Design and Testing of Sustainable Processes to Produce Bio-Toluene

This proposal addresses the need for process solvents and basic aromatic feedstocks. Drug products, and their manufacture, involve large amounts of these, which contribute greatly to the drug’s carbon footprint. Toluene is used ubiquitously in large volume by pharma in drug manufacture, however there is currently no way of producing bio-toluene that could be used as an alternative. This project will evaluate several ideas to make these materials sustainably and generate data to confirm the processes have the potential to be greener than the current alternative. The project will scale-up selected method(s) to prepare evaluation samples. The project requires skills in continuous flow chemo- and biocatalytic methods, so, unusually, the project involves a close collaboration between the named academics at Leeds and York, with the student able to commute as appropriate. They will learn practical aspects of sustainable chemistry at each institution, including, chemo- and bio- catalysis, analytical methods, LCA, automated optimisation, continuous flow methods and scale-up.

<p>Work at the University of Leeds has recently developed processed, produced litre-sized evaluation samples of bio-acetone and bio-acetonitrile, and exploitation of this is the subject of a new large project that the University of Leeds are part of and will run alongside this studentship. This proposal aims to identify commercially viable routes to bio-toluene. Whilst toluene has undesirable human and animal toxicity effects, and is on the amber list of sustainable solvents, it is so widely used in the pharma-related industry that it ought to be a target bio-substitution solvent, at least as an interim. Toluene has highly desirable physical properties that make it a process solvent of choice: it is apolar, solubilising apolar reactants; is (largely)immiscible with water for extractions; forms a useful water azeotrope to facilitate solvent drying; has a boiling point high enough to prevent VOC loss, enable containment and minimise human exposure, but low enough to minimise distillation energy requirements; facilitates intermediate crystallisations; is available in bulk at low cost; can be recycled or incinerated and is increasingly being considered within membrane separation processes. There are two reported European initiatives to produce bio-aromatics, however, reading the websites it looks as though these are new bio-based materials employing lignin. To transform lignin (poly)phenolic monomers into toluene, requires difficult separations and costly chemistry to remove oxygen atoms, so these approaches are probably long-term. As opposed to petrochemical solvents that are produced through cracking/separation or simple reaction processes, bio-based feedstocks require chemical steps to remove molecular complexity. Functional groups, often containing oxygen, require dehydration, reduction, oxidation or other steps. Since toluene is not produced naturally by biosystems, to make it sustainably requires suitable, simple, low-cost transformations of abundant feedstocks. In this regard, several novel approaches are suggested, and the project will involve lab-scale evaluation of these or other as they arise, along with lifecycle assessments, to ensure their performance would be an improvement over the current source.        </p> <p>Work will start with 6 months evaluation of a new route to bio-toluene starting from a terpene that is produced at ~45,000 tonnes/a. The literature suggests dehydrogenation can be effected using a hetereogenous catalyst. The project will evaluate this chemistry in continuous flow using neat terpene and optimise the yield and separation. Capture and use of the co-product, either as bio-feedstock in its own right or as a fuel to offset process energy demands. The second step catalytic cracking using a heterogenous Lewis acid catalyst, but might also be done enzymatically. This catalyst, and alternatives, will be evaluated using continuous flow systems, potentially carried-out as an automated optimisation using at-line GC with the aim of improving efficiency and reducing the energy requirement. Several other routes to bio-toluene and relate materials will also be evaluated, using bio-based feedstocks and biocatalytic methods. A key part of this work will be to develop continuous flow reactions and separations using expertise and existing methods developed in York and Leeds. Opportunities to telescope the bioreactions will be sought, with the aim of developing efficient, scaleable and cost-effective ways of making these materials. </p> <p><strong>Year 1.</strong> Evaluate Route 1. Learn about process development, continuous flow, separation, analysis and optimisation.</p> <p><strong>Year 2.</strong> Evaluate Route 2. Learn about biocatalysis, supported enzymes and apply techniques from Year 1. Attend international conference.</p> <p><strong>Year 3.</strong> Evaluate other routes and carry-out LCA, cost evaluation and scale-up. Thesis write-up (3-6 months).</p> <p><strong>Management and Training:</strong></p> <p>A high-quality student interested in biocatalysis, continuous flow and process development will be recruited. The academic team will meet weekly with the student. The student will work closely with other students in the Leeds and York labs working in this general area. LCA training will be provided by Dr Keeran Ward, expert in this area. The student will receive invaluable coaching in the scientific areas mentioned above and will also receive a wide variety of soft-skill training. In addition to this they will participate in regular iPRD, GCCE and departmental seminars, conferences, industry club and attend and present at one inter/national conference a year. The student will be rounded in the skills needed to develop their career in this field, making them well-placed to be employed in the pharma industry or academia.</p> <p class="MsoNoSpacing"><strong>Eligibility Criteria</strong></p> <ul> <li>Applicants must be eligible to pay fees at the Home (UK) rate.</li> </ul> <p><strong>Other Conditions</strong></p> <ul> <li>Awards must be taken up by 1st October 2026.</li> <li>Applicants must live within a reasonable distance of the University of Leeds whilst in receipt of this scholarship.</li> </ul>

<p>Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the <em><strong>Planned Course of Study section that you are applying for PHD Chemistry FT</strong></em>, in the research information section, please state clearly that the research project you wish to be considered for is <em><strong>Design and Testing of Sustainable Processes to Produce Bio-Toluene</strong></em>, and mention <a href="https://eps.leeds.ac.uk/chemical-engineering/staff/409/professor-john-blacker">Professor John Blacker | School of Chemistry| University of Leeds</a> as your proposed supervisor and in the finance section, please state clearly that you are applying for the <em><strong>School of Chemistry Scholarship 2026/27 (Research Grant Grant: Green Solvents).</strong></em></p> <p>Applications will be considered after the closing date of Tuesday 30 June 2026.  Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application.  We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p>Please ensure you provide your supporting documents by the closing date of Tuesday 30 June 2026: </p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date including grading scheme</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> </ul> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p class="MsoNoSpacing" style="text-align:start; margin-bottom:24px">A highly competitive School of Chemistry Studentship in collaboration with the Schools of Mechanical Engineering and Chemical & Process Engineering, in support of the Research Grant: Industrialising UK Bio-based Solvents for Global Medicine Manufacturing, providing the award of full academic fees, together with a tax-free maintenance grant at the standard UKRI rate of £21,805 per year for 3.5 years. There are no additional allowances for travel, research expenses, conference attendance or any other costs.<br /> <br /> You will be responsible for paying the overtime fee in full in your writing up/overtime year (£340 in Session 2025/26), but the scholarship maintenance allowance will continue to be paid for up to 6 months in the final year of award.</p> <p>Please note that there is only 1 funded place available to UK applicants only.  If you are successful in securing an academic offer for PhD study, this does not mean that you have been successful in securing an offer of funding.</p> <p>Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information about this project, please contact Professor John Blacker by email to <a href="mailto:j.blacker@leeds.ac.uk">j.blacker@leeds.ac.uk</a> or by calling +44 (0)113 343 8239.</p> <p>For further information about your application, please contact the Postgraduate Research Admissions team at <a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a>.</p>