Investigation of Agricultural Biomass Residues in Liquefaction Process

Abstract

The use of agricultural biomass residues as an alternative of fossil derivatives have been extensively investigated in the last years due to environmental concerns. In this context, the liquefaction appears as an alternative to use these renewable sources to produce green materials. The present work aims to synthesize polyols from the cassava peels (CP), lemon bagasse (LB) and rice husk (RH) in order to obtain biopolyols suitable to produce polyurethane foams and add value to these residues. Besides the production of the green foams, this work has also the objective to evaluate how composition of the biomass (e.g.: solid, lignin and holocellulose content) can be related to the process yield and the characteristics of the biopolyol (e.g: hydroxyl number). The polyols were synthesized from the biomass liquefaction, using crude glycerol as solvent (a by-product of biodiesel industry) and sulfuric acid as catalyst. The liquefaction was performed using an autoclave, operated at 125 °C and 1.84 atm. Liquefaction yield varied from 38 to 91 %, according to biomass and process parameters used. It was observed that CP, which has the higher volatile solids content and the lower lignin plus holocellulose content, had the higher liquefaction yield. Polyol's hydroxyl number from RH had the lowest values and lower variation, according to process parameters. Liquefaction yield and hydroxyl number from LB presented great response to process parameters used.

Numerical and Experimental Analysis of Thermochemical Treatment for the Liquefaction of Lemon Bagasse in a Jacketed Vessel

“…From this time, it can be observed that the behaviour of Polyol 1 and 2, started being similar to Polyol 3 (and crude glycerol). Although the polyols have higher density and viscosity compared to crude glycerol [23], the heat changes the fluid properties, which may favour the heat transfer by conduction and natural convection.…”