Numerical Study of Solid Biomass Fuel in a Gasifier System

2014 ◽  
Vol 953-954 ◽  
pp. 191-194
Author(s):  
Ming Yung Wang ◽  
Hsiao Kang Ma
Keyword(s):  
Numerical Study ◽  
Fixed Bed ◽  
Biomass Fuel ◽  
Waste Biomass ◽  
Operation Condition ◽  
Fire Dynamics ◽  
Fuel Gas ◽  
Cold Gas Efficiency ◽  
Downdraft Fixed Bed ◽  
Solid Biomass

In this study, the gasification processes of different Taiwan’s agriculture wastes were studied by using software of Fire Dynamics Simulator (FDS), which developed by American National Institute of Standards and Technology (NIST), to build a model of downdraft fixed bed gasifier. Details of the operation condition for the Taiwan’s agriculture waste biomass fuel in the gasifier were obtained. They include traction fan speed, leakage air, internal temperature, moisture, and cold gas efficiency. The simulated results are found in small type fixed bed biomass gasifier under traction fan initial speed is 0.2m/s, the leakage air in the gasification area is less than 10% of the amount of wind quantity by traction fan and moisture content of solid biomass is limited at 10% ~ 20%(vol.) that temperature in gasification zone with steady supply fuel gas condition is near 850~900°C.

Hydrogen Generation by Gasification of Rice Husk in an Integrated Fuel Cell Processor

2006 ◽  
Author(s):  
Kuen-Song Lin ◽  
Chi-Nan Ku ◽  
Chien-Te Hsieh ◽  
Shih-Hung Chan ◽  
Ay Su
Keyword(s):  
Fuel Cell ◽  
Rice Husk ◽  
High Purity ◽  
Hydrogen Generation ◽  
Fixed Bed ◽  
Reaction System ◽  
Pure Hydrogen ◽  
Fuel Gas ◽  
Cold Gas Efficiency ◽  
High Purity Hydrogen

Fuel processing is defined as conversion of any biomass, hydrocarbons or organics to a fuel gas reformate suitable for fuel cell (FC) anode reaction system. Rice husk is one of the potential organic sources of hydrogen and heat energy that can be generated from rice husk gasification processes. The high-purity hydrogen fed to the FC stack for power generation makes waste rice husk utilization system economically and environmentally attractive. Thus, the main objectives of this work were to develop a rice husk gasification process and the potential applications of high-purity hydrogen from syngas (CO and H2) on stationary power generator of FC system. In the lab-scale fixed-bed and bench-scale downdraft experimental approaches, gasification of rice husk was accompanied by a substantial production of syngas at 760–900 K. It was found that in addition to over 90% of syngas generation, approximately 7.17 × 105 kcal/hr of thermal energy was recovered and the cold gas efficiency was 78–86% when the gasifier was operated at O/C atomic ratios between 1.1 and 1.3. The product syngas can be further separated by pressure swing adsorption and Pd membrane purification units, which effectively purified and generated 99.999% pure hydrogen in an integrated FC Processor. Finally, cost or benefit analysis of a rice husk gasifier of 10-TPD (tons per day) was also performed to confirm the economic potential for such a recycling practice and determine if further development of stationary FC system would be warranted.

scholarly journals MATHEMATICAL MODELLING OF WOOD GASIFICATION WITH TARRY PRODUCTS DECOMPOSITION ON ACTIVE MATERIAL PARTICLES

2019 ◽  
Vol 20 (11-12) ◽  
pp. 107-117 ◽  
Author(s):  
I. G. Donskoy
Keyword(s):  
Power Plants ◽  
Numerical Study ◽  
Active Material ◽  
Fixed Bed ◽  
Fuel Mixture ◽  
Combustible Material ◽  
Wood Fuel ◽  
Heat Value ◽  
Combustible Gases ◽  
Downdraft Fixed Bed

The work is devoted to the numerical study of the process of downdraft fixed-bed gasification of woody biomass. Such processes are used to produce combustible gases at lowcapacity power plants. To improve the quality of the produced gas, it is proposed to use a mixture of wood fuel with a non-combustible material that can exhibit catalytic activity in the decomposition of undesired tary products. Adding a non-combustible material leads to lower heat value of fuel mixture, but contributes to a deeper gas purification. The aim of the study is to select the optimal "active material / wood fuel" ratio and to determine the minimum material activity at which its addition to the fuel becomes effective.

scholarly journals Application of Recycle System on a Cocoa Pod Husks Gasification in a Fixed-Bed Downdraft Gasifier to Produce Low Tar Fuel Gas

2019 ◽  
Vol 14 (2) ◽  
pp. 120-129
Author(s):  
Sunu Herwi Pranolo ◽  
Joko Waluyo ◽  
Jenni Prasetiyo ◽  
Muhammad Ibrahim Hanif
Keyword(s):  
Combustion Engine ◽  
Fixed Bed ◽  
Gravimetric Method ◽  
Producer Gas ◽  
Fuel Gas ◽  
Downdraft Gasifier ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Volumetric Rate ◽  
Cocoa Pod Husks

Biomass gasification is potentially generating not only producer gas but also tarry components. Practically, the gas may substitute traditional fuel in an internal combustion engine after reducing the tar. This research examined a producer gas recycle system to reduce tar component of producer gas generated with cocoa pod husks gasification using air as gasifying agent in a fixed-bed downdraft gasifier. Cocoa pod husks feed sizes were +1” sieve, -1”+ 0.5” sieve, and -0.5” sieve. The gasification process was operated at the temperature range of 491 – 940oC and at various gasifying agent volumetric rates of 62.84; 125,68; and 188.53 NL/min or at equivalent ratio range of 0.014 – 0.042. A recycle system of outlet producer gas to gasifier was set at volumetric rates of 0.139; 0.196; and 0.240 L/min. The performance of the system was evaluated with analyzing the tar component using gravimetric method of ASTM D5068-13, and the gas component of CO, H2, CO2 and CH4 compositions in producer gas were analyzed using Gas Chromatography GC-2014 Shimadzu sensor TCD-14. This recycle system succeeded in reducing tar content as much as 97.19% at 0.139 L/min of recycle volumetric rate and at biomass feed size of -1”+0.5” sieve. The producer gas contained CO, H2, CO2 and CH4 of 23.29%, 2.66%, 13.30%, and 14.18% respectively. The recycle system cold gas efficiency was observed 65.24% at gasifying agent volumetric rate of 188.53 L/min and at biomass feed size of +1” sieve.

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.

scholarly journals Sampling and Analysis of Alkali in High-Temperature, High-Pressure Gasification Streams

1985 ◽  
Author(s):  
Cynthia K. McCurry ◽  
Robert R. Romanosky
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Turbines ◽  
Fixed Bed ◽  
Atomic Emission ◽  
Sampling System ◽  
Fuel Gas ◽  
Gas Streams ◽  
Coal Gasifier ◽  
High Temperature High Pressure

This paper describes the experiences leading to successful sampling of hot, contaminated, coal-derived gas streams for alkali constituents using advanced spectrometers. This activity was integrated with a multi-phase, combustion test program which addressed the use of minimally treated, coal-derived fuel gas in gas turbines. Alkali contaminants in coal-derived fuels are a source of concern, as they may induce corrosion of and deposition on turbine components. Real-time measurement of alkali concentrations in gasifier output fuel gas streams is important in evaluating these effects on turbine performance. An automated, dual-channel, flame atomic emission spectrometer was used to obtain on-line measurements of total sodium and potassium mass loadings (vapors and particles) in two process streams at the General Electric fixed-bed coal gasifier and turbine combustor simulator facility in Schenectady, New York. Alkali measurements were taken on (1) slipstreams of high temperature, high pressure, minimally clean, low-Btu fuel gas containing entrained particles from the gasifier and (2) a slipstream of the exhaust gas from the combustor/turbine simulator. Alkali detection limits for the analyzer were found to be on the order of one part per billion. Providing a representative sample to the alkali analyzer at the limited flows required by the instrument was a major challenge of this activity. Several approaches and sampling hardware configurations were utilized with varying degrees of success during this testing campaign. The resulting information formed the basis for a second generation sampling system which has recently been successfully utilized to measure alkali concentrations in slipstreams from the described fixed-bed coal gasifier and turbine combustor simulator.

scholarly journals Continuous Fixed-Bed Column Studies on Congo Red Dye Adsorption-Desorption Using Free and Immobilized Nelumbo nucifera Leaf Adsorbent

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 54
Author(s):  
Vairavel Parimelazhagan ◽  
Gautham Jeppu ◽  
Nakul Rampal
Keyword(s):  
Congo Red ◽  
Agricultural Waste ◽  
Fixed Bed ◽  
Dye Adsorption ◽  
Nelumbo Nucifera ◽  
Substantial Contribution ◽  
Flow Mode ◽  
Waste Biomass ◽  
Column Studies ◽  
Fixed Bed Column

The adsorption of Congo red (CR), an azo dye, from aqueous solution using free and immobilized agricultural waste biomass of Nelumbo nucifera (lotus) has been studied separately in a continuous fixed-bed column operation. The N. nucifera leaf powder adsorbent was immobilized in various polymeric matrices and the maximum decolorization efficiency (83.64%) of CR occurred using the polymeric matrix sodium silicate. The maximum efficacy (72.87%) of CR dye desorption was obtained using the solvent methanol. Reusability studies of free and immobilized adsorbents for the decolorization of CR dye were carried out separately in three runs in continuous mode. The % color removal and equilibrium dye uptake of the regenerated free and immobilized adsorbents decreased significantly after the first cycle. The decolorization efficiencies of CR dye adsorption were 53.66% and 43.33%; equilibrium dye uptakes were 1.179 mg g–1 and 0.783 mg g–1 in the third run of operation with free and immobilized adsorbent, respectively. The column experimental data fit very well to the Thomas and Yoon–Nelson models for the free and immobilized adsorbent with coefficients of correlation R2 ≥ 0.976 in various runs. The study concludes that free and immobilized N. nucifera can be efficiently used for the removal of CR from synthetic and industrial wastewater in a continuous flow mode. It makes a substantial contribution to the development of new biomass materials for monitoring and remediation of toxic dye-contaminated water resources.

scholarly journals Development of a New Stoichiometric Equilibrium-Based Model for Wood Chips and Mixed Paper Wastes Gasification by ASPEN Plus

2019 ◽  
Author(s):  
Sahar Safarianbana ◽  
Runar Unnthorsson ◽  
Christiaan Richter
Keyword(s):  
Moisture Content ◽  
Aspen Plus ◽  
Wood Chips ◽  
Thermochemical Conversion ◽  
Waste Biomass ◽  
Operation Conditions ◽  
High Heating Value ◽  
Cold Gas Efficiency ◽  
Wide Range ◽  
Steady State Simulation

Abstract Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.

scholarly journals Solid Biomass to Medium CV Gas Conversion With Rich Combustion

2019 ◽  
Author(s):  
Gordon E. Andrews ◽  
Aysha Irshad ◽  
Herodotus N. Phylaktou ◽  
Bernard M. Gibbs
Keyword(s):  
Cone Calorimeter ◽  
Fixed Bed ◽  
Radiant Heat ◽  
Exhaust Gas ◽  
Sensible Heat ◽  
Gas Temperature ◽  
Heated Sample ◽  
Fuel Feed ◽  
The Rich ◽  
Solid Biomass

Abstract A modified cone calorimeter for controlled atmosphere combustion was used to investigate the gases released from fixed bed rich combustion of solid biomass. The cone calorimeter was used with 50 kW/m2 of radiant heat that simulated a larger gasification system. The test specimen in the cone calorimeter is 100mm square and this sits on a load cell so that the mass burn rate can be determined. Pine wood was burned with fixed air ventilation that created rich combustion at 1.5–4 equivalence ratio, Ø. The raw exhaust gas was sampled using a multi-hole gas sample probe in a discharge chimney above the cone heater, connected via heated sample lines, filters and pumps to the heated Gasmet FTIR. The FTIR was calibrated for 60 species, including 40+ hydrocarbons. The hydrogen in the gas was computed from the measured CO concentration using the water-gas shift reaction. The exhaust gas temperature was also measured so that the sensible heat from the gasification zone was included in the energy balance. The GCV of the pine was 18.8 MJ/kgpine and at the optimum Ø the energy in the rich combustion zone gases was 14.5 MJ/kgpine, which is a 77% energy conversion from solid biomass to a gaseous fuel feed for potential gas turbine applications. This conversion efficiency is comparable with the best conventional gasification of biomass and higher than most published conversion efficiencies for coal gasifiers. Of the energy in the gas from the rich combustion 35% was from the CO, 20% from hydrogen, 35% from hydrocarbons and 10% sensible heat. Ash remained in the rich burning gasification zone. As the biomass is a carbon neutral fuel there is no need to convert the gasified gases to hydrogen, with the associated energy losses.

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