The radical mechanism of coal pyrolysis
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Due to the complexity of coal, as well as the complexity of the chemical changes that occur during coal pyrolysis, it is difficult to clearly explain the mechanism of coal pyrolysis; currently, the radical mechanism is generally preferred. Some scholars have analyzed that, within the macromolecular structure of coal, in addition to aromatic nuclei (or condensed aromatic nuclei) with high molecular weights, there are also small molecular compounds with lower molecular weights that are bound within the pores of its spatial structure, held together by hydrogen bonds, van der Waals forces, etc. Moreover, both aromatic rings and hydrogenated aromatic rings possess a considerable number of side chains ； Between the aromatic nuclei, there are also “bridge bonds” in the form of single or double bonds, forming a large network structure. In the macromolecular structure of coal, common \"bridge bonds\" include -CH2-CH2-, -CH2-, N-, -N-, =CH-, -O-, -S-, etc., among which -CH2- and -O- are the most common. During the pyrolysis of coal, these bonds break to form free radicals, which can combine with each other to form semi-coke and become inactive, or they can combine with small molecular free radicals (such as H, CH3, etc.) to form small molecular compounds that are released into the volatiles. Based on the radical mechanism, if sufficient hydrogen and small-molecule radicals such as methyl radicals are introduced from the outside to combine with the formed radicals, it should be possible to stabilize these radicals, thereby increasing the yield of low-molecular-weight compounds during the pyrolysis process. This is also one of the directions of our research; we hope to share it with everyone in our future lives and progress together. Of course, we still need to make further efforts and gather more evidence to verify the mechanism of the pyrolysis reaction, so as to provide theoretical and technical guidance for the comprehensive utilization of coal and reduce China’s dependence on foreign oil.
Coal pyrolysis… an old topic as well as a new one; why are there few replies? There must be quite a few that have been done..
Currently, there are methods to improve the coking properties of non-coking coals (such as long-flame coals) by adding a modifier; I have been wondering if this mechanism is being utilized.
Reply to 2# Dongdong: Everyone is currently busy making money and getting professional titles and such. I focus on the project that is likely to yield results more easily and quickly. When it comes to researching principles, progress is very slow, and there’s a high risk of achieving nothing at all; who would want to take the time to devote themselves patiently to such research? I hope that people with insight and capability can encourage those who engage in fundamental research.
The radical mechanism of coal pyrolysis mainly refers to the following: 1. When coal is heated, volatiles are released, resulting in many radical fragments of coal. These radical fragments are stabilized by low-molecular-weight radicals such as hydrogen radicals or methyl radicals, leading to the formation of tar and gases. Radical polymerization and polycondensation reactions then occur, producing semi-coke. 2. Thermal decomposition of tar caused by prolonged heating.
Coal chemical industry will surely flourish after the decline of petroleum resources. Dear masters, may I ask why the radical reactions in coal pyrolysis take such a long time? ?
Let’s learn *research together~:lol
Indeed, it takes too long to achieve results when working on mechanisms. But it’s necessary to do it anyway. .
Could the original poster provide some technical materials, or relevant websites? I’m really eager to learn about the latest advances in this field! Thank you first!
Thank you to the original poster; I was wondering if you could provide some more detailed information for everyone to learn from*.