scholarly journals Biomass to Syngas: Modified Non-Stoichiometric Thermodynamic Models for the Downdraft Biomass Gasification

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5668
Author(s):  
Hafiz Muhammad Uzair Ayub ◽  
Sang Jin Park ◽  
Michael Binns
Keyword(s):  
Crop Residues ◽  
Biomass Gasification ◽  
Thermochemical Conversion ◽  
Equilibrium Models ◽  
Gaseous Fuels ◽  
Gasification Process ◽  
Model Predictions ◽  
Experimental Values ◽  
Solid Biomass ◽  
Stoichiometric Models

Biomass gasification is the most reliable thermochemical conversion technology for the conversion of biomass into gaseous fuels such as H2, CO, and CH4. The performance of a gasification process can be estimated using thermodynamic equilibrium models. This type of model generally assumes the system reaches equilibrium, while in reality the system may only approach equilibrium leading to some errors between experimental and model results. In this study non-stoichiometric equilibrium models are modified and improved with correction factors inserted into the design equations so that when the Gibbs free energy is minimized model predictions will more closely match experimental values. The equilibrium models are implemented in MatLab and optimized based on experimental values from the literature using the optimization toolbox. The modified non-stoichiometric models are shown to be more accurate than unmodified models based on the calculated root mean square error values. These models can be applied for various types of solid biomass for the production of syngas through biomass gasification processes such as wood, agricultural, and crop residues.

Mathematical Modeling of a Biomass Steam Gasifier—A Modified Equilibrium Approach

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Thomas Gröbl ◽  
Heimo Walter
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Models ◽  
Present Article ◽  
Equilibrium Model ◽  
Conversion Process ◽  
Thermochemical Conversion ◽  
Equilibrium Models ◽  
Gasification Process ◽  
Equilibrium Approach ◽  
Made In

A large potential is contributed to the energetic utilization of biomass, whereby thermochemical gasification seems to be especially interesting. In order to contribute to a better understanding of the thermochemical conversion process in the gasifier, mathematical models are used. An intensive effort is made in development of mathematical models describing the gasification process and a large number of models, considerably differing in their degree of simplification, and their applications are reported in literature. In the present article, a brief review of models applied, mainly focused on equilibrium models, is provided and a robust and flexible modified stoichiometric equilibrium model, for modeling a novel gasifier, is presented.

scholarly journals A Comprehensive Literature Review of Thermochemical Conversion of Biomass for Syngas Production and Associated Challenge

2019 ◽  
Vol 38 (2) ◽  
pp. 495-512
Author(s):  
Ghulamullah Maitlo ◽  
Rasool Bux Mahar ◽  
Zulfiqar Ali Bhatti ◽  
Imran Nazir
Keyword(s):  
Fossil Fuels ◽  
Fixed Bed ◽  
Biomass Gasification ◽  
Gaseous Product ◽  
Gas Production ◽  
Thermochemical Conversion ◽  
Producer Gas ◽  
Syngas Production ◽  
Gasification Process

The interest in the thermochemical conversion of biomass for producer gas production since last decade has increased because of the growing attention to the application of sustainable energy resources. Application of biomass resources is a valid alternative to fossil fuels as it is a renewable energy source. The valuable gaseous product obtained through thermochemical conversion of organic material is syngas, whereas the solid product obtained is char. This review deals with the state of the art of biomass gasification technologies and the quality of syngas gathered through the application of different gasifiers along with the effect of different operating parameters on the quality of producer gas. Main steps in gasification process including drying, oxidation, pyrolysis and reduction effects on syngas production and quality are presented in this review. An overview of various types of gasifiers used in lignocellulosic biomass gasification processes, fixed bed and fluidized bed and entrained flow gasifiers are discussed. The effects of various process parameters such as particle size, steam and biomass ratio, equivalence ratio, effects of temperature, pressure and gasifying agents are discussed. Depending on the priorities of several researchers, the optimum value of different anticipated productivities in the gasification process comprising better quality syngas production improved lower heating value, higher syngas production, improved cold gas efficiency, carbon conversion efficiency, production of char and tar have been reviewed.

AN OVERVIEW OF HYDROGEN FUEL FROM BIOMASS GASIFICATION - COST EFFECTIVE ENERGY FOR DEVELOPING ECONOMY

2021 ◽  
Vol 36 (1) ◽  
pp. 42-52
Author(s):  
F. N Osuolale ◽  
K. A. Babatunde ◽  
O.O Agbede ◽  
A. F Olawuni ◽  
A.J Fatukasi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Cost Effective ◽  
Biomass Gasification ◽  
Operating Conditions ◽  
Thermochemical Conversion ◽  
Gasification Process ◽  
Product Gas ◽  
Economic Process ◽  
Percentage Yield ◽  
Different Sources

Hydrogen has the potential to be a clean and sustainable alternative to fossil fuel especially if it is produced from renewable sources such as biomass. Gasification is the thermochemical conversion of biomass to a mixture of gases including hydrogen. The percentage yield of each constituent of the mixture is a function of some factors. This article highlights various parameters such as operating conditions; gasifier type; biomass type and composition; and gasification agents that influence the yield of hydrogen in the product gas. Economic evaluation of hydrogen from different sources was also presented. The hydrogen production from gasification process appears to be the most economic process amongst other hydrogen production processes considered. The process has the potential to be developed as an alternative to the conventional hydrogen production process.

scholarly journals A Holistic Review on Biomass Gasification Modified Equilibrium Models

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 160 ◽  
Author(s):  
Sérgio Ferreira ◽  
Eliseu Monteiro ◽  
Paulo Brito ◽  
Cândida Vilarinho
Keyword(s):  
Mathematical Models ◽  
Thermodynamic Equilibrium ◽  
Model Prediction ◽  
Biomass Gasification ◽  
Correction Factors ◽  
Equilibrium Models ◽  
Gasification Process ◽  
Empirical Correction ◽  
Holistic Review ◽  
Almost All

Biomass gasification is realized as a settled process to produce energy in a sustainable form, between all the biomass-based energy generation routes. Consequently, there are a renewed interest in biomass gasification promoting the research of different mathematical models to enlighten and comprehend gasification process complexities. This review is focused on the thermodynamic equilibrium models, which is the class of models that seems to be more developed. It is verified that the review articles available in the literature do not address non-stoichiometric methods, as well as an ambiguous categorization of stoichiometric and non-stoichiometric methods. Therefore, the main purpose of this article is to review the non-stoichiometric equilibrium models and categorize them, and review the different stoichiometric equilibrium model’s categorization available in the literature. The modeling procedures adopted for the different modeling categories are compared. Conclusion can be drawn that almost all equilibrium models are modified by the inclusion of empirical correction factors that improves the model prediction capabilities but with loss of generality.

Steam Biomass Gasification - Effect of Temperature

2016 ◽  
Vol 832 ◽  
pp. 49-54 ◽  
Author(s):  
Marek Baláš ◽  
Martin Lisý ◽  
Jiří Pospíšil
Keyword(s):  
Negative Impact ◽  
Common Knowledge ◽  
Calorific Value ◽  
Biomass Gasification ◽  
Transformation Process ◽  
Effect Of Temperature ◽  
Producer Gas ◽  
Gaseous Fuels ◽  
Gasification Process ◽  
The Impact

Gasification is one of the technologies for utilization of biomass. Gasification is a transformation process that converts solid fuels into gaseous fuels. The gaseous fuel may be subsequently applied in other technologies with all the benefits that gaseous fuels provide. The principle of biomass gasification is a common knowledge. It is thermochemical decomposition oof the fuel in presence of gasification agent. Heat from the endothermic reaction is obtained by a partial combustion of the fuel (autothermal gasification) or the heat is supplied into a gasifier from the outside (allothermal gasification). Oxygen for the partial combustion is supplied in the gasification medium. Quality, composition and amount of the producer gas depend on many factors which include type of the gasifier, operating temperature and pressure, fuel properties (moisture content) and type and amount of gasification medium. Commonly, air, steam and oxygen and their combinations are used as a gasification medium. Every kind of gasification agents has its significant advantages and disadvantages.Research and analysis of the gasification process must pay special attention to all operating parameters which affect quality and amount of the producer gas that is the efficiency of the conversion itself. Composition of the producer gas, calorific value, and content and composition of impurities are especially observed as these are the basic characteristics directly affecting subsequent application of the gas. Steam addition has a significant impact on gas composition. Steam decomposition into hydrogen and oxygen, and their subsequent reactions increases amount of combustibles, hydrogen, methane and other hydrocarbons. Steam addition in the gasification also affects amount and composition of tar and has a negative impact on heat balance.Energy Institute at the Brno University of Technology has a long tradition in research of biomass gasification in atmospheric fluidized bed reactors. Air was used as a gasification medium. This paper describes our experience with gasification using a mixture of air and steam. We analysed the whole process and in this paper we wish to describe the impact of temperature on outputs of the process, especially temperature of leaving steam and temperature of gasification reactions.

Dynamic Modeling for Temperature Prediction in a Fluidized Bed Biomass Gasification Process

2021 ◽  
Author(s):  
Ibtihaj Khurram Faridi ◽  
Evangelos Tsotsas ◽  
Wolfram Heineken ◽  
Marcus Koegler ◽  
Abdolreza Kharaghani
Keyword(s):  
Fluidized Bed ◽  
Dynamic Modeling ◽  
Biomass Gasification ◽  
Temperature Prediction ◽  
Gasification Process

scholarly journals Investigations of long-term trends in the ionosphere with world-wide ionosonde observations*

2005 ◽  
Vol 2 ◽  
pp. 253-258 ◽  
Author(s):  
J. Bremer
Keyword(s):  
Data Series ◽  
Model Calculations ◽  
Maximum Electron Density ◽  
Model Predictions ◽  
Density Values ◽  
Long Term Trends ◽  
Experimental Values ◽  
The Individual ◽  
Global Mean

Abstract. Basing on model calculations by Roble and Dickinson (1989) for an increasing content of atmospheric greenhouse gases in the Earth’s atmosphere Rishbeth (1990) predicted a lowering of the ionospheric F2- and E-regions. Later Rishbeth and Roble (1992) also predicted characteristic longterm changes of the maximum electron density values of the ionospheric E-, F1-, and F2-layers. Long-term observations at more than 100 ionosonde stations have been analyzed to test these model predictions. In the E- and F1-layers the derived experimental results agree reasonably with the model trends (lowering of h'E and increase of ƒoE and ƒoF1, in the E-layer the experimental values are however markedly stronger than the model data). In the ionospheric F2-region the variability of the trends derived at the different individual stations for hmF2 as well as ƒoF2 values is too large to estimate reasonable global mean trends. The reason of the large differences between the individual trends is not quite clear. Strong dynamical effects may play an important role in the F2-region. But also inhomogeneous data series due to technical changes as well as changes in the evaluation algorithms used during the long observation periods may influence the trend analyses.

scholarly journals Integrating LCA with Process Modeling for the Energetic and Environmental Assessment of a CHP Biomass Gasification Plant: A Case Study in Thessaly, Greece

Eng ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 2-30
Author(s):  
Ioannis Voultsos ◽  
Dimitrios Katsourinis ◽  
Dimitrios Giannopoulos ◽  
Maria Founti
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Moisture Content ◽  
Process Simulation ◽  
Energy Savings ◽  
Biomass Gasification ◽  
Lower Efficiency ◽  
Technical Parameters ◽  
Gasification Process ◽  
Gasification Plant

The energetic and environmental performance of a cogeneration biomass gasification plant, situated in Thessaly, Greece is evaluated via a methodology combining process simulation and Life Cycle Assessment (LCA). Initially, the gasification process of the most common agricultural residues found in the Thessaly region is simulated to establish the effect of technical parameters such as gasification temperature, equivalence ratio and raw biomass moisture content. It is shown that a maximum gasification efficiency of approximately 70% can be reached for all feedstock types. Lower efficiency values are associated with increased raw biomass moisture content. Next, the gasifier model is up-scaled, achieving the operation of a 1 MWel and 2.25 MWth cogeneration plant. The Life Cycle Assessment of the operation of the cogeneration unit is conducted using as input the performance data from the process simulation. Global Warming Potential and the Cumulative Demand of Non-Renewable Fossil Energy results suggest that the component which had the major share in both impact categories is the self-consumption of electricity of the plant. Finally, the key conclusion of the present study is the quantification of carbon dioxide mitigation and non-renewable energy savings by comparing the biomass cogeneration unit operation with conventional reference cases.

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