Pretreatment and Thermochemical and Biological Processing of Biomass - Introduction to Chemicals from Biomass - page 82

Table 3.5 ( Continued )

Conversion method Process conditions Major products Advantages Disadvantages

Torrefaction Inert atmosphere at temperatures

between 200 and 300°C
Microwave torrefaction
Temperature: >350°C;
in the frequency band of 300 MHz to
300 GHz

Torrefied biomass
with increased
energy density
Microwave
torrefaction
Bio-oil, gas, and
charcoal

Mild condition Limited availability of microwave

apparatus and at extremely high cost;
the microwaves can be reflected,
absorbed and/or transmitted by the
material before reaching the biomass

Fermentation Fermentation temperature at 20-30°C;

treatment period for about a weeks;
medium with around 30 g L -1 glucose
and 1.5 g L -1 nitrogen source for
example yeast extract

Chemicals,
biofuels,
biopolymers

Low energy requirement;
wide range of chemicals
can be produced

Long conversion time;
labor intensive

AD Oxygen depleted environment;

C/N ratio of feedstock: 15-30

Biogas Low energy requirement;

capable of processing a
wide range of biomass;
power generation from
biogas combustion

Methane yield depends on substrate;
require downstream processes to
upgrade biogas