This PhD project will develop and validate sorption-enhanced gasification with calcium looping (SEG-CaL) using biomass, residues and calcium-rich materials. It will assess how feedstock, sorbent, and operating conditions affect gas composition, H₂ production, CO₂ capture, stability and scale-up. The work combines characterisation, TGA, batch gasification and pilot testing. The project is co-funded by the European Union and the Estonian Ministry of Education and Research TEM-TA205.
The project will address the following key areas:
SEG-CaL integrates biomass (BM) and residue gasification with in-situ CO₂ capture: a calcium-based sorbent captures CO₂ and forms CaCO₃. This interaction can improve H2 content, but it also introduces technical questions related to sorbent reactivity, ash interactions, heat transfer, circulation, etc. The PhD research novelty lies in the integrated Lab-to-pilot investigation of SEG-CaL using locally available BM, residues and calcium-rich circular resources. The PhD will evaluate secondary materials as sorbents and determine how their interactions with feedstock ash and gasification products affect CO₂ capture, H2-rich gas formation, carbon conversion and cyclic stability. Pilot-scale validation will be used to verify laboratory findings, identify practical limitations and generate data for environmental, techno-economic and industrial assessment.
The research will address the following questions:
How do the composition, mineralogy and morphology of locally available calcium-rich materials influence carbonation capacity, cyclic stability and interaction with BM and residue-derived ash?
Which laboratory-scale measurements and material-performance indicators can reliably predict sorbent behaviour and process performance during pilot-scale operation?
How do feedstock properties and operating conditions govern the coupling between gasification, in-situ CO2 capture and H2-rich gas formation?
And test the following hypotheses:
Selected local calcium-rich materials can provide effective CO2 capture while supporting gasification of representative BM and residue streams.
In-situ CO2 removal can shift the gasification chemistry towards higher H2 production and improved carbon conversion under suitable operating conditions.
The interaction between sorbent properties, feedstock ash and operating conditions is a major determinant of cyclic stability and pilot-scale performance and can be described using laboratory-to-pilot correlations.
Responsibilities and (foreseen) tasks:
Select, prepare and characterise representative biomass, residue, ash-derived and calcium-rich sorbent materials.
Perform thermogravimetric and complementary laboratory experiments to determine gasification, carbonation, calcination and sorbent-cycling behaviour.
Investigate the effects of feedstock composition, ash constituents and sorbent properties on gasification reactions and CO2 capture.
Plan and conduct batch-scale gasification experiments under selected temperature, steam and sorbent conditions.
Measure and evaluate syngas composition, hydrogen production, CO2 capture, carbon conversion and relevant process-performance indicators.
Assess sorbent stability, deactivation, attrition, agglomeration, fouling and other material or operational limitations relevant to scale-up.
Contribute to the design, modification, commissioning and safe operation of the integrated fluidised-bed combustion-pyrolysis pilot facility.
Conduct pilot validation campaigns and compare pilot observations with laboratory results and process-model predictions.
Collaborate with researchers, doctoral students, technical staff and project partners.
· Publish research results in peer-reviewed journals and present findings at international conferences.
Contribute to the supervision of BSc and MSc students, and willingness to assist in teaching where appropriate.
Applicants should fulfil the following requirements:
A master's degree in chemical engineering, energy technology, process engineering, environmental engineering, materials science, chemistry, mechanical engineering or another closely related subject.
Proven experience in fluidized bed processes, high-temperature experimental research, particularly combustion or gasification.
A clear interest in biomass and residue conversion, gasification, CO2 capture, calcium or chemical looping, hydrogen production or related energy technologies.
Ability to plan experiments, analyse results critically and document research in a reproducible manner.
Strong analytical and problem-solving skills and the ability to work independently and as part of a multidisciplinary research team.
Good written and spoken English, at least B2 level according to the Common European Framework of Reference for Languages.
Additional general requirements can be found at theTalTech PhD admission homepage.
Applicants should submit:
A cover letter outlining the applicant's motivation and relevant experience.
A CV, including education, research experience, technical skills and a list of publications, where applicable.
A short research plan describing the proposed research strategy, experimental approach and expected contribution to the SEG-CaL project.
Proposed titles and brief outlines of at least three potential scientific publications arising from the research.
Previous work, such as a master's thesis, scientific articles, technical reports or conference contributions, demonstrating relevant research experience.
The following experience is beneficial:
Practical experience in thermochemical processes, such as gasification, pyrolysis, combustion, chemical/calcium looping, or another high-temperature reactor research.
Experience with thermogravimetric analysis and the interpretation of reaction kinetics or cyclic sorbent behaviour.
Experience with biomass, waste-derived materials, ash chemistry or calcium-based sorbents.
Experience with gas analysis, including gas chromatography, infrared gas analysis or comparable methods.
Experience operating laboratory or pilot-scale equipment and working safely with high temperatures, steam and reactive gases.
Technical report writing, scientific publication, conference presentation and collaboration in an international research environment.
We offer:
A 4-year PhD position in the Department of Energy Technology at Tallinn University of Technology. This is a full-time paid employment in accordance with TalTech's doctoral employment conditions, including social security.
A doctoral research position in the Department of Energy Technology at Tallinn University of Technology, connected to the Tem-TA205 project.
The opportunity to work on an interdisciplinary research topic combining biomass and residue conversion, in-situ CO2 capture, calcium looping, hydrogen-rich gas production and pilot-scale process validation.
A research environment with access to relevant laboratory, analytical, computational and pilot facilities.
·
The opportunity to contribute to a newly funded project promoting collaboration between academic, public-sector and industrial partners.
Opportunities for professional development, scientific collaboration and international networking.
Support for conference travel and research dissemination.
Supervisors:
Main supervisor: Researcher Mais Hanna Suleiman Baqain, School of Engineering: Department of Energy Technology: Research Group of Sustainable Energy and Fuels
Co-Supervisor: Senior Researcher Dmitri Nešumajev, School of Engineering: Department of Energy Technology: Research Group of Sustainable Energy and Fuels
Tallinn University of Technology (TalTech) is an international scientific community with approximately 9,000 students and 2,000 employees; it is one of the largest universities in Estonia, the leading EU country in digitalisation. The university's strengths are broad multidisciplinary study/research interests, a modern research environment, and strong collaboration with international educational and research institutions. TalTech is aiming to be an organisation leading the way to a sustainable digital future.
The Department of Energy Technology at Tallinn University of Technology provides a multidisciplinary research environment for thermochemical conversion, biomass and waste valorisation, gasification, combustion, carbon capture and sustainable energy systems. It has laboratory and pilot-scale facilities for thermochemical processing, fluidised-bed operation, gas analysis and process development, supported by expertise in reactor engineering, materials characterisation, thermodynamic analysis, process modelling and energy-system assessment.
For information about the admission process, please visit the PhD Admission homepage or contact the doctoral admission team at docstudy@taltech.ee.
Applications can be submitted from 15.10.2026 to 16.11.2026
For further info, please contact:
Dr. Mais Baqain Mais.baqain@taltech.ee, and Dr. Dmitri Nešumajev dmitri.nesumajev@taltech.ee
