3.2 Effect of Hydrothermal Media
The hydrothermal media are generally called solvents, and they enhance the stability
and solubility of the depolymerized macromolecules. Under subcritical conditions,
these solvents act not as molecules but as radicals and induce the ionic reactions
[52]. In most of the cases, deionized water is used as solvent, and sometimes
Nanopure
® water having ionic purity of 18.2 MΩ was used to eliminate any effects
caused by the minerals present in tap water [46]. Few other studies [36, 40–43]
revealed that replacing a portion of water with compounds like ethanol, methanol,
acetone, and 2-propanol enhances the ionic product of the mixture yielding maximum biocrude and minimum biochar at 50:50 solvent to water ratio as shown in
Figs. 4 and 5.
3.3 Effect of Biomass to Solvent Ratio
The amount of solvent/hydrothermal media present inside the reactor is very crucial
for the process. If the quantity is very less, it enhances carbonization, and on excess it
promotes gasification of all residual materials irrespective whether it is of lignocellulosic or algal origin. Hence the biomass to solvent ratio has to be maintained
carefully. Tungal and Shende [34] explained the effect of biomass to solvent ratio on
Fig. 3 Effect of temperature on yield of hydrothermal products
Hydrothermal Conversion of Biomass into Fuel and Fine Chemicals
213
The hydrothermal media are generally called solvents, and they enhance the stability
and solubility of the depolymerized macromolecules. Under subcritical conditions,
these solvents act not as molecules but as radicals and induce the ionic reactions
[52]. In most of the cases, deionized water is used as solvent, and sometimes
Nanopure
® water having ionic purity of 18.2 MΩ was used to eliminate any effects
caused by the minerals present in tap water [46]. Few other studies [36, 40–43]
revealed that replacing a portion of water with compounds like ethanol, methanol,
acetone, and 2-propanol enhances the ionic product of the mixture yielding maximum biocrude and minimum biochar at 50:50 solvent to water ratio as shown in
Figs. 4 and 5.
3.3 Effect of Biomass to Solvent Ratio
The amount of solvent/hydrothermal media present inside the reactor is very crucial
for the process. If the quantity is very less, it enhances carbonization, and on excess it
promotes gasification of all residual materials irrespective whether it is of lignocellulosic or algal origin. Hence the biomass to solvent ratio has to be maintained
carefully. Tungal and Shende [34] explained the effect of biomass to solvent ratio on
Fig. 3 Effect of temperature on yield of hydrothermal products
Hydrothermal Conversion of Biomass into Fuel and Fine Chemicals
213