Biomedical Engineering Reference
In-Depth Information
but also increase the difficulty of cellulase hydrolysis, which have an impact on
the concentration and purity of hydrolysate, making the consequent biotransfor-
mation process more difficult and reducing effectiveness.
4. Product-coupled recycling is insufficient, and energy consumption is too large.
5. Just the simple combination of the existing conventional techniques with equip-
ments, lacking of systematic and optimum engineering researches.
In summary, the key scientific issue for the development of the biomass-
refining industry is establishing a lignocellulosic biomass-refining process for a new
generation of biological and chemical industries to achieve cost-effective conversion
of the biomass and biorefining industry. The fundamental reason is that the biomass
conversion process is a systematic project; relying on a single discipline or single
technology makes it difficult to achieve high-value utilization of biomass. It is nec-
essary to develop key innovative processes and technology platforms for biomass. In
addition, long-term and short-term goals must be combined to stabilize the current
biomass utilization industry with natural lignocellulose as a raw material to further
improve technologies, such as clean technology for papermaking, straw protein feed
production technology, and the application of cellulase in all relevant industries.
The long-term goals, such as new clean energy and raw materials for biochemical
engineering, will be achieved based on industrial-scale short-term goals.
1.4.3
Enzymes: The Key to Open the Biomass Resource
Treasure
The utilization of plant resources needs to convert macromolecules such as starch,
cellulose, hemicellulose, lignin, and the like into low molecular weight substances
such as glucose for use as the raw materials for fuel and organic chemical engi-
neering industries. The research methods include physical, chemical, and biological
transformation.
Regarding physical and chemical methods, macromolecular components such
as cellulose and lignin are degraded into low molecular weight hydrocarbons,
flammable gases, and liquids by pyrolysis, fractionation, redox degradation, hydrol-
ysis, and acid hydrolysis, which can be used directly or after the separation and
purification as raw materials for the energy or chemical industries. Generally,
these methods have disadvantages such as high energy consumption, low yield,
and serious pollution. Therefore, they are usually used as auxiliary means of
biotransformation because of lack of practicality when used alone.
The bioconversion method degrades lignocellulose into glucose biologically and
then converts the latter into a variety of chemicals. Enzymes play a key role in a
variety of conversion processes, such as the degradation of starch and cellulose into
glucose, which is carried out successfully using amylase and cellulase, respectively.
Then, glucose is further converted into various chemical products depending on a
variety of microorganisms under the effects of different types of enzymes within the
cells.
