Special issue (Volume 17, Issue 5&6) of International Journal of Chemical Reactor Engineering (IJCRE) to honour Prof.Dr. Timur Doğu ve Prof.Dr. Gülşen Doğu is published. We are grateful to Prof.Dr. Timur Doğu and Prof.Dr.Gülşen Doğu for their contribution to Chemical Reaction Engineering.(https://www.degruyter.com/view/j/ijcre.2019.17.issue-6/issue-files/ijcre...).