KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 3 of 3
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Biofuel upgrading via catalytic deoxygenation in trickle bed reactor: Crucial issue in selection of pressure regulator type
    (2024-01-01)
    Pongsiriyakul, Kanokthip
    ;
    Kiatkittipong, Worapon
    ;
    Lim, Jun Wei
    ;
    Najdanovic-Visak, Vesna
    ;
    Wongsakulphasatch, Suwimol
    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 °C, 50 bar of hydrogen over Ni/γ-Al<inf>2</inf>O<inf>3</inf> 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 N<inf>2</inf> 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.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Catalytic Hydrotreating of Crude Pongamia pinnata Oil to Bio-Hydrogenated Diesel over Sulfided NiMo Catalyst
    (2022-02-01)
    Plaola, Yuwadee
    ;
    Leangsiri, Wanwipa
    ;
    Pongsiriyakul, Kanokthip
    ;
    Kiatkittipong, Worapon
    ;
    Srifa, Atthapon
    This work studied the catalytic activity and stability of Ni-MoS2 supported on γ-Al2O3, SiO2, and TiO2 toward deoxygenation of different feedstocks, i.e., crude Pongamia pinnata oil (PPO) and refined palm olein (RPO). PPO was used as a renewable feedstock for bio-hydrogenated diesel production via catalytic hydrotreating under a temperature of 330 °C, H2 pressure of 50 bar, WHSV of 1.5 h<sup>−1</sup>, and H2/oil (v/v) of 1000 cm<sup>3</sup>/cm<sup>3</sup> under continuous operation. The oil yield from a Soxhlet extraction of PPO was up to 26 wt.% on a dry basis, mainly consisting of C18 fatty acids. The catalytic activity in terms of conversion and diesel yield was in the same trend as increasing in the order of NiMo/γ-Al2O3 > NiMo/TiO2 > NiMo/SiO2. The hydrodeoxygenation (HDO) activity was more favorable over the sulfided NiMo supported on γ-Al2O3 and TiO2, while a high DCO was observed over the sulfided NiMo/SiO2 catalyst, which related to the properties of the support material and the intensity of metal–support interaction. The deactivation of NiMo/SiO2 and NiMo/TiO2 occurred in a short period, due to the phosphorus and alkali impurities in PPO which were not found in the case of RPO. NiMo/γ-Al2O3 exhibited the high resistance of impure feedstock with excellent stabil-ity. This indicates that the catalytic performance is influenced by the purity of the feedstock as well as the characteristics of the catalysts.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Techno-economic analysis of co-production of bio-hydrogenated diesel from palm oil and methanol
    (2021-09-15)
    Phichitsurathaworn, Nitipat
    ;
    Simasatitkul, Lida
    ;
    Amornraksa, Suksun
    ;
    Anantpinijwatna, Amata
    ;
    Charoensuppanimit, Pongtorn
    A bio-hydrogenated diesel (BHD) or green diesel is produced from refined bleached deodorized palm oil (RBDPO) via a heterogeneous catalytic reaction which requires high hydrogen to oil volumetric ratio for a complete conversion of oil. In this regard, a hydrogen recovery process is required to reduce a high amount of hydrogen loss in a gas by-product. This work proposes coupling the conventional BHD process with a production of methanol, a valuable co-product, and performs its techno-economic evaluation in comparison with the stand-alone BHD process. The results showed that the BHD process coupled with the methanol synthesis can recover by 46.3% of discharged hydrogen and reduce 14% of carbon dioxide and carbon monoxide emissions from the production process. Furthermore, methanol synthesis could improve the internal rate of return (IRR) by 23.2%, shorten the payback period by 2.81 years, and increase the net present value (NPV) by 54.41 million USD relative to the BHD process. Finally, environment potential impact of both processes are analyzed. The most significant on the environment is hydro-processing stage and both processes provide same environmental results.