see document / Master of Science

M.S.

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

In paper pulp production, many details can be optimized. For optimal separation of soap from black liquor, it is important to know the amount of soap in the black liquor. A project to produce a method for sampling black liquor and a method for measuring how much soap is present in black liquor by centrifugation was done at Södra Cell Mönsterås. Through centrifugation faster analysis can be done. It took a long time to develop a satisfactory sampling method, but with the help of careful checking of temperature and time, a method was achieved that worked at temperatures between 90 and 100°C, which were the temperatures that were most frequently found, but are higher than the optimum temperature for soap separation. The black liquor turned out to be inhomogeneous, so the project failed to obtain an optimal analysis method within the framework of this project. In the experiment, the centrifuge settings were optimized to 87°C, 2500 rpm and 10 minutes Further attempts could provide more optimal settings for the centrifuge and a substitute for black liquor could make a validation of the centrifuge possible. / Pappersmassaproduktion är komplex, och en rad faktorer kan optimeras. En viktig parameter vid såpavskiljning är innehållet såpa i svartlut eftersom en värdefull produkt, tallolja utvinns av såpa. Projektet syftar till att ta fram en metod för provtagning av svartlut och en metod för att mäta halten såpa i svartluten genom centrifugering. Genom centrifugering kan snabbare analyser göras.  Arbetet har utförts på Södra Cell Mönsterås. Arbetet att utveckla en tillfredsställande provtagningsmetod var komplicerad, men med hjälp av noggrann koll på temperatur och tid uppnåddes en metod som fungerade vid temperaturer mellan 90 och 100°C, vilket var de temperaturer som oftast fanns, men som är högre än optimal temperatur för såpavskiljning. Svartluten visade sig vara inhomogen, därför lyckades det inte att få fram en optimal analysmetod inom ramen av detta projekt. I försöket optimerades centrifugens inställningar till 87°C, 2500 rpm (varv per minut) och 10 minuter. Vidare försök skulle kunna ge mer optimala inställningar för centrifugen genom den utvecklade prov, och ett substitut för svartlut skulle kunne göra en validering av centrifugen möjlig.

No description available.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1979. / Bibliography: leaves 138-142.

Background. Tall oil production at Södra Cell is an important byproduct produced at the facility in Mörrum. This process is monitored using a vast system of interconnected sensors that continuously monitor the system. At this time, these systems are operated under manual control without any guidance from data-driven analysis. Therefore, we propose an integrated alarm detection system based on the sensor data. Objectives. This study investigates the possibility of using a data-driven analysis system to detect decreases in the targeted variable. Three different approaches are investigated and evaluated on their performance to understand how these approaches can be used to improve the production process by predicting the changes of the target value.  Methods. Three quasi-experiments are conducted to understand how well different machine learning methods can predict and be used in the production process of tall oil. Each experiment is executed independently of each other with their own setup. Results. Out of three different machine learning methods that were tested, had neural network perform the best, while the two methods that observe the historical data trends seem to have problems with the specific data set. Conclusions. From this research, it can be stated that a neural network algorithm can accurately predict changes in the chemical production process. There are multiple machine learning algorithms that can further be used to improve production at Södra Cell.

M.S.

This report is intended to provide the reader with an extensive background information on hydrode oxygenation (HDO) of Tall Oil Pitch (TOP), combined with results from chemical property analyses of the same. Firstly, the importance of hydrogenation and oxygen removal for a biomass-based feed material is highlighted. The chemical nature of TOP in general is described and the target for the research work is identified. It is decided to evaluate the possibility of TOP as a prospective material for achieving partial oxygen removal. The effect of catalysis on HDO behavior is assessed, and subsequently, conventional commercial catalysts are selected. Chemical analyses of the feed mixture provided data on various properties, which can then be correlated to the products from hydrogenation. Kinematic viscosity of TOP is determined, followed by acid number and saponification number tests to evaluate the free acid and total acid contents respectively. Reasoning for any deviations are highlighted and suggestions are provided to control deviation in process parameters. GC/MS analysisof the tall oil sample is also conducted to understand the presence of oxygen-containing species. Carbon residue and ash tests revealed the coking and ash forming tendency of the samples. In addition, XRF spectroscopy results indicated the metal presence in the TOP sample. Experimental trials are carried out to sulphide the catalysts prior to use in hydrogenation experiments. Catalyst sulphidation procedure is also outlined. Furthermore, the lab-scale reactor is tested for hydrogenation to determine challenges that normally arise during high-pressure working conditions. In addition to discussion of challenges regarding batch hydrogenations and sulfidations, proposals on future work in this domain is outlined, along with suggestions on an experimental pathway forward.

Tall oil is a mixture of rosin acids, fatty acids, and non-acids resulting from acidification of the soaps separating out from the kraft pulp process evaporator liquor. The present uses of tall oil center chiefly around its fatty acid content, but are limited for some purposes because of the rosin content. Separation of these constituents makes each available as such. The rosin, as crystalline abietic acid, has specific possibilities as a raw material. Rosin and fatty acids are separated chiefly by distillation, although chemical means and extraction have been proposed to overcome such objections as corrosion and losses as pitch, incurred in distillation. Chlorination is used as a step in the purification of tall oil, or to produce a sticky chlorinated oil, but no separation based on the use of chlorine appears to have been proposed. It was proposed in this investigation to chlorinate the fatty acid double bonds in hopes that the properties of this product would be such as to permit of a separation. The effects of solvent, light, heat, and catalysts were studied to determine the optimum conditions for such a reaction, and the effect of chlorination upon the rosin and fatty acids, respectively, under specific conditions was determined, It was found that the use of CCl₄ solvent and ultraviolet light accelerate chlorine consumption and promote the addition of chlorine, but do not entirely stifle the substitution reaction. Rosin and fatty acid double bonds are attacked to about an equal extent under these conditions. The chlorinated oil is entirely soluble in most common solvents at room temperature. Petroleum ether insolubles increase slightly over the amount obtained from untreated oil. It is recommended that the range of chlorination conditions be extended to a more complete study of possible results, and that other chemical attacks be investigated. / Master of Science