کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5204339 | 1381958 | 2007 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Flame retarding of wood by impregnation with boric acid - Pyrolysis products and char oxidation rates Flame retarding of wood by impregnation with boric acid - Pyrolysis products and char oxidation rates](/preview/png/5204339.png)
The pyrolysis of fir wood impregnated with boric acid (0-5.4%) has been investigated for heating temperatures of 650 and 800Â K by examining the yields of char, water, permanent gases (CO2, CO, CH4) and total organic products (together with 32 compounds). The yields of the last product class continuously decrease to the advantage of char and water, but the most significant modifications occur for acid contents below 2%. The formation of levoglucosan (with 2-acetylfuran, 5-methyl-2-furaldehyde and other minor species) first and levoglucosenone (with 2-furaldehyde) afterwards is favoured, whereas other compounds generated from the holocellulosic (hydroxyacetaldehyde, hydroxypropanone, acetic acid and minor carbohydrates) and lignin (phenols, cresols) fractions generally decline. Conversion times become longer and volatilization rates are reduced. The oxidation characteristics of char have been studied by means of thermogravimetric analysis and interpreted according to a three-step reaction mechanism. The boric acid treatment lowers the activation energy and reaction order of the most important step (145 versus 226Â kJ/mol and 1.2 versus 0.86, respectively) which also shows lower rates and is slightly delayed.
Journal: Polymer Degradation and Stability - Volume 92, Issue 5, May 2007, Pages 752-764