Accelerating the development of renewable fuels

fuel pump

Infineum UK, a specialty chemicals company, accessed unique facilities to perform the first structural investigation into the behaviour of biodiesel under high pressures.

The challenge

The development of reliable, efficient renewable fuels, including biodiesel, is vital to meet net-zero commitments. Biodiesel is a
renewable, clean-burning fuel derived from plants or animals and can be used in existing diesel engines without modifications. The widespread use of biodiesel as a renewable fuel offers many potential advantages, and so investigating the behaviour of biodiesel candidates under operating conditions is important. Undesired phase-changes at high temperatures or pressures could lead to potentially serious consequences. Under the high pressures within a fuel-injection system, formation of crystals within fuel could block the injection nozzle inside the engine, causing major issues.

The experiment

The research undertaken by Infineum UK aimed to investigate the behaviour of biodiesel, in particular one of its main components, methyl stearate, under high pressures. The research group used a high-pressure cell at ISIS Neutron and Muon Source, which operates a neutron diffractometer optimised for studies of the structural changes in materials that occur under high pressure.

The crystallisation behaviour of methyl stearate studied using neutron diffraction was combined with complementary high-pressure X-ray diffraction experiments at Diamond Light Source. The group observed four transitions between different structural phases, therefore better understanding how biodiesel behaves under high pressures. One of these phases contained plate-like crystals, formation of which could have serious consequences if crystallisation occurred in a fuel-injection system.

The results

This research has helped Infineum better understand the process, behaviour and consequences of using biodiesel at high pressures, in particular the observed crystallisation of methyl stearate, which could impede engine operation.

"State of the art facilities, along with their expertise, have been instrumental in helping us to carry out critical R&D to allow us to remain competitive and sustainable within the renewable fuels sector."

Peter Dowding
Chief Research Scientist, Infineum Ltd