Environmental Engineering Reference
production. In order to derive a stable and cost-effective approach, a greater fun-
damental understanding is needed of the exact effects of these processes on plant
anatomy. These are difficult experiments to conduct and in Chapter 1 “Heat and
Mass Transport in Processing of Lignocellulosic Biomass for Fuels and Chemicals”,
Viamajala et al. provide an in-depth report on the effects of heat and mass
transport on the efficiency of biomass conversion. Further, Wu et al. in Chapter 2
“Biofuels from Lignocellulosic Biomass”, give the matter a more detailed consider-
ation by comparing thermochemical and biochemical approaches to the production
of biofuel from lignocellulosic biomass.
As compared to gas and oil, relatively greater potential reserves exist for both
coal and uranium (probably on the order of a century) but neither is renewable and
each is associated with its own environmental conundrum (carbon release and waste
storage, respectively). Linus Pauling expressed a particular concern for the destruc-
tion of the element uranium, saying “In a thousand or ten thousand years the world
may require uranium for a purpose about which we are currently ignorant.” .
Looking beyond the immediate temporal horizon, we are unavoidably confronted
with the need to develop permanently renewable sources of energy.
Earth's most plentiful and renewable energy resources typically include sunlight,
wind, geothermal heat, water (rivers, tides and waves), and biomass. All of these are
suitable for the generation of electricity but biomass is the current main renewable
feedstock for the production of “liquid” fuels - typically ethanol, and biodiesel and
possibly to include butanol, hydrogen and methane. These liquid fuels, or energy
carriers lie at the heart of the solution to the global energy problem, since they
are the materials currently most suitable for use in the transportation sector and
for the direct replacement of the immediately endangered fossil resources of oil
and gas. Vasudevan et al. in Chapter 3 “Environmentally Sustainable Biofuels -
The Case for Biodiesel, Biobutanol and Cellulosic Ethanol” provide a detailed dis-
cussion of the case for ethanol, butanol and biodiesel. Significantly, a potential
technical hurdle confronting the production of biofuels is the efficiency of utiliza-
tion of hemicellulose-derived sugars. In Chapter 4 “Biotechnological Applications
of Hemicellulosic Derived Sugars: State-of-the-Art”, Chandel et al. examine the
challenges associated with the successful utilization of this second most abundant
polysaccharide in nature.
Energy-yielding materials are found in various guises, one of which is garbage.
Although not always classified as a resource, garbage clearly is renewable (increas-
ingly so, in fact), and processes that convert it into energy are obviously dually
beneficial. In Chapter 5 “Tactical Garbage to Energy Refinery (TGER)”, Valdes
and Warner present a hybrid biological/thermochemical system designed for the
conversion of military garbage into ethanol and electricity, with clear potential for
applications in the civilian sector.
Agricultural waste (e.g. livestock, manure, crop residues, food wastes etc.)
is a high impact feedstock with particular utility in the production of bio-
gas. In Chapter 6 “Production of Methane Biogas as Fuel Through Anaerobic
Digestion”, Yu and Schanbacher discuss the anaerobic conversion of biomass
to methane. Untreated wastewater also contains biodegradable organics that can