The pulp and paper industry holds a reputation in the public eye for being a large consumer of water. This dissertation analyses water usage within the industry with a particular application to the South African pulp and paper industry. Unlike in other paper-producing countries, water in South Africa is a scarce commodity with a wide range of consumers. Faced with this, it is important for the leaders of the paper industry to have a tool with which to manage water consumption. This dissertation analyses the water usage aspects (including volumes needed and water quality needed) of the different processes, as well as the impact of different products, describing the reasons for water usage in each process. The application of best available technologies for water reduction is discussed. A theoretical or expected range and norm for water usage for each of seventeen South African mills is derived, based on each mill's particular processes, capacities and products. The actual water usage by each mill was surveyed by personally interviewing personnel at each mill. Comparisons are made between expected and actual water usage, and the total daily water consumption of the industry is derived. Only two mills operate below the expected norm level, most smaller mills operate close to the norm level, while five of the larger mills need to apply various techniques to reduce their water usage. The approximation of mill water usage to the predicted or expected norm clearly supports the hypothesis that water usage can be predicted by analysing process and capacity, and indicates that this dissertation can be used as a tool to manage water usage within the industry. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

The pulp and paper industry holds a reputation in the public eye for being a large consumer of water. This dissertation analyses water usage within the industry with a particular application to the South African pulp and paper industry. Unlike in other paper-producing countries, water in South Africa is a scarce commodity with a wide range of consumers. Faced with this, it is important for the leaders of the paper industry to have a tool with which to manage water consumption. This dissertation analyses the water usage aspects (including volumes needed and water quality needed) of the different processes, as well as the impact of different products, describing the reasons for water usage in each process. The application of best available technologies for water reduction is discussed. A theoretical or expected range and norm for water usage for each of seventeen South African mills is derived, based on each mill's particular processes, capacities and products. The actual water usage by each mill was surveyed by personally interviewing personnel at each mill. Comparisons are made between expected and actual water usage, and the total daily water consumption of the industry is derived. Only two mills operate below the expected norm level, most smaller mills operate close to the norm level, while five of the larger mills need to apply various techniques to reduce their water usage. The approximation of mill water usage to the predicted or expected norm clearly supports the hypothesis that water usage can be predicted by analysing process and capacity, and indicates that this dissertation can be used as a tool to manage water usage within the industry. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

An experiment was designed to test the hypothesis that each softwood pulp is unique and requires a specific, well defined mechanical treatment to derive its maximum strength potential. Three bleached softwood Kraft pulps and respective wood samples were sourced from both the Northern and Southern Hemispheres. The raw fibre characteristics of P. patula (Southern Hemisphere), P. menziesii (Northern Hemisphere) and P. mariana (Northern Hemisphere) were measured and compared. The raw pulp sheets were refined at different energies and intensities under controlled laboratory conditions using a 12” single disc pilot refiner. Results were assessed to determine the raw fibre characteristics, optimum refining conditions and the relative refined strength potential for each of the three samples. Results from anatomy measurements on the three wood samples differed significantly. P. patula exhibited a relatively high proportion of springwood growth in the early growing years. As the P. patula aged and formed mature wood there was a significant increase in the frequency of latewood formation. This was characterized by an abrupt and significant increase in the wall thickness, beyond that of the two Northern softwood samples. When the cell wall thickness increased, the lumen width and fibre diameter of the P. patula decreased significantly, yielding extremely coarse, stiff fibres. The Northern P .mariana and P. menziesii samples were characterized by a relatively consistent transition between high and low densities from the pith to the bark of the tree. The Southern P. patula had a unique density trend with an increasing frequency of high density peaks indicative of an increased latewood formation from the pith to the bark. The slower growing Northern P. menziesii and P. mariana samples did not have as clear a differentiation in fibre characteristics between juvenile and mature wood formation. The Northern samples did however contain a significantly higher proportion of juvenile latewood growth than the P. patula. However, the difference in fibre characteristics between earlywood and latewood formation was not as significant as that noted with the Southern P. patula Fibre morphology measurements on the unrefined bleached Kraft pulps also revealed significant differences between the three samples. The average MORFI LAB01 results on the P. patula defined fibres with a high coarseness and relatively low number of fibres per gram of pulp. The extremely coarse latewood fibres formed during mature wood growth being the most likely source. However, P. patula was also characterized with a high fibre flexibility and large lumen, characteristics consistent with earlywood fibres. The Pulmac Z-Span 3000 was used to define the individual fibre strength, when due consideration was given to the number of fibres per gram, the corrected Pulmac results suggested P. patula had the strongest fibres. When refined, using a standard disc refining programme, P. patula exhibited a fast freeness development. Conventional thinking would suggest that this was an indication of a weaker fibre. However, this species had a robust morphology compared to the Northern Hemisphere woods. The theory developed in this dissertation suggests that the effect of coarseness and the concomitant number of fibres per gram plays a significant role. These two parameters are not included in the “traditional” refining calculations. The applied refining load and intensity was calculated on the flow of the pulp passing through the refiner. The calculation did not consider the actual number of fibres present in that specific volume. The implication is that when a fixed refining load is applied to a pulp with coarse fibres there may be a higher effective load on those fewer fibres (resulting in fibre cutting and fines generation). In this case, the Northern samples have a comparatively low coarseness and more fibres per gram with each receiving a smaller portion of the total load and intensity. In terms of refined pulp properties, P. patula developed a relatively high bulk and tear index consistent with coarse, rigid fibres. The Northern P. mariana and P. menziesii samples produced a pulp with good tensile properties, consistent with a greater number of finer, collapsible fibres with a higher relative bonding area. P. patula fibres were extremely heterogeneous in nature containing the smallest relative lumen width during latewood formation and the largest lumen width during earlywood growth. As a result, P. patula contains extremes of both fine and coarse fibres in the same blend. It may be more beneficial for this species than the others to improve both the tear and tensile properties through fibre fractionation with appropriate development of the separate accepts and rejects streams. In terms of fibre development, low intensity refining parameters maximized the tensile strength of the Southern P. patula. The Northern P. mariana and P. menziesii samples had a greater number of fibres per gram of pulp requiring both a higher refining energy and intensity to develop the pulp to its maximum potential. To develop optimum tear results, high intensity refining, with a relatively low specific energy provided optimum results for all 3 samples. Results confirmed that there were significant differences in the fibre morphology both between the three different species and between the two Hemispheres. There was strong evidence that the fibre characteristics dictate the manner in which a fibre responds to refining which in turn determines the relative contribution to specific refined pulp properties. It may be possible to use fibre characteristics to determine the appropriate refining parameters for optimal fibre development which will enhance the value of the end product. To derive the maximum strength potential from P. patula pulp samples, it is recommended that further studies investigate Hydracyclone fractionation and the concomitant benefits of refining the separate streams. Furthermore, a separate study on fibre morphology and refining characteristics of the same species grown in both the Northern and Southern Hemisphere would provide valuable insight. / Thesis (M.Sc.Eng)-University of KwaZulu-Natal, Durban, 2009.

The chemistry of the batch cooking process at Sappi Saiccor, relating to both the pulp and liquor, was investigated with the aim of using kinetic expressions to develop an improved process control model. The mill produces dissolving pulps using the acid sulphite method. Three process reactions were identified as important: cellulose hydrolysis, delignification and hemicellulose dissolution. Of these, cellulose hydrolysis is the most important since the primary aim is to achieve a targeted cellulose degree of polymerisation (DP) or viscosity (DP is commonly expressed in terms of this measurement). This is directly determined by the rate of this reaction during the cook, and the acidity of the cooking liquor was found to be the key factor. As existing equipment was not suitable for obtaining the data required to perform a kinetic analysis, a pilot plant was constructed. A commercially available probe was used for the first time to measure pH directly. The measured acidity is not directly equivalent to hydrogen ion activity at these temperatures and pressures; however, since the conditions of each cook are similar the errors incurred were found to be constant from cook to cook. The probe was found to be prone to drift due to ageing and this was accounted for by using an 'on line' calibration based on a liquor analysis. The kinetics of the cellulose hydrolysis reaction were determined using the on-line measurement of acidity and the concept of degradation increase (DI) which relates the reduction in DP value to the rate at which the polymeric chains are split. Delignification and hemicellulose dissolution were examined, since it is beneficial to maximise these reactions to reduce the quantities of chemicals consumed during the bleaching process. A model for controlling cooks to a set target cellulose DP value within a set time was developed based on the reaction kinetics. This was capable of predicting cooking conditions required with sufficient accuracy to control the cellulose DP value to within ±6 cp SNIA on the viscosity scale. / Thesis (M.Sc.Eng.)-University of Natal, 1992.

Submitted in the fulfillment of the requirements for the degree of Master of Technology, Durban University of Technology, Durban, South Africa, 2011. / The main objective of this study was to evaluate the feasibility of conversion of crude tall oil and tall oil fatty acids into biodiesel. During the Kraft pulping process, Crude Tall Oil originates as tall oil soap, which is separated from recovered black liquor. The soap is then converted to Crude Tall Oil by acidulation with sulphuric acid. The Crude Tall Oil is then fractionated by distillation to produce tall oil fatty acids (TOFA), rosin and pitch. There were a number of conversional methods that were considered but proved to be inappropriate. A base-catalyzed method was inappropriate with due to the high free fatty acid content on the feedstock, and the acid-base catalyzed method was inappropriate due to the long reaction times and large excess of methanol required. An enzyme based conversion method was also found to be inappropriate because of the high price attached to the purchasing of the enzymes and the stability of the enzyme. A procedure of choice was the supercritical methanol treatment, due to the fact that it requires no separate catalyst. A procedure was developed for both the feedstocks (i.e. crude tall oil and tall oil fatty acids) using the supercritical methanol treatment. In supercritical methanol treatment, feedstock and methanol were charged to a reactor and were subjected to temperatures and pressures beyond the critical point of methanol (Tc = 240 °C, Pc = 35 bar). The maximum biodiesel yield obtained from Crude tall oil was 66% and was 81% for the tall oil fatty acids that was produced in a single stage process. The temperature and methanol to feedstock ratio effects was also found to yield a maximum biodiesel yield at 325°C and 40:1 respectively. A 20 minutes reaction time was found to be appropriate for the maximum yield of biodiesel. The final biodiesel produced was also evaluated against a commercial biodiesel product and its parameters measured. The biodiesel resulting from the tall oil fatty acid yielded parameters that were acceptable according to ASTM D6751 specifications for biodiesel. The biodiesel produced from the crude tall oil did not meet the ASTM D6751 specification, and this was mostly attributed to the presence of unsaponifiables which hindered the conversion of oil into biodiesel. / M

O Brasil ocupa a quarta colocação no ranking mundial de produção de celulose, sendo que quase 90% da matéria prima é madeira de fibra curta, especificamente do gênero Eucalyptus. O processo de produção de celulose mais utilizado pela grande maioria das indústrias do mundo todo é o químico e, entre os processos químicos modificados está o Compact CookingTM, que é reconhecido por gerar polpas de alta resistência físico-mecânica e boa branqueabilidade. Aditivos de cozimento são amplamente utilizados no processo de fabricação da celulose, pois permitem melhores rendimento e qualidade do produto obtido. O presente trabalho teve como objetivo avaliar a eficiência de quatro aditivos na polpação kraft de eucalipto através do processo Compact CookingTM, buscando melhorias no rendimento do processo e ganho na qualidade da polpa produzida. Os cozimentos foram conduzidos em digestor laboratorial da marca TSI com bomba dosadora acoplada. O tempo total de cozimento foi de 457 minutos, com temperatura máxima de 165º C, resultando em um perfil de cozimento com fator H de 2100. Os aditivos testados foram antraquinona, aditivo 2, aditivo 3 e xilenossulfonato de sódio. A antraquinona e os aditivos 2 e 3 foram aplicados em carga de 0,05% (base madeira) e o xilenossulfonato de sódio foi testado em três cargas: 2, 4 e 8 kg.ton-1 (base madeira). Os resultados obtidos mostraram que o uso do xilenossulfonato de sódio como aditivo na polpação kraft, levando em consideração as especificidades desta pesquisa, não gerou benefícios ao processo e, por isso, o mesmo não foi utilizado nos passos seguintes deste estudo. A antraquinona possibilitou a redução de um ponto percentual de álcali ativo aplicado e consequente ganho de rendimento de 1,6% em relação ao tratamento sem aditivo. Tanto para o aditivo 2 quanto para o aditivo 3 foi possível alcançar o mesmo grau de deslignificação (número kappa 17 ± 05) com redução de cinco pontos percentuais de álcali ativo aplicado em relação ao tratamento testemunha, gerando ganho de 2,3 e 2,4% em rendimento. A viscosidade das polpas com a antraquinona e com os aditivos 2 e 3 também aumentou de maneira significativa se comparada à polpa sem aditivo, sendo os melhores resultados alcançados nos tratamentos com os aditivos 2 e 3; tais aditivos também possibilitaram a maior queda nos valores de consumo específico de madeira e teor de sólidos gerados. Quando testadas em relação a propriedades físico-mecânicas, as polpas produzidas com a utilização dos aditivos 2 e 3 apresentaram as melhores performances, com benefícios na tração, estouro e resistência à passagem de ar. É possível concluir que, para a madeira e processo de polpação utilizados neste trabalho, os aditivos 2 e 3 se mostraram bastante superiores à antraquinona. Assim, fica a sugestão para que mais trabalhos e estudos sejam desenvolvidos com estes produtos, buscando o melhor conhecimento dos mesmos e a comprovação de tal desempenho para a produção de polpa celulósica. / Brazil occupies the fourth place in global pulp production ranking and almost 90% of the raw material used for the national production is hardwood, specifically Eucalyptus. The most used process for pulp production by industries worldwide is the chemical pulping and among the modified chemical processes, there is Compact CookingTM. This one is recognized for producing pulps with high resistance and good bleachability. Additives are widely used in the pulp production process, as they allow better yield and quality of the final product. This study aimed at evaluating the effectiveness of four additives in Eucalyptus kraft pulping, by using Compact CookingTM process, seeking for improvements in process yield and in the pulp quality. The pulp simulation was conducted in laboratory digester that had a pump coupled in it. The total cooking time was 457 minutes, with maximum temperature of 165º C, resulting in a cooking profile with H factor value equal to 2100. The additives used were anthraquinone, additive 2, additive 3 and sodium xylenesulphonate. The anthraquinone and additives 2 and 3 were applied in 0.05% wood base and sodium xylenesulphonate was tested in three loads: 2, 4 and 8 kg.ton-1 (wood base). The results showed that the use of sodium xylenesulphonate as an additive in kraft pulping, considering the specific case of this research, didn\'t generated benefits in the process and, because of this, it was eliminated from the next steps of this research project. Anthraquinone allowed the reduction of 1% in alkali applied and consequent 1.6% yield gain compared to treatment without additive. For both additives 2 and 3, it was possible to achieve the same delignification level (kappa number 17 ± 0.5) by reducing 5% of alkali applied in comparison to the control treatment and this allowed yield gain of 2.3 and 2.4%. The viscosity of the pulp produced by using anthraquinone and additives 2 and 3 increased significantly compared to the pulp without the chemicals, and better results were achieved for treatments with additives 2 and 3; with these additives the pulping process reached the lowest values on wood specific consumption and generated solids. When tested for the physical and mechanical properties, the pulps produced with additives 2 and 3 showed better performances, with benefits in tensile index, burst index and resistance to air flow. Therefore, it was possible to conclude that, for the wood and the pulping process used in this study, additives 2 and 3 showed better results than anthraquinone. The suggestion is that more studies must be developed with these two chemical products, with the objective of reaffirming such good performance in the pulp production.

No description available.

Graduation date: 1995

Graduation date: 1994

The period around the end of the First World War saw the organization of tech­nological research in Sweden. It was at this time that work began at the Wood Pulp Research Association, at the Swedish Institute for Metals Research and at the Swedish Academy of Engineering Sciences. The latter organization had as its basic aim the promotion of technical and scientific research and thereby the support of Swedish industry and the utilization of natural resources. The disser­tation is concerned with the background of these institutions. The indirect cause of the founding of the Academy was a parliamentary motion in 1916 which resulted in an enquiry into an institute responsible for energy and fuel matters. The enquiry led to the conclusion that there existed a need for a central institution for technological research as a whole. Other issues which played a part in the sequence of events that led to the founding of the Academy, were the demand from industry for a modernization of Swedish government administration and the conflict that existed between scientifically- oriented engineers with roots in civil service traditions and the »modern» engine­ers who emphasized the role of the engineer as an industrial manager trained in economics etc. The Academy came into being with the aim of bridging this conflict and of establishing a state agency corresponding to the older Swedish Academy of Agriculture. The Wood Pulp Research Association was founded by the pulp industry, which originally had not been based on any systematic research or development work. After the turn of the century, interest in the chemistry of wood and other related substances began to increase. All early research efforts had one aim in common: the utilization of waste material from the forestry industry. The Asso­ciation was established at the end of 1917 and was jointly owned by a majority of the larger pulp companies. Due to an economic crisis in the pulp industry, the organization was abolished in 1922. The Swedish Institute for Metals Research was originally a metalographic research laboratory established as a result of cooperation between State and industry. The Institute was engaged primarily in basic research, dominated by work based on advanced X-ray spectroscopy. / digitalisering@umu