Investigation into the characteristics and possible applications of biomass gasification by-products from a downdraft gasifier system
- Authors: Melapi, Aviwe
- Date: 2015
- Subjects: Biomass gasification -- South Africa -- Eastern Cape , Renewable energy sources -- South Africa -- Eastern Cape , Biomass energy -- South Africa -- Eastern Cape , Crop residue management -- South Africa -- Eastern Cape , Coal gasification -- South Africa -- Eastern Cape , Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11348 , http://hdl.handle.net/10353/d1020174 , Biomass gasification -- South Africa -- Eastern Cape , Renewable energy sources -- South Africa -- Eastern Cape , Biomass energy -- South Africa -- Eastern Cape , Crop residue management -- South Africa -- Eastern Cape , Coal gasification -- South Africa -- Eastern Cape , Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape
- Description: Biomass gasification has attracted the interest of researchers because it produces zero carbon to the atmosphere. This technology does not only produce syngas but also the byproducts which can be used for various application depending on quality.The study conducted at Melani village in Alice in the Eastern Cape of South Africa was aimed at investigating the possible applications of the gasification byproducts instead of being thrown away. Pine wood was employed as the parent feedstock material for the gasifier. Biomass gasification by-products were then collected for further analysis. The studied by-products included tar(condensate), char, soot and resin. These materials were also blended to produce strong materials.The essence of the blending was to generate ideal material that is strong but light at the same time.The elemental analysis of the samples performed by CHNS analyser revealed that carbon element is in large quantities in all samples. The FTIR spectra showed almost similar results for all the studied samples, since the samples are end products of lignocellulosegasification. SEM gave the sticky images of resin as well as porous char structures. Char showed a higher heating value of 35.37MJ/Kg when compared to other by-products samples.
- Full Text:
- Date Issued: 2015
- Authors: Melapi, Aviwe
- Date: 2015
- Subjects: Biomass gasification -- South Africa -- Eastern Cape , Renewable energy sources -- South Africa -- Eastern Cape , Biomass energy -- South Africa -- Eastern Cape , Crop residue management -- South Africa -- Eastern Cape , Coal gasification -- South Africa -- Eastern Cape , Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11348 , http://hdl.handle.net/10353/d1020174 , Biomass gasification -- South Africa -- Eastern Cape , Renewable energy sources -- South Africa -- Eastern Cape , Biomass energy -- South Africa -- Eastern Cape , Crop residue management -- South Africa -- Eastern Cape , Coal gasification -- South Africa -- Eastern Cape , Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape
- Description: Biomass gasification has attracted the interest of researchers because it produces zero carbon to the atmosphere. This technology does not only produce syngas but also the byproducts which can be used for various application depending on quality.The study conducted at Melani village in Alice in the Eastern Cape of South Africa was aimed at investigating the possible applications of the gasification byproducts instead of being thrown away. Pine wood was employed as the parent feedstock material for the gasifier. Biomass gasification by-products were then collected for further analysis. The studied by-products included tar(condensate), char, soot and resin. These materials were also blended to produce strong materials.The essence of the blending was to generate ideal material that is strong but light at the same time.The elemental analysis of the samples performed by CHNS analyser revealed that carbon element is in large quantities in all samples. The FTIR spectra showed almost similar results for all the studied samples, since the samples are end products of lignocellulosegasification. SEM gave the sticky images of resin as well as porous char structures. Char showed a higher heating value of 35.37MJ/Kg when compared to other by-products samples.
- Full Text:
- Date Issued: 2015
Ni(II) and Pb(II) dithiocarbamate complexes as precursors for the synthesis of HDA-capped NiS and PbS nanoparticles
- Authors: Chintso, Thobani
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11349 , http://hdl.handle.net/10353/d1020201
- Description: Ni(II) and Pb(II) dithiocarbamate complexes were synthesized and characterized by elemental analysis, UV-Vis, FTIR and TGA and some of the Ni(II) complexes and one Pb(II) were further analyzed by 1H-NMR and 13C-NMR spectroscopy. Generally all the dithiocarbamate ligands are soluble in water while the complexes were soluble mostly in solvents such as chloroform, toluene, DMSO and DCM. Based on the elemental analysis, the dithiocarbamate complexes are formulated as four coordinate (tetrahedral or square planar) compounds. However, the FTIR showed that each of the dithiocarbamate ligands acted as bidentate ligand through two sulfur atoms. The TGA of the most complexes showed one major decomposition step to give respective metal sulfide above 200 oC. In this research project, dithiocarbamate complexes were used as single source precursor for the synthesis of metal sulfide nanoparticles. We studied the optical and structural properties of metal sulfide nanoparticles using UV-Vis, photoluminescence (PL), powder X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorption spectra of the metal sulfide nanoparticles are blue shifted in respect to bulk material and they also showed broad emission. The XRD of the NiS nanoparticles were indexed to the cubic and rhombohedral phase, with crystallite sizes of 15 - 18 nm. The XRD of PbS nanoparticles were indexed to the face centered cubic and cubic rock salts, with the crystallite sizes 12 - 18 nm. The TEM images of the metal sulfide nanoparticles showed particles with spherical and rectangular shapes with crystallite sizes 4 - 35 nm.
- Full Text:
- Date Issued: 2015
- Authors: Chintso, Thobani
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11349 , http://hdl.handle.net/10353/d1020201
- Description: Ni(II) and Pb(II) dithiocarbamate complexes were synthesized and characterized by elemental analysis, UV-Vis, FTIR and TGA and some of the Ni(II) complexes and one Pb(II) were further analyzed by 1H-NMR and 13C-NMR spectroscopy. Generally all the dithiocarbamate ligands are soluble in water while the complexes were soluble mostly in solvents such as chloroform, toluene, DMSO and DCM. Based on the elemental analysis, the dithiocarbamate complexes are formulated as four coordinate (tetrahedral or square planar) compounds. However, the FTIR showed that each of the dithiocarbamate ligands acted as bidentate ligand through two sulfur atoms. The TGA of the most complexes showed one major decomposition step to give respective metal sulfide above 200 oC. In this research project, dithiocarbamate complexes were used as single source precursor for the synthesis of metal sulfide nanoparticles. We studied the optical and structural properties of metal sulfide nanoparticles using UV-Vis, photoluminescence (PL), powder X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorption spectra of the metal sulfide nanoparticles are blue shifted in respect to bulk material and they also showed broad emission. The XRD of the NiS nanoparticles were indexed to the cubic and rhombohedral phase, with crystallite sizes of 15 - 18 nm. The XRD of PbS nanoparticles were indexed to the face centered cubic and cubic rock salts, with the crystallite sizes 12 - 18 nm. The TEM images of the metal sulfide nanoparticles showed particles with spherical and rectangular shapes with crystallite sizes 4 - 35 nm.
- Full Text:
- Date Issued: 2015
Synthesis and characterization of Ru(II) phenyl-3-indenylidene olefin metathesis type complexes
- Authors: Yalezo, Ntsikelelo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11351 , http://hdl.handle.net/10353/d1021128
- Description: In this study, a series of Ru(II) phenyl-3-indenylidene complexes with general formula of [RuCl2(NHC)(Ind)(L)] (where L= triphenylphosphine, pyridine and NHC = five different types of N-heterocyclic carbene ligands), have been synthesized and characterized using FT-IR, UV-Vis, elementally analysis and melting/decomposition point. The N,N’-diarylimidazolinium chlorides have been used as N-heterocyclic carbene precursors and were synthesized from their corresponding N,N’-diarylformamidines and further characterized using 1H-NMR, 13C-NMR, FTIR and melting point determination. The infrared spectra of the N,N’-diarylimidazolinium chlorides show a quaternary nature (R2N=C+) with broad vibration band in region 3300-3400 cm-1. The disappearance of this vibration band in the infrared spectra of the ruthenium(II) complexes was used to confirm the coordination of the ligand to the ruthenium ions. The percentage analysis of carbon, hydrogen and nitrogen obtained corresponded with the calculated percentages of these atoms in the complexes with the slight difference of less than 1%. The electronic spectra of the complexes show three distinct absorption bands. The two bands are due to intraligand charge transfers transition assigned to π→π*, n→π* and third band is due to d-d transition, signifying the presence of the metal ion. The synthesized Ru(II) complexes did not show any of melting, however a change in colour was observed signifying the decomposition of the complexes.
- Full Text:
- Date Issued: 2015
- Authors: Yalezo, Ntsikelelo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11351 , http://hdl.handle.net/10353/d1021128
- Description: In this study, a series of Ru(II) phenyl-3-indenylidene complexes with general formula of [RuCl2(NHC)(Ind)(L)] (where L= triphenylphosphine, pyridine and NHC = five different types of N-heterocyclic carbene ligands), have been synthesized and characterized using FT-IR, UV-Vis, elementally analysis and melting/decomposition point. The N,N’-diarylimidazolinium chlorides have been used as N-heterocyclic carbene precursors and were synthesized from their corresponding N,N’-diarylformamidines and further characterized using 1H-NMR, 13C-NMR, FTIR and melting point determination. The infrared spectra of the N,N’-diarylimidazolinium chlorides show a quaternary nature (R2N=C+) with broad vibration band in region 3300-3400 cm-1. The disappearance of this vibration band in the infrared spectra of the ruthenium(II) complexes was used to confirm the coordination of the ligand to the ruthenium ions. The percentage analysis of carbon, hydrogen and nitrogen obtained corresponded with the calculated percentages of these atoms in the complexes with the slight difference of less than 1%. The electronic spectra of the complexes show three distinct absorption bands. The two bands are due to intraligand charge transfers transition assigned to π→π*, n→π* and third band is due to d-d transition, signifying the presence of the metal ion. The synthesized Ru(II) complexes did not show any of melting, however a change in colour was observed signifying the decomposition of the complexes.
- Full Text:
- Date Issued: 2015
Synthesis, characterisation and evaluation of functionalized Lignocelluloses-clay nanocomposites for organic pollutant removal from water
- Authors: Mafukidze, Donovan M
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11356 , http://hdl.handle.net/10353/d1021296
- Description: PMPSgLig-NaMMT nanocomposites were prepared from methacryloxypropyltrimethoxysilane (MPS), lignocellulose and montmorillonite clay. The potential enhancement of organic pollutant adsorption capabilities of PMPSgLig-NaMMT nanocomposite from water through functionalization was investigated. PMPSgLig-NaMMT was functionalized by esterification and etherification using different methods so as to increase the surface hydrophobicity of the material and hence improve its compatibility with the target pollutants. Specific chemical routes specially tailored for PMPSgLig-NaMMT were established for functionalization mostly based on the common esterification (Fischer esterification) and etherification (Williamson‟s etherification) reactions. In the functionalization methods, factors such as pH environment, nanocomposite composition, nature of functionalization moiety, and use of or absence of solvents and their variations were studied. FT-IR, XRD, SEM and TGA were used to characterize the synthesized and functionalized nanoadsorbents. The techniques showed successful functionalization via esterification and etherification methods albeit to different extents, with clear retention of the material‟s original structure though there were signs of degradation with some methods. Characterization was supported by adsorption studies to validate implications and draw conclusions. The use of 1,10-phenathroline as a model organic pollutant in water in the adsorption studies showed that adsorbents conformed to monolayer adsorption following pseudo-second order kinetics for adsorption of organic pollutants accurately represented. Most importantly the studies revealed the significant impact of the nanocomposite composition on the overall absorbent performance. Adsorption studies also showed that functionalization via esterification methods gave rise to better adsorbents.
- Full Text:
- Date Issued: 2015
- Authors: Mafukidze, Donovan M
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11356 , http://hdl.handle.net/10353/d1021296
- Description: PMPSgLig-NaMMT nanocomposites were prepared from methacryloxypropyltrimethoxysilane (MPS), lignocellulose and montmorillonite clay. The potential enhancement of organic pollutant adsorption capabilities of PMPSgLig-NaMMT nanocomposite from water through functionalization was investigated. PMPSgLig-NaMMT was functionalized by esterification and etherification using different methods so as to increase the surface hydrophobicity of the material and hence improve its compatibility with the target pollutants. Specific chemical routes specially tailored for PMPSgLig-NaMMT were established for functionalization mostly based on the common esterification (Fischer esterification) and etherification (Williamson‟s etherification) reactions. In the functionalization methods, factors such as pH environment, nanocomposite composition, nature of functionalization moiety, and use of or absence of solvents and their variations were studied. FT-IR, XRD, SEM and TGA were used to characterize the synthesized and functionalized nanoadsorbents. The techniques showed successful functionalization via esterification and etherification methods albeit to different extents, with clear retention of the material‟s original structure though there were signs of degradation with some methods. Characterization was supported by adsorption studies to validate implications and draw conclusions. The use of 1,10-phenathroline as a model organic pollutant in water in the adsorption studies showed that adsorbents conformed to monolayer adsorption following pseudo-second order kinetics for adsorption of organic pollutants accurately represented. Most importantly the studies revealed the significant impact of the nanocomposite composition on the overall absorbent performance. Adsorption studies also showed that functionalization via esterification methods gave rise to better adsorbents.
- Full Text:
- Date Issued: 2015
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