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Water for Energy and Fuel Production
and they show nearly twofold variation in biogas production even within different
types of plants and plant materials. Energy crops are extensively used as pure or
co-substrate for anaerobic digestion. In general, easily degradable biomass results
in biogas production. The biogas generated from landfills generally contains about
50%–55% methane and the remaining composition consists of largely CO 2 and traces
of water, hydrogen, and other impurities. Thus, the nature of feedstock makes a
significant difference in the level and composition of biogas production.
A vast amount of literature on the effect of feedstock on biogas production
is available. A brief summary of this literature is outlined in Table 8.3. Biogas
production from some of these feedstock is further discussed below in Sections 8.4.1
through 8.4.12.
8.4.1 Coir PiTh
Coir pith is a lignocellulosic agro residue that is produced as a byproduct in coir
industry in large quantities. Kunchikannan et al. [56] examined the production of
methane from this waste material by anaerobic digestion. The study indicated that
the yield of methane is 38.1% per kilogram of dry pith weight in 44 days; the yield
can be improved by about 1.5 times by the reduction of particle size. The increase
in acidity during the digestion process decreases the methane yield, whereas an
increase in alkalinity does not significantly change the methane yield.
8.4.2 Whey
The wastes from various food industries are capable of generating methane due to
their high organic content. Whey is normally used as a component of dairy products
or as an additive for food product. Beszedes et al. [60] examined biogas generation
from membrane-separated fractions, that is, permeate and concentrate of whey. The
study examined the effects of pH, thermal, and microwave pretreatment, and their
combinations on the biogas yield. The pretreatment had a significant effect on the
biogas yield. The hydrolysis of large molecules enhanced the biodegradability of
whey, thereby increasing the productions of biogas and methane. The long-time classical heat treatment and the microwave radiation in an acidic medium significantly
increased the methane production. The concentrate of whey was more adaptable to
anaerobic digestion than the permeate or the whole whey.
8.4.3 diSTillery SPenT WASh
Distillery spent wash is a major pollutant in water. In recent years, methane is generated from anaerobic digestion of distillery spent wash by fixed-film systems and
two-phase anaerobic systems. Pathe et al. [58] showed that a treatment option that
involved two-stage aerobic oxidation processes (activated sludge and extended aeration) followed by a physical chemical treatment using lime, polyaluminum chloride,
polyelectrolyte, and carbon adsorption as the tertiary treatment can be the most efficient method for methane generation from the distillery spent wash. The treated
effluent can be used for green belt development and in the agriculture industry.
Water for Energy and Fuel Production
and they show nearly twofold variation in biogas production even within different
types of plants and plant materials. Energy crops are extensively used as pure or
co-substrate for anaerobic digestion. In general, easily degradable biomass results
in biogas production. The biogas generated from landfills generally contains about
50%–55% methane and the remaining composition consists of largely CO 2 and traces
of water, hydrogen, and other impurities. Thus, the nature of feedstock makes a
significant difference in the level and composition of biogas production.
A vast amount of literature on the effect of feedstock on biogas production
is available. A brief summary of this literature is outlined in Table 8.3. Biogas
production from some of these feedstock is further discussed below in Sections 8.4.1
through 8.4.12.
8.4.1 Coir PiTh
Coir pith is a lignocellulosic agro residue that is produced as a byproduct in coir
industry in large quantities. Kunchikannan et al. [56] examined the production of
methane from this waste material by anaerobic digestion. The study indicated that
the yield of methane is 38.1% per kilogram of dry pith weight in 44 days; the yield
can be improved by about 1.5 times by the reduction of particle size. The increase
in acidity during the digestion process decreases the methane yield, whereas an
increase in alkalinity does not significantly change the methane yield.
8.4.2 Whey
The wastes from various food industries are capable of generating methane due to
their high organic content. Whey is normally used as a component of dairy products
or as an additive for food product. Beszedes et al. [60] examined biogas generation
from membrane-separated fractions, that is, permeate and concentrate of whey. The
study examined the effects of pH, thermal, and microwave pretreatment, and their
combinations on the biogas yield. The pretreatment had a significant effect on the
biogas yield. The hydrolysis of large molecules enhanced the biodegradability of
whey, thereby increasing the productions of biogas and methane. The long-time classical heat treatment and the microwave radiation in an acidic medium significantly
increased the methane production. The concentrate of whey was more adaptable to
anaerobic digestion than the permeate or the whole whey.
8.4.3 diSTillery SPenT WASh
Distillery spent wash is a major pollutant in water. In recent years, methane is generated from anaerobic digestion of distillery spent wash by fixed-film systems and
two-phase anaerobic systems. Pathe et al. [58] showed that a treatment option that
involved two-stage aerobic oxidation processes (activated sludge and extended aeration) followed by a physical chemical treatment using lime, polyaluminum chloride,
polyelectrolyte, and carbon adsorption as the tertiary treatment can be the most efficient method for methane generation from the distillery spent wash. The treated
effluent can be used for green belt development and in the agriculture industry.