Impacts of Organic Structures and Inherent Minerals of Coal on Soot Formation during Pyrolysis

Abstract

The pyrolysis of four pairs of raw and acid-washed coals under N2 atmosphere was carried out in a drop tube reactor at 1250 °C. The results show that both organic structures and metal elements have an important influence on the formation of soot. The total area of aromatic and aliphatic hydrogen absorption bands is positively correlated with soot yield. Aromatic compounds have a greater contribution to soot and tar formation. The absorption band area of oxygen structures in coal FTIR spectra is negatively correlated with the soot conversion rate of tar. During pyrolysis, metal substances in coal can catalyze the dehydrogenation and deoxygenation of tar, reduce the content and stability of the aliphatic compound, and catalyze aromatic ring rupturing. More importantly, gasified metals can inhibit the polymerization reaction of aromatic compounds.

Simulation of Turbulent Combustion in a Large Pulverized Coal Boiler Based on Turbulent Radiation Interaction and the Modified Soot Model

“…In this process, the evolution of soot includes nucleation, agglomeration, surface growth, and oxidation processes. 40 From the primary product of coal combustion, the small-molecule PAH begins to condense into a nucleus as initial soot, after which the main gas-phase PAH attached to the soot grows and then undergoes collision agglomeration and oxidation in OH and O. Saggese 41 research shows that nucleation is mainly a small-molecule benzene ring. Depending on CPD calculation, we assume that the precursor X prec generated by soot is the benzene ring C 6 H 6 .…”

“…Because of the lack of oxygen in this area, a large amount of tar will be quickly converted to soot. In this process, the evolution of soot includes nucleation, agglomeration, surface growth, and oxidation processes . From the primary product of coal combustion, the small-molecule PAH begins to condense into a nucleus as initial soot, after which the main gas-phase PAH attached to the soot grows and then undergoes collision agglomeration and oxidation in OH and O. Saggese research shows that nucleation is mainly a small-molecule benzene ring.…”

Optimization of Thermal Parameters of the Coke Oven Battery by Modified Methodology of Temperature Measurement in Heating Flues as the Management Tool in the Cokemaking Industry

“…The conventional coking process involves the heat transfer of the required level through ceramic of each of the coke oven battery heating flues to a coal charge loaded in the chamber at a given time. The pyrolysis process, which occurs as a result of the coal charge temperature increase, leads to the production both hot coke and volatiles-raw gas, tar and benzol (and sometimes even soot when the coking process is not conducted properly [10]). Since the heat demand for the pyrolysis process in the subsequent intervals of the coking cycle is diversified, considering its constant supply during stable battery operation, there are consequently observed temperature changes in the heating flues.…”

Early porosity generation in organic-sulfur-rich mudstones

“…Organic porosity becomes dominant as burial diagenesis eliminates much of the primary inorganic porosity through compaction, grain re-orientation, ductile deformation [3][4][5] , and cementation 6-9 , while secondary organic porosity is created through transformation of solid kerogen and bitumen into liquid hydrocarbons [10][11][12][13][14][15][16] . Additionally, inorganic pores can be extensively occluded by solid OM when viscous bitumen and oil migrate into those pores and then undergo secondary cracking into lighter uid hydrocarbons and residual solid bitumen and pyrobitumen 13,[16][17][18][19][20][21] .…”