scholarly journals Mathematical modeling of thermal decomposition of resins in the process of reversed gasification of plant biomass

2020 ◽  
Vol 22 (5) ◽  
pp. 83-93
Author(s):  
I. G. Donskoy
Keyword(s):  
Thermal Decomposition ◽  
Plant Biomass ◽  
Fixed Bed ◽  
Kinetic Scheme ◽  
Gasification Process ◽  
Bed Height ◽  
Oxidation Stage ◽  
Optimal Values ◽  
Gasification Efficiency ◽  
Limiting Values

THE PURPOSE. Of this work is to estimate parameters for a sufficiently comlete thermal decomposition of tarry products of the fixed-bed gasification of wood fuel. METHODS. To this end, mathematical models are used in different statements: the decomposition of the tar is considered in the approximations of one- and two-reaction kinetic scheme; to assess the influence of the bed height and temperature, the convection-diffusionreaction equation with a given temperature distribution along the length of the reaction zone is used; the temperature of the gasification process is estimated from experimental data and thermodynamic calculations. Along with the numerical model of the decomposition of the tar, a simplified analytical expression (for large Peclet numbers) is applied, the limits of its applicability are determined. RESULTS. Of calculations show that the efficiency of the airblown gasification of wood is determined by the temperature level of the oxidation stage: in the range of modes in which the optimal values of efficiency are achieved, the conversion of tarry products does not proceed sufficiently completely due to kinetic limitations; an increase in the specific consumption of the oxidizer leads to a decrease in efficiency due to stoichiometric reasons. CONCLUSION. Physicochemical limitations do not allow reaching the limiting values of gasification efficiency, shifting the optimal modes towards increasing the specific air consumption; a decrease in the yield of tar requires, first of all, changes in the thermal modes of gasification (for example, external heating or an increase in the oxygen concentration).

scholarly journals SIMULASI PENGARUH UKURAN PARTIKEL DAN EQUIVALENCE RATIO DALAM PROSES GASIFIKASI TANDAN KOSONG KELAPA SAWIT

2016 ◽  
Vol 17 (2) ◽  
pp. 101-109
Author(s):  
Sabar Pangihutan Simanungkalit ◽  
Dieni Mansur ◽  
Nino Rinaldi
Keyword(s):  
Particle Size ◽  
Equivalence Ratio ◽  
Fixed Bed ◽  
Process Time ◽  
Ansys Fluent ◽  
Empty Fruit Bunches ◽  
Carbon Efficiency ◽  
Gasification Process ◽  
Batch Simulation ◽  
Gasification Efficiency

In this study, a simulation for gasification process of oil palm empty fruit bunches waste (OPEFB) using a fixed bed gasifier (throat downdraft) by varying the particle size of OPEFB and equivalence ratio (ER) was investigated. The rate of fuel consumption was 10 kg/h with air as the oxidizing medium and 1 hour process time for 1 batch. Simulation was performed with two-dimensional approach (2D) using Computational Fluid Dynamics (CFD) ANSYS FLUENT 14 software. Simulation results show that ideal amount of equivalence ratio (ER) for gasification process of OPEFB pellets with diameter (φ) of 6 mm and 8 mm is 0.1 ≤ ER ≤ 0.2. ER variation affects the higher heating value of syngas (HHV), the carbon efficiency (ηC), gasification efficiency and temperature distribution in the gasification reactor. Variations in particle size did not have a significant effect in the gasification process.Keywords: CFD, OPEFB gasification, particle size, equivalence ratio

scholarly journals The Influence of Fuel and Steam Consumption on Characteristics of Fixed Bed Process of Woody Biomass Steam Gasification with Intensive Heat Supply

2021 ◽  
pp. 13-22
Author(s):  
I. Donskoy
Keyword(s):  
Plant Biomass ◽  
Renewable Energy Sources ◽  
Fixed Bed ◽  
Steam Gasification ◽  
Energy Utilization ◽  
Solar Thermal Energy ◽  
Gasification Process ◽  
Calculation Results ◽  
Calculated Fraction

Plant biomass is one of the most widespread renewable energy sources. Energy utilization of biomass allows solving some problems associated with the development of off-grid energy systems and the processing of combustible waste (primarily agricultural and forestry waste). This paper is devoted to the study of an allothermal gasification process of plant biomass materials using a kinetic-thermodynamic model developed by the author. The gasification process is considered stationary, and steam is used as a gasification agent. The power of the supplied heat is considered constant (10 kW). One of the significant tasks related to allothermal gasification is to choose flowrate parameters so that the heat supplied is efficiently used in chemical reactions without the threat of reactor overheating. The determination of the boundaries of the safe gasifier operation involved variant calculations with a view to optimizing the gasification conditions. The calculation results show that the allothermal gasification process can proceed with a thermochemical efficiency of about 70%. For each fixed fuel consumption level, there is an optimal fuel-steam ratio. The complete conversion of biomass requires sufficiently high temperatures. The produced gas contains a significant steam fraction (>50 vol%) even under optimal conditions. The calculated fraction of hydrogen in dry gas is up to 60vol%. The data obtained can be used to assess the efficiency of energy units with biomass gasification using high-temperature sources, for example, in systems that use and store solar thermal energy.

scholarly journals EXPERIMENTAL STUDIES ON GASIFICATION PERFORMANCE OF SAWDUST AND SAWDUST PELLET IN A DOWNDRAFT BIOMASS GASIFIER

2020 ◽  
Vol 5 (2) ◽  
pp. 22-28
Author(s):  
Fatin Zafirah Mansur ◽  
Che Ku Mohammad Faizal ◽  
N. A. Fazli ◽  
S. M. Atnaw ◽  
S. A. Sulaiman
Keyword(s):  
Equivalence Ratio ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Carbon Conversion ◽  
Oxidizing Agent ◽  
Heating Value ◽  
Gasification Process ◽  
Fixed Condition ◽  
Gasification Efficiency ◽  
Gasification Temperature

In this work, a comparative analysis of the gasification process of sawdust (SW) and sawdust pellet (SWP) utilizing a downdraft gasifier was performed. The gasification was conducted in a research-scale fixed-bed gasifier applying air as an oxidizing agent. The comparison between the raw (sawdust, SW) and treated biomass (sawdust pellet, SWP) was investigated for the syngas composition and gasification performance at the fixed condition of gasification temperature at 750 °C and equivalence ratio of 0.25. The gasification performance was tabulated in the form of heating value of the syngas (HHVsyngas), gasification efficiency (ηGE) and carbon conversion efficiency (ηCCE). It was found out that SWP produced the highest H2 and the lowest CO2. Furthermore, SWP also present the better gasification performance than SW. SWP achieved the high HHVsyngas, ηGE, and ηCCE at 4.2152 MJ/Nm3, 24% and 37%, respectively.

Product distribution and kinetic scheme for the fixed bed thermal decomposition of sewage sludge

2009 ◽  
Vol 145 (3) ◽  
pp. 412-419 ◽  
Author(s):  
C. Casajus ◽  
J. Abrego ◽  
F. Marias ◽  
J. Vaxelaire ◽  
J.L. Sánchez ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Fixed Bed ◽  
Kinetic Scheme ◽  
Product Distribution

Municipal Solid Waste Treatment Using Plasma Gasification with the Potential Production of Synthesis Gas (Syngas)

2019 ◽  
Vol 2 (1) ◽  
pp. 8-12
Author(s):  
Angela Hartati ◽  
Diah Indriani Widiputri ◽  
Arbi Dimyati
Keyword(s):  
Waste Treatment ◽  
Composition Analysis ◽  
Energy Agency ◽  
Plasma Gasification ◽  
Gasification Process ◽  
Solid Waste Treatment ◽  
Pre Treatment ◽  
Waste Separation ◽  
Gasification Efficiency ◽  
Arc Plasma Torch

This research was conducted for the purpose to overcome Indonesia waste problem. The samples are classified into garden waste, paper waste, wood, food waste, and MSW with objective to identify which type of waste give out more syngas since there is waste separation in Indonesia. All samples were treated by plasma gasification without pre-treatment (drying). Arc plasma torch used in this experiment was made by National Nuclear Energy Agency (BATAN) and used Argon as the gas source. Then the torch was connected to self-designed gasification chamber and gas washing system before injected into a gas bas for composition analysis. Another objective is to identify factors that may affect the gasification efficiency and the experiment shows that moisture content is not really affecting the efficiency but the duration of the process. The mass reduction of each samples were recorded, then the gas produced from the gasification process were analyzed. The result shows that food has the highest mass percentage reduced and producing the highest amount of hydrogen amongst other samples. However, treating MSW also produce considerably high amount of hydrogen. In conclusion, MSW direct treatment (without separation) using plasma gasification is feasible since it still produces desirable quality of syngas.

scholarly journals Green energy technology from buriti (Mauritia flexuosa L. f.) for Brazilian agro-extractive communities

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Munique Gonçalves Guimarães ◽  
Rafael Benjamin Werneburg Evaristo ◽  
Augusto César de Mendonça Brasil ◽  
Grace Ferreira Ghesti
Keyword(s):  
Lignin Content ◽  
Fixed Bed ◽  
Thermal Conversion ◽  
Volatile Matter ◽  
Matter Content ◽  
Green Energy ◽  
Fixed Bed Reactor ◽  
Gasification Process ◽  
Mauritia Flexuosa ◽  
Immediate Analysis

AbstractThe present work analyzed the energy generation potential of Buriti (Mauritia flexuosa L. f.) by thermochemical reactions. The experimental part of the study performed immediate analyses, elemental analyses, lignocellulosic analysis, thermogravimetric analysis, calorific values, and syn gas concentrations measurements of the gasification of Buriti in a fixed-bed reactor. Additionally, numerical simulations estimated the syn gas concentrations of the gasification reactions of Buriti. The immediate analysis showed that Buriti has the highest ash content (4.66%) and highest volatile matter content (85%) compared to other Brazilian biomass analyzed, but the higher heating value was only 18.28 MJ.kg−1. The elemental analysis revealed that the oxygen to carbon ratio was 0.51 while hydrogen to carbon ratio was 1.74, indicating a good thermal conversion efficiency. The Lignocellulosic analysis of Buriti resulted in a high content of holocellulose (69.64%), a lignin content of 28.21% and extractives content of 7.52%. The thermogravimetry of the Buriti indicated that the highest mass loss (51.92%) occurred in a temperature range between 150 °C and 370 °C. Lastly, the experimental gasification study in a fixed-bed updraft gasifier resulted in syn gas concentrations of 14.4% of CO, 11.5% of CO2 and 17.5% of H2 while the numerical simulation results confirmed an optimal equivalence ratio of 1.7 to maximize CO and H2 concentrations. Therefore, based on the results presented by the present work, the gasification process is adequate to transform Buriti wastes into energy resources. Graphic abstract

Optimization of a Biomass Micro-Gasification Process for the Production of Synthesis Gas From Palm Shell

2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula
Keyword(s):  
Particle Size ◽  
Fixed Bed ◽  
High Energy ◽  
Operating Conditions ◽  
Air Velocity ◽  
Output Variable ◽  
Heating Value ◽  
Palm Shell ◽  
Gasification Process ◽  
Air Speed

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.

scholarly journals Column Efficiency of Fluoride Removal Using Quaternized Palm Kernel Shell (QPKS)

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ayu Haslija Abu Bakar ◽  
Luqman Chuah Abdullah ◽  
Nur Amirah Mohd Zahri ◽  
Ma’an Alkhatib
Keyword(s):  
Fluoride Concentration ◽  
Fixed Bed ◽  
Palm Kernel ◽  
Fluoride Removal ◽  
Trimethylammonium Chloride ◽  
Transfer Resistance ◽  
Adsorption Models ◽  
Palm Kernel Shell ◽  
Bed Height ◽  
Fixed Bed Adsorption

In this research, the adsorption potential of quaternized palm kernel shell (QPKS) to remove F− from aqueous solution was investigated using fixed-bed adsorption column. Raw palm kernel shell waste was reacted with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHMAC) in order to modify the surface charge. The effects of inlet F− concentrations (2–12 mg/l) and QPKS bed height (2–10 cm) with optimum pH (pH = 3) on the breakthrough characteristics of the adsorption system were determined. In the fixed-bed column, breakthrough time increases with increasing bed height due to increasing amount of active site on adsorbents to adsorb the fluoride ion. Decreasing trend of breakthrough values was obtained with increasing initial fluoride concentration due to greater driving force for the transfer process to overcome the mass transfer resistance in the column. The adsorptions were fitted to three well-established fixed-bed adsorption models, namely, Thomas, Yoon–Nelson, and Adams–Bohart models. The results fitted well to the Thomas and Yoon–Nelson models with correlation coefficient, R2 ≥ 0.96.

Sign in / Sign up

Export Citation Format

Share Document