particulate residues, which are readily biodegradable. Pretreatments such as chemical, physical (mechanical), and enzymatic hydrolysis render the waste treatment
energy drain and costly. Compounds such as metal monomers, metal oxides,
nanoparticles, and synergistic factors have been investigated for their potential to
increase the activities of microorganisms and increase hydrogen production [15]. Of
course, such processes can be used when the prime objective is biofuel production
rather than waste treatment only.
A variety of wastes or their combinations have been investigated for their
potential to produce sustainable H 2 during dark anaerobic fermentation in batch
and continuous studies. Many industrial wastewaters have been investigated for their
potential to produce hydrogen by mixed culture dark fermentation. These wastes
include bean curd manufacturing waste [16], jackfruit peel [17], noodle making
waste [18], olive pulp [19], olive pulp wastewater [20–24], pulp and paper industry
wastewater, rice bran, wheat bran [25], rice slurry [26], rice winery wastewater [8],
starch-manufacturing waste [27], starch-rich wastewater [28], sugar factory wastewater [29], sweet potato starch residue [27], and tofu wastewater [30].
1.1 Quantities of the Organic Waste Suitable for H 2
Production
Industrial processes handling organic plant material generate large quantities of
waste containing fractions of the raw and processed material. For example, the
percent of the annually wasted fraction out of the total processed material is around
30–50% for fruits and vegetables processing industry; 30% for cereals; 40–50% for
root crops; 20% for oilseeds, meat, and dairy; and 30% for fish [31]. Globally,
around 1.3 billion tonnes of the food produced in the world for human consumption
is wasted every year [31]. In the European countries, the wastes generated (tonnes)
by some food processing industries are sugar beet pulp (4,840,000), brewers’ spent
grains (340,0000), fruits’ pulp (apple and peach) (310,000), and onion peeling waste
(500). Figure 8.1 shows the percentage of non-utilized raw material in carbohydraterich food processing wastes which could be used as substrates for H 2 production.
The food industry supply chain generates a large amount of organic waste which
is biodegradable and could be fed to bioreactors to sustain H 2 production. In the UK,
for example, the manufacturing element of the food industry supply chain generates
about 2.5 million tonnes of food waste annually [33]; this is almost 30% of the
amount of domestic food waste generated by the UK households [33]. The global
whey production is 150–200 million tonnes, and it is increasing at a rate of 2% per
year [34].
Production of palm and olive oil generates waste suitable for H 2 production.
Around 2.5 tonnes of palm oil mill effluent (POME) and 1.3 tonnes of empty bunch
are generated from the production of a tonne of palm oil [35]. POME is produced in
large amounts worldwide. For example, Malaysia generated around 44 Â 10
6 tonnes
8 Biohydrogen of Industrial Waste
327
energy drain and costly. Compounds such as metal monomers, metal oxides,
nanoparticles, and synergistic factors have been investigated for their potential to
increase the activities of microorganisms and increase hydrogen production [15]. Of
course, such processes can be used when the prime objective is biofuel production
rather than waste treatment only.
A variety of wastes or their combinations have been investigated for their
potential to produce sustainable H 2 during dark anaerobic fermentation in batch
and continuous studies. Many industrial wastewaters have been investigated for their
potential to produce hydrogen by mixed culture dark fermentation. These wastes
include bean curd manufacturing waste [16], jackfruit peel [17], noodle making
waste [18], olive pulp [19], olive pulp wastewater [20–24], pulp and paper industry
wastewater, rice bran, wheat bran [25], rice slurry [26], rice winery wastewater [8],
starch-manufacturing waste [27], starch-rich wastewater [28], sugar factory wastewater [29], sweet potato starch residue [27], and tofu wastewater [30].
1.1 Quantities of the Organic Waste Suitable for H 2
Production
Industrial processes handling organic plant material generate large quantities of
waste containing fractions of the raw and processed material. For example, the
percent of the annually wasted fraction out of the total processed material is around
30–50% for fruits and vegetables processing industry; 30% for cereals; 40–50% for
root crops; 20% for oilseeds, meat, and dairy; and 30% for fish [31]. Globally,
around 1.3 billion tonnes of the food produced in the world for human consumption
is wasted every year [31]. In the European countries, the wastes generated (tonnes)
by some food processing industries are sugar beet pulp (4,840,000), brewers’ spent
grains (340,0000), fruits’ pulp (apple and peach) (310,000), and onion peeling waste
(500). Figure 8.1 shows the percentage of non-utilized raw material in carbohydraterich food processing wastes which could be used as substrates for H 2 production.
The food industry supply chain generates a large amount of organic waste which
is biodegradable and could be fed to bioreactors to sustain H 2 production. In the UK,
for example, the manufacturing element of the food industry supply chain generates
about 2.5 million tonnes of food waste annually [33]; this is almost 30% of the
amount of domestic food waste generated by the UK households [33]. The global
whey production is 150–200 million tonnes, and it is increasing at a rate of 2% per
year [34].
Production of palm and olive oil generates waste suitable for H 2 production.
Around 2.5 tonnes of palm oil mill effluent (POME) and 1.3 tonnes of empty bunch
are generated from the production of a tonne of palm oil [35]. POME is produced in
large amounts worldwide. For example, Malaysia generated around 44 Â 10
6 tonnes
8 Biohydrogen of Industrial Waste
327