(386c) Evolving Topochemistry of Acer Saccharum Chips during Pretreatment Determined By Confocal Raman Microscopy
To this end the authors have made use of an analytical instrument finding increasing utility in the field, the confocal raman microscope (CRM). Acer sacchrum wood chips were subject to hot water pretreatment at 160o C for varying times. Samples from this treatment were transversely microtomed into 10Î¼m thick sections for analysis by CRM. This was coupled with gravimetric analyses as well as other spectroscopic techniques. Quantitative and qualitative analysis at the sub-cellular level for whole wood chips at real industrial reaction conditions is shown for the first time. A preferential de-lignification from the secondary wall to the compound middle lamella was observed. As pretreatment severity increased, it was seen that samples lost the clear delineation between morphological layers of the cell wall, becoming internally heterogeneous as compared to untreated samples. It is deduced this is due to limited mass transport capabilities within the wood chip, as previous works have shown that in non-mass transport limited scenarios the cell wall maintains its distinct, homogeneous layers. The quantitative data gained herein presents the possibility to increase our understanding of and model the physio-chemical processes occurring within the cell wall as a result of LHW and similar hydrolytic pretreatments.