Use of carbonium ion scavengers in the hot water pretreatment of spruce wood
Monday, April 28, 2014: 2:45 PM
Grand Ballroom D-E, lobby level (Hilton Clearwater Beach)
Thomas Pielhop1, Michael Studer2 and Philipp Rudolf von Rohr1, (1)Insitute of Process Engineering, ETH Zurich, Zurich, Switzerland, (2)School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Zollikofen, Switzerland
Autohydrolysis pretreatments of lignocellulosic biomass like liquid hot water and steam pretreatment are attractive pretreatment methods regarding cost-savings potential. However, repolymerisation reactions of lignin fragments via carbonium ions, which are formed in autohydrolysis processes, hinder the disintegration of the wood structure [1].

We could show that the enzymatic saccharification following a hot water pretreatment of lignocellulosic biomass was enhanced by the use of carbonium ion scavengers. Spruce wood underwent a hot water pretreatment with 2% w/w (based on raw dry biomass) of 2-naphtol, which can act as a carbonium ion scavenger for lignin fragments. In the subsequent enzymatic hydrolysis of the cellulose, the glucose yield could be increased up to 46% compared to the control. We assume that the suppression of lignin recondensation reactions enhanced the digestibility of the cellulose. As a proof of concept, it was shown that crossing agents for lignin fragments in the pretreatment like resorcinol decreased sugar yields [2].

The influence of several pretreatment parameters (severity, scavenger loading, biomass particle size) and a range of potential carbonium ion scavengers (e.g. alcohols, amines) have been studied. Current research focuses on transferring the technology from hot-water to steam (explosion) treatment, which is of more commercial relevance. Results from these studies will be presented.


[1]  Wayman, M., Lora, J. H.: Aspen autohydrolysis - The effects of 2-naphtol and other aromatic compounds. Tappi 61(6): 55-57 (1978).

[2]  Pielhop, T., Studer, M., Rudolf von Rohr, P.: Use of carbonium ion scavengers in the treatment of lignocellulosic biomass. Vol. WO/2013/068092