Study of increasing thermodynamic efficiency and hydrogen amount in the process of solid fuels and biomass gasification
Authors:
- Władysław Mitianiec
Abstract
The effect of fuel composition such as hard coal and biomass in fluidized bed on the thermodynamic efficiency of three gasifier types, low heating value (LHV) and syngas composition was studied by simulation in CFD program. The paper presents various small gasification systems with fluidized bed of water-coal mixture and water-biomass mixture both with oxygen (air) and without oxygen. The work presents the extended mathematical model of gasification process taking into account also 13 kinetic chemical reactions enabled to apply them in CFD program. The chemical model is based on surface reactions given in the model of Equivalent Reactor Network (ERN) in Ansys Energetico. Simulation of gasification of different reactor designs enabled to obtain the mass concentration of chemical compounds in the syngas which influenced on thermodynamic efficiency and LHV. Additionally, heating of the gasifier walls by electrical system without air gives higher mass ratio of hydrogen (15%) and carbon monoxide (75%) in the syngas than in the oxidized gasification system. The simulation tests showed high thermodynamic efficiency, taking into account the exergy above 80%, both for the oxygen gasification of hard coal-slurry and biomass as well as for the externally heated gasifier without the supply of oxygen. The highest thermodynamic efficiency was obtained during gasification of energy willow in the oxidation reactor due to the large difference in LHV of syngas and fuel. Obtaining the maximum possible mass ratio of H2 in syngas and a high thermal efficiency for the OXGR system from the gasification of subbituminous coal dust occurs at a ratio C/O2 = 0.314 and at almost stoichiometric ratio of C/H2O=0.63. In the case of gasification of biomass in the form of finely ground energy willow in the OXGR system, these ratios were respectively: O2/C=1.82 and C/H2O=0.47. While maintaining the almost stoichiometric ratio C/H2O = 0.75, resulting from the water-gas shift reaction, low heating value of the syngas for the analysed gasification systems was over 25 MJ/kg. The paper shows comparison of mass fractions of CO, H2, H2O, H2S, CO2, O2, CH4, tar and other chemical compounds in the syngas. Application of the gasification reactor with external heated walls and without oxygen inflow produces the syngas without tar and volatile species in comparison to the systems with additional oxygen supply. In oxidized reactors the syngas contains a large amount of CO2 about 25 – 30% of total mass.
- Record ID
- CUT1030bc4449c0463e9be9d89f3a22b4cc
- Publication categories
- ;
- Author
- Journal series
- International Journal of Hydrogen Energy, ISSN 0360-3199, e-ISSN 1879-3487
- Issue year
- 2023
- Vol
- 48
- No
- 31
- Pages
- 11709-11726
- Other elements of collation
- rys.; tab.; wykr.; Bibliografia (liczba pozycji) - 62; Oznaczenie streszczenia - Abstr.; Data udostępnienia on-line - 2022-05-01; Numeracja w czasopiśmie - Vol. 48, Iss. 31
- Keywords in English
- fuel slurry, external heated gasifier, numerical model, chemical reactions, caloric value, syngas components
- ASJC Classification
- ; ; ;
- DOI
- DOI:10.1016/j.ijhydene.2022.03.191 Opening in a new tab
- URL
- https://www.sciencedirect.com/science/article/abs/pii/S0360319922013246 Opening in a new tab
- Related project
- Opracowanie rozproszonej i małoskalowej technologii wytwarzania energii elektrycznej z paliw stałych takich jak biomasa, osady ściekowe i węgiel w oparciu o instalację pilotażową składającą się ze zgazowarki paliw stałych oraz agregatowego silnika spalinowego ze swobodnym tłokiem. . Project leader at PK: , ,
- Language
- eng (en) English
- Score (nominal)
- 140
- Score source
- journalList
- Score
- Publication indicators
- Additional fields
- Indeksowana w: Web of Science, Scopus
- Uniform Resource Identifier
- https://cris.pk.edu.pl/info/article/CUT1030bc4449c0463e9be9d89f3a22b4cc/
- URN
urn:pkr-prod:CUT1030bc4449c0463e9be9d89f3a22b4cc
* presented citation count is obtained through Internet information analysis, and it is close to the number calculated by the Publish or PerishOpening in a new tab system.