6.3 Waste Material-Based Hydrogen Generation
67
Fig. 6.1 Conversion of plastic in carbon nanotubes and sustainable hydrogen
aromatic hydrocarbons, CO 2 and CO. Supercritical CO 2 ensured the complete and
quick dissociation. In a parallel reaction, Ni acetate tetrahydrate was also pyrolyzed
so as to get the Ni nanoparticles. Ni nanoparticles are excellent catalyst for the growth
of carbon nanotubes. The nanotubes were then allowed to grow by tip-growth model
via the Ni nanoparticle-supported small organic molecule thermal decomposition.
The Pd nanoparticles were allowed to develop on the surface of the nanoparticles
by using the aqueous solution of PdCl 2 (liquid phase synthesis followed by the
subsequent reduction of the adsorbed Pd
2+ ions. The prepared nanomaterials were
employed in electrochemical hydrogen evolution reaction via the splitting of water.
The carbon nanotube performance was poor when employed as catalyst; however,
it improved drastically when decorated with the Pd nanoparticles [32]. This can be
associated to the high reduction potential of the Pd.
A group of researchers have reported a work which addresses the simultaneous
production of carbon-black nanospheres and hydrogen from the thermal pyrolysis
of different waste polymers. For the purpose, the samples of the four different
waste plastic polymers, i.e., polyvinyl chloride, polypropylene, acrylonitrile butadiene styrene, and polyethylene, were charged into a furnace with twin thermal
plasma jet. This led to the pyrolysis of the substrate polymers. The pyrolysis resulted
in the formation of different gases and residues. The formed gaseous components
were analyzed with optical emission spectrometer (OES) and gas chromatography
[33] for the determination of the composition of the components. The analysis indicated that the gaseous product contains H 2 , CH 4 , C 2 H 2 , C 2 H 6 , C 2 H 4 , C 3 H 8 , C 3 H 6 ,
C 4 H 10 , C 5 H 12 , and C 4 . Analysis of all four polymers gaseous products showed that
the hydrogen has maximum concentration among all other gases. Another important
fact revealed by the analysis is that none of the gaseous mixture showed the presence of carbon monoxide. The formed solid residue was analyzed with XRD, TEM,
and SEM. The characterization showed the ultrapure carbon-black nanospheres were
formed by the acrylonitrile butadiene styrene pyrolytic decomposition [34].
67
Fig. 6.1 Conversion of plastic in carbon nanotubes and sustainable hydrogen
aromatic hydrocarbons, CO 2 and CO. Supercritical CO 2 ensured the complete and
quick dissociation. In a parallel reaction, Ni acetate tetrahydrate was also pyrolyzed
so as to get the Ni nanoparticles. Ni nanoparticles are excellent catalyst for the growth
of carbon nanotubes. The nanotubes were then allowed to grow by tip-growth model
via the Ni nanoparticle-supported small organic molecule thermal decomposition.
The Pd nanoparticles were allowed to develop on the surface of the nanoparticles
by using the aqueous solution of PdCl 2 (liquid phase synthesis followed by the
subsequent reduction of the adsorbed Pd
2+ ions. The prepared nanomaterials were
employed in electrochemical hydrogen evolution reaction via the splitting of water.
The carbon nanotube performance was poor when employed as catalyst; however,
it improved drastically when decorated with the Pd nanoparticles [32]. This can be
associated to the high reduction potential of the Pd.
A group of researchers have reported a work which addresses the simultaneous
production of carbon-black nanospheres and hydrogen from the thermal pyrolysis
of different waste polymers. For the purpose, the samples of the four different
waste plastic polymers, i.e., polyvinyl chloride, polypropylene, acrylonitrile butadiene styrene, and polyethylene, were charged into a furnace with twin thermal
plasma jet. This led to the pyrolysis of the substrate polymers. The pyrolysis resulted
in the formation of different gases and residues. The formed gaseous components
were analyzed with optical emission spectrometer (OES) and gas chromatography
[33] for the determination of the composition of the components. The analysis indicated that the gaseous product contains H 2 , CH 4 , C 2 H 2 , C 2 H 6 , C 2 H 4 , C 3 H 8 , C 3 H 6 ,
C 4 H 10 , C 5 H 12 , and C 4 . Analysis of all four polymers gaseous products showed that
the hydrogen has maximum concentration among all other gases. Another important
fact revealed by the analysis is that none of the gaseous mixture showed the presence of carbon monoxide. The formed solid residue was analyzed with XRD, TEM,
and SEM. The characterization showed the ultrapure carbon-black nanospheres were
formed by the acrylonitrile butadiene styrene pyrolytic decomposition [34].