Abstract:
Lignocellulosic biomass is an abundant and sustainable resource for producing biopolymers, chemicals,
biofuels, and high-value-added compounds. The primary refining processes, which includes
pretreatment, fractionation, and separation of components, as well as structural disconnection or
partial structural change, are necessary to achieve high-value utilization of lignocellulosic materials.
However, conventional pretreatment processes for biomass valorization aim to obtain high yields of
cellulose without concern for utilizing other components. Focusing on a single component of
lignocellulose is not only a waste of resources but also causes serious environmental pollution. This
study proposed a novel and efficient biomass processing concept that, for the first time, couples two
key technologies (hydrodynamic cavitation and hydrothermal separation) to enable almost all the
biomass to be used for a range of high-valued products, including biopolymers and extractives. The
conceptual design of coupling of hydrodynamic cavitation and hydrothermal separation was then
modeled and simulated to evaluate the ease of coupling in terms of component yield and overall
extraction efficiency and observed how the coupling process was affected by the process parameters
with an optimal overall extraction efficiency. The simulation results showed that the coupling of the
HC and HTS processes had a maximum of 25.5% higher overall extraction efficiency than the single HC
process and 18.2% higher efficiency than the single HTS process for woodchips. The process
parameters, including HTS temperature, HTS residence time, and S/L ratio affected component yield
and overall extraction efficiency. The maximum overall extraction efficiency was predicted by the
statistical approach of 80.20 ± 5.04% with a regression coefficient (R-sq) of 99.33% at optimal
conditions (S/L ratio 10%, HC pressure 3 bar, HC temperature 60℃, HC residence time 20 min, HTS
temperature 210 ℃, HTS residence time 25 min, and HTS pressure of 19.04 bar). The coupling of
hydrodynamic cavitation and hydrothermal separation showed better biomass utilization than the
conventional pretreatment processes. This coupled process focuses on more utilization of biomass
rather than only one yield, which will reduce the waste with minimal environmental effect and increase
the potential use of biomass from different perspectives.
