At-Line Sampling and Characterization of Pyrolytic Vapors from Biomass Feedstock Blends Using SPME-GC/MS-PCA: Influence of Char on Fast Pyrolysis

Abstract

Solid-phase microextraction (SPME) coupled with gas chromatography−mass spectrometry (GC−MS) analysis was used for the at-line sampling of pyrolytic vapors produced during the fast pyrolysis of biomass. The pure and binary blends of switchgrass (SWG) and pine harvest residues (PT6) were used as biomass feedstocks. Sequential SPME sampling allowed for monitoring of changes in the pyrolysis vapors as char accumulated in the fluid bed. The relative concentration and composition of the pyrolysis vapors desorbed from the SPME fibers were investigated using GC−MS, and the resulting chromatograms were analyzed using principal component analysis (PCA) to compare the composition of the pyrolysis vapors over the course of the pyrolysis run. The chemical compositions of both carbohydrate and lignin fragments varied as the char builds up in the reactor bed. Fragments derived from cellulose and hemicelluloses included anhydrosugars, furans, and light-oxygenated compounds. Lignin fragments included methoxyphenols, phenolic ketones, aldehydes, and low-molecular-weight aromatics. The composition of the carbohydrate fragments changed more than those of the lignin fragments as the char built up in the fluid bed. This combination of SPME-GC/MS-PCA was a novel, easy, and effective method for measuring the composition and changes in the composition of pyrolysis vapors during the fast pyrolysis process. This work also highlighted the effect of char build-up on the composition of the overall pyrolysis vapors.

Involvement of Cooking Oils in Hydrothermal Carbonization of Food Waste

“…Food waste is generated by almost every person on earth on a daily basis, an annual output of 1.3 billion tons, which accounts for almost 1/3 of the urban waste. , Food waste contains nutrients and generally abundant moisture, serving as a culture medium for microorganisms, which creates unpleasant odors and other environmental issues. , Direct disposal of food waste is a waste of chemical energy and material value, as food waste is a carbonaceous material. It can be further utilized as a feedstock for production of fuel and functional materials via thermochemical routes such as hydrothermal carbonization (HTC), , pyrolysis, , activation, , etc.…”

“…3,4 Direct disposal of food waste is a waste of chemical energy and material value, as food waste is a carbonaceous material. It can be further utilized as a feedstock for production of fuel and functional materials via thermochemical routes such as hydrothermal carbonization (HTC), 5,6 pyrolysis, 7,8 activation, 9,10 etc.…”