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Department of Chemical Engineering and Biotechnology



Samuel published his first paper on tailoring oxygen carriers for chemical looping epoxidation (CLE)

Samuel's recent work demonstrates the synergy between two strontium ferrite perovskites: SrFeO3 and Sr3Fe2O7 when used as oxygen carriers for chemical looping epoxidation. Separately, each of the perovskites is worst than a fair mix of both materials, and this applies to all properties: rate of oxygen release and uptake, stability in cycling, selectivity towards the epoxide (here: ethylene oxide). Samuel's work proves that we can tailor the performance of oxygen carriers, matching their chemical potential with reaction requirements. We are looking forward to the next step, Samuel!


Gabra S., Marek E.J., Poulston S., Williams G., Dennis J.S. The use of strontium ferrite perovskite as an oxygen carrier in the chemical looping epoxidation of ethylene. Applied Catalysis B: Environmental.


Kenny published his first paper on chemical looping combustion (CLOU)

Kenny's first paper on CLOU with biomass char and CuO particles is out (link below). This is an important piece of work developing the first analytical solution to char conversion in a CLOU setup. The model allows predicting the burnout time in any CLOU setup easily, for any stoichiometric oxides (CLOU particles). We are looking forward to the next part of this research. Stay tuned!

Kwong K., Mao R, Scott S.A., Dennis J.S., Marek E.J., 2020. Analysis of the rate of combustion of biomass char in a fluidised bed of CLOU Particles. Chemical Engineering Journal,


New paper co-authored by E.J. Marek. Does the reaction product influence the process in gasification? Yes, and it's quite a change.

Most studies use Ergun's rate of reaction to describe gasification of a solid char by CO2 into a gases fuel, carbon monoxide. Ergun's expression seems to have it all... and, indeed, that's why it is so successfully used (e.g., Marek EJ et al. 2018). In this study, led by Dr Yaoyao Zheng, we show that Ergun did not include the inhibiting effect of CO, and this omission influences the rate significantly! We propose a new expression for the rate that captures also the influence of CO. Have a look at the paper below. It will be presented in January at the International Symposium on Combustion. Great work Yaoyao and good luck at the conference!

Zheng Y, Marek E.J., Scott S.A. 2020 The effect of CO on CO2-char gasification. Proc Combust Inst.

New paper co-authored by E.J. Marek is out. Can we model chemical-looping with a discretised porous particle? Yes, we can.

Some materials are porous, others are not. Obviously this influences their reactivity in heterogeneous reactions. To observe the progress of a reaction, we modelled hematite particles under reduction with CO/CO2 mixture. Results show how different two materials with identical chemical composition can be. Here we had one type of hematite derived from ore, the other synthesised in the lab.

Jovanovic R., Marek E.J., 2020 Percolation theory applied in modelling of Fe2O3 reduction during chemical looping combustion. Chem. Eng. J.




New paper co-authored by E.J. Marek is out. This time the story involves microbes.



Some bacteria are amazingly effective in producing CaCO3. This biomineralised carbonate can have a bountiful range of applications in construction engineering. The paper characterises how efficiently various bacteria strains precipitate CaCO3. The image shows three mineral presentations of precipitated CaCO3 - all created by microbes.

Saracho, A.C., Haigh, S.K., Hata, T., Soga, K., Farsang, S., Redfern, S.A.T., Marek, E., 2020. Characterisation of CaCO3 phases during strain-specific ureolytic precipitation. Sci. Rep. 10, 1–12.


IIBs projects finished.

Jo, Alex, Udayin, Shekeil, Walid, and Luke finished their IIB projects and submitted their research reports. Congrats!


IIBs presenting their research projects.

Jo, Alex, Udayin, Shekeil, Walid, and Luke presented their research projects today. They gave a 6-min teaser presentation at the Department, followed by a poster session. Noone has any doubts these are our new experts on the combustion of waste fuels, CO/CO2 ratios from burning chars, promoters in CL epoxidation. Well done!

If you have problems with incomplete combustion (e.g., CO in the off-gas), go and talk to Jo and Alex.

Luke and Walid can tell you how to determine the CO/CO2 ratio from combustion of char, and then model for the burnout time.

If you have a catalytic reaction, go to Shekeil and Udayin to discuss promoters.


Boom is joining the Combustion Group.

Jiratheep Pruchyathamkorn - Boom is joining our group for his 8-week Mini research project. Boom is a NanoDTC student and he will be using his nano-skills to look at materials for CL-epoxidation. He will investigate how do the CL-catalysts work and which phases are active in reactions.


We are saying good-bye to Prof. John Davidson.

Prof. John Davidson passed away. He was the brightest and kindest supervisor, mentor and colleague. Without him, the group will not be the same. We will continue his fundamental work on fluidisation, hoping that would make him proud. He will be deeply missed.


Investigating redox kinetics of SrFeO3-δ. Another paper out in the world.

This is a second paper from Richard Goerke's Ph.D. thesis. Here, we determined kinetic parameters for SrFeO3-based perovskites. It is the first study, in which the dependence between pO2, non-stoichiometry of perovskite (δ), and the temperature is experimentally investigated. The paper is linked here.



Andras and Thomas' paper in Combustion and Flame is out!

These guys did a great job during their IIB project with us. Both are now working as chemical engineers! Congrats about the paper and about your new careers!

Free access link is here. In this paper, we describe how to determine important parameters for biomass and char (obtained after pyrolysis of biomass). Only by getting the parameters, such as thermal conductivity, right, can we model the energy conversion of biomass correctly.


Samuel around the globe: now in Beijing, China

Samuel Gabra has been invited to a Graduate Conference at the Tshigua University in China. Samuel received a full scholarship for this, being selected as the only Ph.D. student from Cambridge. We have no pictures of him in China just yet, so the readers just need to believe this news.


Samuel at a conference in the US

Samuel Gabra is presenting his research at the AIChE Conference in Orlando, US. This year the theme is "Transforming the Future through Chemical Engineering".

On Wednesday, Nov 13, Samuel will be presenting a paper titled: "MoVNbTeO for Chemical Looping - Oxidative Dehydrogenation of Ethan", co-authored with Dr S.A. Scott, G. Williams, S. Poulston, Prof. J.S. Dennis. The session will be in a Regency Ballroom!





The Combustion group gets bigger

Welcome two new Ph.D. students, Thomas and Ben!

In October, Thomas Z. Sun and Ben Houlton have joined our group. Both will be working on chemical looping. Good luck with your Ph.D. and welcome!