56
5 Biomass Decomposition and Nanotechnology
nanoparticles were synthesized by making the collective solution of FeCl 3 · 6H 2 O
and FeCl 2 .4H 2 O in distilled water. In a separate beaker, NaOH was heated at 80 °C
and Ar was flown in it, and the formally prepared solution was added to it dropwise
resulting in the formation of homogenized small particles. After the completion
of the reaction, black precipitates were formed which were crystallize. Hematite
nanoparticles were prepared by making the solution of FeCl 3 in distilled water.
The solution was then placed in oven at 100 °C for 72 h. Afterward, the solution
of magnetite nanoparticles and hematite nanoparticles was mixed together to obtain
maghemite nanoparticles. The prepared maghemite nanoparticles were analyzed with
SEM and particle dimensions were found to be in the range of 55 nm. When the
nanoparticles were employed in the fermentation it was observed that the amount of
hydrogen generated by employing maghemite nanoparticles along with the bacteria
culture was greater (104.75 ± 12.39 mL-H 2 /g) than the amount generated with the
bacteria culture (66.22 ± 4.88 mL-H 2 /g) alone. The improved production of hydrogen
by using the maghemite nanoparticles is associated with their ability to enhance the
bioactivity of hydrogen-generating microbes [30].
Zhidan et al. reported the use of carbon nanotubes for the generation of hydrogen
form biomass via Ruminococcaceae fermentation. The study employed hydrogen
producing reactors instead of microbial consortium with retained hydrogen product
was used. Carbon nanotubes improved the retention of the microbes. Seed sludge
with inactivated methanogenic bacteria was used as the biomass in the study. The
biomass was treated with alkali for the adjustment of the pH. Pre-made carbon
nanotubes with 12 nm diameter were used for the process. The study concluded
that the carbon nanotubes noticeably intensified the biomass retention and reduced
the startup time of the reaction. Carbon nanotubes also offered larger flocculation
capacity to Ruminococcaceae, hence improving the yield of hydrogen [31].
Laurent et al. used metallic and metallic oxide nanoparticles restrained on the
porous silica and added them on Clostridium butyricum-assisted biomass fermentation for hydrogen generation. For the preparation of nanoparticles, metallic salts of
Ag, Cu, Pd, and Fe were used. The prepared nanoparticles were encapsulated inside
the porous silica with co-gelation process. The process allows the doping of cations
with inorganic matrix at the molecular scale in a single step. Congelation allows the
simultaneous hydrolysis and condensation of two alkoxy silanes. All the metallic
nanoparticles anchored in silica were calcined at a high temperature for the removal
of organic moieties. After calcination as the final step, the products were reduced in
hydrogen atmosphere. All the prepared nanoparticles showed greater production of
H 2 as compared to the blank experiments and the nanoparticles without silica matrix.
The Pd/SiO 2 , Ag/SiO 2 , Fe/SiO 2 , and Cu/SiO 2 nanoparticles liberated ~95.8, ~93.8,
~119.4, and ~103.9 mL, respectively, of H 2 from the 5 g/L of glucose, where the
referenced culture generated ~87 mL of H 2 [32].
There are many other studies which involve the use of nanotechnology in biomass
conversion to hydrogen either by biochemical or thermochemical process. A brief
account of the few is given in Table 5.1: Nanotechnology in biomass conversion to
hydrogen.
5 Biomass Decomposition and Nanotechnology
nanoparticles were synthesized by making the collective solution of FeCl 3 · 6H 2 O
and FeCl 2 .4H 2 O in distilled water. In a separate beaker, NaOH was heated at 80 °C
and Ar was flown in it, and the formally prepared solution was added to it dropwise
resulting in the formation of homogenized small particles. After the completion
of the reaction, black precipitates were formed which were crystallize. Hematite
nanoparticles were prepared by making the solution of FeCl 3 in distilled water.
The solution was then placed in oven at 100 °C for 72 h. Afterward, the solution
of magnetite nanoparticles and hematite nanoparticles was mixed together to obtain
maghemite nanoparticles. The prepared maghemite nanoparticles were analyzed with
SEM and particle dimensions were found to be in the range of 55 nm. When the
nanoparticles were employed in the fermentation it was observed that the amount of
hydrogen generated by employing maghemite nanoparticles along with the bacteria
culture was greater (104.75 ± 12.39 mL-H 2 /g) than the amount generated with the
bacteria culture (66.22 ± 4.88 mL-H 2 /g) alone. The improved production of hydrogen
by using the maghemite nanoparticles is associated with their ability to enhance the
bioactivity of hydrogen-generating microbes [30].
Zhidan et al. reported the use of carbon nanotubes for the generation of hydrogen
form biomass via Ruminococcaceae fermentation. The study employed hydrogen
producing reactors instead of microbial consortium with retained hydrogen product
was used. Carbon nanotubes improved the retention of the microbes. Seed sludge
with inactivated methanogenic bacteria was used as the biomass in the study. The
biomass was treated with alkali for the adjustment of the pH. Pre-made carbon
nanotubes with 12 nm diameter were used for the process. The study concluded
that the carbon nanotubes noticeably intensified the biomass retention and reduced
the startup time of the reaction. Carbon nanotubes also offered larger flocculation
capacity to Ruminococcaceae, hence improving the yield of hydrogen [31].
Laurent et al. used metallic and metallic oxide nanoparticles restrained on the
porous silica and added them on Clostridium butyricum-assisted biomass fermentation for hydrogen generation. For the preparation of nanoparticles, metallic salts of
Ag, Cu, Pd, and Fe were used. The prepared nanoparticles were encapsulated inside
the porous silica with co-gelation process. The process allows the doping of cations
with inorganic matrix at the molecular scale in a single step. Congelation allows the
simultaneous hydrolysis and condensation of two alkoxy silanes. All the metallic
nanoparticles anchored in silica were calcined at a high temperature for the removal
of organic moieties. After calcination as the final step, the products were reduced in
hydrogen atmosphere. All the prepared nanoparticles showed greater production of
H 2 as compared to the blank experiments and the nanoparticles without silica matrix.
The Pd/SiO 2 , Ag/SiO 2 , Fe/SiO 2 , and Cu/SiO 2 nanoparticles liberated ~95.8, ~93.8,
~119.4, and ~103.9 mL, respectively, of H 2 from the 5 g/L of glucose, where the
referenced culture generated ~87 mL of H 2 [32].
There are many other studies which involve the use of nanotechnology in biomass
conversion to hydrogen either by biochemical or thermochemical process. A brief
account of the few is given in Table 5.1: Nanotechnology in biomass conversion to
hydrogen.