Young renewable energy pioneers share future vision

Earlier this year, three students from UK universities were recognised for their academic research into renewable energy technologies, as part of Privilege Finance’s Innovation Award.

Here, the winners share insights from their research and their perspectives on what opportunities lie ahead for the renewables industry.

Award winner – Sarah Farthing, PhD student, University of Nottingham

Research: Hydrothermal carbonisation

Sarah Farthing, a former PhD student from the University of Nottingham, was awarded the top prize for her research on hydrothermal carbonisation, and its role in producing a valuable resource from products that would typically be considered as ‘by-products’ or waste.

The process is mostly used in Europe for processing of specific wastes by just a few authorities and remains heavily incentivised.

However, Sarah explains that hydrothermal carbonisation can be used to treat wet waste, producing a material called hydrochar. This hydrochar can then be used as a solid biomass fuel if it is of high enough quality, or to help sequester carbon in soil and improve soil quality, due to its nutrient-rich properties – an area where there is much research in progress.

“The hydrothermal carbonisation process mimics the formation of coal, but on a much faster timescale. By heating wet materials to approximately 250°C, at a pressure of about 40 bar, hydrochar can be produced.

“Typically, biofuels are produced using consistent biomass materials, such as wood chips and grasses. However, these have uses on their own without any processing, so growing them and then processing to produce hydrochar, a relatively low-grade biofuel, isn’t economically efficient.

“Because of this, I was primarily interested in producing hydrochar using food waste, sewage and digestate from anaerobic digestion,” she says.

She explains that a core part of her thesis was investigating the economic feasibility of scaling up hydrothermal carbonisation to add value to digestate from anaerobic digesters in the UK.

“I found that with digestate, food waste and sewage, processing using hydrothermal carbonisation can be profitable if it costs at least £25 per tonne to dispose of the input in its waste form, which means hydrothermal carbonisation could provide a cheaper alternative.

Sarah sees potential for hydrothermal carbonisation to process digestate from city-based AD plants.

“The government is keen to make use of food waste and processing it using AD to produce biogas is one of the technologies they are supporting. On a farm-based AD plant, the digestate produced tends to be spread back on the land as an organic fertiliser.

“However, with larger-scale facilities based in more urban locations, a more sustainable solution for the digestate is needed, as it isn’t efficient to transport it long distances.”

“A hydrothermal carbonisation processing unit could be integrated into the plant infrastructure, with heat being recovered from the process to warm the digester, improving the self-sufficiency of the biogas-generating process too.”

Part of the climate change solution

Sarah’s research is just one example of the inspiring work being done in academia towards mitigating climate change – a significant issue which she recognises needs a balanced and pragmatic approach.

“As our knowledge develops, and we understand which solutions to climate change are the best in scientific terms, we also need to look what is most easily-achievable given the infrastructure the UK already has.

“For example, the UK already has an extensive wind power infrastructure but the energy generation of this technology is intermittent. In this instance, capturing energy as it’s generated and storing it for on-demand, using improved energy storage solutions, will play a significant role in managing climate change.”

Runners up – Miranda Mirzad and George Wells, MSc students, University of Manchester

Research: Hydrogen fuel cell technology

Miranda Mirzad and George Wells both concentrated on hydrogen fuel cell technology for their separate dissertation projects, which led to them securing joint ‘runners up’ prizes at the awards giving.

Hydrogen fuel cell technology is frequently described as the renewable energy solution of the future. The scaling up of hydrogen fuel is a key part of the UK government’s strategy to cut greenhouse gases and also features in US President Joe Biden’s $2 trillion plan to combat climate change. However, despite the technology being in existence for years, it has faced challenges in commercialisation due to cost barriers and durability of its material make up.

To address these challenges, George’s research focused on optimising the membrane of high temperature hydrogen fuel cells, to increase the amount of electrical power generated.

“Hydrogen fuel cells convert the chemical energy from hydrogen to electrical energy using use chemical reactions. The membrane is crucial to the process, as it only allow the particles needed for the process to pass through, preventing disruptions to the chemistry,” explains George.

“High temperature hydrogen fuel cells have greater energy outputs than their lower temperature equivalents, however they are still limited by what’s possible using the industry standard membranes.

“I introduced graphene oxide to the other materials used to produce an industry standard membrane, to try to improve the wattage.

“As a chemical compound, graphene oxide is known to simultaneously increase strength and electrical outputs when it’s used in combination with other materials. This made it exciting to research, however the results from my experiment were not conclusive.”

Miranda’s research was focused on platinum catalysts, which are situated either side of the membrane in a hydrogen fuel cell and are responsible for providing the right conditions for the chemical reactions to take place. She investigated how the cost of catalysts can be reduced, to help remove one of the main barriers to the commercialisation of hydrogen fuel cells, also using a form of graphene oxide.

“Platinum is rare and expensive, so for my research I tried making a hybrid catalyst, using nitrogen-doped, electrochemically-exfoliated graphene oxide (NrEGO) integrated with intercalated carbon black.

“I tried different ratios of the two materials and tested these against each other and also against the industrial standard platinum-based catalyst.”

The tests assessed electrical conductivity, polarisation and power density, which are all important factors in determining the electrical output from a hydrogen fuel cell.

“The results showed the optimum proportion of the two compounds together of a 2:3 ratio. As this was lab-based work, the next step will be further research to translate it to commercial scale production.

“The future of hydrogen fuel cells depends on continuing this type of research and developing a catalyst which is both better and cheaper than the current industrial standard,” she says.

Battery storage will be key

As well as sharing insight into their research, Sarah and George also offered their perspectives on how to collectively tackle the warming of the planet.

George agrees that there is most potential in development of battery storage technologies. “The renewable energy technologies exist, we need to be able to store this green energy for use in electric cars,” he says.

“A global view is needed. Many countries, particularly in Africa and Asia, will transition to cleaner fossil fuels like natural gas and LPG first, before turning to renewables.

“It’s important that the technological work is put in now, to speed up the process of worldwide adoption of renewable energy.”

Miranda takes a practical perspective and urges caution against jumping on any ‘quick-fix’.

“There won’t be a stand-alone technology which makes net zero a reality. It will have to be a team effort,” she says.

“The actions of governments, energy companies and the public will drive progress towards a world with green power. Appetite for green energy and willingness to switch provider based on this will be a factor in energy companies’ decisions, as much as government policy decisions.

“As well as hydrogen, renewable energy technologies such as wind, solar and biofuels will all contribute. Non-renewable but cleaner technologies such as nuclear power will also contribute to the transition.”

The award

The Innovation Award was launched by Privilege Finance in 2020 to showcase opportunities in the renewable energy sector, and to attract and retain young talent to the industry.

The final judging panel included specialists from cross-industries including – Thomas Minter from Malaby Biogas, Kiara Zennaro from the REA and Bioenergy Insight’s Dawn Stephens-Borg.

The award winner and runners-up received cash prizes of £1,000 and £750 respectively, as well as mentoring and access to industry contacts for a 12-month period.

This year, the award has been relaunched as the Climate Change Thought Leadership Award. It is now open to any student whose research is focused on a solution to climate change. 2021 applications are open, and more information can be found by visiting https://www.privilege.finance/climate-change-thought-leadership-award/.

 

As seen in Bioenergy Insight