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

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

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

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.


2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula

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.


2016 ◽  
Vol 19 (3) ◽  
pp. 96-109
Author(s):  
Phung Thi Kim Le ◽  
Viet Tan Tran ◽  
Thien Luu Minh Nguyen ◽  
Viet Vuong Pham ◽  
Truc Thanh Nguyen ◽  
...  

Finding alternative energy sources for fossil fuels was a global matter of concern, especially in developing countries. Rice husk, an abundant biomass in Viet Nam, was used to partially replace fossil fuels by gasification process. The study was conducted on the pilot plant fixed bed up-draft gasifier with two kind of gasification agents, pure air and air-steam mixture. Mathematical modeling and computer simulations were also used to describe and optimize the gasification processes. Mathematical modeling was based on Computational Fluid Dynamics method and simulation was carried by using Ansys Fluent software. Changes in outlet composition of syngas components (CO, CO2, CH4, H2O, H2) and temperature of process, in relation with ratio of steam in gasification agents, were presented. Obtained results indicated concentration of CH4, H2 in outlet was increased significantly when using air-steam gasification agents than pure air. The discrepancies among the gasification agents were determined to improve the actual process.


2019 ◽  
Vol 8 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Poramate Sittisun ◽  
Nakorn Tippayawong ◽  
Sirivatch Shimpalee

This work studied generation of producer gas using oxygen-enriched air and steam mixture as gasifying medium. Corn residues consisting of cobs and stover were used as biomass feedstock. Both corn residues were pelletized and gasified separately with normal air, oxygen enriched air and steam mixture in a fixed bed reactor. Effects of oxygen concentration in enriched air (21-50%), equivalence ratio (0.15-0.35), and steam to biomass ratio (0-0.8) on the yield of product gas, the combustible gas composition such as H2, CO, and CH4, the lower heating value (LHV), and the gasification efficiency were investigated. It was found that the decrease in nitrogen dilution in oxygen enriched air increased proportion of combustible gas components, improved the LHV of producer gas, but gasification efficiency was not affected. The increase in equivalence ratio favoured high product gas yield but decreased combustible gas components and LHV. It was also observed that introduction of steam enhanced H2 production but excessive steam degraded fuel gas quality and decreased gasification efficiency. The highest gasification efficiency of each oxygen concentration was at equivalence ratio of 0.3 and steam to biomass ratio of 0.58 for cob, and 0.22 and 0.68 for stover, respectively. ©2019. CBIORE-IJRED. All rights reserved


Author(s):  
I. G. Donskoy

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).


2019 ◽  
Vol 2 (1) ◽  
pp. 8-12
Author(s):  
Angela Hartati ◽  
Diah Indriani Widiputri ◽  
Arbi Dimyati

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.


Author(s):  
Joana Freitas Campana ◽  
Kaio Pandolfi Pessotti ◽  
Carlos Eduardo Silva Abreu ◽  
Patrick de Jesus

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Munique Gonçalves Guimarães ◽  
Rafael Benjamin Werneburg Evaristo ◽  
Augusto César de Mendonça Brasil ◽  
Grace Ferreira Ghesti

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


Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.


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