@article{scholars20274,
            year = {2024},
         journal = {Fuel},
            note = {cited By 0},
          volume = {355},
           title = {Biofuel upgrading via catalytic deoxygenation in trickle bed reactor: Crucial issue in selection of pressure regulator type},
             doi = {10.1016/j.fuel.2023.129456},
             url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85175562772&doi=10.1016\%2fj.fuel.2023.129456&partnerID=40&md5=33cf8d8a54133e06700a98ed77ed8a3d},
          author = {Pongsiriyakul, K. and Kiatkittipong, W. and Lim, J. W. and Najdanovic-Visak, V. and Wongsakulphasatch, S. and Kiatkittipong, K. and Srifa, A. and Eiad-ua, A. and Boonyasuwat, S. and Assabumrungrat, S.},
        keywords = {Benchmarking; Chemical reactors; Diesel engines; Feedstocks; Gases; Nickel; Palm oil, Back pressure regulators; Bio-hydrogenated diesel; Catalysts deactivation; Gas-phases; Multiphases; Nickel catalyst; Reactor configuration; Regulator systems; Renewable energies; Tricklebed reactors, Catalyst deactivation},
        abstract = {Trickle bed reactors (TBRs) are commonly used in various chemical and associated processes. The selection of a proper back pressure regulator (BPR) is crucial for maintaining the system's upstream pressure. In this study, we investigate the impact of BPR selection on deoxygenation reaction in a TBR with two typical types of BPR, including gas-phase type back pressure regulator (Gas-BPR) and multiphase type back pressure regulator (Multi-BPR). Notably, Gas-BPR introduces interruptions and pressure drops during the sampling step, impacting the hydrogen flow rate, while Multi-BPR ensures more consistent hydrogen flow. To examine the performance of BPR systems, hydrotreating experiments were conducted at 330 {\^A}oC, 50 bar of hydrogen over Ni/{\^I}3-Al2O3 catalyst using crude Pongamia pinnata oil as a feedstock and refined palm olein as a benchmark. Insignificant difference in the reaction performance between Multi-BPR and Gas-BPR systems was observed when using refined palm olein. Interestingly, there was a significant difference between the two systems when feeding with crude Pongamia pinnata oil. The multi-BPR system demonstrated superior performance, achieving 100 conversion of the feedstock over a prolonged period compared to the interrupted hydrogen flow in the Gas-BPR system. Further characterization of fresh and spent catalysts using N2 sorption, XRD, SEM-EDS and TGA-DTG-DSC techniques revealed that a gum and coke formation was a reason for the rapid catalyst deactivation. Furthermore, the interrupted flow in the Gas-BPR system led to substantial gum production, ultimately causing a blockage in the reactor bed. Consequently, for feedstocks with high impurities, a robust continuous flow of hydrogen is essential. Thus, the study strongly recommends selecting Multi-BPR for continuous operation in TBRs to enhance efficiency and avoid catalyst deactivation. {\^A}{\copyright} 2023 Elsevier Ltd}
}