Commercialisation of plastic waste derived fuel for generating electricity

Project details

Funding body: EPSRC - Innovate UK (grant details).

Collaborators: Collaborating with Farad Dailami in UWE Bristol's Department of Engineering, Design and Mathematics.

Dates: 2017 - 2019.

Project summary

Distributed power and security of electrical supply; with the advent of photovoltaic, wind, wave and other power generation technologies, there is a growing trend for the electrical energy generation to become more and more distributed. However, many of these power-generating systems, because of their reliance on natural effects, suffer from short-term peaks and troughs in their energy production. In many cases, diesel engine generating sets provide a viable option to reduce the variability and augment the electrical generating capacity and dynamically optimise contribution from each source to the distributed electrical power generation.

The regulations defining incineration as a recovery process rather than a disposal activity are very demanding and generally require the incineration plant to have a high efficiency. The route of converting mixed plastic waste in to diesel fuel immediately removes the ambiguity of waste disposal versus waste recovery and as such would be highly desirable by local authorities and waste management companies.

Long-term maintenance of capital equipment depends, amongst other factors, on better sensors, data acquisition, data analysis and ultimately more capable predictive software models; in terms of sustainability 'engineering systems for life' is a strategic initiative that is gaining ground. The aim is to develop methodologies that can 'guarantee the required and predictable performance of complex engineering system throughout its expected operational life with optimum whole-life cost, taking in into account design, manufacture, maintenance, repair, overhaul and disposal or re-use'. A contribution to the development of this goal would be realised from the development of 'wear models' that allow predictive maintenance of diesel engine power plants. In the context of diesel engine power plants a key decision would be the choice between large slow speed longer lasting engines, which have good specific fuel consumption values but are expensive to acquire and install. The alternative is a high-speed multi-engine facility, which may be potentially cheaper to implement, but have shorter life and poorer SFC values. This work will contribute to this decision-making problem.

This research project will investigate Plaxx and a standard diesel fuel and compare them in terms of engine performance, engine emissions, wear and reliability. Trials on two single cylinder small engines have already demonstrated that Plaxx is a viable fuel for diesel engines. As part of this programme, Plaxx will also be used on a multi cylinder engine, a large fully instrumented single cylinder engine and finally on 1MW generating set for extended runs and power supply to the grid. The two small single cylinder engine-generating sets will be equipped with variety of sensors to measure amongst other parameters, Plaxx and distillate diesel SFC, thermal and volumetric efficiencies and engine emissions. One of the single cylinder engines will have a modified liner incorporating a wear sensor to measure real time wear of liner. Lubricating oil samples will be monitored to measure metallic debris in real time and relate this to engine wear and performance. A series of designed experiments will be performed to relate the interaction of the various factors on performance, emissions and wear.

These trials will be performed for a range of fuel blends and load conditions. The aim is to develop predictive models and validate these models on the large single cylinder engine and in the longer term identify optimum running conditions for the 1MW engine. The investigation will develop a methodology to assist future planners with the type and mix of diesel engine power generating facilities in terms of engine size and fuel blends. Using Plaxx produced at the waste handling yards, it will be possible to perform waste recovery by processing mixed plastic waste and provide electrical energy for the grid, sending less waste to landfill sites.

For more details, email Professor Jim Longhurst.