PYROLYTIC BEHAVIOUR OF SWITCHGRASS BIOMASS FROM DIFFERENT CYTOTYPES AND CUTTING SYSTEM

摘要

Analytical pyrolysis was applied to investigate the composition of pyrolysate from seven switchgrasssamples differing in cytotype and cutting systems. The content of ash in original samples ranged from 3.2 to 6.4%,cellulose from 31 to 44% , lignin from 3.5 to 8.7%. Pyrolyses were conducted at 700 ℃ with a microscale pyrolysisapparatus (pyroprobe) and evolved products were analysed by GC-MS (lignin phenols, C5-C6 carbohydratefragments), GC-MS after trimethylsilylation (levoglucosan) and GC-FID (acetic acid, propionic acid, acetol).Pyrolysates of all the samples were dominated by acetic acid (3.7-5.2%), acetol, 0.9-1.5%, 4-vinylphenol (0.3-1.2%),4-vinylguaiacol (0.2-0.5%) and levoglucosan (0.2-2%). Yields of total quantified products (18 compounds) rangedfrom 7 to 11% and tended to increase with increasing lignocellulose and decreasing ash content.