Comparison of normal and reverse precipitation methods in the preparation of Cu/ZnO/Al2O3 catalysts for hydrogenolysis of butyl butyrate

2014 ◽  
Vol 54 ◽  
pp. 1-5 ◽  
Author(s):  
Cheonwoo Jeong ◽  
Jongha Park ◽  
Jong Wook Bae ◽  
Young-Woong Suh
2018 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Abdalla Mustafa Walwil

The aim of this educational work is targeting chemistry students and interested instructors. The presented work will analyze the mass spectrum of butyl butyrate (butyl butanoate). The analysis will concentrate on the mechanisms showing how the characteristic fragments are formed. The mechanisms discussed in this paper include α-cleavage, β-cleavage, McLafferty Rearrangements, first and second proton transfer, a double proton transfer. 


Author(s):  
Manish Kumar ◽  
Srinibas Karmakar ◽  
Sonu Kumar ◽  
Saptarshi Basu

Potential alternative fuels that can mitigate environmental pollution from gas turbine engines (due to steep growth in the aviation sector globally) are getting significant attention. Spray behavior plays a significant role in influencing the combustion performance of such alternative fuels. In the present study, spray characteristics of Kerosene-based fuel (Jet A-1) and alternative aviation fuels such as butyl butyrate, butanol, and their blends with Jet A-1 are investigated using an air-blast atomizer under different atomizing air-to-fuel ratios. Phase Doppler Interferometry has been employed to obtain the droplet size and velocity distribution of various fuels. A high-speed shadowgraphy technique has also been adopted to make a comparison of ligament breakup characteristics and droplet formation of these alternative biofuels with that of Jet A-1. An effort is made to understand how the variation in fuel properties (mainly viscosity) influences atomization. Due to the higher viscosity of butanol, the SMD is higher, and the droplet formation seems to be delayed compared to Jet A-1. In contrast, the lower viscosity of butyl butyrate promotes faster droplet formation. The effects of the blending of these biofuels with Jet A-1 on atomization characteristics are also compared with that of Jet A-1.


2003 ◽  
Vol 405 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Sandra Garcı́a-Garabal ◽  
Eulogio Jiménez ◽  
Luisa Segade ◽  
Herminio Casas ◽  
Carlos Franjo ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Feng ◽  
Jie Zhang ◽  
Yuechao Ma ◽  
Yiming Feng ◽  
Shangjun Wang ◽  
...  

AbstractBioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3 g/L butyl acetate and 1.6 g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses.


2019 ◽  
Vol 570 ◽  
pp. 31-41 ◽  
Author(s):  
Asmaa Jrad ◽  
Belal J. Abu Tarboush ◽  
Mohamad Hmadeh ◽  
Mohammad Ahmad

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 351
Author(s):  
Anna Knaislová ◽  
Hong Vu ◽  
Petr Dvořák

The influence of ultrasound and microwaves on extraction of copper, nickel, and cobalt from manganese deep-sea nodules by reductive ammoniacal leaching in the presence of ammonium thiosulfate as a reducing agent was studied. The ultrasonic ammoniacal leaching provides higher metals extraction, while the effect of microwaves on the metals extraction under the studied leaching conditions is insignificant. In general, increasing leaching temperature increases significantly extraction of the metals of interest. At high temperatures, extraction efficiencies of copper, nickel, and cobalt decrease over longer leaching duration as a result of decomposition of the metals amino-complexes and reverse precipitation of metals. However, during the ultrasonic leaching at a temperature of 85 °C, the extraction of nickel remains almost unchanged over longer leaching durations and does not follow the decreasing course, observed in the extraction of copper and cobalt. The finding suggests that nickel can be selectively extracted from the nodules by the ultrasonic leaching. The maximal extraction efficiency of copper, nickel, and cobalt was 83%, 71%, and 32%, respectively, when the reductive ultrasonic ammoniacal leaching was carried out at 85 °C for 90 min. In the presence of microwaves, the maximal extraction efficiency of copper, nickel, and cobalt was 67%, 48%, and 8%, respectively, when the reductive ultrasonic ammoniacal leaching was carried out at the output power of 60 W for 210 min.


2017 ◽  
Vol 79 (7) ◽  
Author(s):  
Ida Nurhazwani Abd Rahman ◽  
Fatin Myra Abd Manan ◽  
Nur Haziqah Che Marzuki ◽  
Naji A. Mahat ◽  
Nursyafreena Attan ◽  
...  

Being the prevailing approach for producing esters such as butyl butyrate, the use of chemical route has been linked to numerous disadvantages. Hence, a green alternative method for higher yield production of butyl butyrate by esterification reaction utilizing Novozyme 435 as biocatalysts in a solvent-less system may prove useful. Such approach can be further improved by optimizing the relevant reaction parameters using the Response Surface Methodology by the Box-Benkhen Design attempted in this present study. The reaction parameters evaluated were: substrate molar ratio, time and temperature, and the response of each parameter was measured as percentage conversion yield. Using the Design Expert 7.1.6 optimization functions, the two sets of optimum conditions selected viz. [i] molar ratio butyric acid:butanol 1:3.93, 9.93 h at 56.09°C and [ii] molar ratio butyric acid:butanol 1:3.35, 9.79 h at 53.90°C had afforded the highest yield of butyl butyrate i.e. 99.62% and 99.55%, respectively. The ester product obtained from the reaction were confirmed as butyl butyrate by FTIR and GC. Therefore, the results substantiated the applicability of the RSM prediction technique as well as efficacy of Novozyme 435 as biocatalysts in the high yield solvent-less synthesis of butyl butyrate, adhering to the philosophy of Green Chemistry.


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