A Review on Zeolite Application for Aromatic Production from Non-Petroleum Carbon-Based Resources

The application of zeolite catalyst has been expanded to support on-purpose sustainable technology. This review focused on zeolite application to produce aromatic compounds from non-petroleum carbon-based resources, including methanol, CO2, CO, and biomass. For COx resources, the two main routes for producing aromatics products are discussed, i.e., the olefinic and the oxygenates-mediated route. Moreover, several improvement strategies for enhancing catalytic performance are also discussed, i.e., the addition of metal components, tuning the metal and zeolite structure, and modifying the reaction process. Finally, prospects for future development are formulated

A Review on Zeolite Application for Aromatic Production from Non-Petroleum Carbon-Based Resources

The application of zeolite catalyst has been expanded to support on-purpose sustainable technology. This review focused on zeolite application to produce aromatic compounds from non-petroleum carbon-based resources, including methanol, CO2, CO, and biomass. For COx resources, the two main routes for producing aromatics products are discussed, i.e., the olefinic and the oxygenates-mediated route. Moreover, several improvement strategies for enhancing catalytic performance are also discussed, i.e., the addition of metal components, tuning the metal and zeolite structure, and modifying the reaction process. Finally, prospects for future development are formulated

Green chemicals from D-glucose: Systematic studies on catalytic effects of inorganic salts on the chemo-selectivity and yield in aqueous solutions

The use of inorganic salts as catalysts for the reactions of D-glucose in aqueous solutions in a batch reactor is reported. The type of salt and effect of reaction time were examined in detail at a fixed salt (5 mM) and dglucose concentration (0.1 M) and at a temperature of 140°C. Al(III) and Cr(II) salts gave the highest conversion of D-glucose. Typical reaction products were organic acids like lactic acid, levulinic acid, furanics like hydroxymethylfurfural and insoluble products (humins). The chemoselectivity is a clear function of the type of inorganic salt. For Al(III), the major water soluble product was lactic acid, for Zn(II) HMF was formed in the highest yields. A reaction scheme is proposed to explain the observed product compositions.

Green chemicals from D-glucose: Systematic studies on catalytic effects of inorganic salts on the chemo-selectivity and yield in aqueous solutions

The use of inorganic salts as catalysts for the reactions of D-glucose in aqueous solutions in a batch reactor is reported. The type of salt and effect of reaction time were examined in detail at a fixed salt (5 mM) and dglucose concentration (0.1 M) and at a temperature of 140°C. Al(III) and Cr(II) salts gave the highest conversion of D-glucose. Typical reaction products were organic acids like lactic acid, levulinic acid, furanics like hydroxymethylfurfural and insoluble products (humins). The chemoselectivity is a clear function of the type of inorganic salt. For Al(III), the major water soluble product was lactic acid, for Zn(II) HMF was formed in the highest yields. A reaction scheme is proposed to explain the observed product compositions.

Modelling Based Analysis and Optimization of Simultaneous Saccharification and Fermentation for the Production of Lignocellulosic-Based Xylitol

Simultaneous saccharification and fermentation (SSF) configuration offers efficient use of the reactor. In this configuration, both hydrolysis and fermentation processes are conducted simultaneously in a single bioreactor, and the overall processes may be accelerated. However, problems may arise if both processes have different optimum conditions, and therefore process optimization is required. This paper presents a mathematical model over SSF strategy implementation for producing xylitol from the hemicellulose component of lignocellulosic materials. The model comprises the hydrolysis of hemicellulose and the fermentation of hydrolysate into xylitol. The model was simulated for various process temperatures, prior hydrolysis time, and inoculum concentration. Simulation of the developed kinetics model shows that the optimum SSF temperature is 36 °C, whereas conducting prior hydrolysis at its optimum hydrolysis temperature will further shorten the processing time and increase the xylitol productivity. On the other hand, increasing the inoculum size will shorten the processing time further. For an initial xylan concentration of 100 g/L, the best condition is obtained by performing 21-hour prior hydrolysis at 60 °C, followed by SSF at 36 °C by adding 2.0 g/L inoculum, giving 46.27 g/L xylitol within 77 hours of total processing time. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Catalytic conversion of dihydroxyacetone to lactic acid using metal salts in water

We herein present a study on the application of homogeneous catalysts in the form of metal salts on the conversion of trioses, such as dihydroxyacetone (DHA), and glyceraldehyde (GLY) to lactic acid (LA) in water. A wide range of metal salts (26 in total) were examined. AlIII salts were identified as the most promising and essentially quantitative LA yields (>90 mol %) were obtained at 140 °C and a reaction time of 90 min. A reaction pathway is proposed and a kinetic model using the power law approach was developed for the conversion of DHA to LA with pyruvaldehyde (PRV) as the intermediate. Good agreement between experimental data and the model was obtained. Model predictions, supported by experiments, indicate that a high yield of LA is favoured in dilute solutions of DHA (0.1 M) at elevated temperatures (180 °C) and reaction times less than 10.

The Catalytic Conversion of D-Glucose to 5-Hydroxymethylfurfural in DMSO Using Metal Salts

A wide range of metal halides and triflates were examined for the conversion of D-glucose to HMF in DMSO. Chromium and aluminium salts were identified as the most promising catalysts. The effect of process variables like initial D-glucose concentration (0.1–1.5 M), reaction time (5–360 min) and reaction temperature (100–140 °C) on the yield of HMF were examined at a fixed Al(OTf)3 concentration (50 mM). Highest yields of HMF (60 mol%) were obtained using 1 M D-glucose (16 wt%), Al(OTf)3 (5 mol%) at a temperature of 140 °C. A reaction pathway involving initial isomerisation of D-glucose to D-fructose followed by a number of dehydration steps is proposed. Kinetic analysis reveals that the reaction is second order in D-glucose with an activation energy of 138 kJ mol-1.