Aromatization of glycerol/alcohol mixtures over zeolite H-ZSM-5

Jang, Hyung-Su; Bae, Kyungbok; Shin, Mi; Kim, Sung Min; Kim, Chul‐Ung; Suh, Young‐Woong

doi:10.1016/j.fuel.2014.05.086

Cited by 48 publications

(36 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, a method for converting glycerol/alcohol mixtures to aromatics has been developed with similarity to the MTG process. 23 Similar to the MTO or MTP reactions, a dehydration reaction over the acid catalyst occurs first in the GTO reaction. Rapid deactivation caused by the formation of carbonaceous deposits on the surfaces or in the channels of zeolite catalysts has been a serious limitation that must be overcome for these materials to be useful for industrial applications.…”

Section: ■ Introductionmentioning

confidence: 99%

Selective Conversion of Glycerol into Propylene: Single-Step versus Tandem Process

Zhao

et al. 2016

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Dehydration and catalytic cracking reactions can be combined to convert glycerol into light olefins using solid acid catalysts. The combination is suitable for a singlestep process to convert glycerol into light olefins at high temperatures (26−36% selectivity at 873 K). However, large quantities of carbon oxides are produced (31−39% CO x selectivity), and catalyst deactivation also occurs. High light olefin selectivity (62−65%) and a smaller quantity of carbon oxides (11−12% CO x selectivity) can be obtained by using a tandem process involving the dehydration of glycerol and subsequent catalytic cracking of the dehydration products (mainly acetol and acrolein). Furthermore, the ratio of propylene to ethylene can be adjusted by changing the dehydration catalysts to favor the production of acetol or acrolein: Acetol forms propylene, and acrolein forms ethylene. To overcome the fast deactivation of acid catalysts in glycerol dehydration, the hydrogenolysis and catalytic cracking reactions can be synchronized to convert glycerol into hydrocarbons using a combination of metal and acid catalysts. The single-step conversion of glycerol over a metal or bifunctional catalyst formed alcohols and paraffin. The highest selectivity for propylene production (approximately 76%) was obtained in a tandem process via the selective hydrogenolysis of glycerol to propanols over Pt/ZSM-5 catalysts followed by the catalytic dehydration/cracking of propanols to propylene over ZSM-5 catalysts at low temperatures (523 K). The selectivity for propylene was improved by increasing the Si/Al ratio of the ZSM-5 catalysts and the reaction time. Under these conditions, economically competitive crude glycerol (mainly mixtures of glycerol and methanol) can be used to synthesize light olefins (approximately 61% selectivity) with a long lifetime (∼500 h) in single-route reactions by increasing the cracking temperature to 773 K, which is suitable for practical methanol to propylene process.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Selective Conversion of Glycerol into Propylene: Single-Step versus Tandem Process

Zhao

et al. 2016

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…4,5 However, the sharp increase in biodiesel production has led to the abundance of low-cost glycerol as the main byproduct from the transesterification process. 6,7 Several studies have indicated that glycerol production will exceed actual industrial demand by six times in 2020. 8 Thus, studies are being conducted for new applications of glycerol in the chemical industry not only because of its huge availability, but also for its remarkable characteristics such as edibility, nontoxicity, and biodegradablility.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Modeling, Thermodynamic, and Mass-Transfer Studies of Gas-Phase Glycerol Dehydration to Acrolein over Supported Silicotungstic Acid Catalyst

Talebian‐Kiakalaieh

Amin

2015

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The kinetics of gas-phase glycerol dehydration in a packed-bed reactor over a highly active and stable supported silicotungstic acid catalyst with zirconium oxide and nanosized aluminum oxide (30HZ-20A) was investigated. The kinetic study is based on the optimal reaction conditions determined by response surface methodology. The reaction rate followed first-order kinetics with the activation energy and frequency factor, E = 27.5 kJ/mol and A = 5.35 × 10 5 s −1 , respectively. Based on thermodynamic analysis, the values of ΔH°and ΔS°of the endothermic reaction were 14.70 and 0.09 kJ/(mol K), respectively, and ΔG°= −12.12 kJ/mol. The mass-transfer analysis revealed the pellet sizes of d p < 1 μm proceeded under reaction-limiting conditions. Experimental results confirmed high efficacy of the tested catalyst due to unity effectiveness factor and very low Thiele modulus.

show abstract

“…Moreover, it could also be seen in Figure b that the formation of trimethylbenzenes was improved after the introduction of methanol into glycerol, whereas the mixture of glycerol/ethanol or glycerol/n‐propanol lead to the preferential production of ethylbenzene and ethylmethylbenzenes, in good agreement with previous reports by Hyung‐Su Jang, indicating that the composition of aromatic products was depended on the introduced alcohol, i. e. the aromatization procedure was affected by the introduced alcohol. In case of the glycerol/methanol feed, framework methoxy species would be generated after initial physisorption of methanol to the Bronsted acid sites of HZSM‐5 through H‐bonding, which could be further transformed into trimethylbenzene and durene via alkylation reaction with BTX, leading to the higher production of trimethylbenzene and durene.…”

Section: Resultsmentioning

confidence: 99%

“…Hoang et al., Luo et al . and Jang et al . all found that HZSM‐5 was the most effective catalyst for the reaction of glycerol to aromatics (GTA) due to its adjustable acidity and three‐dimensional, 10‐ring micropores matching with aromatics molecules ,.…”

Section: Introductionmentioning

confidence: 99%

“…However, the problems of coke deposition over HZSM‐5 which resulted in either a poisoning of the acid sites or a blockage of zeolite micropore channels during the GTA procedure were rarely discussed, while the coking behavior has been discussed in detail in the aromatization properties of methanol, alkanes and olefins . Moreover, although the conversion of GTA over H‐ZSM‐5 under different operating parameters, such as solvents, reaction temperature, weight hourly space velocity (WHSV) and acidity distribution varied with Si/Al ratio of HZSM‐5, has been reported by Jang et al . and Tamiyakul et al., they only paid attention to the variation of aromatics yields, more detailed explanation on the distributions of total products during the GTA process was not made.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study on Catalytic Performance and Deactivation Behavior of HZSM‐5 in Aromatization of Glycerol

et al. 2018

View full text Add to dashboard Cite

We have investigated both the catalytic performance and deactivation behavior of HZSM‐5 under aromatization of glycerol condition which represents an alternative aromatics manufacturing route for using “green” fuel sources to replace the traditional fossil fuels. The effects of solvents, glycerol contents, reaction temperature and weight hourly space velocity (WHSV) on product distribution and coking process over HZSM‐5 were studied. Three stages could be clearly distinguished in HZSM‐5 catalyzed glycerol to aromatics (GTA) process: induction stage, auto‐catalytic stage and rapid deactivation stage. The synergetic effect between methanol and glycerol promoted the conversion of glycerol dehydrated products into aromatic hydrocarbons, resulting in higher yields of aromatics and lower coking rate. More glycerol content in the feed would result in more low temperature coke originated from aldehydes/ketones and less high temperature coke derived from polyaromatics. Under the selected optimum reaction conditions of 450 °C, WHSV=0.71 mL ⋅ g−1 ⋅ h−1 with an methanol/glycerol ratio of 40/60 over HZSM‐5 catalyst, the aromatics yields reached 42.1 % and the catalyst lifetime was 14.5 h. Higher temperature and lower WHSV benefited the production of harder coke while lower temperature and higher WHSV enhances the formation of softer coke.

show abstract

Aromatization of glycerol/alcohol mixtures over zeolite H-ZSM-5

Cited by 48 publications

References 16 publications

Selective Conversion of Glycerol into Propylene: Single-Step versus Tandem Process

Selective Conversion of Glycerol into Propylene: Single-Step versus Tandem Process

Kinetic Modeling, Thermodynamic, and Mass-Transfer Studies of Gas-Phase Glycerol Dehydration to Acrolein over Supported Silicotungstic Acid Catalyst

Study on Catalytic Performance and Deactivation Behavior of HZSM‐5 in Aromatization of Glycerol

Contact Info

Product

Resources

About