The new process will increase the production of biodiesel by using the waste left over from its production process.

This will allow the recycling of a non-desired by-product such as crude glycerol produced when biodiesel is formed from vegetable oil, and convert this into an ingredient to produce even more biodiesel.

The crude glycerol contains many impurities and it is costly to purify and re-use it in other areas.

The researchers have reacted glycerol with water to convert it into methanol, which could be used as a starting reactant to create more biodiesel.

The use of recycled methanol is expected to increase the biodiesel production by close to 10%.

Cardiff Catalysis Institute director Professor Graham Hutchings said: "Biodiesel manufacture is a growing part of the EU fuel pool, with statutory amounts being required to be added to diesel that is derived from fossil fuels.

"We’ve provided unprecedented chemistry that highlights the potential to manufacture biodiesel in a much more environmentally friendly, and potentially cheaper, way, by converting an undesired by-product into a valuable chemical that can be reused in the process."

The EU is aimed at having 10% of the transport fuel from renewable sources such as biofuels in every EU country by 2020.

Cardiff Catalysis Institute deputy director Stuart Taylor said: "We set out to establish ways in which the waste product glycerol could be used to form other useful compounds, but we were surprised when we found that feeding glycerol and water over such a simple catalyst gave such valuable products and interesting chemistry.

"This research has the potential to transform the way in which waste is dealt with, and seriously improve the quality of life by reducing carbon emissions from fossil fuels and encourage efficient use of resources."