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.

Coal Gasification Characteristics in a 2MWth Second-Generation PFB Gasifier

2005 ◽  
Author(s):  
Xiao Rui ◽  
Baosheng Jin ◽  
Yunquan Xiong ◽  
Yufeng Duan ◽  
Zhaoping Zhong ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Pilot Scale ◽  
Test Results ◽  
Fuel Gas ◽  
Gasification Process ◽  
Feasibility Research ◽  
Fluid Bed ◽  
Long Time ◽  
Run Test ◽  
Gasification Temperature

Coal gasification process and equipment feasibility research were carried out in a 2 MW thermal input pressurized spout-fluid bed pilot-scale gasifier and a long-time-run test was performed to study the effects of operating parameters on coal partial gasification behaviors. The test results have demonstrated the feasibility of the gasifier to provide suitable fuel gas and residual char for downstream system of 2G PFBC-CC. The concentration of methane decreased at higher gasification temperature due to the secondary cracking of methane while the carbon conversion increased, and the concentration of hydrogen increased with an increase of steam flow rate. The main experimental results were compared with those of pilot-scale facilities in the world.

Investigation of Ammonia Formation During Gasification in an Air Blown Spouted Bed

2002 ◽  
Author(s):  
N. Paterson ◽  
Y. Zhuo ◽  
D. R. Dugwell ◽  
R. Kandiyoti
Keyword(s):  
Temperature Control ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Laboratory Scale ◽  
Spouted Bed ◽  
Fuel Gas ◽  
Bed Temperature ◽  
Control Options ◽  
High Concentrations ◽  
Ammonia Formation

High NH3 concentrations were measured in the fuel gas produced by a pilot scale, air blown gasifier that was operated by British Coal. A laboratory scale gasifier has subsequently been developed to investigate the reactions that produce these potentially high concentrations. It has been found that in addition to the NH3 formed through pyrolytic processes, the introduction of steam (or H2 produced by its decomposition) increases the amount formed. The latter reaction produced the higher proportion of the total NH3. The effect of the gasifier operating conditions on the amount of NH3 formed has been studied. The main control options to minimise the NH3 formed are using an alternative method of bed temperature control (i.e. avoid the use of steam), operating with higher bed temperatures and operation at lower pressures.

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.

Combustion of Medium Heating Value Coal Gas at Turbine Operating Conditions

1982 ◽  
Author(s):  
J. A. Schwab ◽  
D. C. Cicero ◽  
R. S. Basel
Keyword(s):  
Combustion Efficiency ◽  
Primary Objective ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Gas Combustion ◽  
Fuel Gas ◽  
Heating Value ◽  
Gasification Process

The work described in this paper is part of the effort performed under Department of Energy (DOE) Contract DE-AC21-80ET14752. The primary objective of this contract is to demonstrate the viability of the Westinghouse pressurized, fluidized bed gasification process for production of low and medium heating value fuel gas. One of many secondary objectives is to conduct combustion tests with medium heating value gas produced by the DOE/Westinghouse gasifier. In late 1980 and 1981, tests were performed on an experimental Westinghouse combustor during normal gasifier operation at the Test and Development Center. Pollutant emissions and combustion efficiency were evaluated as a function of inlet temperature, air-to-fuel ratio, pressure and reference velocity. Results for medium heating value gas combustion are presented along with combustion test results on distillate and coal derived liquid fuels.

scholarly journals Process characterization and energy balance of air wood residues gasification using continuous operated pilot scale reactor

2020 ◽  
Vol 180 ◽  
pp. 02018
Author(s):  
Cora Gheorghe-Bulmau ◽  
Raluca Nicoleta Tirtea ◽  
Gabriela Ionescu ◽  
Cosmin Marculescu
Keyword(s):  
Energy Balance ◽  
Rotary Kiln ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Major Influence ◽  
Fuel Gas ◽  
Gasification Process ◽  
Process Characterization ◽  
Pilot Scale Reactor

This work aimed to study the effect of gasification process operating conditions on syngas composition and properties, and process efficiency. A rotary kiln gasifier lab-scale pilot plant with capacity ≅ 30 kg/h and a power of 30 kWe was used for gasification tests applied to cherry wood at different loads, for a temperature of about 600°C, while the air was used as gasification agent for all tests. The syngas composition was measured and analyzed. The results have shown that conversion of wood cherry through gasification lead to a lean fuel gas of 3.5 MJ/Nm3 and installation characteristics have a major influence both on process and syngas properties. This is happened because the rotary kiln gasifier allows some air infiltrations, and consequently a high N2 content in the syngas composition. The energy balance of the cherry biomass gasification processes was calculated. It was found also that gas density varies slightly from 1.26 to 1.43 kg/m3, while the specific heat of the gas varies from 1.04 to 1.34 kJ/kgK.

Application of a Pilot-Scale Pulsed Electrocoagulation system to OCC-Based Paper Mill Effluent

TAPPI Journal ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 14-20 ◽  
Author(s):  
YUAN-SHING PERNG ◽  
EUGENE I-CHEN WANG ◽  
SHIH-TSUNG YU ◽  
AN-YI CHANG
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Paper Mill ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Optimal Dosage ◽  
Water Quality Indicators ◽  
Paper Mill Effluent ◽  
Treated Effluent ◽  
True Color

Trends toward closure of white water recirculation loops in papermaking often lead to a need for system modifications. We conducted a pilot-scale study using pulsed electrocoagulation technology to treat the effluent of an old corrugated containerboard (OCC)-based paper mill in order to evaluate its treatment performance. The operating variables were a current density of 0–240 A/m2, a hydraulic retention time (HRT) of 8–16 min, and a coagulant (anionic polyacrylamide) dosage of 0–22 mg/L. Water quality indicators investigated were electrical con-ductivity, suspended solids (SS), chemical oxygen demand (COD), and true color. The results were encouraging. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS, COD, and true color were 39.8%, 85.7%, 70.5%, and 97.1%, respectively (with an HRT of 16 min). The use of a coagulant enhanced the removal of both conductivity and COD. With an optimal dosage of 20 mg/L and a shortened HRT of 10 min, the highest removal achieved for the four water quality indicators were 37.7%, 88.7%, 74.2%, and 91.7%, respectively. The water qualities thus attained should be adequate to allow reuse of a substantial portion of the treated effluent as process water makeup in papermaking.

A pilot web former designed to study retention-formation relationships

2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Montmorillonite Clay ◽  
Speed Ratio ◽  
Good Reproducibility ◽  
Total Solids ◽  
Retention Aids ◽  
Solids Content ◽  
Relationship Of ◽  
The Relationship

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

Dynamic Modeling of CATOFIN® Fixed-Bed Iso-Butane Dehydrogenation Reactor for Operational Optimization

2016 ◽  
Vol 14 (1) ◽  
pp. 491-515 ◽  
Author(s):  
Zeeshan Nawaz
Keyword(s):  
Coke Formation ◽  
Fixed Bed ◽  
Process Intensification ◽  
Operating Conditions ◽  
Catalytic Dehydrogenation ◽  
Heating Rates ◽  
Reactor Model ◽  
Fuel Gas ◽  
Bed Temperature ◽  
Operational Optimization

AbstractThe catalytic dehydrogenation of iso-butane to iso-butylene is an equilibrium limited endothermic reaction and requires high temperature. The catalyst deactivates quickly, due to deposition of carbonaceous species and countered by periodic regeneration. The reaction-engineering constraints are tied up with operation and/or technology design features. CATOFIN® is a sophisticated commercialized technology for propane/iso-butane dehydrogenation using multiple adiabatic fixed-bed reactors having Cr2O3/Al2O3 as catalyst, that undergo cyclic operations (~18–30m); dehydrogenation, regeneration, evacuation, purging and reduction. It is always a concern, how to maintain CATOFIN® reactor at an optimum production, while overcoming gradual decrease of heat in catalyst bed and deactivation. A homogeneous one-dimensional dynamic reactor model for a commercial CATOFIN® fixed-bed iso-butane dehydrogenation reactor is developed in an equation oriented (EO) platform Aspen Custom Modeler (ACM), for operational optimization and process intensification. Both reaction and regeneration steps were modeled and results were validated. The model predicts the dynamic behavior and demonstrates the extent of catalyst utilization with operating conditions and time, coke formation and removal, etc. The model computes optimum catalyst bed temperature profiles, feed rate, pre-heating, rates for reaction and regeneration, fuel gas requirement, optimum catalyst amount, overall cycle time optimization, and suggest best operational philosophy.

Analysis of Vapor Evaporation Loss in Filling Gasoline into Tank

2011 ◽  
Vol 347-353 ◽  
pp. 372-375 ◽  
Author(s):  
Wei Qiu Huang ◽  
Feng Li ◽  
Shu Hua Zhao ◽  
Jing Zhong
Keyword(s):  
Mass Transfer ◽  
Experimental System ◽  
Pilot Scale ◽  
Convective Transport ◽  
Operating Conditions ◽  
Vapor Concentration ◽  
Air Mass ◽  
Evaporation Loss ◽  
Gas Space ◽  
Gasoline Evaporation

A pilot-scale experimental system of filling gasoline into a tank was built to investigate gasoline vapor-air mass transfer in the tank gas space and the vapor evaporation loss from the tank in different operating conditions. The results showed that the higher the location of filling pipe exit inside the tank, the quicker the speed of the filling gasoline, and the higher the initial vapor concentration in the tank gas space, then the more severe the vapor-air convective transport and the larger the gasoline evaporation loss rates.

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