Effects of Acid and Organosolv Pretreatments on the Analytical Fast Pyrolysis Products of Green Coconut Fiber

The present study evaluated the effects of acid and organosolv pretreatments on the analytical fast pyrolysis products of green coconut fiber (GCF), a residue from the coconut processing industry. Untreated and pretreated biomasses were characterized by chemical composition, crystallinity, functional groups, and thermal stability. Fast pyrolysis experiments were carried out in a pyrolysis–gas chromatography-mass spectrometry (Py-GC/MS) apparatus in the absence and presence of HZSM-5 zeolite. Both pretreatments effectively removed hemicellulose, ashes, and extractives, increasing cellulose content and crystallinity. Organosolv pretreatment with glycerol also promoted the reduction of Klason lignin in GCF from 35.68 to 28.68%, while acid pretreated GCF had 45.51% Klason lignin. In pyrolysis without a catalyst, acid and organosolv pretreatments reduced the selectivity of C1-C4 compounds from 47.05% to 23.22% and 25.31%, respectively. The generation of phenol and methylphenols from GCF increased after acid and organosolv pretreatments. With the aid of HZSM-5, high benzene-toluene-ethylbenzene-xylene (BTEX) values were obtained using acid-pretreated GCF (72.0%) and organosolv-pretreated GCF (71.1%) when compared to experiments with untreated GCF (64.9%). Pyrolysis vapors from organosolv-pretreated GCF also have a low selectivity of naphthalenes (9.63%). Thus, chemical pretreatments ratified their role in improving the bio-oil, raising the GCF as an opportunity to produce phenol or monoaromatics via fast pyrolysis.