Monosaccharide Recovery from Peat and Peatified Wood by Ultrasonication Pretreatment and Hydrothermal Treatment

Moriyasu Nonaka,Satoshi Kumagai,Tsuyoshi Hirajima

doi:10.4236/ijcce.2017.62003

Abstract

Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.

Highlights

Peat is present in vast swamps in tropical rainforests and is presumed an extensive low-quality carbonaceous resource with the estimated occupation area of 16.5 - 27 million hectares in Indonesia alone [1]
Xylose is mainly a hydrolysis product from hemicellulose. These monosaccharides in the liquid phase decompose further into organic acids. These successive hydrothermal reactions seem to occur in a short time, because organic acids are always detected with monosaccharides
For peat, 15% of cellulose is extracted as glucose while approximately 40% of the total is recovered as monosaccharides, and approximately 15% of the total carbohydrate content is further transformed to organic acids

Summary

Introduction

Peat is present in vast swamps in tropical rainforests and is presumed an extensive low-quality carbonaceous resource with the estimated occupation area of 16.5 - 27 million hectares in Indonesia alone [1]. Mursito et al demonstrated the potential of hydrothermal treatment as a technique for recovering valuable chemicals, combustible gases, and high-calorie solid fuels from peat [2]. They showed the existence of the biomass components of cellulose and hemicellulose in raw peat through a nuclear magnetic resonance (NMR) spectroscopic study [3]. These carbohydrates have attracted attention as sources of sugars. Our efforts focused on the recovery of monosaccharides from peat and peatified wood by hydrothermal treatment and the facilitation of monosaccharide recovery by ultrasonic irradiation pretreatment

Experimental

Results and Discussion

Conclusion