The pyrolysis of pulverized coal takes only a few hundred milliseconds, and the coal combustion/pyrolysis process produces carbon black quickly. The formation of carbon black particles mainly includes their initial nucleation, growth process, fusion, and polymerization [7]. The coal tar generated by the primary pyrolysis of coal contains a ...
The crushed coal particles with the size of 12 mm were selected as feedstock. The results of the proximate analysis and the ultimate analysis of bituminous coal are shown in Table N 2 gas and the simulated fuel gas were used as fluidizing gas. According to previous research results (Ni et al., 2014), the main components of the fuel gas released from the coal pyrolysis in the fluidized ...
The pyrolysis characteristics of Shenmu coal under an atmosphere containing H2 (40%) and another containing CH4 (40%) were studied via a thermogravimetric analysis, and the kinetic parameters of pyrolysis were calculated by using a distributed activation energy model (DAEM). The results showed that H2 promoted the cleavage of CHlike functional groups by providing reactive hydrogen groups to ...
Pyrolysis is an effective and mild coal conversion process. The polygeneration technology based on coal pyrolysis can produce many valuable products such as highcalori c pyrolysis gas, upgraded coal tar, and clean solid fuel char or coke, which will realize multilevel efficient utilization of coal,2 The
As a comprehensive description of the functional groups effect on various volatile products during coal pyrolysis process, it is found that both alkyl and oxygencontaining groups can reduce the BDEs of the bridge bonds between aromatic rings during pyrolysis process, and the effect of oxygencontaining groups is more obvious. ...
The complexity of coal combustion has made more researchers divide the combustion process into two stages: pyrolysis and late combustion. Up to now, many studies have been done on transformation behavior of nitrogen during coal pyrolysis [16], [17] and occurrence state and content of nitrogen in coal [18] .
This technology builds upon decades of experience with gasification of coal. Both approaches have the potential advantages of being relatively insensitive to feedstock type, both suffer from production of unwanted byproducts. ... Slow pyrolysis is a conventional pyrolysis process whereby the heating rate is kept slow (approximately oC/s ...
During the actual pyrolysis process, the physicochemical structure of coal will be decomposed with the generation of products, such as tar, char, and gaseous compounds [21], [22].Generally, the coal pyrolysis process consists of primary devolatilization reactions and subsequent secondary reactions [23], [24].In this work, to combine the mass transfer with pyrolysis kinetics more conveniently ...
The coal samples were pulverized, grounded and sieved to a particle size of less than 75 μm before storing in a desiccator for use. The property analyses of the coals were shown in Table 1. TGA and TGMS experiments. Pyrolysis of the coals was conducted with a TG (50H, Shimadzu, Japan). In. Characterization of coals
aims to combine the conversion of biowaste and biomethanethrough innovative catalysed pyrolysis with chemical leaching, to fully convert biowaste into green hydrogen and biocoal, and recover critical (inorganic) raw materials. The result of the process is a material to be used in steelmaking as a substitute forfossil coke,
Pyrolysis, which is the initial stage of the coal conversion process, is a significant approach to realize efficient coal resource utilization. Current research on the mechanism of the coal pyrolysis reaction primarily focuses on aspects such as the generation law of pyrolysis products [6], evolution characteristics of the chemical structure [7 ...
N 2 is an important nitrogencontaining product in the process of coal pyrolysis, and understanding its formation mechanism is crucial to control NO x emissions in coal combustion. In this paper, the pyrrolepyridine dinitrogen structure and dipyridine nitrogen structure were selected as the carbonaceous surfaces to investigate effect of different nitrogen forms on N 2 production.
Also, we investigate the catalytic activity of the catalysts in coal pyrolysis process. 2 Methodology and Experiments. Preparation of NiCo Ternary Molten Salt Crystal Catalysts. The molten salt crystal synthesis method has been proposed by Rockwell International Corporation in 1965 . And it is an efficient method for the preparation of ...
(1), where m 0, m t were the initial mass of coal and the mass at a given time during the pyrolysis process, respectively. And m ∞ was the final mass of coal sample when the pyrolysis process was completed. (1) α = m 0m t m 0m ∞. The heating rate β was defined as Eq. (2). (2) β = d T d t
From the perspective of coal chemistry, the evolution behavior of inorganic minerals in coal has an obvious impact on the operating parameters and stability of the coal thermal conversion process. Coal pyrolysis is a key step and an important component of thermal transformation, in which minerals become important factors affecting the process ...
the yield of pyrolysis products. Jiang et al. investigated an integrated process of coal pyrolysis with steam reforming of propane (CPSRP) to improve tar yield using Ni/Al2O3 as a reforming catalyst [15]. The results suggested that the CPSRP and the integrated coal pyrolysis with steam reforming of methane (CPSRM) or methane with a few propane
The pyrolysis of coal is a good method for producing liquid fuels and other chemicals; however, the yields of these products are limited due to low content of hydrogen in coal. Hydropyrolysis, a pyrolysis process under hydrogen, is an effective method to improve tar yield and quality, but high cost of pure hydrogen hinders its industrial ...
The generating rule of H 2 O(g) in coal oxidation and pyrolysis process was similar, probably due to evaporation. All of the output of gas production led to coal mass loss, and CO 2 gas played an important role. Accordingly, we inferred that the intensity of composite reaction between coal and oxygen was stronger than a chemical reaction could ...
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. The word is coined from the Greekderived elements pyro "fire", ... Typical organic products obtained by pyrolysis of coal (X = CH, N).
The pyrolysis process consists of a very complex set of reactions involving the formation of radicals. The overall decomposition of coal is open to manipulation by a variety of experimental conditions. Due to the nature of the coal conversion processes distinction should be made between slow Cheating rate < 1 K/s) and rapid Cheating rate > 1000 ...
In this study, coal fly ash was functionalized, using a simple onestep process (loading with Al3+ and sulfonation), to yield a solid acid catalyst (S/AlCFA) with strong acid sites. The catalyst was then used to produce furfural from xylose in a biphasic system (H2O(NaCl)/tetrahydrofuran). The furfural yield reached 82% at 180 °C60 min with catalyst/xylose ratio of : (w/w).
More importantly, during the pyrolysis process of 3560 mesh coal, the largest amount of coalchar and the smallest amount of coaltar are not only obtained, but highquality syngas is also obtained. Through the characterization of coaltar, it is found that coaltar is mainly composed of aromatic compounds, and the content can reach more ...
The purpose of this paper was to explore the relationship between the volatilization of arsenic and sulfur during the pyrolysis process. The study covered pyrolysis of three coals with different arsenic and sulfur contents under different temperatures. The mode of occurrence of sulfur and arsenic in coal were determined respectively.
Depolymerization of coal increases the tar yield in coal pyrolysis and enhances the thermoplasticity of the coal, which makes coal more favorable for producing coke and other valueadded products like graphite electrodes, carbon fiber, aromatic chemicals, etc. In this study, the authors have proposed a novel coal depolymerization method that combines the oxidation reactions by molecular oxygen ...
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