scholarly journals Theoretical and experimental studies of fixed-bed coal gasification reactors. Final report

1983 ◽  
Author(s):  
B. Joseph ◽  
A. Bhattacharya ◽  
L. Salam ◽  
M.P. Dudukovic
Keyword(s):  
Coal Gasification ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Final Report

Experimental studies of human vigilance: Final report.

1963 ◽  
Author(s):  
Jack A. Adams
Keyword(s):  
Experimental Studies ◽  
Final Report

Experimental studies on runaway of catalytic fixed-bed reactors (vinyl-acetate-synthesis)

1980 ◽  
Vol 35 (1-2) ◽  
pp. 249-257 ◽  
Author(s):  
G. Emig ◽  
H. Hofmann ◽  
U. Hoffmann ◽  
U. Fiand
Keyword(s):  
Vinyl Acetate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Fixed Bed Reactors ◽  
Vinyl Acetate Synthesis

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

scholarly journals Experimental studies of the Negative Ion of Hydrogen. Final Report

1999 ◽  
Author(s):  
Howard C. Bryant
Keyword(s):  
Experimental Studies ◽  
Negative Ion ◽  
Final Report

Modeling of Drying Process of Bittim Nuts (pistacia terebinthus) in a Fixed Bed Dryer System by Using Extreme Learning Machine

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Asım Balbay ◽  
Engin Avci ◽  
Ömer Şahin ◽  
Resul Coteli
Keyword(s):  
Extreme Learning Machine ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Learning Rule ◽  
Activation Function ◽  
Optimal Topology ◽  
Gradient Based ◽  
Learning Machine ◽  
Pistacia Terebinthus ◽  
Hidden Neurons

Abstract Artificial neural networks (ANNs) have been widely used in modeling of various systems. Training of ANNs is commonly performed by backpropagation based on a gradient-based learning rule. However, it is well-known that such learning rule has several shortcomings such as slow convergence and training failures. This paper proposes a modeling technique based on Extreme Learning Machine (ELM) eliminating disadvantages of backpropagation based on a gradient-based learning rule for the drying of bittim (pistacia terebinthus). The samples for ELM based model are obtained by experimental studies. In experimental studies, the sample mass loss rate as a function time was investigated in different air velocities (0.5 and 1 m/s) and air temperatures (40, 60 and 80°C) in a designed dryer system. The obtained samples from experiments are used for training and testing of ELM. Further, some parameters of ELM such as type of activation function and the number of hidden neurons are set to obtain the best possible modelling results. The obtained prediction results show that ELM algorithm with tangent sigmoid activation function and 20 hidden neurons is appeared to be most optimal topology since maximum R2 and minimum rms (0.0500) and cov (0.2256) values are obtained. Thus, it is concluded that ELM can be used as an effective modelling tool in the drying of bittim (pistacia terebinthus) in fixed bed dryer system.

Pretreatment processes for membrane filtration of raw water containing manganese

2001 ◽  
Vol 1 (5-6) ◽  
pp. 341-348 ◽  
Author(s):  
S. Takizawa ◽  
L. Fu ◽  
N. Pradhan ◽  
T. Ike ◽  
M. Ohtaki ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Manganese Concentration ◽  
Fluidised Bed ◽  
Raw Water ◽  
Biological Pretreatment ◽  
Manganese Removal ◽  
Time Required

Experimental studies on chemical and biological pretreatments in membrane filtration processes were carried out to removal manganese contained in raw water and to prevent membrane fouling due to manganese. Two types of the pretreatment reactors, i.e. the fluidised-bed and fixed-bed configurations, were compared in the biological pretreatment experiments. New synthetic media (tubular polypropylene, I.D. 3 mm, O.D. 4 mm, length 5 mm) were used in all three experiments as a manganese-oxidising catalyst. The chemical pretreatment using sodium hypochlorite was effective in manganese removal and controlling membrane fouling; more than 0.8 mg-Cl2/L of chlorine dose was necessary to bring the manganese concentration from 0.4 mg/L in raw water to less than 0.05 mg/L. The biological pretreatment for manganese removal required a long start-up period of more than 40 days. The fixed-bed biological pretreatment was superior in manganese removal and in control of membrane fouling to the fluidised-bed biological pretreatment, which showed wash-out of the attached bacteria resulting in membrane fouling. The linear velocity and the empty-bed retention time required for the treatment of 0.14 mg-Mn/L in the fixed-bed biological pretreatment was 206 m/d and 8.0 minutes, respectively.

scholarly journals Assessment of coal gasification in a pressurized fixed bed gasifier using an ASPEN plus and Euler–Euler model

2020 ◽  
Vol 7 (3) ◽  
pp. 516-535
Author(s):  
Tamer M. Ismail ◽  
Mingliang Shi ◽  
Jianliang Xu ◽  
Xueli Chen ◽  
Fuchen Wang ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Fixed Bed ◽  
Size Variation ◽  
Aspen Plus ◽  
Two Dimensional ◽  
Cfd Model ◽  
Gas Generation ◽  
Gasification Process ◽  
Promising Tool ◽  
Euler Model

Abstract With the help of Aspen Plus, a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier. A developed and validated two dimensional CFD model for coal gasification has been used to predict and assess the viability of the syngas generation from coal gasification employing the updraft fixed bed gasifier. The process rate model and the sub-model of gas generation are determined. The particle size variation and char burning during gasification are also taken into account. In order to verify the model and increase the understanding of gasification characteristics, a set of experiments and numerical comparisons have been carried out. The simulated results in the bed are used to predict the composition of syngas and the conversion of carbon. The model proposed in this paper is a promising tool for simulating the coal gasification process in a fixed bed gasifier.

Industrial Fixed-Bed Coal Gasification: An Economic Alternative to Deregulated Natural Gas

1981 ◽  
Author(s):  
Rolf E. Maurer
Keyword(s):  
Natural Gas ◽  
Coal Gasification ◽  
Fixed Bed
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