کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5134516 | 1492954 | 2017 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: On the alternating physicochemical characteristics of Colombian coal during pyrolysis On the alternating physicochemical characteristics of Colombian coal during pyrolysis](/preview/png/5134516.png)
- During coal pyrolysis aromatic compounds and hydrocarbons are released.
- ATR-IR bands show rearrangement of the char above 600 °C pyrolysis temperature.
- Increase of surface area, density and sorption capacity up to 600 °C.
- Two changes of hydrophobicity during pyrolysis.
A Colombian hard coal was stepwise pyrolyzed from 200 to 800 °C, and the resulting changes in surface and material properties were investigated by thermogravimetric analysis and volumetric adsorption techniques as well as by density, surface area, ATR-IR and GC/MS measurements. It was observed that a loss of volatile compounds occurred up to a pyrolysis temperature of 600 °C. These compounds were identified as CO, CO2 and H2O and mainly large substituted aromatic compounds and long-chain hydrocarbons. The loss of functional groups was also monitored by a decrease of related IR bands. The devolatilization was found to cause an increase in density and surface area; the adsorbed amount of CO2 and O2 increased in this temperature region as well. The char pyrolyzed at 600 °C was the only sample with a hydrophobic surface. Increasing the temperature to 800 °C led to no further mass loss, but to a structural reorganization of the char indicated by the reappearance of aromatic IR bands. This high-temperature restructuring resulted in a decrease of density, surface area and adsorbed gas amount.
Journal: Journal of Analytical and Applied Pyrolysis - Volume 123, January 2017, Pages 12-19