• Title/Summary/Keyword: Microwave-assisted reaction

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Microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to sugars and ethanol: a review

  • Puligundla, Pradeep;Oh, Sang-Eun;Mok, Chulkyoon
    • Carbon letters
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    • v.17 no.1
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    • pp.1-10
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    • 2016
  • Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

A Review of Microwave-assisted Technology for Biodiesel Production (마이크로파를 이용한 바이오디젤 전환 기술 동향 분석)

  • PARK, JO YONG;JEON, CHEOL-HWAN;KIM, JAE-KON;PARK, CHEON-KYU
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.5
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    • pp.584-599
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    • 2017
  • Biodiesel is renewable, eco-friendly, clean burning diesel replacement that is consisted of short chain alkyl ester. Biodiesel is derived from the transesterification of vegetables oils or animal fats with alcohol. The process has some technical problems that must be resolved to reduce the high operation cost. Eco-friendly physical technologies by using microwave have successfully improved the transesterification for biodiesel production. This paper attempts to extensively review microwave-assisted technology for biodiesel production. Additionally, different types of catalyst for biodiesel production have been summarized. It is concluded that the microwave-assisted technique improves the reaction rate significantly in comparison with conventional methods. Therefore it can be a suitable method of reducing the reaction time and can also decreases the cost of biodiesel production.

Microwave-Assisted Acid-Hydolysis of Laminaria Japonica and its Ethanol Productivity: Comparison with Conventional Heating (마이크로파를 이용한 다시마의 산 가수분해와 에탄올 생산성: 재래식 가열과 비교)

  • Song, Myoung-Ki;Na, Choon-Ki
    • New & Renewable Energy
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    • v.9 no.2
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    • pp.5-14
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    • 2013
  • The efficiency of microwave-assisted acid hydrolysis of seaweeds for the production of ethanol was investigated and its effect on hydrolysis into reducing sugar and fermentation into ethanol evaluated as compared with those by conventional heating. A brown seaweed, Laminaria japonica (10-100g/L) was hydrolysed under dilute acidic condition (0.5N $H_2SO_4$, $100^{\circ}C$) with two sorts of heating: microwave irradiation for ${\leq}10min$ and conventional heating for 10-60min. Microwave-assisted hydrolysis was shown to be more efficient. A similar range of reducing sugar and ethanol yields as with the conventional autoclave heating procedure(${\geq}30min$) was observed, but it was obvious that production of ethanol from microwave-assisted hydrolysis had a 3 times faster reaction rate leading to very short production times, lower energy consumption/loss than from the conventional heating mode, and higher biomass loading without significant reducing ethanol yield, thus microwave-assisted acid hydrolysis is a potential alternative method for more effective hydrolysis of Laminaria japonica.

Efficient Microwave-assisted Deoxydehydration (DODH) Reactions: Synthesis of Adipic Acid from Galactose (마이크로웨이브를 이용한 효율적인 탈산소탈수(DODH) 반응: 갈락토스 유래 아디픽산의 합성)

  • Shin, Nara;Kwon, Sohyun;Kim, Young Gyu
    • Applied Chemistry for Engineering
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    • v.28 no.2
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    • pp.165-170
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    • 2017
  • An efficient synthetic process for bio-based adipic acid, a monomer for nylon 66, was developed from galactose. Galactaric acid, prepared from a mild oxidation of galactose using a Pt catalyst, was successfully converted to muconate, a key intermediate for adipic acid, by an efficient microwave-assisted DODH (deoxydehydration) reaction. The high efficiency of the microwave-assisted reaction greatly reduced the overall reaction time to 30 min. and resulted in an excellent yield of 97% of muconate. The catalytic hydrogenation of muconate followed by the acidic hydrolysis successfully produced the desired adipic acid in high purity after recrystallization.

Novel Syntheses of Symmetric Alkyl-substituted β-Diketimines with Dimethylsulfate Assisted by Microwave

  • Yoon, Saetbyeol;Lee, Byoungki;Lee, EungJoon;Lee, Ik Mo
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2871-2876
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    • 2013
  • We present an efficient and new preparative method for the symmetric ${\beta}$-diketimines assisted by microwave. A series of N,N'-symmetrically alkyl substituted ${\beta}$-diketimines have been synthesized from the reaction of O-acylation with dimethylsulfate. Higher reproducibility and yield, lower cost and much improved green nature originated from no solvent condition and higher energy efficiency due to faster reaction time are major merits of this new method. In addition to these merits, almost every kind of ${\beta}$-diketimines including alkyl-substituted ${\beta}$-diketimines little reported yet has been successfully prepared. Much wider applications of these compounds in various fields are expected.