Effect of gas temperature and oxygen concentration on single particle ignition behavior of biomass fuels

Simões, Graça Maria Jegundo; Magalhães, Duarte; Rabaçal, M.; Costa, Mário

doi:10.1016/j.proci.2016.06.102

Cited by 68 publications

(38 citation statements)

References 13 publications

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“…As the bulk gas temperature increases from 1173K to 1773K, it is clear that one sees a shorter burnout time for the single KY coal particle ( a1 which causes the O2 concentration to decrease rapidly and thus produces a higher CO2 release peak, while a lack of O2 on the char surface results in more CO generation and thus a higher CO release peak. These modeling results are consistent with the modeling work of other researchers studying single coal particle combustion [34,[46][47][48], suggesting the reliability and applicability of the single-particle coal combustion model to provide the necessary information to determine the kinetic parameters for arsenic needed here.…”

Section: Single Coal Particle Combustion Characteristicssupporting

confidence: 87%

Vaporization model for arsenic during single-particle coal combustion: Model development

Liu

Wang

Zhang

et al. 2019

Combustion and Flame

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The kinetic parameters for chemical reactions associated with the vaporization of arsenic species are rarely reported due to the difficulties in obtaining suitably purified arsenic compounds as well as the issues associated with the extreme toxicity of many arsenic species. Here, we used a single-particle coal combustion model combined with a vaporization yield model of arsenic fitted by experimental data, which was used to determine the activation energy and frequency factor of the oxidation/decomposition reactions of arsenic species in this work, namely: As-org, FeAsS, FeAsO4 and Ca3(AsO4)2. The combustion kinetics of volatile/char and arsenic thermodynamic properties were used to model the vaporization zone and intensity of emissions for arsenic compounds. The results show that the reaction kinetic parameters of these arsenic species could be determined within an order of magnitude despite the variation of compositions in the coal sample and temperature, and this approach provides a new method to determine the reaction kinetics of hazardous elements such as As. Combining the vaporization yield and reaction kinetics of arsenic species with the single-particle coal combustion model, a novel vaporization model of arsenic was developed. With this model, the temporal evolution of combustion parameters (temperature, conversion ratio of coal, particle porosity, flue gas concentration) as well as arsenic vaporization ratio and As2O3(g) concentration can be predicted at the microscopic level. Model applications and predictions can be found in Part 2 of this work [Vaporization model of arsenic during single-particle coal combustion: Part 2. Numerical simulation].

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Section: Single Coal Particle Combustion Characteristicssupporting

confidence: 87%

Vaporization model for arsenic during single-particle coal combustion: Model development

Liu

Wang

Zhang

et al. 2019

Combustion and Flame

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“…The devolatilisation and char oxidation rates, ignition delays and burnout times of burning solid fuel particles largely depend on the surrounding conditions [1,2]. The hot gas temperature, rapid heating ratesand oxygen concentration contribute to discrepantignition delaysand flame intensities [3,4].Fast pyrolysis increases the soot production from solid fuel particles, particularly at high temperatures, whensoot is relatively more reactive [5,6].Such reactivity, along with the high volume fraction of soot particles,greatly influences thecombustion performance inindustrialapplications,because sooty flamesradiate large amounts of heat. In general,pulverised solid fuel particles immediately reach high temperatures during combustion, forming a sooty flame with release of volatile matter, tar, soot and ash in the early stages [7,8].…”

Section: Introductionmentioning

confidence: 99%

Flame structures and ignition characteristics of torrefied and raw sewage sludge particles at rapid heating rates

Mock

Lee

Choi

et al. 2017

Fuel

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Torrefactionis a promising method for improving the quality of pulverised solid fuel, as itincreases the flame stability,radiative heat transfer and energy density of the fuel.Raw sewage sludge contains less fixed carbon and more ash compounds than other biomasses; consequently, it has poorenergy quality witha long ignition delay and forms arelatively low, sooty flame. In this study,we directly investigate the combustion behavioursof particles with varying degrees of torrefaction by burning them at 1340 K.Thetorrefied particles were prepared at different temperatures(473 K or 573 K) for different residence times (10minor 30min).The experimental parameters examined were the size range of the particles (150-215μmand 255-300 μm)and the O 2 percentage(10-40%).The particles wereentrained from a 3 cold carrier gas into a hot gas stream, igniting a volatile flame that was extinguished a few millisecondslater. These temporal variations in the burning particles weredetected byin-situ high speed photography (7000 frames/s).Thetorrefactiondegree affected the flame structure and varied the ignition delay, due to the mismatched reactivity and soot formation at rapid heating rates. The mosttorrefied sludge particlesexhibited a relatively luminous volatile cloudand a large flame, while preserving the duration of volatile combustion. These observations confirm theimproved pulverised combustion of the torrefied sludge particles. We also obtained valuable flame parameters (radius, intensity and combustion time) of the differentlytorrefied sludge particles.

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“…Supplying an adequate amount of oxygen and proper mixing of the fuel with air are the most important factors in the combustion process and guarantee the complete Energies 2021, 14, 7476 2 of 11 combustion process [8]. Otherwise, products such as soot and polycyclic aromatic hydrocarbons (PAHs), which include, e.g., benzo(a)pyrene, are formed [3].…”

Section: Introductionmentioning

confidence: 99%

Study of the Properties and Particulate Matter Content of the Gas from the Innovative Pilot-Scale Gasification Installation with Integrated Ceramic Filter

et al. 2021

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This paper presents a study on the application of a ceramic filter in the biomass gasification process and its efficiency in particulate matter removal from the process gas and flue gas. A significant advantage of this type of filter is its high efficiency in small particle removal (<1 µm). This feature allows us to reach the much lower emissions that are required by the applicable standards. The study was performed using an original biomass gasification installation, where conifer scobs were used as feedstock. The installation, its operation and measurement methodology are described in the article. The study included the analysis of process gas and particulate matter, as well as particulate matter content before and after the filter was applied. The measurements indicate that the efficiency of particulate matter removal reaches 99.1%. The analysis of particulate matter in the process gas allowed us to determine that its content was 18.26%, and additionally it was indicated that it contained combustible parts, which undergo combustion in the combustion chamber. It was found that the content of particulate matter is reduced 11 times when compared to the process gas before the filter. An accurate estimation of particulate matter content in flue gas has been also shown for the system without the ceramic filter. As a result, the method allowed us to determine the overall efficiency of particulate matter removal using the ceramic filter, which is equal to 99.9% or 2 mg/m3 (N). The performed study shows that pre-combustion particulate matter removal is preferred over post-combustion particulate matter removal from flue gas. The reason is that the stream of process gas is several times smaller than the flue gas stream, thus the required size of the filter is smaller. Furthermore, process gas filtering allows us to keep the heat transfer surfaces clean, which preserves high thermal efficiency and durability of equipment. The presented results of performed tests are the early stage of the development of the technology of process gas refining in the waste gasification process. The final target is to reach standards similar to those in the case of natural gas.

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Effect of gas temperature and oxygen concentration on single particle ignition behavior of biomass fuels

Cited by 68 publications

References 13 publications

Vaporization model for arsenic during single-particle coal combustion: Model development

Vaporization model for arsenic during single-particle coal combustion: Model development

Flame structures and ignition characteristics of torrefied and raw sewage sludge particles at rapid heating rates

Study of the Properties and Particulate Matter Content of the Gas from the Innovative Pilot-Scale Gasification Installation with Integrated Ceramic Filter

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