Biomedical Engineering Reference
In-Depth Information
design, processing, and production of biomass products. The production process for
biomass product engineering refers to the biomass feedstock refining process that
aims at the desired product function and utilizes one or more functional molecules in
the biomass feedstock to design the corresponding product, which is the selectively
structural fractionation process of biomass feedstock.
4.5.2
Status Analysis of Selectively Structural
Fractionation Technology
4.5.2.1
Product Engineering of Biomass
Lignocellulosic raw materials are functional supramolecular structures interwo-
ven by the cellulose, hemicellulose, and lignin. The multicomponent structure
determines the diversification of the biomass-based products throughout bio-based
energy, materials, and chemicals and other fields.
First, biomass energy products such as fuel ethanol, biodiesel, and pyrolysis
bio-oil are booming. Ethanol mixed with a certain percentage of gasoline can be
used as a gasoline engine fuel, and the engine need not be changed if less than
25 % ethanol content is used. The ethanol has a larger octane value than gasoline
and contains oxygen; it is both antiknock and an accelerant. Raw materials for
fuel ethanol include starch (such as corn), sugar feedstock (such as sucrose), and
lignocellulose (such as straw) and are currently dominated by the starch and sugar
feedstock. Lignocellulose to produce fuel ethanol is technically feasible but has not
broken through the economic costs. In the long term, by the limitations of starch
and sugar feedstock production, the use of lignocellulose materials to produce fuel
ethanol is the ultimate goal [
55
]. Biodiesel is the fatty acid methyl esters derived
from animal, plant, or microbial oil and methanol by a methyl esterification reaction;
it can completely replace fossil diesel oil directly used as diesel fuel. With the
advantages of low sulfur content, biodegradability, and environmental friendliness,
it has received much attention. At present, biodiesel production technology is mature
and has achieved industrialization, but the problem is the lack of an abundant lipid
source and high production costs. The price makes it difficult to compete with fossil
diesel fuel. Hence, finding new sources of oil and the development of efficient low-
cost lipase and clean and efficient catalyst are the focus for current study [
56
-
58
].
Pyrolysis bio-oil is a liquid fuel from biomass using the thermochemical conversion
method. The thermochemical process is rapid and efficient, but the pyrolysis bio-oil
composition is complex, low quality, and unstable, so there are many issues that
need to be solved [
59
]. The use of biomass energy products not only can reduce the
dependence on fossil fuels, but also, because of the characteristics of zero emissions
of carbon dioxide in its life cycle, can slow the “greenhouse effect” caused by the
increase of atmospheric carbon dioxide.
