title: Effects of torrefaction and densification on switchgrass pyrolysis products.
abstract: The pyrolysis behaviors of four types of pretreated switchgrass (torrefied at 230 and 270°C, densification, and torrefaction at 270°C followed by densification) were studied at three temperatures (500, 600, 700°C) using a pyroprobe attached to a gas chromatogram mass spectroscopy (Py-GC/MS). The torrefaction of switchgrass improved its oxygen to carbon ratio and energy content. Contents of anhydrous sugars and phenols in pyrolysis products of torrefied switchgrass were higher than those in pyrolysis products of raw switchgrass. As the torrefaction temperature increased from 230 to 270°C, the contents of anhydrous sugars and phenols in pyrolysis products increased whereas content of guaiacols decreased. High pyrolysis temperature (600 and 700°C as compared to 500°C) enhanced decomposition of lignin and anhydrous sugars, leading to increase in phenols, aromatics and furans. Densification enhanced depolymerization of cellulose and hemicellulose during pyrolysis.
authors.affiliation: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Zixu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Madhura
authors.initials: M
authors.lastname: Sarkar
authors.affiliation: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA. Electronic address: ajay.kumar@okstate.edu.
authors.forename: Ajay
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Biofuels and Renewable Energy Technology Department, Idaho National Laboratory, 750 University Blvd, Idaho Falls, ID, USA.
authors.forename: Jaya Shankar
authors.initials: JS
authors.lastname: Tumuluru
authors.affiliation: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Huhnke
mesh_terms: D001709:Biotechnology / Q000379:methods*; D006358:Hot Temperature; D008897:Panicum / Q000378:metabolism*
keywords: Densification; Py-GC/MS; Pyrolysis; Switchgrass; Torrefaction