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Biofuel compatibility with Grant boilers
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Biofuel compatibility with Grant boilers

Since 2010, Grant Engineering’s R&D Team have undertaken research, including field trials, into the use of biofuels with Grant condensing oil boilers. In this blog, Paul Wakefield, Managing Director at Grant UK talks through the research and explains how Grant’s boilers are biofuel compatible.

Much discussion has taken place in recent years about how rural, hard-to-heat homes can be decarbonised. Such properties tend to have a higher heat demand due to their build, construction type and limited insulation and to transform them into buildings suitable for an electrical heating system, such as a heat pump, would incur higher installation costs for the homeowner. A more cost-effective alternative is therefore needed for these off-gas, rural homes which are currently being heated by oil.

Grant Engineering have always positioned themselves as pioneers in the heating sector and recently, we welcomed a breakthrough with research into biofuels. This breakthrough will provide the alternative renewable heating solution these hard-to-heat homes need, reducing their carbon emissions with little disruption..

An introduction to the research project 
The research has involved working with OFTEC on more sustainable, waste derived low carbon liquid fuels and testing these in Grant boilers, enabling them to be biofuel compatible. Working with third level institutions, industry partners and renewable fuel producers, Grant’s R&D Team have completed trials, testing the use of biofuels in Grant’s boiler appliances. In the early days of research, the options available were narrowed down to a few potential bio and synthetic fuels that would achieve greenhouse gas reduction as well as being commercially viable. 

It began in 2010 with developing a boiler that could use a biofuel called FAME (fatty acid methyl esters). The R&D Team managed to use a 30% blend of FAME with regular kerosene successfully. However, challenges arose when increasing the FAME component above 30% resulting in fuel stability issues, particularly in cold conditions.

Hydrotreated Vegetable Oil (HVO)
The breakthrough came in 2020, during the testing and field trialing of boilers successfully using a 100% biofuel known as Hydrotreated Vegetable Oil (HVO). HVO feedstocks are generally used oils that contain rapeseed oil, sunflower oil, soybean oil and non-food oils such as jatropha oil and algae oil as well as waste animal fats. Waste and residue oils are now a substantial contributor to the feedstock which makes this biofuel even more sustainable.

HVO is produced in the process of hydrogenation, which is treatment with hydrogen. Whereas FAME production is by esterification, the HVO process uses hydrogen and not methanol as the catalyst. As a result, it is not glycerine but propane that is the by-product of hydrogenation. Another important difference between the two processes is the fact that hydrogenation removes all oxygen from the vegetable oils while esterification does not. It gives an advantage to the HVO production as it helps to avoid oxidation.

In Europe, a Finnish company called Neste is the largest producer of HVO with plants in Finland and Rotterdam. Other producers include Italian Energy company ENI and French Energy company TOTAL. There are other plants currently under construction that will also be able to produce HVO throughout the EU and UK. While feedstock such as sunflower and soya bean oil can take from the food chain, Neste, for example, spends 70% of all its R&D investments in pursuit of suitable new raw materials, especially waste and residues. With year-on-year increases, the supply from waste and residue material reached 80% in 2019 which endorses the sustainability of the fuel. Neste, together with other HVO producers, are focusing on the utilisation of lower quality waste and residue materials, as well as on the development of promising new raw materials, such as algae and microbial oils.

The results
The use of HVO, either at 100% (which results in a reduction in carbon emissions to 0.036kgCO2/kWh) or a percentage blend with kerosene, will allow rural and hard-to-heat homes to transition to a renewable, green alternative from 100% kerosene at an affordable cost and with minimum disruption to their home lives. While heat pumps are a perfect solution for new builds due to the heat loss of these homes now being perfectly matched to accommodate a low temperature heating system, retrofits can be more difficult. Some rural, older properties have a layout, construction and existing heating design which makes them unsuitable for a heat pump unless significant changes are made to the building, changes which can incur additional installation costs.

Biofuels can provide a viable, low carbon solution for older homes using high temperature heating systems, such as an oil boiler, because upgrading to a biofuel compatible boiler can be less expensive and will require minimal changes to the system.

Converting to biofuels
When a homeowner chooses a new Grant condensing boiler, they will be futureproofing their home because all Grant boilers are compatible for use with HVO. When HVO supplies becomes available to a property, only a few minor modifications need to be made to the boiler, swapping it from kerosene oil to HVO. These modifications include adapting the size of the fuel injector nozzle, fuel pump pressure and blast tube, all of which can be carried out by the service engineer during an annual service, making life simple for homeowners and for heating engineers. Older Grant condensing boilers may also be adapted to HVO but this may require a new biofuel burner that is matched with the specific boiler. Again, this can be carried out by a service technician during an annual service.

The next steps
The outcome of this research is incredibly exciting for the heating sector, specifically for those homes which are not currently suited to low temperature systems. HVO biofuel, working with Grant boilers, provides another low carbon heating solution for UK homes which can play a part in helping existing residential housing stock to be decarbonised. While HVO supplies here in the UK continue to establish themselves so that more homes can access this biofuel, installers who fit a Grant boiler can provide their customers with a biofuel compatible boiler which can be converted to HVO operation simply and with minimal disruption. 

Discover Grant's biofuel compatible oil boilers range here.

Paul Wakefield
Managing Director at Grant UK