Activity of nanocasted oxides for gas-phase dehydration of glycerol

Qin

et al. 2016

Ind. Eng. Chem. Res.

This paper presents a facile and economical route to synthesizing hierarchical porous ZSM-5 zeolite (HP-ZSM-5) by an ultrasound-assisted method as a long-life catalyst for the glycerol dehydration reaction, which is an important reaction for the sustainable production of acrolein from biobased glycerol. The systematic characterizations indicate that the HP-ZSM-5 catalyst possesses large intracrystal mesopores and abundant accessible acid sites. The ultrasonic treatment and violent stirring play a critical role in the synthesis process. Compared with commercial ZSM-5 zeolite (C-ZSM-5), the turnover-frequency value at time zero of the HP-ZSM-5 catalyst increased nearly 1 times, and the lifetime of the HP-ZSM-5 catalyst was prolonged 9 times. The HP-ZSM-5 catalyst exhibits a slower coking rate with higher coke tolerance, the coke preferentially form inside the intracrystal mesopores, and the ratio of hardly removed graphitic carbon is lower than that of C-ZSM-5. The HP-ZSM-5 catalyst exhibits prominent stability of nearly 50 h and a high acrolein selectivity of 82%.

Section: Introductionmentioning

confidence: 99%

Hierarchical ZSM-5 Zeolite Synthesized by an Ultrasound-Assisted Method as a Long-Life Catalyst for Dehydration of Glycerol to Acrolein

Qin

et al. 2016

Ind. Eng. Chem. Res.

“…Various species were identified as the catalytic active sites for the formation of acetol, depending on the catalyst studied. Researchers pointed out that the formation of 29 is favored on basic sites for Ce, Co, La and Ru oxide catalysts. ,,, Similarly, Auroux et al. showed that reducing the concentration and strength of acid sites promoted the formation of acetol on calcium phosphate systems .…”

Section: Upgrading Of Polyolsmentioning

confidence: 99%

“…Researchers pointed out that the formation of 29 is favored on basic sites for Ce, Co, La and Ru oxide catalysts. 260,261,269,270 Similarly, Auroux et al showed that reducing the concentration and strength of acid sites promoted the formation of acetol on calcium phosphate systems. 271 Suprun and Papp pointed out that transition metal oxides supported on Al 2 O 3 −PO 4 with low acidity were more favorable for acetol formation.…”

Section: Carbonation Into Propylenementioning

confidence: 99%

“…In some examples, molecular hydrogen was co-fed with glycerol. Co-feeding hydrogen promoted the dehydration reaction and inhibited the formation of coke, thus preventing catalyst deactivation. , Silver-, aluminum-, cerium-, ,− chromium-, copper-, ,,− and lanthanum- , as well as cobalt- and ruthenium-based catalysts were reported as efficient heterogeneous catalysts for the reaction. The most relevant catalysts and optimized conditions for hydroxyacetone formation are summarized in Table .…”

Section: Upgrading Of Polyolsmentioning

confidence: 99%

See 1 more Smart Citation

Continuous Flow Upgrading of Selected C₂–C₆Platform Chemicals Derived from Biomass

et al. 2020

The ever increasing industrial production of commodity and specialty chemicals inexorably depletes the finite primary fossil resources available on Earth. The forecast of population growth over the next 3 decades is a very strong incentive for the identification of alternative primary resources other than petro-based ones. In contrast with fossil resources, renewable biomass is a virtually inexhaustible reservoir of chemical building blocks. Shifting the current industrial paradigm from almost exclusively petro-based resources to alternative bio-based raw materials requires more than vibrant political messages; it requires a profound revision of the concepts and technologies on which industrial chemical processes rely. Only a small fraction of molecules extracted from biomass bears significant chemical and commercial potentials to be considered as ubiquitous chemical platforms upon which a new, bio-based industry can thrive. Owing to its inherent assets in terms of unique process experience, scalability, and reduced environmental footprint, flow chemistry arguably has a major role to play in this context. This review covers a selection of C2 to C6 bio-based chemical platforms with existing commercial markets including polyols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, xylitol, and sorbitol), furanoids (furfural and 5-hydroxymethylfurfural) and carboxylic acids (lactic acid, succinic acid, fumaric acid, malic acid, itaconic acid, and levulinic acid). The aim of this review is to illustrate the various aspects of upgrading bio-based platform molecules toward commodity or specialty chemicals using new process concepts that fall under the umbrella of continuous flow technology and that could change the future perspectives of biorefineries.

Advanced Functional Materials

The Synthetic Strategy for Developing Mesoporous Materials through Nanocasting Route

Kumar¹,

Chowdhury²

2015

Nanocasting is a powerful methodology for creating ordered mesoporous materials that are more diffi cult to synthesize by conventional processes. Synthesis starts with fabrication of inorganic/carbon precursors inside the nanospaces of a mesoporous hard template, which is used as a true mold to produce the mesoporous materials with controllable pore size, morphology of the network. Aft er fabrication inside the nanospaces, the template framework is selectively removed and the mesoporous ordered inorganic/organic material is obtained. In this chapter, a comprehensive literature survey for fabrication of mesoporous materials via mesoporous hard template, e.g., SBA-15, KIT-6, and mesoporous carbon, is presented. First two sections are limited to the basic understanding of nanocasting methodology. Th e later three sections comprise a review of works based on mesoporous silica/carbon template, which has been nurturing till date. A wide range of studies for synthesis of several inorganic compounds range from metal oxides, metal sulfi des, metal carbide phosphate, and ceramics is covered.