Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Today there is renewed interest in using soil improvers with fertilising capability as
the use of inorganic fertilisers results in ground water pollution through leaching and
formation of nitrates in plant materials. Lignin is an important precursor of humic
material in soils and with modification, can be used as a raw material for producing
slow release nitrogenous fertilisers. This project focussed on the use of industrial
residues such as technical lignins which are produced by the South African pulping
industry as well as low grade coals such as lignite occurring in South Africa, for the
production of high-grade humic substances like Novihum TM, using the special
technology developed by the Institute of Plant and Wood Chemistry of the Technical
University of Dresden in Germany. Technicallignins derived from kraft lignin, sugar
cane baggase, autohydrolysis lignin with a trade name Sucrolin, a calcium
lignosulphonate and South African lignites mined in the Kraaifontein and BraekenfeIl
areas as well as German brown coal were subjected to oxidative ammonolysis with
the aim to produce slow release nitrogenous fertilizers.
Curie Point Pyrolysis GCIMS was used to determine the structural composition of the
raw materials and products. Oxidative ammonolysis reactions were carried out on a
laboratory and a pilot plant scale. Highest nitrogen contents were obtained with
Sucrolin lignin followed by the lignite from Germany. The amount of nitrogen that
could be fixed with oxidative ammonolysis varied between 1.44 - 10% for the various
raw materials. The CIN ratios obtained were in the range between 5 - 34. Marginal
differences were observed between the materials modified on lab and pilot plant
scales. There were improvements in the total incorporated nitrogen when the raw
materials were pre-activated with oxidising agents such as hydrogen perxide and a
fungal species, Phanaerochateae chrysosporium prior to oxidative ammonolysis.
Variable amounts of differently bonded nitrogen forms were obtained for the
materials tested due to their structural differences. / AFRIKAANSE OPSOMMING: Daar is deesdae hernude belangstelling in die gebruik van grondverbeteringsmiddels wat
ook 'n bemestingsfunksie het, aangesien die gebruik van anorganiese kunsmis
besoedeling van grondwater deur uitlogingen insypeling veroorsaak, wat weer tot die
vorming van nitrate in plantmateriaallei. Lignien is 'n belangrike voorloper van humiese
materiale in grondstowwe en kan dmv modifisering gebruik word as 'n grondstof vir die
produksie van stadigstikstof vrystellende nitro gene kunsmisstowwe. Die huidige projek
het gefokus op die gebruik van industriële residue en tegniese ligniene wat deur die Suid-
Afrikaanse pulpnywerheid geproduseer word, sowel as lae-graad steenkool soos ligniet
wat in Suid-Afrika aangetrefword, vir die produksie van hoë-graad humiese stowwe soos
Novihum TM. Hierdie produk is mbv spesiale tegnologie deur die Instituut van Plant- en
Houtchemie van die Tegniese Universiteit van Dresden in Duitsland ontwikkel.
In hierdie ondersoek is verskeie Suid-Afrikaanse tegniese ligniene soos Kraft lignien,
suikerriet bagasse, 'n outohidrolise lignien met die naam van Sucrolin en 'n
kalsiumlignosulfonaat sowel as SA ligniete, afkomstig van Brackenfell en Kraaifontein,
gebied en Duitse bruinkool, aan oksidatiewe ammonolise onderwerp om sodoende
verskillende, stadigvrstellende, stikstofryke kunsmisstowwe te vervaardig.
Curie Punt Pirolise GC/MS is gebruik om die chemiese struktuur van die grondstowwe
en produkte vas te stel. Oksidatiewe ammonolise reaksies is op 'n laboratorium en
loodsaanlegskaal. uitgevoer. Die hoogste stikstofinhoud is met Sucrolin lignien verkry,
gevolg deur die ligniet van Duitsland. Die hoeveelheid stikstof wat dmv oksidatiewe
ammonlise bereik kon word, het tussen 1.44 en 10% gewissel. Die CIN verhoudings wat
verkry was, het varieer tussen 5 en 34. Marginale verskille is tussen laboratorium - en
loodsaanlegsskaal gemodifiseerde grondstowwe waargeneem. Daar was verhogings in
stikstofinhoud wanneer die grondstowwe vooraf met oksiderende middels soos
waterstofperoksied of swamkultur soos Phanaerochatae chrysosporium, aktiveer is.
Stikstof is op verskillende maniere en in verskillende hoeveelhede gebind.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53548 |
| Date | January 2003 |
| Creators | Tyhoda, Luvuyo |
| Contributors | Gerischer, G. R. F., Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 74 p. : ill. |
| Rights | Stellenbosch University |
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