• Title/Summary/Keyword: Solid-acid catalyst

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Production of Levulinic Acid from Glucosamine Using Solid Acid Catalyst (고체 산촉매를 이용한 글루코사민으로부터 레불린산 생산)

  • Park, Mi-Ra;Kim, Hyo Seon;Kim, Sung-Koo;Jeong, Gwi-Taek
    • Korean Chemical Engineering Research
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    • v.56 no.1
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    • pp.61-65
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    • 2018
  • In this study, the conversion of glucosamine, which is a major monomer in chitin/chitosan of crustacean shell, using solid acid catalyst was performed to obtain chemical intermediates such as levulinic acid and 5-hydroxymethyl furfural (5-HMF). The conversion reaction was optimized with four reaction factors of selection of ionic resin catalyst, reaction temperature, catalyst amount, and reaction time. As an optimized result, the highest levulinic acid yield was achieved approximately 36.86% under the determined conditions (Amberlyst 15 as a solid-acid catalyst, $180^{\circ}C$, 5% catalyst amount and 60 min). On the other hand, 5-HMF yield was found to be 0.91% at the condition.

Effect of Reaction Factors on Reducing Sugar Production from Enteromorpha intestinalis Using Solid Acid Catalyst (고체 산촉매를 이용한 창자파래로부터 환원당 생산에 미치는 인자들의 영향)

  • Jeong, Gwi-Taek;Park, Don-Hee
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.478-481
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    • 2015
  • In this study, the hydrolysis of green macro-algae Enteromorpha intestinalis using solid acid catalyst was conducted to obtain total reducing sugar. The hydrolysis was optimized with four reaction parameters of liquid-to-solid (L/S) ratio, catalyst amount, reaction temperature, and reaction time. As a optimized result, the highest TRS of 7.74 g/L was obtained under condition of 7.5 L/S ratio, $140^{\circ}C$, 15% catalyst amount and 2 hr. By the way, at this condition, only 0.13 g/L 5-HMF was detected. The solid acid-catalyzed hydrolysis of marine resources had the potential in the field of bioenergy.

Catalytic Conversion of Cellulose to Cellulose Acetate Propionate (CAP) Over SO42-/ZrO2 Solid Acid Catalyst

  • Leng, Yixin;Zhang, Yun;Huang, Chunxiang;Liu, Xiaocheng;Wu, Yuzhen
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1160-1164
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    • 2013
  • The solid super acid catalyst $SO{_4}^{2-}$/$ZrO_2$ was prepared by impregnation method using $ZrO_2$ as the catalyst support. Catalyst forming was taken into consideration in order to separate catalyst from the mixture of cellulose acetate propionate (CAP). $Al_2O_3$ and sesbania gum powder were selected as binding agent and auxiliary agent respectively. The catalytic properties were evaluated through esterification of cellulose with acetic anhydride, propionic anhydride and characterized by XRD, FTIR and $NH_3$-TPD. In this paper, the effects of concentration of $H_2SO_4$ impregnated, calcination temperature, esterification temperature and esterification time on the yield, acyl content and viscosity of CAP were investigated. The results showed that $SO{_4}^{2-}/ZrO_2$ successfully catalyzed CAP synthesis over catalysts impregnated in 0.75 mol/L $H_2SO_4$ and calcined at $500^{\circ}C$. The yield, acetyl content and propionyl content of CAP reached the maximum value of 105.3%, 29.9% and 25.8% reacted at $50^{\circ}C$ for 8 h.

Trimerization of Isobutene over Solid Acid Catalysts under Wide Reaction Conditions

  • Yoon, Ji-Woong;Jhung, Sung-Hwa;Kim, Tae-Jin;Lee, Hee-Du;Jang, Nak-Han;Chang, Jong-San
    • Bulletin of the Korean Chemical Society
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    • v.28 no.11
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    • pp.2075-2078
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    • 2007
  • Oligomerization of isobutene has been investigated using a few solid acid catalysts in order to produce efficiently triisobutenes that are useful chemical feedstocks for heavy alkylates and neo-acids. Several reaction conditions such as space velocity and isobutene concentration are evaluated, and a few cation exchange resins with various acid capacities were compared in the reaction. High trimers selectivity and high conversion can be obtained over a catalyst containing high acid capacity at low space velocity and relatively low isobutene concentration. The stability of a catalyst for the reaction is high when the acid capacity of the catalyst is high (for example Amberlyst-35).

Carbon-Based Solid Acid as an Efficient and Reusable Catalyst for the Synthesis of 1,8-Dioxodecahydroacridines Under Solvent-Free Conditions

  • Davoodnia, Abolghasem;Khojastehnezhad, Amir;Tavakoli-Hoseini, Niloofar
    • Bulletin of the Korean Chemical Society
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    • v.32 no.7
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    • pp.2243-2248
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    • 2011
  • Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of dimedone, aromatic aldehydes, and a nitrogen source (ammonium acetate or aromatic amines) under solvent-free conditions, giving rise to 1,8-dioxodecahydroacridines in high yields. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.

Synthesis, Characterization and Application of Poly(4-vinylpyridine)-Supported Brønsted Acid as Reusable Catalyst for Acetylation Reaction

  • Borah, Kalyan Jyoti;Dutta, Papia;Borah, Ruli
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.225-228
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    • 2011
  • Poly(4-vinylpyridine)-supported $Br{\phi}nsted$ acids (P4VP-HX) were prepared by wet impregnation technique. These supported acids were found as efficient heterogeneous green catalysts for acetylation of alcohol, amine and phenol with different catalytic activities. The wide application of P4VP-HX as reusable solid acid catalyst in organic reactions is possible because of its simple preparation and handling, stability, simple work up procedure.

Fabrication of a solid catalyst using coal fly ash and its utilization for producing biodiesel

  • Go, Young Wook;Yeom, Sung Ho
    • Environmental Engineering Research
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    • v.24 no.2
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    • pp.324-330
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    • 2019
  • To recycle raw fly ash (RFA), a waste from thermal power plants, it was used to prepare solid catalysts which have many advantages compared with homogenous catalysts. When biodiesel was produced from soybean oil using RFA, only 1.2% of biodiesel conversion was obtained. A metal hydroxide, NaOH, KOH or $Ca(OH)_2$, was mixed with the acid-treated fly ash (ATFA), and the mixture was calcined at $700^{\circ}C$ for 3 h to prepare the solid catalyst. The solid catalyst prepared by mixing ATFA with NaOH, designated as SC-Na, showed a better performance than those prepared by mixing ATFA with KOH or $Ca(OH)_2$, respectively. The optimal mass ratio of ATFA with NaOH was 1:3, at which the proportion of $Na_2O$ increased to 60.2% in SC-Na, and 97.8% of biodiesel conversion was achieved under optimal reaction conditions (2 w% SC-Na relative to oil and 5 mL-methanol/g-oil at $50^{\circ}C$ for 4 h). Finally, a batch operation was repeatedly carried out to test the feasibility of reusing the solid catalyst, and more than 96% biodiesel conversion was stably achieved for the third round of operations. This study shows that RFA was successfully recycled to solid catalysts through a simple preparation method, and the solid catalyst was reused for the production of biodiesel with high conversion.

Catalytic Dehydration of Methanol to Dimethyl Ether (DME) over Solid-Acid Catalysts

  • Jun, Ki-Won;Lee, Hye-Soon;Rho, Hyun-Seog;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.803-807
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    • 2002
  • The conversion of dimethyl ether(DME) has been carried out over $\gamma-alumina$, silica-alumina, and modified $\gamma-aluminal$ catalysts. Especially, the water effect has been investigated on purpose to develop a suitable catalyst for one-step synthesis of DME from $CO_2$ hydrgenation, The $\gamma-Al_2O_3$ modified with 1 wt% silica is more active and less deactivated by water than unmodified one. $CO_2has$ no effect on catalytic dehydration of methanol to DME.