This bachelor thesis is written as a Minor Field Studies (MFS) project and funded by SIDA, Sweden’s International Development Cooperation Agency. The project was made in cooperation with Engineers Without Borders Sweden and the local organization Asulma Centre in Nairobi. As a part of their Integrated Solar Research collaboration between the two organizations, the project strives to contribute to the United Nations sustainable development goals. Most households in Kenya rely on wood, charcoal and other sources of fossil fuel to use for cooking food. Unfortunately, these fuels produce smoke that causes great problems for the environment and for human health and can, in the worst cases, be lethal. It is estimated that 23 000 Kenyans die yearly from household air pollution produced from the fossil fueled stoves. Using the sun to cook food is a cheap alternative to conventional methods that are also more sustainable as it does not produce any smoke. The aim of this research was to study, analyze and optimize the model of a solar cooker called a conical cooker. In order to improve a previously developed concept of the conical cooker, this project focuses on what material and manufacturing methods should be used. A functional means tree was used to generate concepts, which were then analyzed using tools such as EduPack and an evaluation matrix based on a developed specification of requirements. After analyzing all the plausible options, it was suggested that the conical body should be made from a 1 mm (gauge 19) stainless steel sheet that has been mechanically polished and then joined together by crimping to shape the cone. The resulting product would cost 1430 KSH to manufacture, which is just below the cost of today’s cooker. It is also produced to withstand corrosion damage as well as maintain a reflective surface in order to work as a sufficient solar cooking method. This would be a cheap alternative that reduces health risks among the citizens of Kenya. However, as a solar cooker, it must be used together with other solutions as the sun is not always available which is why the project is called the Integradet Solar Cooking project. / Denna kandidatuppsats är skriven som ett Minor Field Studies (MFS)-projekt och finansierades av SIDA, Sveriges biståndsmyndighet. Projektet genomfördes i samarbete Ingenjörer Utan Gränser Sverige och den lokala organisationen Asulma Centre i Nairobi. Som en del av ett samarbete mellan de två organisationerna strävar detta projekt efter att bidra till Förenta Nationernas hållbara utvecklingsmål. De flesta hushåll i Kenya förlitar sig på ved, kol och andra fossila bränslekällor för att laga mat. Tyvärr producerar dessa bränslen rök som orsakar stora problem för miljön och människors hälsa och kan i värsta fall vara dödliga. Uppskattningsvis dör 23 000 kenyaner årligen till följd av luftföroreningar i hemmet som produceras av spisar med fossila bränslen. Att använda solen för att laga mat är ett billigt alternativ till konventionella metoder som dessutom är mer hållbart eftersom det inte producerar någon rök. Syftet med denna forskning var att studera, analysera och optimera modellen för en solkokare som kallas en konisk kokare. För att förbättra ett tidigare utvecklat koncept av den koniska kokaren fokuserade detta projekt på vilket material och vilka tillverkningsmetoder som bör användas. Ett funktionsmedelträd användes för att generera koncept som sedan analyserades med hjälp av bland annat EduPack och en utvärderingsmatris som baserats på en framtagen kravspecifikation. Efter att ha analyserat alla möjliga alternativ föreslogs att den koniska kroppen bör tillverkas genom att skära ut önskad form ur en 1 mm rostfri stålplåt (gauge 19). Plåten i rostfritt stål ska sedan mekaniskt poleras och sedan sammanfogas med falsning för att forma konen. Den resulterande produkten skulle kosta 1430 KSH (112 SEK) att tillverka, vilket är strax under priset för dagens kokare. Den är också konstruerad för att motstå korrosionsskador och behålla en reflekterande yta för att fungera som en effektiv solkokningsmetod. Detta skulle vara ett billigt alternativ som minskar hälsoriskerna bland lokalbefolkningen i Kenya. En solkokare måste dock användas tillsammans med andra lösningar eftersom solen inte alltid är tillgänglig varför projektet kallas för det Integrerade solmatlagningsprojektet.

In  Kenya, lack of clean cooking services affect around 80 % of the population. A range of improved cookstoves (ICS) have been produced to address this. This study aims to investigate the long-term usage of an improved stove, the biochar producing gasifier. The stove was distributed to 150 rural households divided between three regions in Kenya, in a research project in 2016. This follow-up study looked at areas of stove satisfaction and dissatisfaction among participants, as well as identifying key factors which separate users from non-users. All 150 were asked a few questions over the phone and 30 were visited for in-depth, survey-based interviews. Most households used the traditional three stone open fire stove for everyday purposes, sometimes complemented by the gasifier or other ICSs[CS1] [CS2] . 60 % of households used the gasifier at least monthly. Users and non-users rated the gasifier stove similarly. They varied in terms of stove ownership with users owning on average half a stove more than non-users. User households were generally larger. The gasifier was a fuel efficient stove and created little smoke, but was considered too small and required tiresome fuel preparation. The reported problems cannot be fixed unless thoroughly changing the stove design and possibly the gasification process itself, and without addressing them the gasifier is unlikely to replace the three stone stove. The study recognizes the potential of the gasifier as an improved stove, but calls for creative redesign in order to achieve mass adoption. / I Kenya påverkar bristen på matlagningsutrustning som är säker ur hälso- och miljösynpunkt runt 80 % av befolkningen. Traditionellt lagas mat över öppen  eld. En mängd spisar har producerats i syfte att förändra detta. I denna studie undersöktes långtidsanvändningen av en spis, en biokolsproducerande förgasningsspis. Spisen delades ut till 150 hushåll på landsbygden, jämnt fördelade på tre regioner i landet i ett forskningsprojekt år 2016-7. Denna uppföljningsstudie tittar på vilka aspekter hos spisen som forskningsdeltagarna tyckt om respektive funnit utmanande, samt vad som skiljde användare från de som slutat använda spisen. En kort telefonintervju gjordes med alla, och med 30 gjordes djupgående, enkätbaserade intervjuer. Resultaten visade att de flesta hushåll lagade mat över öppen eld till vardags, ibland kompletterat med förgasningsspisen eller andra spisar. 60 % av hushållen använde förgasningsspisen  minst en gång i månaden. Användare och icke-användare hade liknande åsikter om förgasningsspisen. Användare ägde i genomsnitt en halv spis mer än icke-användare. Hushåll som använde förgasningsspisen var generellt sett större. Förgasningsspisen ansågs vara en bränslesnål spis och bara skapa en liten mängd rök, men ansågs vara för liten. Den krävde också mer ansträngande bränsleförberedning. De rapporterade problemen går inte att åtgärda utan att ändra förgasningsspisens design i grunden och eventuellt själva förgasningprocessen, och utan att åtgärda dem kommer förgasningsspisen sannolikt inte att ersätta matlagning över öppen eld. Studien understryker förgasningsspisen potential, men kräver kreativ omdesign för att uppnå massanvändning.

Lignin är en av de vanligaste naturliga råvarorna på jorden och finns mestadels i trä. Nuförtiden är valoriseringen av lignin en av processutvecklingarna för teknologier inom massa- och pappersindustrin. Denna utveckling syftar till att öka värdet av lignin. Traditionellt förbränns genererat lignin, känt som tekniskt lignin, som bränsle i sodapannan som en del av svartlutskomponenter, och denna praxis är används kontinuerligt inom massa- och pappersindustrin. Syftet med detta examensarbete är att undersöka det tekniska ligninet från två specifika träslag, Acacia crassicarpa (Acra) och Eucalyptus Hybrids (Euca), för att öka kunskapen om det tekniska ligninet och hitta lämpliga tillämpningar för dessa råvaror i framtiden. I denna studie isolerades lignin från svartlut som genererats från två olika kokningsmetoder, kraftkokning- och kraftbased dissolvingkokning (KP och DP). Karakteriseringsmetoderna inkluderade molekylviktsfördelning (THF-SEC), analys av ligninets funktionella grupper med fosfor-31 Nuclear Magnetic Resonance (31P-NMR) kvantifiering och ligninets trukturella elementanalys via Two-Dimensional Heteronuclear Single Quantum Correlation NMR (2D-HSQC NMR). Utbytet erhållet från kraftkokning (KP) och kraftbased dissolvingkokning (DP) visade inga skillnader för samtliga prover och resultaten visas inom samma intervall (cirka 0,06-0,08 g/mol svartlut). Molekylviktsfördelningen för KP och DP-kokning ligger fortfarande inom intervallet för kraftlignin Mw (1500-5000 g/mol) och polydispersitetsindex (PDI) för KP hade ett högre värde än DP för båda typerna av undersökta råvaror. För de funktionella grupperna hade Eucalyptus Hybrids högre -OH-halt än Acacia crassicarpa oavsett kokningstyp. 31P-NMR kvantifieringsdata visade tydligt att KP-Euca innehöll den högsta halten av  alifatisk-OH (1,4 mmol/g). DP-Euca hade den högsta halten C5-kondenserad (2,5 mmol/g), medan den högsta mängden Guaiacyl-OH identifierades i DP-Acra (1,2 mmol/g). Fingeravtrycket av kopplingarna som kvantifierades från 2D-NMR HSQC visade att KP hade högre β-O-4', β-5' och β-β' interenhetskopplingar än DP. Dessutom hade Acacia crassicarpa en högre andel interenhetskopplingar än Eucalyptus Hybrids för båda kokmetoderna. De högsta β-O-4'-, β-5'- och β-β'-kopplingarna detekterades i KP-Acra med 3,4 %, 0,5 % respektiv 4,3 %. / Lignin is one of the most abundant natural raw materials on Earth and is mostly found in wood. Nowadays, the valorization of lignin is one of the continual process developments for technologies in the pulp and paper industry. This development is intended to increase the value of lignin. In the traditional approach, generated lignin known as technical lignin is burnt as fuel in the recovery boiler as part of black liquor components, and this practice is still common in the pulp and paper industry. The objective of this thesis work is to explore the technical lignin from specific wood species, Acacia crassicarpa (Acra) and Eucalyptus Hybrids (Euca), to emphasize the knowledge about the technical lignin and finding suitable application for the mentioned raw materials in the future. In this study, lignin was isolated from black liquor generated from two different cooking methods, kraft and kraft dissolving pulp cooking (KP and DP). The Characterization methods included molecular weight distribution by THF-SEC, lignin functional groups analysis via Phosphorus-31 Nuclear Magnetic Resonance (31P-NMR) quantification, and lignin structural elements analysis via Two-Dimensional Heteronuclear Single Quantum Correlation NMR (2D-HSQC NMR). The isolation yield obtained from kraft cooking (KP) and kraft dissolving pulp cooking (DP) did not have drastic differences for all the samples and therefore the results are within the same ranges (around 0.06-0.08 g/mol of black liquor). The molecular weight distribution values of KP and DP cooking are still within the range of kraft lignin Mw (1500-5000 g/mol) and the polydispersity index (PDI) of KP had a higher value than DP for both types of raw material investigated.  For the functional groups, Eucalyptus Hybrids had the higher -OH content than Acacia crassicarpa regardless of the cooking type. The 31P-NMR quantification data showed clearly that KP-Euca was the richest in Aliphatic-OH (1.4 mmol/g). DP-Euca had the greatest amount of C5-Condensed (2.5 mmol/g), while the highest amount of Guaiacyl-OH was identified in DP-Acra (1.2 mmol/g). The fingerprint of the linkages that was quantified from 2D-NMR HSQC showed that KP cooking had a higher β-O-4’, β-5’ and β-β’ interunit linkages than DP cooking. Furthermore, Acacia crassicarpa had a higher interunit linkages percentage than Eucalyptus Hybrids for both cooking methods. The highest β-O-4’, β-5’ and β-β’ linkages were detected in KP-Acra with 3.4 %, 0.5 %, and 4.3 % respectively.

Doctor of Philosophy / Food Science Institute -- Animal Science & Industry / J. Scott Smith / Heterocyclic amines (HCAs) are produced in meats cooked at high temperature, which are potent mutagens and a risk factor for human cancers. Occurrence of HCAs in ready-to-eat (RTE) meat products and cooked meat products based on prevalence of various cooking methods that are preferred among U.S. meat consumers were investigated. The primary HCAs detected in samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline). RTE meat products were ranked in the following order of increasing total HCA content: pepperoni (0.05 ng/g) < hot dogs and deli meat products (0.5 ng/g) < fully cooked bacon (1.1 ng/) < rotisserie chicken meat (1.9 ng/g) < rotisserie chicken skin (16.3 ng/g). In cooked meat products, high levels of total HCAs were found in fried pork (13.91 ng/g), fried fish (14.91 ng/g), and fried bacon (17.91 ng/g). Inhibition of HCAs by rosemary extracts, which were extracted with different solvents, were evaluated in cooked beef patties. Five rosemary extracts were 100W (100% water), 10E (10% ethanol), 20E (20% ethanol), 30E (30% ethanol), and 40E (40% ethanol). Rosemary extract 20E containing a mixture of rosmarinic acid (27.3 mg/g), carnosol (72.9 mg/g), and carnosic acid (4.2 mg/g) showed the greatest inhibition of MeIQx (up to 91.7%) and PhIP (up to 85.3%). The effect of enhancement and marination on HCA formation in meat products was investigated. The addition of salt and phosphate greatly improved the water-holding capacity and decreased HCA formation (up to 58%) in enhanced fresh meat products. An greater reduction of HCAs (up to 79%) was found in marinated fresh meat; the enhancement solution for this meat contained ingredients that exhibited good antioxidant properties.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1985 F66 / Master of Science

Call number: LD2668 .T4 1985 S72 / Master of Science

Master of Science / Food Science Institute - Animal Science & Industry / Fadi M. Aramouni / Determining the optimum cooking instructions for microwavable not-ready-to-eat foods requires an understanding of the factors that affect heating of foods in microwaves. Factors are often studied without consideration of interactions. Consumer-driven factors appear to be the least-studied. Microwave appliance, heat time, flip step, and plate material were studied to determine their effect on final temperature of a frozen hand-held calzone sandwich after heating. Initial studies to ensure wattage stability during testing and a study to narrow down the plates to be tested were also executed. In the central experiment, a calzone was heated on a microwavable plate for one minute, then flipped or not flipped and heated again for the remaining time in each of four microwave ovens. The microwave ovens differed in age and manufacturer, but were of similar stated wattage. Probes were attached to a data logger and temperatures were recorded every 5 seconds for 2 minutes post-heating to attain the average maximum temperature and lowest maximum temperature for each run. The data was evaluated by analysis of variance and significant differences were compared using Tukey means. All factors had significant effects on average maximum temperature and lowest maximum temperature with the exception of the flip step (p< .05). Plate type was the most critical factor. Calzones heated on paper plates were significantly hotter than those on stoneware plates (p<.05). Significant differences were also observed among microwaves and heat times (p<.05). An interaction between microwave and plate type indicated the effect of plate type was not consistent across all microwaves (p<.05). Although flip step, as tested, was not a significant factor, a follow-up experiment to de-couple the effect of the physical flipping of the calzone and the stopping of the microwave during the heating process indicated that the stopping of the microwave was more critical to heating than the actual flip step. A follow-up study of plate type, microwave and heat time in higher-wattage microwaves showed that microwave appliance and heat time again had significant effects on temperature (p<.05), however; plate type was not a significant factor in the higher-wattage microwaves. The effect of plate type was dependent on the exact microwave used. Various plate types and multiple microwaves in each wattage range should be used for development of microwavable frozen calzones because wattage alone cannot predict performance and because of the interaction between microwave and plate type.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Pulp and paper mills are being placed under increasing pressure to maximise the use of the biomass being processed for pulp, and move towards integrated biorefineries (IFBRs), where a diverse range of products can be produced and not just pulp exclusively. Extracting hemicelluloses prior to the pulping process could increase the profitability of the mills as the hemicelluloses could be used to produce a number of additional products. Hemicelluloses are a plant polysaccharides with the most abundant hemicellulose in hardwoods being xylan, with xylose being the primary monosaccharide constituent of xylan. The majority of pulps produced in the Southern Hemisphere are done with hardwoods as feedstock, typically with the Kraft process. The attraction of the concept of extracting hemicellulose prior to pulping is further augmented by the fact that hemicellulose is underutilised in the Kraft process. In the Kraft process the hemicellulose is dissolved during pulping and burned along with lignin for the production of energy, however, hemicellulose has about half the heating value when compared to that of lignin. The main objective of this study was to find a pre-extraction method that is effective in releasing xylan from Eucalyptus grandis, the most important hardwood feedstock used for pulping in the Southern Hemisphere. The method also needs to be practical in terms of integrating it into the Kraft process and should have a minimal effect on pulp yield and subsequent paper qualities. Xylan extractions from E. grandis as feedstock were carried out with white liquor, green liquor and NaOH. Green liquor is the dissolved smelt originating from the recovery boiler in the Kraft process and consists mainly sodium carbonate and sodium sulphide. White liquor’s principal components include sodium hydroxide and sodium sulphide and is used in the digesters during the pulping stage of the Kraft process. NaOH is a make up chemical used in the Kraft process. These chemicals were chosen since they are all already present within the Kraft process. The suitability of these chemicals as xylan extraction methods is further bolstered by the fact that their alkalinity may actually reduce chemical usage in pulping. This provides scope for integration of hemicellulose extraction into Kraft pulping without implementing major changes to the existing industrial process. Moreover, alkali chemicals for pre-extraction allow for minimal effect on resulting pulp and paper. In terms of the extracted product, the alkaline conditions provided by these chemicals create conditions that are suitable for a high degree of polymerisation of hemicelluloses. Xylan pre-extracted chips from selected extraction conditions were subjected to varying pulping conditions, to replicate pulp yields and properties obtained with untreated E. grandis chips when using conventional pulping. Handsheets were also produced from the pulps produced under the highest pulp yield conditions, and these were tested for pulp quality properties. Furthermore, mass balances were performed to gauge the impact that hemicellulose pre-extraction would have using green liquor, white liquor and NaOH on the sodium and sulphur balances of the mill. From the extractions performed, the highest fraction of xylan recovered was 15.15% w/w utilising 2M NaOH, at 120°C for 90 minutes extraction time. This was followed by white liquor extraction at 13.27% w/w utilising 20% AA at 140°C for 90 minutes. Green liquor extraction produced the lowest xylan recovery at 7.83% w/w with 2% TTA and 160°C with an h-factor of 800. The residues from selected extraction conditions were utilised for these pulping optimisation experiments. Selected extraction conditions used for further pulping included 2% TTA and 160°C for green liquor, 20% AA and 120°C and 140°C extraction temperature for white liquor, as well as 2M concentration and 120°C for NaOH. The highest yielding pulping conditions were achieved with a 35% reduction in pulping chemicals and 45 minutes pulping time in combination with green liquor pre-extraction, while for pulping combined with white liquor pre-extraction a 50% reduction in chemicals and 30 minute pulping time was preferred. For pulping subsequent to NaOH pre-extraction a 75% reduction in the NaOH dosage and a 45 minute pulp time was preferred. All pulp steps were performed at 170°C. Unbeaten handsheets produced from the selected pulping conditions for white liquor and green liquor extracted chips showed similar physical properties (burst, tear, tensile indices) when compared to the control (pulps from non-extracted chips). However the greater quantity of xylan removed from cellulose fibres with NaOH extraction, resulted in pulps with lower xylan contents, which affected the burst and tear indices of the handsheets formed from these pulps. An increase in tear, while a reduction in the burst index, was observed for the pulp produced from NaOH extracted chips. It was concluded that although white liquor and NaOH extraction allows for greater xylan recovery, the large chemical expenditure associated with these methods will impose significant cost impacts on the existing Kraft process. From mass balances performed, green liquor xylan extraction due to its lower alkalinity, will be more forgiving in terms of additional make up chemical costs. It also allowed for minimum effect on both the pulp and paper quality, thus making it the most practical of the pre-extraction methods. However, whether the additional make chemicals required for the green liquor extraction method will be justified by the quantity of xylan extracted will only be answered by a thorough economic assessment, which was not in the scope of this project. / AFRIKAANSE OPSOMMING: Pulp- en papiermeule word onder toenemende druk geplaas om die gebruik van die biomassa wat vir pulp verwerk word, te maksimaliseer, en om te beweeg na geïntegreerde bioraffinaderye, waar ʼn groot verskeidenheid produkte vervaardig kan word, en nie slegs uitsluitlik pulp nie. Die ekstraksie van hemisellulose voor die verpulpingsproses kan die winsgewendheid van die meule verhoog, aangesien die hemisellulose gebruik kan word vir die vervaardiging van verskeie bykomende produkte. Hemisellulose is ʼn plantpolisakkaried, met xilaan as die hemisellulose wat die oorvloedigste in hardehout gevind word, en met xilose as die primêre monosakkaried-bestanddeel van xilaan. Die meerderheid van die pulp wat in die Suidelike Halfrond geproduseer word, word met hardehout as voerstof gedoen, tipies met behulp van die Kraft-proses. Die aanloklikheid van die konsep om hemisellulose voor verpulping te win, word verder versterk deur die feit dat hemisellulose in die Kraft-proses onderbenut word. In die Kraft-proses word die hemisellulose tydens verpulping opgelos en saam met lignien verbrand vir die opwekking van energie, maar hemisellulose het egter ongeveer die helfte van die verhittingswaarde van dié van lignien. Die vernaamste doelstelling van hierdie studie was om ʼn pre-ekstraksiemetode te vind wat xilaan doeltreffend van Eucalyptus grandis, die belangrikste hardhout-voerstof wat in die Suidelike Halfrond vir verpulping gebruik word, kan vrystel. Die metode moet ook prakties wees met betrekking tot integrering met die Kraft-proses, en dit moet ʼn minimale uitwerking op pulpopbrengs en gevolglike papiergehalte hê. Xilaan-ekstraksie uit E. grandis as voerstof is uitgevoer met wit loog, groen loog en NaOH. Hierdie chemikalieë is gekies omdat hulle reeds in die Kraft-proses teenwoordig is. Die geskiktheid van hierdie chemikalieë as xilaan-ekstraksiemetodes is verder ondersteun deur die feit dat hul alkaliniteit moontlik chemiese verbruik in verpulping kan verlaag, wat ruimte vir die integrasie van hemisellulose-ekstraksie in Kraft-verpulping laat sonder om grootskaalse veranderinge aan bestaande nywerheidsprosesse te implementeer. Alkali-chemikalieë vir preekstraksie lei boonop tot ʼn minimale uitwerking op resultante pulp en papier, terwyl die alkalitoestande, met betrekking tot die geëkstraheerde produk, toestande skep wat geskik is vir ʼn hoë mate van polimerisasie van hemisellulose. Uit die ekstraksies wat uitgevoer is, is die hoogste fraksie xilaan gewin deur die gebruik van NaOH teen 15.15% w/w met 2M NaOH, teen 120 °C vir 90 minute ekstraksietyd. Dit is gevolg deur witloog-ekstraksie teen 13.27% w/w met die gebruik van 20% AA teen 140 °C vir 90 minute. Groenloog-ekstraksie het die laagste xilaan-winning teen 7.83% w/w met 2% TTA en 160°C met ʼn h-faktor van 800 voortgebring. Houtspaanders wat aan xilaan-pre-ekstraksie met groen loog onderwerp is, het pulp met kappanommers en opbrengste soortgelyk aan dié van nie-geëkstraheerde spaanders voortgebring toe die chemiese lading met 35% verlaag is, in verhouding tot dít wat vir niegeëkstraheerde spaanders gebruik is. Xilaan-pre-geëkstraheerde spaanders met wit loog het ʼn 50%-vermindering in verpulpingschemikalieë gelewer in verhouding tot houtspaanders wat aan konvensionele verpulping onderwerp is. Die chemiese reduksie van groen loog was minder as dié van wit loog weens die laer alkalilading wat tydens hemisellulose-ekstraksie voor verpulping gebruik is. Vir witloog-ekstraksie kon pulpopbrengste gehandhaaf word, alhoewel pregeëkstraheerde spaanders met wit loog ʼn neiging getoon het om pulp met laer kappanommers voort te bring. Alhoewel pulp wat uit houtspaanders gemaak is wat aan NaOH-ekstraksie onderwerp is, gelei het tot ʼn 75%-vermindering van NaOH gebruik in verhouding tot dié van konvensionele verpulping, is verwag dat geen NaOH benodig sou word nie, aangesien die houtspaanders reeds tydens xilaan-ekstraksie aan 2M NaOH blootgestel is. Voorts, in die literatuur is verpulping uitgevoer ná 2M NaOH-ekstraksie sonder dat die toevoeging van NaOH tydens verpulping nodig was [61]. Handvelle is vervaardig uit die pulp wat in die hoogste pulpopbrengs-toestande vervaardig is, en dit is vir pulpgehalte-eienskappe getoets. Die verpulpingstoestande met die hoogste opbrengs is bereik met ʼn 35%-vermindering van verpulpingschemikalieë en 45 minute verpulpingstyd in kombinasie met groenloog-pre-ekstraksie, terwyl vir verpulping met witloogpre- ekstraksie ʼn 50%-vermindering van chemikalieë en 30 minute verpulpingstyd verkies is. Vir verpulping ná NaOH-pre-ekstraksie is ʼn 75%-vermindering van die NaOH-dosis en 45 minute verpulpingstyd verkies. Alle verpulpingstappe is teen 170°C uitgevoer. Ongeklopte handvelle vervaardig uit die gekose verpulpingstoestande vir witloog- en groenloog- geëkstraheerde spaanders het soortgelyke fisiese eienskappe getoon (bars-, skeuren trek-indeks) in vergelyking met die kontrole (pulp uit nie-geëkstraheerde spaanders). Die grootste hoeveelheid xilaan is egter uit sellulose vesel met NaOH-ekstraksie verkry, wat gelei het tot pulp met laer xilaaninhoud, wat die bars- en skeur-indeks van die handvelle wat uit hierdie pulp vervaardig is, beïnvloed het. ʼn Toename in die skeur-indeks, met ʼn afname in die bars-indeks, is waargeneem vir die pulp wat uit NaOH-geëkstraheerde spaanders vervaardig is. Die gevolgtrekking is gemaak dat alhoewel witloog- en NaOH-ekstraksie groter xilaanwinning moontlik maak, die groot chemiese uitgawe geassosieer met hierdie metode ʼn aanmerklike koste-impak vir die bestaande Kraft-proses inhou. Groenloog-xilaanekstraksie sal, weens die laer alkaliniteit, meer geskik wees met betrekking tot die koste van bykomende aanvullende chemikalieë. Dit hou ook ʼn kleiner uitwerking op die pulp- en papiergehalte in, wat dit dus die praktieste van die pre-ekstraksiemetodes maak. Of die bykomende chemikalieë nodig vir die witloog- en NaOH-ekstraksies egter geregverdig kan word deur die hoeveelheid xilaan wat gewin is, kan slegs deur ʼn deeglike ekonomiese assessering beantwoord word, wat nie binne die omvang van hierdie projek geval het nie.