Preface
xix
and (3) large growth in waste conversion industry to generate biogas that
can also be reformed to produce hydrogen. In sum, the role of steam to
produce hydrogen will significantly increase in outgoing years.
3. Role of water as a reactant, a reaction medium, and a catalyst
Recent developments showing the significant changes in the properties of water
at elevated temperatures and pressures have galvanized a significant amount
of R&D in making synthetic solid, liquid, and gaseous fuels from a variety
of feedstock using water. At elevated temperatures and pressures, water possesses unique organic, liquid-like properties. The hydrothermal processes at
high temperatures and pressures accelerate the conversion of biomass to more
coal-like solids, oil-like liquids (biocrudes), and gases containing methane and
hydrogen. This technology has a very bright and growing future.
Water has also been used as a medium to carry out the catalytic aqueousphase reforming of selective carbohydrates to produce hydrogen, syngas,
alkanes, and other monofunctional products that can be further upgraded
to produce a variety of fuels, fuel additives, and chemicals. This selective
catalytic process has resulted in the birth of a new “Bioforming process,”
which also has a significant growth potential.
There have been other interesting developments in the use of water as
a reactant. The acid-catalyzed hydrolysis has been successfully used to
produce active and versatile chemicals such as levulinic acid, furfural,
gamma-valerolactone from cellulose, and carbohydrates. These chemicals
can provide platforms for many fuels, fuel additives, and useful chemicals.
This technology has a bright future and has resulted in the development of
the “Biofine process.”
Anaerobic digestion of waste to produce hydrogen and methane has been
practiced for a long time. This is one of the most efficient energy conversion
processes. An increase in waste production worldwide (e.g., municipal solid
waste that will reach close to one billion tons per year in few years) will
increase the application of this process. Water is an important part of this
biochemical process.
The use of water in hydrolysis and fermentation processes will also grow
significantly as more emphasis on conversion of lignocellulose to ethanol and
higher alcohols is mandated all over the world. The production of ethanol will
significantly grow and increase the role of water in the fermentation industry.
4. Role of supercritical water in the production of synthetic fuels
Since the late 1970s, the use of supercritical water to convert all carbonaceous materials to synthetic fuels and chemicals has been rapidly increasing. Supercritical water possesses some very unique properties, which allow
easy conversion of many carbon-based feedstock to liquid fuels, methane,
and hydrogen. In recent years, this technology has been widely exploited to
produce hydrogen. The growth in this technology will be accompanied by
a significant growth in the use of water.
5. Role of water as a direct source for fuels and energy
Hydrogen can be generated by water dissociation. This subject has been
very heavily researched in recent years. Technologies such as electrolysis,
xix
and (3) large growth in waste conversion industry to generate biogas that
can also be reformed to produce hydrogen. In sum, the role of steam to
produce hydrogen will significantly increase in outgoing years.
3. Role of water as a reactant, a reaction medium, and a catalyst
Recent developments showing the significant changes in the properties of water
at elevated temperatures and pressures have galvanized a significant amount
of R&D in making synthetic solid, liquid, and gaseous fuels from a variety
of feedstock using water. At elevated temperatures and pressures, water possesses unique organic, liquid-like properties. The hydrothermal processes at
high temperatures and pressures accelerate the conversion of biomass to more
coal-like solids, oil-like liquids (biocrudes), and gases containing methane and
hydrogen. This technology has a very bright and growing future.
Water has also been used as a medium to carry out the catalytic aqueousphase reforming of selective carbohydrates to produce hydrogen, syngas,
alkanes, and other monofunctional products that can be further upgraded
to produce a variety of fuels, fuel additives, and chemicals. This selective
catalytic process has resulted in the birth of a new “Bioforming process,”
which also has a significant growth potential.
There have been other interesting developments in the use of water as
a reactant. The acid-catalyzed hydrolysis has been successfully used to
produce active and versatile chemicals such as levulinic acid, furfural,
gamma-valerolactone from cellulose, and carbohydrates. These chemicals
can provide platforms for many fuels, fuel additives, and useful chemicals.
This technology has a bright future and has resulted in the development of
the “Biofine process.”
Anaerobic digestion of waste to produce hydrogen and methane has been
practiced for a long time. This is one of the most efficient energy conversion
processes. An increase in waste production worldwide (e.g., municipal solid
waste that will reach close to one billion tons per year in few years) will
increase the application of this process. Water is an important part of this
biochemical process.
The use of water in hydrolysis and fermentation processes will also grow
significantly as more emphasis on conversion of lignocellulose to ethanol and
higher alcohols is mandated all over the world. The production of ethanol will
significantly grow and increase the role of water in the fermentation industry.
4. Role of supercritical water in the production of synthetic fuels
Since the late 1970s, the use of supercritical water to convert all carbonaceous materials to synthetic fuels and chemicals has been rapidly increasing. Supercritical water possesses some very unique properties, which allow
easy conversion of many carbon-based feedstock to liquid fuels, methane,
and hydrogen. In recent years, this technology has been widely exploited to
produce hydrogen. The growth in this technology will be accompanied by
a significant growth in the use of water.
5. Role of water as a direct source for fuels and energy
Hydrogen can be generated by water dissociation. This subject has been
very heavily researched in recent years. Technologies such as electrolysis,