scholarly journals Hydrogenation of Nitrobenzene over a Pd/Al2O3Catalyst - Mechanism and Effect of the Main Operating Conditions

2015 ◽  
Vol 38 (9) ◽  
pp. 1625-1636 ◽  
Author(s):  
Clara Sá Couto ◽  
Luis M. Madeira ◽  
Clemente Pedro Nunes ◽  
Paulo Araújo
Keyword(s):  
Operating Conditions ◽  
Main Operating

scholarly journals Simulation of a Downdraft Gasifier for Production of Syngas from Different Biomass Feedstocks

2021 ◽  
Vol 5 (2) ◽  
pp. 20
Author(s):  
Mateus Paiva ◽  
Admilson Vieira ◽  
Helder T. Gomes ◽  
Paulo Brito
Keyword(s):  
Modeling And Simulation ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Fuel Gas ◽  
Heating Value ◽  
Downdraft Gasifier ◽  
Process Operation ◽  
Independent Parameters ◽  
Gasification Temperature ◽  
Main Operating

In the evaluation of gasification processes, estimating the composition of the fuel gas for different conditions is fundamental to identify the best operating conditions. In this way, modeling and simulation of gasification provide an analysis of the process performance, allowing for resource and time savings in pilot-scale process operation, as it predicts the behavior and analyzes the effects of different variables on the process. Thus, the focus of this work was the modeling and simulation of biomass gasification processes using the UniSim Design chemical process software, in order to satisfactorily reproduce the operation behavior of a downdraft gasifier. The study was performed for two residual biomasses (forest and agricultural) in order to predict the produced syngas composition. The reactors simulated gasification by minimizing the free energy of Gibbs. The main operating parameters considered were the equivalence ratio (ER), steam to biomass ratio (SBR), and gasification temperature (independent variables). In the simulations, a sensitivity analysis was carried out, where the effects of these parameters on the composition of syngas, flow of syngas, and heating value (dependent variables) were studied, in order to maximize these three variables in the process with the choice of the best parameters of operation. The model is able to predict the performance of the gasifier and it is qualified to analyze the behavior of the independent parameters in the gasification results. With a temperature between 850 and 950 °C, SBR up to 0.2, and ER between 0.3 and 0.5, the best operating conditions are obtained for maximizing the composition of the syngas in CO and H2.

Oxidation of cosmetic wastewaters with H2O2 using a Fe/γ-Al2O3 catalyst

2010 ◽  
Vol 61 (6) ◽  
pp. 1631-1636 ◽  
Author(s):  
P. Bautista ◽  
A. F. Mohedano ◽  
J. A. Casas ◽  
J. A. Zazo ◽  
J. J. Rodriguez
Keyword(s):  
Space Time ◽  
Operating Conditions ◽  
Peroxide Oxidation ◽  
Sewer System ◽  
Allowable Limit ◽  
Wet Peroxide Oxidation ◽  
Initial Load ◽  
Lower Temperature ◽  
Al2o3 Catalyst ◽  
Main Operating

A catalyst based on Fe supported on γ-Al2O3 has been prepared and tested for catalytic wet peroxide oxidation (CWPO) of cosmetic wastewaters. The influence of the main operating conditions (space-time, temperature, and H2O2 dose) have been investigated. Working with this self-made Fe/γ-Al2O3 catalyst at 85°C, with a space-time of 9.4 kgcat h/kgCOD and a dose of H2O2, corresponding to 0.5 times the theoretical stoichiometric H2O2/COD ratio, a substantial COD reduction (around 80%) has been reached with a complete consumption of H2O2. The locally allowable limit of COD for industrial wastewaters discharge to the municipal sewer system can be achieved at lower temperature and space-time. The catalyst showed a high stability in 100 h time on stream tests, where COD and TOC reductions around 82 and 60%, respectively, were maintained working at 85°C and 9.4 kgcat h/kgCOD space-time. Fe leaching from the catalyst upon that time on stream was lower than 3% of the initial load.

Absorption of Sulphur Dioxide from Flue Gas with Sodium Alkali Solution in Packed Columns

2011 ◽  
Vol 383-390 ◽  
pp. 6409-6415 ◽  
Author(s):  
Wei Zhi Wang ◽  
Chun Guang Yang ◽  
Jin Rui Zhang
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Packed Column ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Solution Temperature ◽  
Operational Conditions ◽  
So2 Removal ◽  
Superficial Gas Velocity ◽  
Main Operating

The objective of this work was to study the sodium alkali(Na2S03) FGD process in a pilot-scale column packed column of diameter 0.4m. Main operating conditions affecting SO2 removal efficiency were investigated experimentally. These conditions include pH value of the absorption solution, liquid-gas ratio, superficial gas velocity, inlet SO2 concentration, temperature of absorption solution and initial Na2SO3 molar concentration. The relation between the ratio of desulfurization and every parameter was investigated. And the suitable operational conditions of SO2 absorption in lab are recommended. The experimental results show that SO2 removal efficiency may be over 80% under the following conditions: pH=6-7,L/G=1-2L/m3, gas superficial velocity is 1-1.5m/s, absorption solution temperature is under 50°C,initial [Na2SO3]≈0.3-0.5mol/L,and SO2 initial concentration is 4300 mg/m3. The experimental data can provide the necessary basic data for the design and operation of the practical desulfurization equipments.

scholarly journals JUSTIFICATION OF FILLERS USING IN THE BEARING STRUCTURES COMPONENTS OF FREIGHT CARS

2021 ◽  
Vol 1 (38) ◽  
pp. 5-13
Author(s):  
S. Panchenko ◽  
O. Fomin ◽  
G. Vatulia ◽  
A. Lovska ◽  
S. Deryzemlia ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Rolling Stock ◽  
Necessary Condition ◽  
Operational Conditions ◽  
Maintenance Work ◽  
Closed Structure ◽  
The Creation ◽  
The Cost ◽  
Bearing Structure ◽  
Main Operating

To reduce the load on the freight cars frames under operational conditions, it has been suggested that to use fillers in their components. Fillers using is advisable in the most loaded elements of the bearing structure, namely, the spine beam. Therefore, a necessary condition for filler using in the spine beam is the creation of its closed structure. The dynamic load of railcars was carried out, taking into account the proposed provisions. Calculations have shown with filler using, the maximum accelerations acting on the bearing structures of wagons are 4% lower than those accelerations obtained for bearing structures without fillers. The results of determining the main strength indicators of bearing structures of freight cars are presented, taking into account the fillers using in their components. It has been established that the strength of the frames of the considered types of wagons under the main operating conditions is ensured. At the same time, the maximum equivalent stresses in the bearing structures of wagons are 4-9% lower than those in typical frame structures. The conducted research will contribute to the creation of innovative structures of rolling stock and reduce the cost of its maintenance work in operation.

scholarly journals Determining the Traction Characteristic of a Tractor in Operating Conditions

2018 ◽  
Vol 12 (5) ◽  
pp. 25-30 ◽  
Author(s):  
A. G. Arzhenovskiy ◽  
D. S. Kozlov ◽  
N. A. Petrishchev
Keyword(s):  
Fuel Consumption ◽  
Energy Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Fuel Supply ◽  
Traction Characteristic ◽  
Engine Crankshaft ◽  
Inductive Sensors ◽  
Main Operating ◽  
Traction Power

One of the most important aspects in terms of increasing the efficiency of agricultural production is the improvement of the methods and tools of determining the main operating indicators of tractors as they influence the productivity, efficiency and ecological safety of machine­tractor units. (Research purpose) To develop a method for obtaining traction characteristics of a tractor, which make it possible to reduce the time needed for measurements under operating conditions, and to design an instrument for economical obtaining of tractors’ traction characteristics under specific farm conditions. (Materials and methods) the authors have chosen a method for determining the energy performance of tractors under operating conditions in a transient mode. They have conducted traction tests of tractors for various modes and soil backgrounds to evaluate its traction­dynamic and fuel­economic indicators. The traction characteristic of a tractor is the dependence of the tractor performance (traction power, speed, hourly and specific fuel consumption, and slipping) on the load at various speeds against a given soil background. However, traction tests require expensive equipment, as well as significant costs and time to prepare and conduct, which leads to their implementation only in the conditions of machine testing stations. (Results and discussion) The authors have developed a method for obtaining traction characteristics of a tractor under operating conditions. Instantly increasing the fuel supply to the maximum, during the tractor acceleration, the engine crankshaft speed and track­measuring wheel were measured at a given speed and against the corresponding soil background ­ with load and without load. It has been revealed that the fuel and economic indicators can be determined using cyclical fuel supply by the fuel pump at the maximum mode on the bench for checking and adjusting the fuel equipment. The authors have developed and assembled a measuring and computing installation that allows processing arrays of data from two inductive sensors. (Conclusions) The proposed method for determining the traction­dynamic and fuel­economic indicators of tractors and the measuring­computing installation that implements it allow obtaining a traction characteristic (speed, slipping, traction power, hourly and specific fuel consumption depending on the load at various speeds against a given soil background) in operating conditions, thus reducing the time and cost of operation.

scholarly journals Concept of freight wagons made of round pipes

2020 ◽  
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska
Keyword(s):  
Graduate Students ◽  
Doctoral Students ◽  
Operating Conditions ◽  
Teaching Aid ◽  
Main Operating ◽  
Freight Wagons

The purpose of the book is to highlight the results and features of the research carried out by the authors on the dynamics and strength of the main types of freight wagons, as well as tank containers made of round pipes under the main operating conditions of loading. Theoretical provisions, methodological foundations and practical solutions for the implementation of round pipes as bearing elements of bodies of the main types of wagons and tank containers are presented. The monograph is intended for scientific and technical specialists, whose activities are related to the design and research of the mechanics of structures of railway wagons, including scientists, designers, researchers, doctoral students and graduate students. Also, the results presented in the monograph may be of interest to specialists, whose activities are related to the design of tank containers. The monograph can be used as a teaching aid for undergraduates and bachelors of relevant specialties.

scholarly journals Analysis of a Hybrid Suspended-Supported Photocatalytic Reactor for the Treatment of Wastewater Containing Benzothiazole and Aniline

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 337 ◽  
Author(s):  
Cristian Ferreiro ◽  
Natalia Villota ◽  
José Lombraña ◽  
María Rivero ◽  
Verónica Zúñiga ◽  
...  
Keyword(s):  
Industrial Effluent ◽  
Supported Catalyst ◽  
Operating Conditions ◽  
Energy Costs ◽  
Photocatalytic Reactor ◽  
Operating Variables ◽  
Ms Analysis ◽  
Photocatalytic Material ◽  
Main Operating

In this work, a study of the main operating variables affecting TiO2/UV photocatalysis was carried out. The treatment of an industrial effluent containing aniline and benzothiazole from the manufacture of accelerants for vulcanization was performed in a TiO2-supported commercial photoreactor. The degradation of both contaminants was monitored by GC-MS analysis. The proposed experiments were able to properly identify the phenomenon of adsorption, as well as to improve the performance of the commercial photoreactor by adding small amounts of TiO2 in suspension. The removal performance, durability of the photocatalytic material, and energy costs were analysed. The results showed that the use of suspensions intensifies the degradation obtaining an improvement of 23.15% with respect to the use of the supported catalyst. For an aniline and benzothiazole solution, the best operating conditions were found at pH = 12.0, introducing 60.0 mg L−1 of suspended TiO2 together with the existing supported catalyst.

scholarly journals Development of an experimental test rig for the pyrolysis of plastic residues and waste tires

2021 ◽  
Vol 238 ◽  
pp. 01013
Author(s):  
Massimo Milani ◽  
Luca Montorsi ◽  
Gabriele Storchi ◽  
Matteo Venturelli ◽  
Carlo Pirola ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Styrene Butadiene Rubber ◽  
Small Scale ◽  
Butadiene Rubber ◽  
Pyrolysis Process ◽  
Experimental Apparatus ◽  
Styrene Butadiene ◽  
Oil Gas ◽  
Main Operating

The paper presents the design of the experimental apparatus developed in order to analyse the performance of a prototype of a pyrolysis system for the exploitation of the plastic residues of industrial processes and the end of life tires. The small scale pilot prototype is specifically designed for carrying out an experimental campaign aimed at determining the influence of different plastic types on the yield and on the quality of the liquid oil, gas and char obtained in the pyrolysis process. The study investigates the effect of different mixture of various plastic products mainly made of polyethylene, styrene butadiene rubber, nylon and natural rubber. The prototype is equipped with a control system able to monitor the main operating parameters of the process, such as the pyrogas pressure and temperature as well as the temperature inside the reactor where the pyrolysis takes place. The monitored variables are employed for deriving correlations among the operating conditions and the yield of the pyrolysis process. Therefore, further analysis concerns experimental measurements in order to estimate the main compounds that are contained in the syngas in comparison to the different plastic wastes analysed. Finally, the emissions of the small-scale prototype are evaluated.

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