AESIR is a 2-year, CASE-funded project to develop and build a high-TRL “plug & participate”, compact, safe, low-cost, modular redox flow battery prototype of 3.5 kW / 10 kWh for incorporating redox couples employing abundant, non-vanadium chemistries. This will be a collaborative effort between the schools of CCE (Prof Peter Nockemann, PI), MAE (Dr. Stephen Glover and Dr Rob Watson), and EEECS (Dr Tim Littler). Industrial partners of the project are SHELL, Seren Technologies and E&I Engineering.
Renewable energy resources, such as solar, wind, tidal, and biomass, are essential to combat the ongoing challenge of fossil fuel use and global climate change. However, these sources produce intermittent output, limiting their full capacity from being harnessed and used. A prime candidate for storing energy on a grid scale is the Redox Flow Battery (RFB), due to its scalability, room temperature operation, and long cycle life (lifetime >30 years, compared to ~5 years for lithium). An RFB can out-perform and under-cost other battery types, but most RFB technology currently relies on vanadium technologies, an element that is non-abundant in Europe, increasingly expensive, and environmentally harmful to extract.
An energy storage system of this size would be particularly attractive to rural and agricultural users in Northern Ireland, where the national grid is unreliable, facilitating optimisation of micro-renewable infrastructure (e.g. wind, energy, solar, anaerobic digesters). However, RFBs are also an enormously growing market for domestic applications. Due to the modular nature of the proposed system, this can also be easily scaled up to larger energy storage solutions such as wind farm storage or grid peak-shaving – applications which also have huge potential for enabling fossil fuel divestment.
Plastic waste that contaminates the environment, in particular the oceans, is now considered one of the key challenges by the EU funding bodies and the UK government alike. In June 2018, the UK Science Minister announced a £20 million Plastics Research and Innovation Fund to stimulate the development of new technologies for plastic removal and recycling, as well as development of more sustainable plastics. There is a strong drive to abandon the current model of “make, use and dispose”, moving to a new circular economy model: “reduce, reuse and recycle”. But - what can be done on a practical level to achieve this change?
An increasingly popular technology is pyrolysis of plastics to fuels (the first plant was commissioned in 2000 in Japan, now there are about 90 across the world). In pyrolysis, waste polyolefin plastics: plastic bags, containers and packaging – are subjected to high temperatures (>400°C), which causes their decomposition to light hydrocarbon fuels: syngas, gasoline, kerosene and diesel, in addition to carbon char. Although this technology produces fuel from waste, it has two crucial drawbacks:
- Economic: low added value of fuels, considering the cost of plastic collection, sorting and pyrolysis
- Environmental: burning fuels generates CO2 to atmosphere, therefore shifting the environmental burden into a different area, rather than eliminating it
A more recent approach, is plastic pyrolysis to waxes instead of fuels; most of waste plastic polyolefins get converted to heavy hydrocarbons (more than 20 carbons in the chain) called waxes, used as waterproofing agents, packaging, candles, personal care products, viscosity modifiers, mound release agents etc. They are high added-value products, and because they are not burned for fuels – do not contribute to CO2 emissions.
In this Invest Northern Ireland-funded project, Dr Swadźba-Kwaśny and her group are looking to valorise the major by-product in plastics-to-was process: the <C20 olefin-paraffin fraction. Using Lewis acidic ionic liquids, they aim to convert the mixed light olefins to base oils: the main component for synthetic lubricants. Ultimately, all olefins generated from waste plastics will be transformed into high added-value products, and none of it will be burned as CO2-emitting fuel.
Marijana Blesic and co-workers investigate the potential of zwitterionic polymers to resist attachment of proteins for use in anti-fouling surfaces.
Anti-fouling surfaces are a critical requirement for a wide range of biomedical applications, with unwanted attachment of proteins posing a risk of medical complications with patients or of medical device failure. Although it suffers drawbacks such as susceptibility to oxidation, such surfaces are typically achieved with poly(ethylene glycol) (PEG) films. However recently zwitterionic polymers have shown promise as an alternative, due to their higher chemical stability and comparible biofouling resistance. Zwitterionic salts (ZWSs) are a novel class of compounds that incorporate an additional zwitterionic moiety (a localised positive and negative charge on a single molecule) onto either the anion or cation of a conventional salt. Like ionic liquids they offer many possibilities to tailor properties to a given task or incorporate into polymers and substrates. However ZWSs exhibit pronounced salting in/out ability that lends itself to anti-fouling properties. Understanding the complex equilibria of water/polymer/ZWS and water/protein/ZWS ternary systems would provide crucial information for this industrially important system.
Development of a SCILL catalyst to utilise gas from AD reactors for the production of green methanol.
With its new applications in alternative fuels (e.g. fuel cells, DME and LPG), there is a huge potential market for methanol production. This project is investigating the possibility of using biogas from anaerobic digestor (AD) plants (640 in the UK) in conjunction with hydrogen produced from a curtailed wind farm (270 in the UK) to produce methanol from a completely renewable source. This green source of methanol has the scope to provide an addition £2 million to the UK economy through production of non-petrochemical fuel.
The project is collaboratively headed by Nancy Artioli and Gosia Swadźba-Kwaśny, and aims to combine both chemical and engineering strategies to improve current gas-to-methanol production methods. This will include development of a new solid catalyst with an ionic liquid layer (SCILL) in conjunction with a novel micro-channel fixed bed reactor.
Sustainable energy storage technology for distribution of renewable power.
Sustainable energy storage technology for distribution of renewable power.
The intermittent nature of renewable energy sources such as solar and wind power poses many challenges in our current energy market, in which power on demand is a key expectation. Energy storage solutions are key to bridging the gap between the wealth of renewable power available, and the limitations of when it is available. Past research has often focused on batteries employing liquid electrolytes and lithium charge carriers, but these devices are often faced with issues of safety (leakage, flammability), limited lifetimes and resource availability (e.g. lithium and cobalt).
Research by the combined groups of Nockemann, Glover, Swadźba-Kwaśny and Holbrey investigates the possibility of solid-state electrolytes incorporating ionic liquid technologies to provide improved safety and allow for the use of more abundant elements, such as sodium or magnesium, as charge carriers. This will provide insight into the possible uses of these solid-state electrolytes in applications such as grid stabilisation and electric vehicles, and their potential to offer safer, faster-charging and longer-lasting rechargeable batteries.
With support from Horiba-MIRA Ltd. and Wrights Group Ltd.
Andrew C. Marr and Patricia C. Marr are investigating applications of ionic liquids in biocatalysis and renewables valorisation.
Ionic liquids have many unique properties that can be applied to invent innovative technological solutions to industrial problems.
Ionic liquids have been shown to stabilise proteins. The addition of ionic liquids to enzymes, and synthetic biocatalysts such as artificial metalloenzymes, can improve the separation and recycling. Bio-derived catalysts can be entrapped within an ionic liquid gel in order to further improve their ease of use.
The tuneable solvent properties of ionic liquids can also be exploited. Ionic liquids can be prepared that are not miscible with water, yet have a high ability to dissolve and extract polar solutes. Coupled with their biocompatibility, this allows bioprocesses to be operated with a layer of ionic liquid that extracts the product as it is formed.
The low volatility of ionic liquids can also assist in bioprocess and renewable separations. In reactions that increase the volatility of the substrate chemical, operating in an ionic liquid enables the reaction to be run under vacuum, thus separating the product from the catalyst as it is formed.
We thank the EPSRC Catalysis Hub and the EU FP7 project GRAIL for support.