Prashant Reddy

Structural characterisation of pretreated solids from flow-through liquid hot water treatment of sugarcane bagasse in a fixed-bed reactor

Untreated sugarcane bagasse and sugarcane bagasse pretreated with flow-through liquid hot water (LHW) treatment (170-207°C and 204-250 ml/min) in a fixed-bed reactor have been structurally characterised. Field emission gun scanning electron microscopy (FEG-SEM) and transmission electron microscopy (TEM) were used to investigate changes in the residues, in particular due to the fate of lignin. FEG-SEM results show that the LHW treatment modified the surface morphology of the pretreated bagasse with lignin droplets being observed on the fibre surface. TEM showed an increase in the plant cell wall porosity and lignin migration across the plant cell wall. Increases in pretreatment temperature were observed to increase the average size and density of lignin droplets on the fibre surface. The results provide evidence that for LHW flow-through treatment, just as for batch treatment, lignin repolymerisation and deposition on the surface of pretreated sugarcane bagasse is an important consideration.

Phase Equilibrium Studies on Ionic Liquid Systems for Industrial Separation Processes of Complex Organic Mixtures

Publisher Summary This chapter focuses on the application of key experimental techniques for the determination of the thermodynamic properties of ionic liquid–organic mixture to effectively screen ionic liquids as solvents in industrial separation processes. The acquisition of experimental liquid–liquid equilibria data for solvent–organic mixtures of interest is invaluable for the screening of potential solvents for liquid–liquid extraction. The measurement of partition coefficients or distribution ratios of various classes of organic solutes in an ionic liquid–water biphasic system, through the use of the shake-flask or slow-stirring methods, has been the subject of numerous investigations. The measurement of the solubility characteristics of ionic liquid–organic solute mixtures is also an active area of research. In particular, the miscibility characteristics of 1,3-dialkylimidazolium–alcohol systems has been studied by several research groups, and the studies investigated the effects of alkyl chain length on the cation, the nature of the anion, and the alkyl chain length of the alcohol to elucidate the structure–property correlations responsible for influencing the solubility behavior of ionic liquid–alcohol mixtures. Studies on ternary liquid–liquid equilibria have centered on specific challenges facing the chemical, petrochemical, pharmaceutical, and biochemical industries.