Synthesis of mesoporous SiO2 xerogel/chitosan mixed-matrix membranes for butanol dehydration

Yi-Feng Lin,Chang-Yu Wu,Ting-Yu Liu,Kun-Yi Andrew Lin,Kuo-Lun Tung,Tsair-Wang Chung 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

Novel mesoporous SiO2 xerogel/chitosan (CS) mixed-matrix membranes (MMMs) were successfully prepared by incorporating sol–gel synthesized SiO2 xerogels into glutaraldehyde (GA) cross-linked CS membranes. The effects of the SiO2 doping amount and the feed temperature on the performance of the separation of butanol and water was also investigated in this study. The 0.25 wt% SiO2 xerogel/CS MMMs possessed the best pervaporation performance and the largest PSI value of 1102 kg/m2h with a permeate flux of 736 g/m2h (Permeability of 3.25 × 10−5 g m m−2 h −1 Pa−1) and a separation factor of 1498 at a feed temperature of 50 °C. This PSI value is not only comparable but also exceeds that of other membranes reported in the literature. The separation factor and the flux of the SiO2 xerogel/CS MMMs in this study clearly exceed the upper limit of the previously reported MMMs. As a result, the as-prepared novel SiO2 xerogel/CS MMMs showed an improved performance during the butanol and water separation process, which raises the possibility of future pervaporation applications using this novel SiO2 xerogel/CS MMMs.

Liquid-phase Environmental Catalytic Applications using MOFs and their derivatives

Kun-Yi Andrew Lin 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

Catalytic hydrogenation of disinfection by-product bromate by cobalt and nickle prussian blue analogues with borohydride

Mao Po-Hsin,박영권,Lin Yi-Feng,Thanh Bui Xuan,Tuan Duong Dinh,Ebrahimi Afshin,Lisak Grzegorz,Tangcharoen Thanit,Lin Kun-Yi Andrew 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

As disinfection is employed extensively, disinfection by-product bromate has become an emerging environmental issue due to its carcinogenic toxicity. For developing an effective alternative approach for reducing bromate, cobalt and nickel-based Prussian Blue (PB) analogues are proposed here for incorporating a convenient reducing agent, NaBH4 (i.e., a H2-rich reagent) for reducing bromate to bromide as cobalt and nickel are recognized as effective metals for catalyzing hydrolysis of NaBH4, and PB exhibits versatile catalytic activity. While CoPB and NiPB are comprised of the same crystalline structure, CoPB exhibits slightly higher specific surface area, more reductive surface, and more superior electron transfer than NiPB, enabling CoPB to accelerate bromate reduction. CoPB also exhibits a higher affinity towards NaBH4 than NiPB based on density functional theory calculations. Moreover, CoPB also exhibits a relatively low activation energy (i.e., 59.5 kJ/mol) of bromate reduction than NiPB (i.e., 63.2 kJ/mol). Furthermore, bromate reduction by CoPB and NiPB could be also considerably enhanced under acidic conditions, and CoPB and NiPB could still effectively remove bromate even in the presence of nitrate, sulfate and phosphate. CoPB and NiPB are also validated to be recyclable for reducing bromate, indicating that CoPB and NiPB are promising heterogeneous catalysts for reducing bromate.

Catalytic production of hexamethylenediamine from renewable feedstocks

이제찬,이영현,김수산,Kwon Eilhann E.,Lin Kun-Yi Andrew 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.6

Renewable biomass-derived chemicals have received considerable interest as a potential substitute for petroleum-derived chemicals. Hexamethylenediamine is a key intermediate in manufacturing nylon 66, a synthetic polymer that is broadly used in society. This article reviews the catalytic production of hexamethylenediamine from biomass-derived chemical feedstocks, and specifically the bio-based routes for obtaining hexamethylenediamine. While methods to directly convert biomass to hexamethylenediamine have yet to be commercialized, the use of heterogeneous catalytic systems via combined processes appears to be a promising and emerging chemical pathway to achieve this goal. Current proposed routes for the renewable production of hexamethylenediamine are not yet entirely competitive with petrochemical production techniques, predominantly because of low efficiency and high cost. However, many opportunities exist to advance technologies that exploit renewable and bio-based feedstocks to generate hexamethylenediamine. Thus, the commercialization of biomass-derived nylon monomers appears achievable in the near future.

Recently developed methods to enhance stability of heterogeneous catalysts for conversion of biomass-derived feedstocks

김수산,Yiu Fai Tsang,Eilhann E.Kwon,Kun-Yi Andrew Lin,이제찬 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.1

Many processes for the conversion of biomass and its derivatives into value-added products (e.g., fuels and chemicals) use heterogeneous catalysts. However, the catalysts often suffer from deactivation under harsh reaction conditions, such as liquid phase at high temperatures and pressures. The catalyst deactivation is a big obstacle to developing industrially relevant biomass conversion processes, including leaching, sintering, and poisoning of metals and collapse of catalyst support. Different approaches have been applied to limit the reversible and irreversible deactivation, highly associated with the kind of catalyst, reactants, reaction conditions, etc. This review presents recent advances in strategies to stabilize heterogeneous catalysts against deactivation for biomass conversion reactions.

Synergistic effect of KCl mixing and melamine/urea mixture in the synthesis of g-C3N4 for photocatalytic removal of tetracycline

Chechia Hu,Zhi-Ting Liu,Kun-Yi Andrew Lin,Wei-Han Wei,Ke-Hsuan Wang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

To prepare g-C3N4 for photocatalytic tetracycline (TC) removal, KCl was employed to mix with or cover thetop of the precursors, namely, melamine and urea. The mixing of KCl with the precursor will result in theincorporation of KClwithin the layer structure of g-C3N4, whereas KCl covering the top might not have suchan effect. Different precursor ratios contributed to the formation of heptazine-rich or triazine-rich units inthe g-C3N4 structure. Melamine applied alone as a precursor will undergo a phase transformation intomelam and triazine-rich g-C3N4, whereas with the addition of urea, the mixture will polymerize to formmelem and heptazine-rich g-C3N4. The KCl-incorporated, heptazine-rich g-C3N4 (KCN80m) exhibited animproved photocatalytic activity for TC removal (greater than 80% during a 120-min period for 50 mL ofa 20-ppm TC solution). The enhanced activity can be attributed to the improved charge separation throughan electron and hole transfer through the K+ and Cl- sites, respectively; the formation of a nanojunctionbetween the triazine and heptazine units of g-C3N4; an increased number of photoexcited electrons, indicatedby the electron paramagnetic resonance spectroscopy results.Wevaried the mixing conditions of KCland precursor ratio to synthesize different KCl-incorporated heptazine-rich g-C3N4 samples for effectiveremoval of TC from water through photocatalysis.

Evaluation of peroxymonosulfate/O3/UV process on a real polluted water with landfill leachate: Feasibility and comparative study

Farshid Ghanbari,Masoumeh Khatebasreh,Mostafa Mahdavianpour,Ali Mashayekh-Salehi,Ehsan Aghayani,Kun-Yi Andrew Lin,Behnam Kazemi Noredinvand 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.7

Landfill leachate is classified as special wastewater because it contains a large amount of hazardous materials that can lead to the pollution of surface water, generating polluted water with landfill leachate (PWLL) with high organic load. This study investigated the treatment of PWLL by peroxymonosulfate (PMS)/O3/UV process. The effects of several operating parameters such as pH, reaction time, O3 and PMS dosage were investigated in detail. The results showed that PMS/O3/UV removed total organic carbon (TOC) (74%), color (98%), ammonia (93%), chemical oxygen demand (COD) (81%), and biochemical oxygen demand (BOD) (69%) in 75 min at optimal conditions (pH=7, PMS=5mM, O3=1.7 mg/min). According to the results, O3 and UV can well activate PMS and promote the ability of the process to remove TOC from PWLL. Adding ferrous ion to PMS/O3/UV increased the TOC removal efficiency (77%), but cobalt ions had no significant effect on the TOC removal. The elimination of TOC by the PMS/O3/UV process follows pseudo-first-order kinetic model with the reaction rate constant of 0.0203 min1. Compared to peroxone/ UV, PMS/O3/UV showed high yield in TOC, COD, color and ammonia removal. Thus the PMS/O3/UV process can be a new approach for treatment of polluted water in low volume.

Periodate activation by concurrent utilization of UV and US for the degradation of para-nitrophenol in water: A synergistic approach

Akbar Eslami,Fayyaz Mehdipour,Rouzan Feizi,Farshid Ghanbari,Kun-Yi Andrew Lin,Amin Bagheri,Soheila Madihi-Bidgoli 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.4

Para-nitrophenol (PNP) is a toxic compound widely used in various industries. The release of PNP into the environment not only threatens human health but the ecosystem. Hence, the treatment of contaminated water is necessary. Periodate (PI) is a new oxidant which is used for the generation of free radicals. In the current work, PI was concurrently activated by ultraviolet (UV) and ultrasound (US) to eliminate PNP from aqueous solution. The effects of operating parameters were studied and complete degradation of PNP was obtained in 30 min. The presence of ferrous ions increased the PNP degradation rate. Scavenging experiments confirmed that HO• and IO • 3 were corresponding agents of the PNP degradation, which the latter had a bold role. The performance of PI/UV/US was examined on real wastewater and the results showed that 70% of total phenol was removed during 60 min. The PNP degradation intermediate was recognized and a pathway of PNP degradation was proposed. Although PI/UV/US process is high energy consuming, its excellent performance can be a rational reason for the scaling up the process.

Synergistic effect of Cu and Ru decoration on g-C3N4 for electrocatalytic CO2 reduction

Chechia Hu,Miao-Ting Liu,Arisu Sakai,Masaaki Yoshida,Kun-Yi Andrew Lin,Chun-Chieh Huang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

Electrocatalytic CO2 reduction is an emerging approach for the reduction of CO2 in a feasible, green, andeffective manner. In this study, bimetallic compounds of Cu and Ru were both decorated onto ap-conjugated g-C3N4 surface (CuxRuyCN), which functioned as an electrode for electrochemical CO2reduction. From the X-ray photoelectron and X-ray absorption spectra, Cu and Ru on CuxRuyCN wereidentified as the oxidative states of CuO/Cu2O and RuO2, respectively. The mixed states of CuO andCu2O served as active sites to both adsorb and activate CO2 for effective reduction, while RuO2synergistically served as the hole-enrichment center and transferred H protons to promote CO2 reduction. Consequently, the electrochemical current density of CuxRuyCN was significantly enhanced comparedwith the corresponding densities of CN or Cu-doped CN. The current density of CuxRuyCN reduced to lessthan 0.05 mA cm2 at an applied voltage of 1.5 V in an air or Ar atmosphere, indicating that the highcurrent density of CuxRuyCN was associated with the flow of CO2 and its reduction. Moreover, the currentdensity of CuxRuyCN was maintained at approximately 0.3 mA cm2 for at least 2000 s at an appliedvoltage of 1.4 V (vs Ag/AgCl), indicating its high stability during CO2 reduction. In summary, both Cuand Ru-modified g-C3N4 samples used to produce CuO/Cu2O- and RuO2-decorated g-C3N4 acted as effectivecatalysts for electrocatalytic CO2 reduction and demonstrated several potential electrochemicalapplications.

Carbon dioxide-cofeeding pyrolysis of pine sawdust over nickle-based catalyst for hydrogen production

Cho, Seong-Heon,Lee, Sang Soo,Jung, Sungyup,Park, Young-Kwon,Lin, Kun-Yi Andrew,Lee, Jechan,Kwon, Eilhann E. Elsevier 2019 Energy conversion and management Vol.201 No.-

<P><B>Abstract</B></P> <P>This study aimed to determine the synergistic effects of CO<SUB>2</SUB> on the catalytic pyrolysis of pine sawdust over a Ni-based catalyst (Ni/SiO<SUB>2</SUB>) to establish a sustainable platform for H<SUB>2</SUB> production. To elucidate the reaction mechanism, the CO<SUB>2</SUB>-cofeeding pyrolysis of pine sawdust was performed. The CO<SUB>2</SUB>-cofeeding pyrolysis of pine sawdust proved that the gas-phase reaction between CO<SUB>2</SUB> and pyrolysates led to the increase in the amount of generated CO. The CO<SUB>2</SUB> enhanced thermal cracking and dehydrogenation. These mechanistic features of CO<SUB>2</SUB> were catalytically enhanced when Ni/SiO<SUB>2</SUB> was employed as heterogeneous catalyst, which led to an increase in the amounts of generated H<SUB>2</SUB> and CO. Hence, the CO that was additionally generated during the gas-phase reaction of CO<SUB>2</SUB> and pyrolysates could be further converted into H<SUB>2</SUB>. In addition, CO<SUB>2</SUB> could be looped in the CO<SUB>2</SUB>-cofeeding pyrolysis of pine sawdust. Furthermore, exploiting CO<SUB>2</SUB> as raw material or reactive gas medium in the catalytic pyrolysis process also offered a strategic means for preventing coke formation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CO<SUB>2</SUB> offers a strategic means to maximize the carbon utilization and H<SUB>2</SUB> production. </LI> <LI> CO<SUB>2</SUB> expedites kinetics of gas phase reaction between CO<SUB>2</SUB> and volatile pyrolysates. </LI> <LI> Ni/SiO<SUB>2</SUB> catalytically enhances mechanistic roles of CO<SUB>2</SUB> in pyrolysis. </LI> <LI> Exploiting CO<SUB>2</SUB> in catalytic pyrolysis could prevent coke formation. </LI> </UL> </P>