require a replacement biodiesel specification preheat burner at a cost of around £350. New biodiesel boilers would simply incorporate a fuel preheat burner as a standard component without incurring any additional costs.

Winter field trials

In December 2005, field trials commenced in a family dwelling using the existing household oil fired boiler modified with a preheat burner. The trials were carried out to evaluate boiler reliability.

The field trials revealed one major problem that affected boiler reliability. The B100 (pure biodiesel) and B50 biodiesel had to be stored around 20-25°C to remain stable, otherwise the fuels become opaque and gradually over time, combustion failure occurred due to the partial blocking of the boilers nozzle fuel filter with crystallised vegetable fats.

The B20 biodiesel did not give any cause for concern. Even at fuel temperatures below freezing, the B20 biodiesel operated without any problems.
During the study, the clean internal condition of the test boilers for each of the biofuels tested suggested that biodiesel is generally compatible with oil-fired boiler technology. In fact the boilers were in cleaner internal condition and had cleaner combustion than using kerosene heating oil.

Fuel storage

B100 and B50 biodiesel fuel tanks and associated pipe work will require thermal insulation and heating to maintain fuel stability, which may be prohibitive to many consumers on cost grounds. However, the B20 biodiesel is not affected by severe winter weather conditions and can possibly be used with existing fuel storage systems without any additional costs.

Natural rubber fuel seals used on heating oil fuel storage tanks, fuel line joints, valves and filters, may require replacing with synthetic rubber seals.

What is biodiesel?

Biodiesel is a liquid biomass fuel made from waste vegetable oil from the food industry, normally described as Fatty Acid Methyl Ester (FAME) and harvested oilseed rape crops, known as Rapeseed Methyl Ester (RME). Biodiesel combustion only produces those carbon emissions the vegetable crops absorb during their lifecycle and is described as a carbon neutral fuel, although during the biodiesel production processes, modest carbon emissions are produced.

Biodiesel production

Vegetable oils have high viscosities (fluid thickness) and are not generally suitable as heating oils. The viscosity is reduced by removing glycerine from the oil using a process called transesterification. This process reduces the viscosity of the vegetable oil making it more suitable as a heating oil replacement.
Carbon emissions savings and agriculture

DTI 2003 figures suggest, nearly 1 million heating oil households consumed 2.7 billion litres of kerosene heating oil producing around 7.5 million tonnes of carbon dioxide emissions. If these households switched to B100 biodiesel, the carbon dioxide savings could be 7.5 million tonnes per annum and diluted B20 biodiesel would save 1.5 million tonnes of carbon dioxide. This represents a considerable improvement over the 1 million tonnes of carbon savings from transport.

The B20 heating market requires 540 million litres of biodiesel sourced from recycling 100,000 tonnes of waste vegetable oil producing 113 million litres of biodiesel and 330,000 Ha of set aside land to produce 427 million litres of biodiesel. Defra prohibits set aside land being used for food crops making it ideal for biodiesel production.

The UK government “Green Fuels Obligation” requires around 1.9 million Ha or 30% of arable land assuming the biofuels used in the UK are not imported. This will directly impact on UK food crop production.

Higher carbon emission savings of 2.8 million tonnes per year can be achieved if domestic heating sectors such as coal and LPG (liquid petroleum gas) switch to biodiesel oil heating appliances.

If this enlarged heating oil market of 2.2 million households used B20 biodiesel, this would require 671,000 Ha of arable land, around 10% of UK arable land and all our waste vegetable oil.

Enlarged Biodiesel Heating Arable Land & Carbon Savings

Fuel Type	Land Resource (Ha)	Carbon Savings
Heating Oil B20	671,296	2.8m tonnes
5% Road Fuel Obligation	1,895,305	1m tonnes

Source: Clean Energy Consultancy

UK produced B20 biodiesel heating oil has environmental, economic and fuel security benefits. Biodiesel heating oil reduces our heating carbon emissions and our reliance on Middle East kerosene while supporting the UK economy as a whole. Are you ready to make the switch? Biodiesel heating, now that’s fuel for thought.