Imperial College London

Prof Jason P. Hallett

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Sustainable Chemical Technology



+44 (0)20 7594 5388j.hallett Website




228bBone BuildingSouth Kensington Campus





Prof Jason Hallett performs research involving the solution behaviour of ionic liquids and the use of ionic liquids in the production of lignocellulosic biofuels, sustainable chemical feedstocks, vaccine manufacturing and waste recycling (particularly for metal-contaminated solid materials). This research is supported by both the UKRI and industry.

Prof Hallett currently serves as a core member of the Supergen Bioenergy Hub and the Future Vaccines Manufacturing Research Hub.

He is also co-founder of 6 spin-out companies based on the group's research:

Lixea, a circular bioeconomy company which uses low-cost ionic liquids to fractionate waste biomass for biofuel, chemical and material production from cellulose and lignin. Lixea operates a pilot plant in Sweden for the Dendronic process, which is the commercial version of the group's ionoSolv process.

Nanomox, which produces advanced materials, especially metal oxides, from metallic waste streams using the ionic-liquid based technology Oxidative Ionothermal Synthesis (OIS), developed in the group.

Bioataraxis, which produces bio-derived furan-based surfactants for detergent and personal care applications. The surfactants demonstarte superior performance to petrochemical surfactants but are fully biodegradable, non-toxic and renewable. They have a similar cost point to market detergents.

DyeRecycle, which extracts dyes from waste textiles and transfers them to new fabrics, enabling easier textile recycling and creating the first circular dyeing process. DyeRecycle uses ionic liquids to achieve a waterless dyeing solution.

CO2Co, which is a recently launched direct air capture company developing extremely large-scale CO2 removal solutions.

Ionic Recovery, which is a circular economy company that de-metallizes a wide range of waste bio-based feedstocks, such as sewage sludge.

A very special company was also founded by one of the group's PhD studnts:

Oorja (Dr Clementine Chambon) is a social enterprise dedicated to changing teh lives of rural farmers i nIndia by bring solar electricity for irrigation, commercial and home use to communities without adequate access to power.

Prof Hallett received his PhD in Chemical Engineering from the Georgia Institute of Technology. He joined Imperial College, first with a Marshall-Sherfield Postdoctoral Fellowship in Sustainable Chemistry and in 2014 was appointed a Senior Lecturer in the Department of Chemical Engineering, before promotion to Reader in 2016 and Professor in 2018. He has authored over 150 articles and holds 10 patents.

PhD opportunities:

PhD studentships: The Department of Chemical Engineering is currently accepting applications from outstanding students for our Departmental PhD Studentships (

These are fully funded 42-month positions with a host academic. If you are interested in applying for a scholarship hosted in my lab, please contact me (

Postdoctoral Openings:

3 positions are currently open:

Research Associate in Circular Textiles and Ionic Liquids

The Department of Chemical Engineering is seeking a Research Associate to join a project funded by the UKRI “Research for a plastics circular economy” call (EP/Y003888/1) to carry out research programmes in the development of novel technologies for textile recycling, including the use of ionic liquids for circular dyeing.

 Textiles for clothing are a major user of plastics, in which the plastic component is frequently combined with natural fibres such as cotton and wool. Globally, 438 million tonnes of plastic were produced in 2017, of which 62 million tonnes were used in the textile industry. In the UK, >1 M tonnes of textile waste are generated annually.

You will focus on assessing the feasibility and advantages of recycling both dyes and fibres separated from multi-material textile waste. The approach will involve separation of cotton from PET, the recovery of fibres and the removal and re-use of dyes. Ionic liquids will be explored as novel solvents with the end goal an integrated process to recycle as much textile material as possible. The project will be performed in collaboration with industrial partners, most notably DyeRecycle (

Research Associate in Design of Novel Plastic Recycling Systems

The Department of Chemical Engineering is seeking a Research Associate to join a project funded by the UKRI “Research for a plastics circular economy” call (EP/Y007824/1) to carry out research programmes in the development of hybrid (bio)chemical/mechanical recycling systems for multi-layer plastic packaging.

Typically made from plastic, paper and aluminium bonded together, multilayer packaging delivers excellent product protection and preservation. Lack of suitable recycling technology, however, means its benefits come at a big environmental price. In collaboration with academic and industrial partners, the post will analyse the integration of ionic liquids with mechanical and biochemical processing to recycle MLP.

You will focus on assessing the feasibility and advantages of the combined recycling approach, benchmarked using energy and mass separating agents (MSA) input per unit of service (e.g. per tonne of useful recovered material) as key performance indicators. The energy and material balances will feed into a preliminary life cycle assessment performed using SimaPro software. The novel technical approaches will be integrated with sustainability assessments to ensure economic viability, validate environmental benefits at an early stage and assess potential routes to implementation.

Research Associate in Fine Chemicals Innovation Analysis

The Department of Chemical Engineering is seeking a Research Associate in Fine Chemical Innovation Analysis to join our vibrant team of researchers.  This post is part of a wider initiative exploring innovation and productivity in different industrial sectors in the UK. This specific project focusses on a sectoral study on innovation and competitiveness in the UK fine chemicals manufacturing industry.

Our objectives for this project are to understand the current landscape and challenges faced, benchmark the current innovation performance historically and against other competitor countries, and develop insights into the types of interventions which will be required to ensure the sector’s future sustainability.

Integrated Biorefinery Research:

This area of research focusses on the simultaneous production of both biofuels and chemical feedstocks from renewable resources, such as from lignocellulosic biomass. This involves a range of research areas in my group, including:

Deconstruction of Biomass using Ionic liquids

Enzymatic Biocatalysis in Protein-friendly Ionic Liquids

Bioprocess Development and Scale-up

Other Ionic Liquids Research:

Vaccine Formulation Development for Room Temperature Storage and Enhanced Delivery

Metal Recovery from Waste Streams

Process, Techno-economic, and Socio-economic Modelling of Ionic Liquid Biorefining

Catalytic Production of Platform Chemicals from Biomass using Ionic Liquids

Interactions of Ionic Liquids with Biopolymers

Recycling Ionic Liquids

Textile and Dye Recycling using Ionic Liquids

Wastewater Treatment using Supported Ionic Liquids

Corrosion in Ionic liquids

Other Research Topics:

Biobased Surfactant Production from Biorefinery Waste

Solvent-based Carbon Capture and Storage Perspectives

Selected Publications

Journal Articles

Mota A, Hallett JP, Kuznetsov ML, et al., 2011, Structural characterization and DFT study of (VO)-O-IV(acac)(2) in imidazolium ionic liquids, Physical Chemistry Chemical Physics, Vol:13, ISSN:1463-9076, Pages:15094-15102

Lui MY, Crowhurst L, Hallett JP, et al., 2011, Salts dissolved in salts: ionic liquid mixtures, Chem. Sci., Vol:2, Pages:1491-1496-1491-1496

Hallett JP, Liotta CL, Ranieri G, et al., 2009, Charge Screening in the S(N)2 Reaction of Charged Electrophiles and Charged Nucleophiles: An Ionic Liquid Effect, Journal of Organic Chemistry, Vol:74, ISSN:0022-3263, Pages:1864-1868

Wells TP, Hallett JP, Williams CK, et al., 2008, Esterification in ionic liquids: The influence of solvent basicity, Journal of Organic Chemistry, Vol:73, ISSN:0022-3263, Pages:5585-5588

Hallett JP, Ford JW, Jones RS, et al., 2008, Hydroformylation catalyst recycle with gas-expanded liquids, Industrial & Engineering Chemistry Research, Vol:47, ISSN:0888-5885, Pages:2585-2589

Ranieri G, Hallett JP, Welton T, 2008, Nucleophilic reactions at cationic centers in ionic liquids and molecular solvents, Industrial & Engineering Chemistry Research, Vol:47, ISSN:0888-5885, Pages:638-644

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