Sheffield, UK: Libertine FPE (“Libertine”), the creator of Smart Engine technology for hybrid electric vehicles and distributed power generation, has demonstrated technology that could help leading truck manufacturers to fulfil pledges to make all heavy-duty vehicles fossil free by 2040.
With Libertine’s technology, hybrid heavy-duty powertrains using a combination of renewable grid power and renewable bioethanol fuel could offer OEMs a practical, cost effective solution to help achieve this vital transition to sustainable fuels and ‘net-zero’ (carbon neutrality).
The project, supported by a grant from the UK Government’s Sustainable Innovation Fund, has shown how a ‘Free Piston’ engine can achieve an improvement in cold start performance using bioethanol by briefly increasing the compression ratio at startup, compensating for chamber wall cooling effects that contribute to misfiring under cold start conditions.
Libertine’s innovation is a linear electrical machine and control technology platform which addresses the challenge of free piston motion control, a challenge which has so far prevented the widespread adoption of Free Piston engine technology that could enable a revolution in sustainable fuel use in ‘hard to electrify’ heavy duty powertrain applications.
This technology enables improved cold start performance using wet or ‘hydrous’ bioethanol fuel, a blend of 90% bioethanol and 10% water (E90W10).
Libertine’s intelliGEN opposed free piston platform was modified for use with wet bioethanol, using a direct injection uniflow scavenged two stroke architecture. Bioethanol was supplied by Ensus, the UK’s largest producer of bioethanol. Combustion testing was performed by MAHLE Powertrain at their Northampton test cell facilities.
During November and December 2020 over 100 tests were performed at MAHLE Powertrain test facilities in order to prove key performance metrics of the control platform, establish baseline combustion performance at a constant compression ratio and with a pre-heated combustion chamber, replicate cold start misfiring encountered in other studies, and demonstrate improved cold start performance by using a variable compression ratio.
Libertine’s CEO Sam Cockerill says: “This is an important result for Libertine that demonstrates the potential of variable compression ratio combustion control strategies made possible by Libertine’s intelliGEN Free Piston platform. Hybridisation with renewable fuels such as bioethanol could play an essential role in the rapid decarbonisation and electrification of transport, especially in heavy duty vehicle and off highway applications where battery technology and charging infrastructure could limit the pace of the transition to net zero.”
Adrian Cooper, MAHLE Powertrain’s Head of New Technology, says “MAHLE Powertrain are excited to be able to utilise our experience in developing, testing and controlling novel concepts to support this successful demonstration of Libertine’s technology.”
Grant Pearson, Ensus Commercial Director says: “Libertine’s work with MAHLE Powertrain and Ensus supports our view that there is a path to a fossil free future using renewable transport fuels such as bioethanol. We are pleased to have been involved in this work, and look forward to further developments in 2021.”
The project was supported through the Small Business Research Initiative (SBRI) Sustainable Innovation Fund Competition which supports organisations to develop and demonstrate new products that help the UK’s clean growth led recovery from the coronavirus (COVID-19) pandemic and accelerate UK’s the transition to net zero.
On 9th December 2020 Sam Cockerill presented details of the intelliGEN platform’s key performance metrics at a webinar organised by the Institute of Mechanical Engineers, which can be viewed here: https://youtu.be/7OLVTXNSUsw
About Libertine
Libertine helps OEMs make better engines for renewable fuels. Libertine’s intelliGEN Opposed Free Piston platform enables development of new products making full use of synthetic, low carbon and renewable fuels. These products will be essential for the decarbonisation of ‘hard to electrify’ transport applications including light and medium duty commercial vehicles, for a proportion of passenger automotive market where vehicle use and recharging constraints are a barrier to electrification, and for a larger range of distributed power generation applications.
About MAHLE Powertrain
MAHLE Powertrain, a wholly-owned subsidiary of MAHLE GmbH (MAHLE), is a world leader in the design, and development of high efficiency engines and electric powertrains, providing engineering services in a broad range of powertrain markets, with a strong focus on gasoline, hybrid, electrification, and alternative fuel engines. Although the largest office and test facility is in Northampton, MAHLE Powertrain is a global company with engineering centres in Stuttgart, Ingolstadt and Munich, Germany; Plymouth MI, USA; Sao Paulo, Brazil and Shanghai, China.
About Ensus
Ensus UK Ltd operates one of Europe’s largest bioethanol plants at Wilton on Teesside in North East England. Locally grown feed quality grain is refined to produce over 400 million litres of bioethanol and 350 thousand tonnes of high protein animal feed. Up to 250 thousand tonnes of carbon dioxide from the production process is cleaned and liquefied each year by a partner company to be used in soft drinks and food production. Since July 2013, Ensus has been a member of the CropEnergies Group which is one of the leading European manufacturers of sustainably produced bioethanol mainly for the fuel sector today.