Acetic acid production by the two-step thermal treatment of tobacco filter

Abstract

The thermolysis of waste tobacco filters (WTFs) was carried out and characterized by thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/ mass spectrometry (Py-GC/MS). The WTFs showed four distinctive derivative TG (DTG) peaks. Such distinctive DTG curves were indicative of the thermal desorption of triacetin (< 220°C), thermal desorption of glycerol tricaprylate (221–270°C), decomposition of cellulose acetate (CA, 281–400°C), and char stabilization (> 400°C). The activation energy (E<sub>a</sub>) (223–279 kcal kg<sup>-1</sup>) in the additives desorption region (220–270°C) were higher than those (169 ± 5.1 kcal kg<sup>-1</sup>) from the WTFs at the main decomposition region of CA (281–400°C). Py-GC/MS suggested that a large amount of acetic acid (AA, 33.0 wt.%) was recovered as the major pyrogenic product stemming from WTF. An increase in AA purity up to 76.2% (except for CO<sub>2</sub>) was achieved in the 2<sup>nd</sup> Py step at 400°C after eliminating the non-target chemicals (nicotine, triacetin, glycerol tricaprylate, and 2-(decanoyloxy)propane-1,3-diyl dioctanoate) through the 1<sup>st</sup> thermal desorption (TD) step to 300°C.