Role of mesopores in Co/ZSM-5 for the direct synthesis of liquid fuel by Fischer–Tropsch synthesis

2018 ◽  
Vol 8 (24) ◽  
pp. 6346-6359 ◽  
Author(s):  
Ji-Eun Min ◽  
Sungtak Kim ◽  
Geunjae Kwak ◽  
Yong Tae Kim ◽  
Seung Ju Han ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Pore Structure ◽  
Liquid Fuel ◽  
Direct Synthesis ◽  
Reaction System ◽  
Complex Reaction ◽  
Fischer Tropsch ◽  
Solid Catalysts ◽  
The Impact

In a complex reaction system, in which gas, liquid, and solid catalysts work together, understanding the impact of mass transfer that varies with the catalyst pore structure is very challenging but also essential to designing selective catalysts.

Modeling of transport phenomena in fixed-bed reactors for the Fischer-Tropsch reaction: a brief literature review

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
José R.G. Sánchez-López ◽  
Angel Martínez-Hernández ◽  
Aracely Hernández-Ramírez
Keyword(s):  
Liquid Fuel ◽  
Transport Phenomena ◽  
Fixed Bed ◽  
Reaction System ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Fuel Production ◽  
Fischer Tropsch ◽  
Fixed Bed Reactors ◽  
The Impact

AbstractCurrently, few processes can be considered practical alternatives to the use of petroleum for liquid fuel production. Among these alternatives, the Fischer-Tropsch synthesis (FTS) reaction has been successfully applied commercially. Nevertheless, many of the fundamentals of this process are difficult to understand because of its complexity, which depends strongly on the catalyst and the reactor design and operating conditions, as the reaction is seriously affected by mass and heat transport issues. Thus, studying this reaction system with transport phenomena models can help to elucidate the impact of different parameters on the reaction. According to the literature, modeling FTS systems with 1D models provides valuable information for understanding the phenomena that occur during this process. However, 2D models must be used to simulate the reactor to correctly predict the reactor variables, particularly the temperature, which is a critical parameter to achieve a suitable distribution of products during the reaction. Thus, this work provides a general resume of the current findings on the modeling of transport phenomena on a particle/pellet level in a tubular fixed-bed reactor.

Understanding the impact of one-dimensional pore containing 10MR and 12MR and aluminium content on MTH reaction pathways: direct synthesis of heteroatom containing UZM-55

2020 ◽  
Vol 10 (3) ◽  
pp. 726-735
Author(s):  
Melissa M. Galey ◽  
Mark A. Miller ◽  
Mary Lanuza ◽  
Sesh Prabhakar ◽  
Christopher P. Nicholas
Keyword(s):  
Pore Structure ◽  
Catalytic Properties ◽  
Direct Synthesis ◽  
Reaction Pathways ◽  
Aluminium Content ◽  
One Dimensional ◽  
The Impact

We directly synthesized one-dimensional zeolite UZM-55 as an aluminosilicate and catalyzed MTH to understand pore structure influence on catalytic properties.

scholarly journals Enhancement of molecular weight reduction of natural rubber in triphasic CO2/toluene/H2O systems with hydrogen peroxide for preparation of biobased polyurethanes

2019 ◽  
Vol 8 (1) ◽  
pp. 288-296 ◽  
Author(s):  
Alif Duereh ◽  
Chokchai Boonchuay ◽  
Piyapong Buahom ◽  
Surat Areerat
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Mass Transfer ◽  
Molecular Weight ◽  
Natural Rubber ◽  
Weight Reduction ◽  
Reaction System ◽  
Oxidizing Agent ◽  
Biobased Polyurethane

Abstract Molecular weight reduction of natural rubber (NR) with hydrogen peroxide (H2O2) oxidizing agent is limited in biphasic water-toluene systems that is attributed to mass transfer. In this work, CO2 was applied to the (aqueous H2O2)-(toluene-NR) systems with the objective of improving reaction efficiency. Experiments were performed on the reaction system with CO2 at 12 MPa and at reaction temperatures and times of 60°C–80°C and 1 h–10 h to evaluate the reaction kinetics. CO2 could enhance the NR molecular weight reduction by lowering the activation energy (from 121 kJ·mol−1 to 38 kJ·mol−1). The role of CO2 in the reaction system seems to be the formation of oxidative peroxycarbonic acid intermediate and promotion of mass transport due to the reduction in the toluene-NR viscosity and interfacial tension. The epoxidized liquid NRs (M̅n=4.9×103 g·mol−1) obtained from NR molecular weight reduction was further processed to prepare hydroxyl telechelic NR (M̅n=1.0×103 g·mol−1) and biobased polyurethane.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

Sign in / Sign up

Export Citation Format

Share Document