Kinetics of the direct DME synthesis from CO2 rich syngas under variation of the CZA-to-γ-Al2O3 ratio of a mixed catalyst bed

Experimental and numerical kinetic investigations for the direct DME synthesis resulted in one of the predictive models with the broadest range of validity in the open literature for the CZA/γ-Al2O3 system.

A simple method for the preparation of a nickel selenide and cobalt selenide mixed catalyst to enhance bifunctional oxygen activity for Zn–air batteries

The mixture Ni0.85Se/Co0.85Se-NHCS-2 displayed superior electrocatalytic performance to that of Ni0.85Se-NHCS or Co0.85Se-NHCS alone. This provided a simple approach to develop ORR/OER bifunctional electrocatalysts for zinc–air batteries.

Structural Contributions to Autocatalysis and Asymmetric Amplification in the Soai Reaction

Diisopropylzinc alkylation of pyrimidine aldehydes – the Soai reaction, with its astonishing attribute of amplifying asymmetric autocatalysis, occupies a unique position in organic chemistry and stands as an eminent challenge for mechanistic elucidation. A new paradigm of ‘mixed catalyst substrate’ experiments with pyrimidine and pyridine systems allows a disconnection of catalysis from autocatalysis, providing insights into the role played by reactant and alkoxide structure. The alkynyl substituent favorably tunes catalyst solubility, aggregation and conformation while modulating substrate reactivity and selectivity. The alkyl groups and the heteroaromatic core play further complementary roles in catalyst aggregation and substrate binding. In the study of these structure activity relationships, novel pyridine substrates demonstrating amplifying autocatalysis were identified. Comparison of three autocatalytic systems representing a continuum of nitrogen Lewis basicity strength suggests how the strength of N-Zn binding events is a predominant contributor towards the rate of autocatalytic progression.<br><div> </div>

Structural Contributions to Autocatalysis and Asymmetric Amplification in the Soai Reaction

Diisopropylzinc alkylation of pyrimidine aldehydes – the Soai reaction, with its astonishing attribute of amplifying asymmetric autocatalysis, occupies a unique position in organic chemistry and stands as an eminent challenge for mechanistic elucidation. A new paradigm of ‘mixed catalyst substrate’ experiments with pyrimidine and pyridine systems allows a disconnection of catalysis from autocatalysis, providing insights into the role played by reactant and alkoxide structure. The alkynyl substituent favorably tunes catalyst solubility, aggregation and conformation while modulating substrate reactivity and selectivity. The alkyl groups and the heteroaromatic core play further complementary roles in catalyst aggregation and substrate binding. In the study of these structure activity relationships, novel pyridine substrates demonstrating amplifying autocatalysis were identified. Comparison of three autocatalytic systems representing a continuum of nitrogen Lewis basicity strength suggests how the strength of N-Zn binding events is a predominant contributor towards the rate of autocatalytic progression.<br><div> </div>

Generating Organic Liquid Products from Catalytic Cracking of Used Cooking Oil over Mechanically Mixed Catalysts

Used cooking oil is unsuitable to use again in the food process, but it may be harnessed as raw material in biofuel production. In this work, used palm oil was reactedvia cracking over mechanically mixed catalystsbetween ZSM-5 and Y-Re-16to generate organic liquid products (OLP). The catalysts used were known for highacidity and lowcost for decomposition, degradation,and deoxygenation of triglycerides. The cracking experiments were conducted in a flow reactor. The experimental variables included reaction temperature between 300-500°C, catalyst loading between 5-20 % w/w, and ratio of mixed catalyst between ZSM-5 and Y-Re-16 from 0-100 % w/w. They were setvia response surface methodology and central composite design of experiments. Both catalysts showed good cracking reaction. The optimum condition for generating the OLP of about 85 % w/w was found at 300°C, 5 % catalyst loading, 97 % ratio of mixed catalyst. The OLPs with different short-chain hydrocarbons between C7-C21 were identified. The main components were 71.43% of diesel, 12.11% of gasoline, and 8.95% of kerosene-like components.©2020. CBIORE-IJRED. All rights reserved

In Situ Pyrolysis of Pine Flowers to Produce Bio-Oil: Effect of Temperature and Catalyst Treatment

Nowadays, the demand for renewable energy increases dramatically which is caused by the crisis of fossil fuel. Bio-oil is one of the environmental renewable energy since it can be produced from biomass. Pine flowers as biomass mostly still become waste so that it has the potential to become a source of energy production. The purpose of this study is to investigate the effect of temperature and catalyst treatment on the characterization of bio-oil obtained. This research was using Zeolit catalyst activated by HCl 4N for six hours and impregnated by Fe2(NO3)3.9H2O. The experiment was carried out at different temperature treatment (450 °C, 500 °C, 550 °C) and different catalyst treatment (non-catalyst, non-impregnated catalyst, and impregnated catalyst). The catalyst and the biomass with size of (-100+120) mesh and (-30+40) mesh, respectively, were mixed where the catalyst used was 5% of the total weight of the biomass. The mixed catalyst-biomass was then put into the reactor to be pyrolyzed. The pyrolysis process was carried out by flowing N2 gas to prevent the presence of oxygen in the reactor. The result showed that optimum bio-oil production, 33.73%, was obtained from the sample with 550 °C with non-impregnated catalyst. The resulting bio-oil has the following properties : dark brown, yield of bio-oil 17.58%-33.73%, pH 2.95-3.56, density 1.055 gr/mL-1.068 gr/mL, and heating value 2,065.07-2,490.40 cal/gr. Finally, the GCMS results with the effect of temperature and catalyst treatment show the difference in the percentage of the phenolic-aromatic compound, acid, hydrocarbon, and ketone.