Catalytic pyrolysis of central German lignite in a semi-continuous rotary kiln — Performance of pulverized one-way ZSM-5 catalyst and ZSM-5-coated beads

Appelt, Jörn; Heschel, Wolfgang; Meyer, Bernd

doi:10.1016/j.fuproc.2015.12.004

Cited by 12 publications

(8 citation statements)

References 17 publications

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“…Appelt et al concluded the protolytic mechanisms during CF of central German lignite over HZSM-5. In this process, increasing catalyst/coal ratios could cause an increase in the alkene structures of the gaseous and liquid reaction products.…”

Section: Fundamental Reaction Mechanismsmentioning

confidence: 99%

“…Pyrolysis volatiles with an aliphatic structure liberated thermally from lignite can react over zeolite. However, only linear and methyl-branched hydrocarbons can pass through the small pores of the HZSM-5 framework. , Additionally, the dissociation reaction precedes a carbenium ion mechanism and a monomolecular scission. Thus, it is not possible for the formation of alkanes via alkenes through a bimolecular process and hydride abstraction as a result of bulky intermediates. , The dissociation reactions are limited to β-scission reactions, whereby low-branched alkenes are adsorbed to Brønsted acid sites.…”

Section: Fundamental Reaction Mechanismsmentioning

confidence: 99%

“…In addition, the presence of metal−Co could provide more hydrogen available to fix the aromatic ring fragments and the small molecular hydrocarbons. Appelt et al 350 concluded the protolytic mechanisms during CF of central German lignite over HZSM-5. In this process, increasing catalyst/coal ratios could cause an increase in the alkene structures of the gaseous and liquid reaction products.…”

Section: Fundamental Reaction Mechanismsmentioning

confidence: 99%

“…However, only linear and methyl-branched hydrocarbons can pass through the small pores of the HZSM-5 framework. 350,351 Additionally, the dissociation reaction precedes a carbenium ion mechanism and a monomolecular scission. Thus, it is not possible for the formation of alkanes via alkenes through a bimolecular process and hydride abstraction as a result of bulky intermediates.…”

Section: Fundamental Reaction Mechanismsmentioning

confidence: 99%

“…Herein, several major breakthroughs are cited in Table 12. Appelt et al 350 performed CP of lignite in the pyrolysis reactor setup consisting of a rotary kiln (tube, dint = 130 mm, l = 2000 mm, and maximum of 10 rpm; kiln, maximum of 10 kW), a feeding unit, and units for product sampling and postcombustion of pyrolysis gas. The reactor could hold the CP of 1 kg of moisture-and ash-free coal assisted by 8.1 kg of ZSM-5coated beads, achieving a higher yield of alkenes and BTEX around 500 °C.…”

Section: Applicationsmentioning

confidence: 99%

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Catalytic Conversion of Coal and Biomass Volatiles: A Review

et al. 2020

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This paper presents a review of recent research on direct upgrading of coal/biomass volatiles into aromatics by catalytic pyrolysis and syngas by gasification with catalytic steam reforming. Coal/biomass valorization is considered an important part to fill up the depletion of modern fossil fuel resources. The catalytic pyrolysis process is a potential approach to improve coal tar/bio-oil quality by minimizing its undesirable properties (high viscosity, corrosivity, instability, etc.) and producing renewable fuels and high-value chemicals, such as aromatics (benzene, toluene, ethylbenzene, xylenes, etc.). Gasification reforming as a promising process for renewable energy utilization can produce H2-rich syngas. The produced syngas can be further synthesized to fuel and chemicals via Fischer–Tropsch synthesis. Thus, this study provides a comprehensive review of the research and development of conversion of coal and biomass volatiles in terms of technological types and catalysts. Aspects related to upgrading technology, the reactor type of catalytic pyrolysis and gasification, and the reaction mechanisms to specific products during the catalytic process are also discussed comprehensively. In particular, catalytic upgrading by fast pyrolysis involves a series of reactions, including deoxygenation, cracking, hydrocarbon pool mechanism, aromatization, and condensation, as well as desulfurization and denitrification in the gasification process. Some key points that are to be addressed for the established process of coal and biomass volatile upgrading may include finding multifunctional catalysts and reactor development for improving the efficiency. Expanding and enhancing knowledge about catalyst utilization and fundamental reaction mechanisms in the thermochemical catalytic conversion technologies of coal and biomass will play an important role in the generation of chemicals and carbon-neutral fuels.

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Section: Fundamental Reaction Mechanismsmentioning

confidence: 99%