Plasma-assisted pretreatment of wheat straw.
O₃ generated in a plasma at atmospheric pressure and room temperature, fed with dried air (or oxygen-enriched dried air), has been used for the degradation of lignin in wheat straw to optimize the enzymatic hydrolysis and to get more fermentable sugars. A fixed bed reactor was used combined with a CO₂ detector and an online technique for O₃ measurement in the fed and exhaust gas allowing continuous measurement of the consumption of O₃. This rendered it possible for us to determine the progress of the pretreatment in real time (online analysis). The process time can be adjusted to produce wheat straw with desired lignin content because of the online analysis. The O₃ consumption of wheat straw and its polymeric components, i.e., cellulose, hemicellulose, and lignin, as well as a mixture of these, dry as well as with 50% water, were studied. Furthermore, the process parameters dry matter content and milled particle size (the extent to which the wheat straw was milled) were investigated and optimized. The developed methodology offered the advantage of a simple and relatively fast (0.5-2 h) pretreatment allowing a dry matter concentration of 45-60%. FTIR measurements did not suggest any structural effects on cellulose and hemicellulose by the O₃ treatment. The cost and the energy consumption for lignin degradation of 100 g of wheat straw were calculated.
Schultz-Jensen
Nadja
N
Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark-DTU, P.O. Box 49, 4000 Roskilde, Denmark. nasc@risoe.dtu.dk
Leipold
Frank
F
Bindslev
Henrik
H
Thomsen
Anne Belinda
AB
D056804:Biofuels; D019149:Bioreactors; D002480:Cellulase / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008031:Lignin / Q000378:metabolism; D010126:Ozone / Q000737:chemistry / Q000378:metabolism; D010316:Particle Size; D058626:Plasma Gases / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014242:Trichoderma / Q000201:enzymology; D014908:Triticum / Q000737:chemistry* / Q000378:metabolism*; D014990:Xylans / Q000378:metabolism
D056804:Biofuels; D058626:Plasma Gases; D014990:Xylans; D010126:Ozone; D008031:Lignin; D002480:Cellulase