Academic literature on the topic 'Soda pulping process Tasmania'

The soda–ethanol process was conceived as a sulfur-free pulping process, which may also be an alternative to conventional alkaline pulping, such as kraft or soda–AQ in the biorefinery context. An in-depth study using two experimental designs was conducted to establish the viability of soda–ethanol delignification of pine sawdust. At first, a simple factorial design involving the ethanol–water ratio (ethanol:water) and the alkaline load (AL, % over dry wood, odw) was applied to define the levels of these variables and their eventual interaction. Then, a 32 experimental design was performed to evaluate the ability of the process concerning the pulping of pine sawdust. The tested conditions were carefully selected to screen a broad range of cooking times (60, 100, and 140 min) and alkaline loads (19.0, 23.3, and 27.6 %odw) to obtain pulps with different extents of delignification (residual lignin contents). Finally, the kraft, soda–AQ, and soda–ethanol treatments were compared. Soda–ethanol pulping was shown to be a suitable delignification stage for a biorefinery scheme of Pinus elliottii and Pinus taeda sawdust. It has many advantages over traditional processes regarding its environmental impact, harmless chemicals, and selectivity. The tested conditions were similar to those frequently used in conventional pulping at an industrial scale, suggesting the technical feasibility of the soda–ethanol process for pine sawdust processing.

Pulping trials were carried out using MEA and the soda process comparing their pulping potentials. The operating conditions such as the concentration of the cooking liquor (50%, 75%, 100%) for MEA and (10%, 15%, 20%) for NaOH, the maximum cooking temperature (150oC, 160oC, 170oC) and cooking time (60, 90, 120minutes) for both processes were investigated systematically to establish optimal pulping conditions. The agro-biomass used in this investigation is Sugarcane Bagasse viewed as alternative raw material for pulp and paper production. The lignin content of Bagasse (19.5%) was low; indicating that Bagasse should be easier to pulp. The optimum cooking conditions (independent variables) for MEA pulping were 75% MEA concentration, 150oC cooking temperature and 90 minutes cooking time. Excel 2013 was used to analyze the effect of independent variables on yield of bagasse pulp and properties of furnished paper from MEA process in comparison with the Soda process which include tear index, tensile index, burst index and folding endurance with errors less than 15% in all cases. The Kappa number range (12.7-16.9), viscosity (270-870 ml/g) and brightness (62.1-93.2%) of bagasse pulp are appropriate for high-brightness printing and writing papers. The physical properties of furnished paper, tear index (13.4 mN.m2/g), tensile index (71Nm/g), Burst index (4.8 KN/g) and folding endurance (82) recommend the cellulosic pulp from Sugarcane Bagasse obtained from the MEA process for strengthening the virgin fiber in recycled papers and also for developing certain types of printing and packaging papers. Due to the awareness towards the negative impact of kraft mill’s effluent to the environment recently, soda pulping started to regain its popularity among the pulp mills especially non-wood based pulp mills. MEA process is more economically attractive given its high pulp yield, despite the significant increase in chemical demand for bleaching. MEA pulping is a good alternative to soda pulping furnishing high pulp yield with less cooking temperature, i.e. 150oC, thereby saving a considerable amount of energy with less odoriferous pollutants and pollution load associated with the soda process.

In a biorefinery framework, a laccase/mediator system treatment following autohydrolysis was carried out for eucalyptus wood prior to soda-anthraquinone pulping. The enzymatic and autohydrolysis conditions, with a view to maximizing the extraction of hemicelluloses while preserving the integrity of glucan, were optimized. Secondly, pulping of solid phase from Eucalyptus globulus wood autohydrolysis and the enzymatic process was carried out and compared with a conventional soda-anthraquinone (AQ) pulping process. The prehydrolysis and enzymatic delignification of the raw material prior to the delignification with soda- Anthraquinone (AQ) results in paper sheets with a lower kappa number and brightness and strength properties close to conventional soda-AQ paper and a liquid fraction rich in hemicellulose compounds that can be used in additional ways. The advantage of this biorefinery scheme is that it requires a lower concentration of chemical reagents, and lower operating times and temperature in the alkaline delignification stage, which represents an economic and environmental improvement over the conventional process.

In this paper, chia plant was characterized in terms of chemical, morphological, and anatomical properties. Chia plant was characterized with low α-cellulose (30.5%); moderate lignin (23.2%) with syringyl to guaiacyl ratio of 1.41; and shorter fiber length (0.67 mm) with thinner cell wall (1.91 μm) and good flexibility coefficient (71.44). Anatomical features showed that chia plant consists of vessels, fibers, parenchyma cells, and collenchyma cells. Chia plant pulping was evaluated in soda-anthraquinone (soda-AQ) and formic acid/peroxyformic acid (FA/PFA) processes. Chia plant was difficult to delignify in the alkaline process. The FA/PFA process produced higher pulp yield at the same kappa number than the soda-AQ process. Unbleached soda-AQ chia pulp exhibited good proper-ties in terms of tensile, bursting, and tearing strengths, even at the unrefined stage, due to high drainability of the pulps. Alkaline peroxide bleached FA/PFA pulp exhibited better papermaking properties and 2% higher brightness than the D0(EP)D1 bleached soda-AQ pulp.

Fast-growing Poplar cooked by Soda-AQ process was studied, by determining the lignin contents including Klason lignin and acid soluble lignin, the yield of pulping, the rate of carbohydtare degradation and the rate of delignification.Results indicated that the delignificaton of Fast-growing Poplar in Soda-AQ pulping can be divided into three distinguishable stages. (a)The initial delignification stage before 140°C,the rate of delignification reaches to 30.87%;(b)The bulk delignification stage, the rate of delignification reaches to 86.97%，in the period from 140°C to 170°C and for 30 min;(c)The residual delignification stage,the rate of delignification exceeds 91.60%. The defibration point was reached when cooking temperature raised to 170°C and for 30 min with 57.50% pulping yield ,24.94 kappa nomber.

This study aimed to investigate the usability of banana pseudo-stem wastes, remaining from banana cultivation, with eco-friendly K-based pulping processes. Three different K-based pulping processes, KOH, KOH-K2SO3, KOH-NH4OH, and soda process as control were studied. The temperature and the total alkali ratio were kept constant, while the cooking time was varied (60 min and 120 min) for each K-based pulping method. It was found that 60 min at 165 °C with 20% alkaline charge (calculated as Na2O) are the optimum conditions for all K-based pulping processes of banana pseudo-stems. K-based pulps produced under the same pulping conditions were compared with the control soda pulp. The pulp samples were characterized in terms of their mechanical, physical, morphological and optical properties. Also, their Fourier-transform infrared spectroscopy analysis was performed. Among the eco-friendly K-based pulping processes investigated here, the KOH process can be considered as a promising alternative for pulping banana pseudo-stem waste, due to the excellent papermaking properties achieved.

The soda pulping modified by green liquor pretreatment was adopted to explore optimal green liquor pretreatment conditions. Results shows that optimum pretreatment conditions are as follows: max temperature, 130°C; holding time, 90min; wood to liquor ratio, 1:4; and green liquor charge, 0.9L/kg. Pretreated reed was pulped under following conditions: heating-up time, 60min; maximum temperature, 160°C; holding time, 60min; NaOH charge, 20% (pretreatment alkali included). Results shows that this process produces pulp with screened yield of 49.05%, Kappa number of 14.6, and viscosity of 1274mL/g. Compared with the results of industrial simulation pulping (21% NaOH), screened yield increases by 2.14%, Kappa number decreases by 5.6 and viscosity rises by 556 mL/g. Therefore, green liquor pretreatment before soda pulping improves pulp performance and yield. Meanwhile the pretreatment utilizes material effectively, thus has practical significance to decrease alkaline consumption and pulping cost.

Oil palm empty fruit bunch (EFB) was evaluated as a raw material for papermaking pulp production. The EFB was chopped, screened, and washed before cooking. Preliminary bench-scale trials were carried out using soda and soda-anthraquinone cooking followed by bleaching using elemental chlorine free and totally chlorine free sequences. Pilot-scale soda cooking was carried out in a 2300 L spherical digester using the soda process followed by a three-stage elemental chlorine free bleaching sequence. Unbleached and bleached EFB pulps were tested for physical and optical properties. Comparisons were made between the properties of the EFB pulps and bleached kraft eucalyptus pulp. The EFB unbleached and bleached pulps were acceptable for papermaking.

A trihybrid clone of Paulownia fortunei x tormentosa x elongata was used for pulp and paper production using the soda-anthraquinone (AQ) process, comparing the results with those from Paulownia fortunei. An autohydrolysis process had been previously carried out on this raw material. A composite central experimental design and a multiple regression were used for modeling and optimizing the process. A valuable liquid phase could be obtained from the autohydrolysis process of Paulownia, trying to minimize cellulose degradation for pulp and paper production. A compromise to maximize the glucan and minimize the xylan contents in the postautohydrolysis solid phase could be achieved at 187.5ºC and 15 minutes. A suitable cellulosic pulp with kappa number ranging from 12.2 to 69.2 and ISO brightness from 18.2 to 30.6% presented better results than those from other studies. Regarding handsheets physical properties (tensile index 37.3 N·m/g ) and viscosity (848 cm3/g), significant improvements could be obtained when compared with previous results of a similar process using Paulownia fortunei or Paulownia elongata.

Neste trabalho, foi realizada a caracterização de ligninas de palha de cana-de-açúcar. O isolamento das ligninas se deu por acidólise branda e por polpação soda, precedida ou não por pré-tratamento com ácido diluído ou por explosão a vapor. A palha de cana e as ligninas foram caracterizadas por Cromatografia Líquida de Alta Eficiência (CLAE), Espectrometrias no Infravermelho (FT-IR) e no Ultravioleta (UV), por Ressonância Magnética Nuclear de Prótons (1H RMN), Cromatografia de Permeação em Gel (GPC), Análise Termogravimétrica (TGA) e Calorimétrica (DSC), Análise Elementar e de Poder Calorífico Superior (PCS). A lignina técnica isolada por acidólise branda apresentou fórmula C9Har2,31Hal4,14O1,27(OH)ph0,58(OH)al1,19(OCH3)1,11 e relação H:G:S de 1 : 3,22 : 3,68, com 20% de condensação e massa molar média de 1908 Da. A cinética de termodegradação dessa lignina em atmosfera inerte se deu com energia de ativação de 13,90 kJ.mol-1, constante pré-exponencial 0,4799 min-1 e 42% em massa de carvão residual. Foram determinados, ainda, o coeficiente de extinção a 280 nm de 26,03 L.g-1 e o Poder Calorífico Superior de 23,72 kJ.g-1. A partir das informações obtidas em todas as análises, foi proposta uma estrutura para esta lignina. A deslignificação via polpação soda mostrou-se eficiente na remoção de lignina da matriz e foi verificado que, durante o processo, ocorre o rompimento de ligações entre a lignina e carboidratos, entretanto, algumas dessas ligações não são rompidas e o resíduo do processo, denominado lignina, contêm cerca de 17% carboidratos. A lignina soda apresentou poder calorífico superior de 25,14 kJ.g-1, 36% em massa de carvão residual e cinética de termodegradação com energia de ativação de 12,73 kJ.mol-1 e k0=0,4195 min-1. Foi verificado que as polpas soda que sofreram pré-tratamentos apresentaram um menor teor de lignina e maior solubilização de hemiceluloses. Estes tratamentos se mostraram eficientes na hidrólise dos complexos lignina-carboidrato e a ligninas obtidas apresentaram os menores teores de carboidrato residual e características estruturais diferentes das demais, mostrando-se mais condensadas em função das reações que ocorrem em meio ácido. Os coeficientes de extinção a 280 nm foram iguais a 24,2 L.g-1 e 23,3 L.g-1, respectivamente para as ligninas de explosão a vapor e pré-tratamento ácido e suas fórmulas estruturais determinadas por 1H RMN foram, respectivamente, C9Har1,59Hal4,12O0,84(OH)ph0,61(OH)al0,88(OCH3)1,51 e C9Har2,12Hal4,23O1,64(OH)ph0,83(OH)al0,58(OCH3)1,10.
In this work, the characterisation of lignins of sugarcane straw was made. The lignins were isolated by moderate acidolysis and soda process, preceded or not by either diluted acid or steam explosion pretreatments. The sugarcane straw and the lignins were characterised by High Performance Liquid Chromatography (HPLC), Infrared (FT-IR) and Ultraviolet (UV) Spectrometry, Proton Nuclear Magnetic Resonance (H1-RMN), Gel Permeation Chromatography (GPC), Thermogravimetrica analysis (TGA) and Differential Scattering Calormietry (DSC), Elemental Analysis and Heat Power (HP). The technical lignin isolated by moderate acidolysis has the formula C9Har2.31Hal4.14O1.27(OH)ph0.58(OH)al1.19(OCH3)1.11, H:G:S ratio of 1 : 3.22 : 3.68, is 20% condensed and its avarage molecular weight is 1908 Da. The thermal degradation kinetics analysis of this lignin in inert atmosphere was carried out, the results obtained were: activation energy of 13.80 kJ.mol-1, pre-exponential constant of 0.4799 min-1 and 42% residual char. The extinction coefficient obtained at 280 nm was 26.03 L.g-1 and the heat power 23.72 kJ.g-1. A structure was proposed for this lignin based on all the information obtained from these analyses. The delignification via soda process was efficient at removing lignin; during the process, the breaking of bonds between the lignin and carbohydrates was noticed, nevertheless, some of these bonds were not broken and the process residue, hereinafter called lignin, contains about 17% carbohydrates. The soda lignin has heat power of 25.14 kJ.g-1, 36% residual char and the thermal degradation kinetics ocurred with activation energy of 12.73 kJ.mol-1 and k0=0.4195 min-1. It was found that pretreated soda pulps have a lower lignin content and higher solubilisation of complexes, the lignins obtained had the lowest residual carbohydrates contents and different structural features from the untreated ones, being more condensed due to the reactions that occur in acid medium. The extinction coefficients at 280 nm obtained are 24.2 L.g-1 and 23.3 L.g-1, the structural formulas determined by 1H RMN are C9Har1.59Hal4.12O0.84(OH)ph0.61(OH)al0.88(OCH3)1.51 and C9Har2.12Hal4.23O1.64(OH)ph0.83(OH)al0.58(OCH3)1.10 for the steam explosion and acid pretreatment lignins, respectively.

Mise en uvre d'un procede de delignification utilisant un reacteur a lit fixe et faible temps de passage, concernant plus particulierement le traitement du bois de peuplier par les procedes a la soude, soude-anthraquinone et kraft. Dans chaque cas, l'etude cinetique fait apparaitre trois regimes distincts et confirme le role essentiel du ph. L'addition de na#2s et/ou de aq ameliore remarquablement la cinetique et la selectivite de la delignification. L'analyse des procedes montre que les reactions de recondensation de la lignine sur les fibres sont peu prononcees. Ceci permet d'obtenir plus rapidement des pates mieux delignifiees et moins degradees qu'en reacteur clos. Ce phenomene est confirme par la caracterisation chimique, spectrometrique et macromoleculaire des lignines recuperees en cours de traitement. Les resultats mettent en evidence des reactions d'hydrolyse et de degradation diverses. Ils confirment le role selectif de na#2s. Il apparait que, quel que soit le type de delignification alcaline, ces reactions de degradation sont les memes

Submitted in fulfillment of the requirements for the Degree of Doctor of Technology: Biological Sciences, M.L. Sultan Technikon, 2002.
The extent of diffusion and surface modification of a purified 23.6 kDa xylanase isolated from Thermomyces lanuginosus on bagasse pulp was evaluated. Polyclonal anti-xylanase antibodies were raised in two rabbits and in conjunction with immunogold labeling and microscopic studies enzyme diffusion and degradation studies were performed. The purity of the xylanase was confirmed by SDS-PAGE and western blots confirmed the antigen-antibody hybrid on the nitrocellulose membrane.
D

The pulp and paper industry uses pulping chemicals for the treatment of bagasse, straw and wood chips. Spent liquor or effluent liquor, with high carbon content is produced and sent to chemical recovery to recover pulping chemicals. In addition, energy from the spent liquor is recovered and utilised to generate steam for electricity supply, thereby reducing fossil fuel power consumption. Spent liquor is destroyed using conventional incineration technology, in a recovery furnace or recovery boiler, which is the heart of chemical recovery. These units have over the past few decades been prone to numerous problems and are a major concern to the pulp and paper industry. They pose a threat to the environment, are expensive to maintain and constitute a safety hazard. Thus the pulp and paper industry is now looking at a replacement technology; an alternative that will effectively regenerate pulping chemicals and recover energy for generating electricity, ultimately to make the plant energy self-sufficient. Gasification technology may be the chosen technology but is yet to be applied to the pulp and paper sector. However, this technology is not new. It has been integrated and used successfully in the petroleum industry for decades, with applications in coal mining and the mineral industry. The overall objective of tills study is to develop a better understanding of gasification using a pilot-scale fluidised bed reactor which was designed and developed at the University of Natal. The reactor, "the Gasifier", is operated at temperatures below the smelt limits of inorganic salts (<750°C) in the spent liquor. In this investigation, spent liquor is injected directly into an inert bed of alwninium oxide grit, which is fluidised by superheated steam. The atomized liquor immediately dries when it contacts the grit in the bed, pyrolyses and the organic carbon is gasified by steam. Pyrolysis and steam gasification reactions are endothennic and require heat. Oxidised sulphur species are partially reduced by reaction with gasifier products, which principally consist of carbon monoxide, carbon dioxide and hydrogen. The reduced sulphur is said to be unstable in the gasifier environment, and reacts with steam and carbon dioxide to form solid sodium carbonate and gaseous hydrogen sulphide. (Rockvam, 2001). The focus of this study will be to determine the Gasifier's ability to gasify spent liquor, from soda and sulphite pulping of bagasse, at different operating conditions. In addition, the fate of process and non-process elements will be investigated. The product gas generated in the gasification of spent soda and sulphite liquors consisted of hydrogen, carbon dioxide, carbon monoxide and methane. In the gasification of spent sulphjte liquor, hydrogen sulphide was also produced. The water-gas shift reaction, which was the main reaction, was found to be temperature dependent. In adilition, organic carbon conversion increased with temperature. Furthermore, most of the sulphur in the bed predominated in the form of hydrogen sulphide with very little sulphur in the form of sulphate. This indicated that gasification would reduce sulphate levels, which are responsible for dead load in a chemical recovery cycle. Finally, an important result was that the aluminium oxide grit was successfully coated. It was previously speculated that this would not be possible.
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.