Biochar systems have been beneficial to Kenyan residents living in the rural areas, particularly in Kwale, following recent research interventions. Biochar system starts from the biomass feedstock sourcing, its production method, and finally its application to soil. The aim of this study is to assess the climate change impacts of the application of biochar in smallholder farms and households in rural Kenya, against the traditional agriculture and cooking practices under realistic conditions and from a life cycle perspective. The scope of this study includes the biomass sourcing identification, biomass availability measurement, cooking practice observation and biochar application during planting season (April to May) at one of the rural areas, the Waa Ward in Kwale County under The Biochar Project. Field observation was carried out to identify and measure on-farm biomass availability and cooking performance. The identification and measurement of biomass weight were conducted through survey and manual scale, respectively. While the cooking performance was observed with uncontrolled Kitchen Performance Test (KPT) method. A life cycle assessment was conducted to evaluate the climate change impact of biochar system in Kwale. The biochar production method, also called the improved system in this study, is compared against the traditional system. This study focuses at the cookstove used for the two systems, Gastov and three-stone open fire. Gastov is a type of Top-Lit UpDraft (TLUD) natural draft gasifier cookstove investigated. The biomass measurement established the biomass and energy availability on-farms in Kwale. Meanwhile, the KPT found that Gastov required lesser fuel for cooking due to higher thermal efficiency in comparison to three-stone open fire. The LCA results showed that the improved system performs better than the traditional system in terms of climate change impacts and that the improved system potentially offset GHG emissions caused by traditional system as well as generates a net carbon credit. Lastly, the ‘hotspot’ of the improved system was identified in the cooking process, although it was also significantly better than the traditional cooking process. The sensitivity analysis showed that both fraction of stable carbon and fraction of non- renewable biomass (fNRB) were major factors in the biochar system in Kwale, Kenya. The conclusion is that the biochar system presents more advantages as applied in Kwale compared to the traditional system through biomass management, improved cooking method, and biochar application to soil.

Innovation is often assigned an important role in mitigating climate impact and achieving sustainable development. Stockholm city has ambitious sustainability goals and aims to be carbon neutral by 2040. This will require an increased capacity when it comes to promoting and implementing innovative sustainability solutions. Climate friendly innovations need to move from environmental profile projects to the new “business as usual”.  The aim of this study is to contribute with knowledge about innovation processes within sustainable development and how they can be promoted.   Strategic Niche Management (SNM) is a model which was developed to support a transition to sustainable development by promoting sustainability innovations. SNM suggests a number of hypotheses regarding important features of successful innovation niches, factors that will increase the potential of innovations to be developed, implemented and spread. Stockholm Biochar project is an innovative project which has received attention for its success and potential to contribute to sustainable development by reducing the city’s net carbon emissions. A case study of the Stockholm Biochar project has been conducted to identify how the project emerged and the main success factors for its development. The case study was complemented with an interview study with personnel from Vinnova, the Swedish innovation agency, focusing on their experience of success factors for innovation processes. SNM:s hypotheses has then been used to analyze the result of the case study, which was also compared to the result of the Vinnova-study. The analysis to a large extent confirms SNM:s hypotheses, regarding what factors contribute to a successful innovation niche, but also provide some specifications and elaborations on what these hypotheses mean in this specific case. This result is used to suggest possible complements to the SNM hypotheses that can be useful in contexts similar to the one studied. The result also points out important success factors that are not covered by the hypotheses suggested in SNM. Particularly the case study shows the important role of passionate enthusiasts as driving forces for innovation processes which is not pointed out in SNM hypotheses. The identified success factors, in combination with the complemented hypotheses, are used to formulate recommendations for how an organization can promote innovation processes within sustainable development. In short, the study shows that successful innovation processes require assigned resources, commitment and strategic work, e.g. visions with clearly stated sustainability goals, continuous evaluations on how innovations are contributing to these goals, active measures for gaining support for the innovation on multiple levels in society, and financial space for the development of innovations. The study also confirms the function of protected innovation niches and suggests that passionate enthusiasts have a significant role in innovations processes. / Innovation och ny teknik tillskrivs ofta en betydelsefull roll för att minska klimatpåverkan och bidra till hållbar utveckling. Stockholms stad har ambitiösa hållbarhetsmål och staden ska bland annat vara koldioxidneutral år 2040. För att uppnå detta har staden identifierat ett behov av ökad förmåga att främja, tillvarata och sprida innovationer som bidrar till hållbar utveckling. Klimatsmarta innovationer behöver gå från spjutspetsprojekt till att bli det nya ”business as usual”.  Syftet med dennastudie är att bidra med kunskap om hur innovationsprocesser inom hållbar stadsutveckling fungerar och hur dessa kan främjas.   Strategic Niche Mangament (SNM) är en modell som har utvecklats för att stödja en omställning till hållbar utveckling genom att just främja innovationsprocesser. SNM presenterar ett antal hypoteser angående vad som bidrar till framgångsrika innovationsnischer, faktorer som skapar gynnsamma förutsättningar för innovationer att utvecklas, implementeras och spridas. Ett innovationsprojekt som fått stor uppmärksamhet för dess framgång och potential att bidra till hållbar utveckling är Stockholms biokolsprojekt. En fallstudie av Biokolsprojektet har därför genomförts för att identifiera hur projektet uppstod och vad som hittills utgjort viktiga framgångsfaktorer. Detta har kompletterats med en intervjustudie med personal från Vinnova med fokus på deras erfarenhet av framgångsfaktorer för innovationsprocesser. SNM:s hypoteser har sedan använts för att analysera resultatet av fallstudien, som även jämförs med resultatet från Vinnovastudien. Resultatet bekräftar i stor utsträckning SNM:s hypoteser men visar också mer konkret vad hypoteserna inneburit i det specifika fallet. Utifrån detta föreslås en möjlig utveckling av hypoteserna som kan vara användbar i sammanhang som liknar det som studerats. Resultatet pekar också på viktiga framgångsfaktorer som inte omfattas av de hypoteser som föreslås i SNM. Framträdande bland dessa framgångsfaktorer är eldsjälars betydelse för innovationsprocesser vilket inte tas upp i SNM:s hypoteser. De identifierade framgångsfaktorerna och utvecklingen av SNM:s hypoteserhar använts för att formulera rekommendationer för hur en organisation kan främja innovationsprocesser inom hållbar utveckling.   Kortfattat visar studien att innovationsprocesser inom hållbar utveckling behöver avsatta resurser, engagemang och strategiskt arbete, t.ex. i form av visioner med tydliga hållbarhetsmål, uppföljning av hur innovationen bidrar till de målen, aktivt arbete för att skapa förankring för innovationen på olika nivåer i samhället, samt ekonomiskt utrymme för innovationer att utvecklas. Studien bekräftar också funktionen av skyddande innovationsnischer och visar på att eldsjälar har en viktig roll i innovationsprocesser.

Globally the emissions of carbon dioxide from anthropogenic activities are an issue regarding the future of our planet. Today the building industry is a large contributor with approximately 10 percent of the total emissions coming from energy usage in the building industry, where about 7 percent of the global CO2 emissions are connected to the cement industry. Since cement is important and today, a non-replaceable material in concrete mixture considering the mechanical properties this is considered as a problem. Concrete is essential to the building and infrastructure industry and therefore it is of great value for society. To be able to lower the impact of concrete manufacturing, different materials are investigated to replace a part of the cement. Today, alternative materials are implemented in the cement compositions to improve the environmental impact. One material commonly used is fly ash, a waste material from coal combusting industries. However, a renewable and carbon emission sinking product could have a great impact on the total emissions from concrete manufacturing. A product that could be suitable for this is biochar, a product from pyrolysis of biomass. Previous studies show properties that could be desirable in concrete manufacturing such as high specific surface area, low bulk density, low thermal conductivity, and sound-absorbing function. Also, there are studies of biochar in cementitious material with promising results. To further investigate the biochar impact on concrete this thesis is conducted. A literature review of previous studies of biochar applications and biochar addition to concrete was conducted. This is to analyse the properties of biochar and the effect of the application on the concrete properties. Also, an experimental study was conducted to further analyse the concrete and compare the findings to previous studies. In this thesis concrete with biochar ratios of 5, 8, and 10 percentages according to the weight of the cement were compared to evaluate the performance properties. This was conducted by a laboratory test where 100 mm cubes were cast and tested for their compressive strength after 28 and 56 days. Other properties which were evaluated were the workability, density, microstructure, and chemical properties. The result showed that the workability was significantly lower for concrete mixtures with biochar addition. Also, the density decreased as the ratio of biochar increased. The same happened to the compressive strength where the comparison species had a compressive strength of 72 MPa after 28 days and the sample with 10 percent had a compressive strength of 52 MPa. However, the sample with 10 percent of biochar had the highest increase of compressive strength after additional 28 days of curing. The FTIR could not show any significant changes between samples with zero biochar addition and the samples with biochar addition / Utsläpp av koldioxid är ett globalt problem som hotar framtiden för vår planet. Idag är byggindustrin en stor bidragande faktor till dessa utsläpp där omkring 10 % av de globala utsläppen kan kopplas till energiförbrukningen i byggindustrin. 7% av de globala utsläppen kommer från cementindustrin. Då cement är ett så pass viktigt material och det saknas ersättande material med samma egenskaper anses detta vara ett problem. Betong är grundläggande för bygg- och infrastrukturmarknaden och är därför viktigt för samhället. För att kunna minska påverkan av betongtillverkningen så utreds olika material för att kunna minska cementandelen i betongen.  Idag finns alternativa material som ersätter en del av cementen för att minska klimatavtrycket. Ett sådant material är flygaska, vilket är ett restmaterial från industrier. Att i stället ersätta detta med ett förnybart bio-baserat material med koldioxidsänkande egenskaper skulle kunna innebära en förbättring av de miljöpåverkande egenskaper som finns hos betongtillverkningen. En produkt som skulle kunna vara lämplig för detta är biokol vilket är en produkt från anaerob förbränning av biomassa. Tidigare studier visar att egenskaper som skulle kunna vara fördelaktiga vid betongtillverkning finns hos biokol. Dessa egenskaper är hög specifik ytarea,låg skrymdensitet, låg värmekonduktivitet och ljudabsorberande egenskaper. Det finns även tidigare studier där biokol har applicerats till betong där resultatet har varit lovande.  Detta examensarbete har skrivits för att ytterligare analysera biokolets inverkan på betongen. För att göra detta har en litteraturstudie sammanställts med tidigare studier av biokol och biokolets inverkan på betong. Detta för att analysera biokolets karaktärsdrag och vilka effekter det har på betongens egenskaper. Till detta har även en experimentell studie gjorts för att ytterligare analysera betongens beteende vid applicering av biokol och för att kunna jämföra resultat från tidigare studier. I detta examensarbete har cementet i betongen ersatts med 5, 8 och 10% biokol av cementets vikt för att kunna jämföra egenskaperna mellan de olika proverna. Detta gjordes genom ett laboratorietest där 100 mm kuber gjöts och testades för tryckhållfastheten efter 28 och 56 dagar. Andra egenskaper som kontrollerades var konsistensen, densiteten och mikrostrukturen genom FTIR test. Resultatet visade att konsistensen påverkades kraftigt då biokol adderades till betongen. Densiteten minskade desto större andel av cementet som byttes ut. Liknande resultat uppmättes för tryckhållfastheten där den minskade från 71,9 MPa för proverna utan biokol till 51,6 MPa för betongen med 10% biokol, detta efter 28 dagar. Dock så kunde det ses att den största tillväxten av hållfasthet efter ytterligare 28 dagars härdning kunde uppmätas i provet med högst andel biokol (10%). Resultatet från FTIR testet kunde inte visa några tydliga skillnader mellan proverna med och utan biokol.

Master of Science / Department of Agronomy / Scott A. Staggenborg / With the increase in bio-energy production there is also an increase in by-products. Without proper disposal, these by-products might cause future economic and/or ecological problems. Land application has potential as a disposal and/or nutrient cycling method if these by-products have nutritive value for agricultural crops. The purpose of the study was to compare the use of two by-products of bio-energy production, dry distillers grains (ethanol) and charcoal(pyrolysis), as fertilizer with urea in corn (Zea mays L.). The experiment consisted of four location-years in Kansas. Treatments were dry distiller’s grains (DDG) no-till and tilled for four location-years and char no-till and tilled for three location-years. No-till urea was used as a baseline for comparison at all location-years. The Nitrogen rates ranged from 45 to 180 kg N ha-1. All source material was spring applied before tillage and planting. The corn yields for DDGs and urea were the almost the same across tillage treatments and locations. For DDG no-till, DDG tilled, and urea, the rates at which to achieve the same yields were 97, 111, 78 kg N ha-1, respectively. Corn yields for char at all rates and tillage treatments were the same as no fertilizer. The char, because of immobilization or lack of decomposition, did not contribute to the nitrogen needs of the corn. Neither material showed any inhibitory or otherwise negative effects on the corn in terms of grain yield compared with the control. But both DDGs and char had to have large amounts of material applied to achieve the same amount of nitrogen as urea. Land application of DDGs and char has potential merit for disposal/nitrogen cycling with DDGs being preferred for its nitrogen contribution.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: In order to test the effect of different plant growth-promoting strategies on Triticum aestivum L. (wheat), we investigated the ability of biochar and a grain-associated soil yeast, to improve the growth of this crop. Our first goal was to study the effect of biochar amendments to sandy soil on the growth and nutrition of wheat in the presence of mycorrhizal fungi. This was accomplished by amending soil with 0%, 1%, 2.5%, 5% and 10% (w/w) biochar and cultivating wheat plants in these soil-biochar mixtures. After harvesting, plant growth and mycorrhizal colonization of roots were measured. In addition, we studied the nutritional physiology of these plants with regards to nitrogen (N), phosphorous (P) and potassium (K) concentrations, as well as the growth efficiencies and uptake rates of these nutrients. We found that wheat growth was improved by biochar amendments to soil, probably as a result of elevated K levels in the plant tissues supplied by the biochar amendments. The second goal of this study was to obtain a soil yeast from the rhizosphere of another monocot in the family Poaceae, i.e. Themeda triandra Forssk. (red grass), and then evaluate this isolate for its ability to improve wheat performance. Three different Cryptococcus species were isolated from the rhizosphere of wild grass, i.e. Cryptococcus zeae, Cryptococcus luteolus and Cryptococcus rajasthanensis. Since C. zeae was previously isolated from maize, an isolate representing this species was selected to be used in further experimentation. With the ultimate goal of testing the ability of this yeast to improve wheat growth, its effect on wheat germination was investigated and compared to that of two other soil yeasts, i.e. Cryptococcus podzolicus CAB 978 and Rhodotorula mucilaginosa CAB 826. These three yeasts were subsequently tested for their ability to improve wheat growth in pot cultures in a greenhouse. After one and two months of growth, the culturable yeasts present in the rhizosphere and bulk soil were enumerated. The effects of these yeasts were elucidated by measuring wheat growth in terms of dry weight, as well as root and shoot relative growth rates (RGR). Changes in wheat nutrition were evaluated by determining the concentrations, growth efficiencies and uptake rates for P, K, zinc (Zn) and iron (Fe). During this study, it was found that only C. zeae CAB 1119 and C. podzolicus CAB 978 were able to enhance seed germination. Similarly, it was shown that C. zeae CAB 1119 was able to improve wheat growth during the first and second month of cultivation, whereas C. podzolicus CAB 978 only improved growth during the first month, and R. mucilaginosa CAB 826 had no effect on growth. This improved growth could be attributed to C. zeae CAB 1119 improving the P, K, Zn and Fe growth efficiency of wheat, which positively influenced the root and shoot RGR, and subsequently wheat growth. Our final goal was to test whether C. zeae CAB 1119 could affect wheat growth and nutrition when cultivated in sandy soil, which contained natural microbial consortia and 10% (w/w) biochar. Plants treated with viable or autoclaved cells of C. zeae CAB 1119, were subsequently cultivated in soil only or soil amended with biochar. After one month, plants were harvested and growth was measured with regards to dry weight, root RGR and shoot RGR. In addition, the concentrations of P, K, Zn and Fe were analyzed for these plants, where after the growth efficiencies and uptake rates were calculated for these four nutrients. Results indicated that plants growing in soil amended with biochar, and treated with viable C. zeae CAB 1119, showed the best growth. The increased root and shoot RGR witnessed in these plants was probably due to increased concentrations of P and K in the plants. This study opens new avenues of research with regards to the bio-fertilizers of wheat. / AFRIKAANSE OPSOMMING: Die uiteindelike doel van die studie was om die effek van verskillende plantgroei bevorderende metodes op die groei van Triticum aestivum L. (koring) te ondersoek. Dus het ons die vermoë van houtskool en ‘n graan-geassosieerde grondgis getoets om die groei van dié plant te bevorder. Die eerste doel van die studie was om die effek van houtskool toedienings tot sanderige grond te evalueer. Dit is bewerkstellig deur 0%, 1%, 2.5%, 5% en 10% (w/w) van die houtskool by die sand toe te voeg en koring in die houtskool-sand mengsels te kweek. Na die verlangde groei tydperk is die koring geoes en die mikorrizale kolonisasie op en in die koring wortels bepaal. Gedurende hierdie studie is die effek van bogenoemde toedienings op die fisiologie van die plante ondersoek deur die konsentrasies, opname tempo’s, en groei ekonomie van die plante vir stikstof (N), fosfaat (P) en kalium (K) te bepaal. Ons het gevind dat die groei van koring deur die toediening van houtskool bevorder is en dit blyk dat dié effek weens die teenwoordigheid van hoë K vlakke in die plantweefsel is. Die tweede doel van ons studie was om ‘n gis vanuit die risosfeer van ‘n monokotiel wat aan die familie Poacea behoort, naamlik Themeda triandra Forssk. (rooigras) te isoleer. Die vermoë van die isolaat om die groei van koring te bevorder was daarna getoets. Drie verskillende Cryptococcus spesies was vanuit die risosfeer van rooigras geïsoleer, nl. Cryptococcus zeae, Cryptococcus luteolus en Cryptococcus rajasthanensis. Omdat C. zeae in ‘n vorige studie vanaf mielies geisoleer was, is ‘n isolaat van hierdie spesie gebruik in verdere eksperimente. Met die doel om te bepaal of dié gisspesie koringgroei kan bevorder, was die effek van C. zeae op die ontkieming van koring bestudeer en vergelyk met dié van twee ander grond giste, nl. Cryptococcus podzolicus CAB 978 en Rhodotorula mucilaginosa CAB 826. Hierdie drie giste is ook ondersoek om die groei van koring in ‘n glashuis te bevorder. Na een en twee maande se groei was die getalle van giste teenwoordig in die risosfeer en grond verder weg van die wortels bepaal. Die effek van dié giste op die groei van koring is bepaal in terme van droë gewig asook die relatiewe wortel en halm groei tempos. Veranderinge in die nutrient status van koring is ondersoek deur die konsentrasies, groei-ekonomie en tempo van opname vir P, K, sink (Zn) en yster (Fe) te bepaal. Ons het gedurende dié studie gevind dat C. zeae CAB 1119 en C. podzolicus CAB 978 die ontkieming van koring kon verbeter. Ons het ook gevind dat C. zeae CAB 1119 die groei van koring gedurende die eerste en tweede maand van groei kon bevorder, terwyl C. podzolicus CAB 978 dit net gedurende die eerste maand kon vermag en R. mucilaginosa CAB 826 geen effek gehad het nie. Die verbeterde groei kon aan C. zeae CAB 1119, wat die P, K, Zn en Fe groei effektiwiteit van die plante verbeter het, toegeskryf word. Die verbetering van groei effektiwiteit het ‘n positiewe invloed op die relatiewe groeisnelheid van die wortels en halms gehad, en dus op koringgroei. Die laaste doel van die studie was om te bepaal of C. zeae CAB 1119 die groei van koring kon bevorder wanneer die koring in sand wat natuurlike mikrobiese populasies bevat en met houtskool aangevul is, gekweek word. Plante is met lewensvatbare of nielewensvatbare selle van C. zeae CAB 1119 behandel en gekweek in sanderige grond, en/of grond waarby 10% (w/w) houtskool toegevoeg is. Die plante is na een maand geoes en die groei bepaal in terme van droë massa en die relatiewe wortel en halm groei tempos. Die konsentrasies van P, K, Zn en Fe in die plante, asook die fisiologie van die plante, nl. groei ekonomie en tempo van opname, met betrekking tot P, K, Zn en Fe is bepaal, Ons het gevind dat plante wat in die houtskool-grond mengsel gekweek is en met lewensvatbare selle van C. zeae CAB 1119 behandel is die beste groei getoon het. Die verbeterde relatiewe groei tempos van die wortels en halms was mees waarskynlik die gevolg van verhoogde P en K konsentrasies in die plante. Hierdie studie toon nuwe resultate in verband met die gebruik van biologiese alternatiewes tot kunsmis.

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Increasing oil prices along with the climate change threat have forced governments, society and the energy sector to consider alternative fuels. Biofuel presents itself as a suitable replacement and has received much attention over recent years. Thermochemical conversion processes such as pyrolysis is a topic of interest for conversion of cheap agricultural wastes into clean energy and valuable products. Fast pyrolysis of biomass is one of the promising technologies for converting biomass into liquid fuels and regarded as a promising feedstock to replace petroleum fuels. Corn residues, corn cob and corn stover, are some of the largest agricultural waste types in South Africa amounting to 8 900 thousand metric tonnes annually (1.7% of world corn production) (Nation Master, 2005). This study looked at the pyrolysis kinetics, the characterisation and quality of by-products from fast pyrolysis of the corn residues and the upgrading of bio-oil. The first objective was to characterise the physical and chemical properties of corn residues in order to determine the suitability of these feedstocks for pyrolytic purposes. Secondly, a study was carried out to obtain the reaction kinetic information and to characterise the behaviour of corn residues during thermal decomposition. The knowledge of biomass pyrolysis kinetics is of importance in the design and optimisation of pyrolytic reactors. Fast pyrolysis experiments were carried out in 2 different reactors: a Lurgi twin screw reactor and a bubbling fluidised bed reactor. The product yields and quality were compared for different types of reactors and biomasses. Finally, a preliminary study on the upgrading of bio-oil to remove the excess water and organics inorder to improve the quality of this liquid fuel was performed. Corn residues biomass are potential thermochemical feedstocks, with the following properties (carbon 50.2 wt. %, hydrogen 5.9 wt. % and Higher heating value 19.14 MJ/kg) for corn cob and (carbon 48.9 wt. %, hydrogen 6.01 wt. % and Higher heating value 18.06 MJ/kg) for corn stover. Corn cobs and corn stover contained very low amounts of nitrogen (0.41-0.57 wt. %) and sulphur (0.03-0.05 wt. %) compared with coal (nitrogen 0.8-1.9 wt. % and sulphur 0.7-1.2 wt. %), making them emit less sulphur oxides than when burning fossil fuels. The corn residues showed three distinct stages in the thermal decomposition process, with peak temperature of pyrolysis shifting to a higher value as the heating rate increased. The activation energies (E) for corn residues, obtained by the application of an iso-conversional method from thermogravimetric tests were in the range of 220 to 270 kJ/mol. The products obtained from fast pyrolysis of corn residues were bio-oil, biochar, water and gas. Higher bio-oil yields were produced from fast pyrolysis of corn residues in a bubbling fluidised bed reactor (47.8 to 51.2 wt. %, dry ash-free) than in a Lurgi twin screw reactor (35.5 to 37 wt. %, dry ash-free). Corn cobs produced higher bio-oil yields than corn stover in both types of reactors. At the optimised operating temperature of 500-530 °C, higher biochar yields were obtained from corn stover than corn cobs in both types of reactors. There were no major differences in the chemical and physical properties of bio-oil produced from the two types of reactors. The biochar properties showed some variation in heating values, carbon content and ash content for the different biomasses. The fast pyrolysis of corn residues produced energy products, bio-oil (Higher heating value = 18.7-25.3 MJ/kg) and biochar (Higher heating value = 19.8-29.3 MJ/kg) comparable with coal (Higher heating value = 16.2-25.9 MJ/kg). The bio-oils produced had some undesirable properties for its application such as acidic (pH 3.8 to 4.3) and high water content (21.3 to 30.5 wt. %). The bio-oil upgrading method (evaporation) increased the heating value and viscosity by removal of light hydrocarbons and water. The corn residues biochar produced had a BET Brynauer-Emmet-Teller (BET) surface area of 96.7 to 158.8 m2/g making it suitable for upgrading for the manufacture of adsorbents. The gas products from fast pyrolysis were analysed by gas chromatography (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ hydrocarbons. The gases had CO2 and CO of more than 80% (v/V) and low heating values (8.82-8.86 MJ/kg). / AFRIKAANSE OPSOMMING: Die styging in olie pryse asook dreigende klimaatsveranderinge het daartoe gelei dat regerings, die samelewing asook die energie sektor alternatiewe energiebronne oorweeg. Biobrandstof as alternatiewe energiebron het in die afgope paar jaar redelik aftrek gekry. Termochemiese omskakelingsprosesse soos pirolise word oorweeg vir die omskakeling van goedkoop landbou afval na groen energie en waardevolle produkte. Snel piroliese van biomassa is een van die mees belowende tegnologië vir die omskakeling van biomassa na vloeibare brandstof en word tans gereken as ’n belowende kandidaat om petroleum brandstof te vervang. Mielieafval, stronke en strooi vorm ’n reuse deel van die Suid Afrikaanse landbou afval. Ongeveer 8900 duisend metrieke ton afval word jaarliks geproduseer wat optel na ongeveer 1.7% van die wêreld se mielie produksie uitmaak (Nation Master, 2005). Hierdie studie het gekk na die kinetika van piroliese, die karakterisering en kwaliteit van by-produkte van snel piroliese afkomstig van mielie-afval asook die opgradering van biobrandstof. Die eerste mikpunt was om die fisiese en chemiese karakteristieke van mielie-afval te bepaal om sodoende die geskiktheid van hierdie afval vir die gebruik tydens piroliese te bepaal. Tweendens is ’n kinetiese studie onderneem om reaksie parameters te bepaal asook die gedrag tydens termiese ontbinding waar te neem. Kennis van die piroliese kinetika van biomassa is van belang juis tydens die ontwerp en optimering van piroliese reaktore. Snel piroliese ekspermente is uitgevoer met behulp van twee verskillende reaktore: ’n Lurgi twee skroef reaktor en ’n borrelende gefluidiseerde-bed reaktor. Die produk opbrengs en kwaliteit is vergelyk. Eindelik is ’n voorlopige studie oor die opgradering van bio-olie uitgevoer deur te kyk na die verwydering van oortollige water en organiese materiaal om die kwaliteit van hierdie vloeibare brandstof te verbeter. Biomassa afkomstig van mielie-afval is ’n potensiële termochemiese voerbron met die volgende kenmerke: mielie stronke- (C - 50.21 massa %, H – 5.9 massa %, HHV – 19.14 MJ/kg); mielie strooi – (C – 48.9 massa %, H – 6.01 massa %, HHV – 18.06 MJ/kg). Beide van hierdie materiale bevat lae hoeveelhede N (0.41-0.57 massa %) and S (0.03-0.05 massa %) in vergelyking met steenkool N (0.8-1.9 massa %) and S (0.7-1.2 massa %). Dit beteken dat hieride bronne van biomassa laer konsentrasies van swael oksiedes vrystel in vergelyking met fossielbrandstowwe. Drie kenmerkende stadia is waargeneem tydens die termiese afbraak van mielie-afval, met die temperatuur piek van piroliese wat skuif na ’n hoër temperatuur soos die verhittingswaarde toeneem. Die waargenome aktiveringsenergie (E) van mielie-afval bereken met behulp van die iso-omskakelings metode van TGA toetse was in die bestek: 220 tot 270 kJ/mol. Die produkte verkry deur Snel Piroliese van mielie-afval was bio-olie, bio-kool en gas. ’n Hoër opbrengs van bio-olie is behaal tydens Snel Piroliese van mielie-afval in die borrelende gefluidiseerde-bed reakctor (47.8 na 51.2 massa %, droog as-vry) in vergelyking met die Lurgi twee skroef reakctor (35.5 na 37 massa %, droog as-vry). Mielie stronke sorg vir ’n hoër opbrengs van bio-olie as mielie strooi in beide reaktore. By die optimum bedryfskondisies is daar in beide reaktor ’n hoër bio-kool opbrengs verkry van mielie stingels teenoor mielie stronke. Geen aansienlike verskille is gevind in die chemise en fisiese kenmerke van van die bio-olie wat geproduseer is in die twee reaktore nie. Daar is wel variasie getoon in die bio-kool kenmerkte van die verskillende Snel Piroliese prosesse. Snel piroliese van mielie-afval lewer energie produkte, bio-olie (HVW = 18.7-25.3MJ/kg) en bio-kool (HVW = 19.8-29.3 MJ/kg) vergelykbaar met steenkool (HVW = 16.2-25.9 MJ/kg). Die bio-olies geproduseer het sommige ongewenste kenmerke getoon byvoorbeeld suurheid (pH 3.8-4.3) asook hoë water inhoud (21.3 – 30.5 massa %). Die metode (indamping) wat gebruik is vir die opgradering van bio-olie het gelei tot die verbetering van die verhittingswaarde asook die toename in viskositeit deur die verwydering van ligte koolwaterstowwe en water. Die mielie-afval bio-kool toon ’n BET (Brunauer-Emmet-Teller) oppervlakte area van 96.7-158.8 m2/g wat dit toepaslik maak as grondstof vir absorbante. The gas geproduseer tydens Snel Piroliese is geanaliseer met behulp van gas chromotografie (GC) as CO2, CO, H2, CH4, C2H4, C2H6, C3H8 and C5+ koolwaterstowwe. Die vlak van CO2 en CO het 80% (v/V) oorskry en met lae verhittingswaardes (8.82-8.86 MJ/kg).

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: According to recent studies, biochar has the potential to improve soil fertility, mitigate climate change, reduce off-site pollution and assist in managing wastes. The application of biochar to soil is not a new concept; Amazonian dark earths are carbon-rich soils with high soil fertility that were created before 1541. Vacuum pyrolysis is a thermo-chemical conversion technique in which biomass is transformed into bio-oil, biochar and non-condensable gas. The objective of this work was to investigate the chemical and physical properties of biochar produced from vacuum pyrolysis of black wattle, vineyard annual prunings and sugar cane bagasse for their potential as soil amendment and adsorbent. The vacuum pyrolysis of black wattle, vineyard prunings and sugar cane bagasse (pyrolysis temperature: 460°C, pressure: 8kPaabs, heating rate: 17°C/min) resulted in biochar yields of 23.5%, 31.0% and 19.7% on a weight basis, respectively. The nature of the biomass had a substantial effect on yields of the products. High ash content combined with high lignin composition led to higher biochar yields for vineyard prunings. The highest surface acidity was observed for sugar cane bagasse (2.3 mmol/g), whereas the lowest surface acidity was observed for vineyard biochar (1.67 mmol/g). Consequently, the pH of the biochars was in the order: vineyard (10.43)> black wattle (9.74)> sugar cane bagasse (6.56). The cation exchange capacities (CEC) of biochars were 122 cmol/kg, 101 cmol/kg and 65 cmol/kg for sugar cane bagasse, black wattle and vineyard, respectively. The electrical conductivities (EC) were highly correlated with feedstock nature. The Ca and K rich vineyard biochar resulted in the highest EC (0.83 dS/m), whilst EC values of black wattle and sugar cane bagasse were 0.67 dS/m and 0.17 dS/m, respectively. Biochars contained substantial amounts of plant-available nutrients, while being low in toxic inorganic content (Pb, As, Cd). The BET surface areas of sugar cane bagasse, black wattle and vineyard were 259 mª/g, 241 mª/g and 91 mª/g, respectively. The adsorption capacity was found to increase with increased contact time and initial solution concentration. The experimental equilibrium time were found to be 3505 min, 1350 min and 150 min for adsorption of 20 mg/L methylene blue solution for vineyard, black wattle and sugar cane bagasse, respectively. Equilibrium data were well fitted to Langmuir and Freundlich isotherms. The maximum adsorption capacities were found to be 15.15 mg/g, 14.49 mg/g and 19.23 mg/g for vineyard, black wattle and sugar cane bagasse when modelled with Langmuir isotherms. The adsorption kinetics was found to follow the pseudo-second order kinetic model. In summary, biochar from sugar cane bagasse is a promising adsorbent for the removal of basic dyes due to its high surface area and microporous structure. This biochar can be applied to slightly acidic soils for nutrient retention and the exchange of nutrients. On the other hand, possessing high amounts of nutrients, biochars from black wattle and vineyard are potential soil amendentment agents. Biochar from black wattle is more beneficial compared to biochar from vineyard due to its higher surface area, microporosity and cation exchange capacity. / AFRIKAANSE OPSOMMING: Volgens onlangse studies, het houtskool die potensiaal om grond vrugbaarheid te verbeter, klimaat verandering te versag, besoedeling te verlaag en ondersteuning te verleen in die bestuur van afval. Die toevoeging van houtskool in grond is nie ‘n nuwe konsep nie; Amazone donker gronde is koolstof ryk gronde met hoë vrugbaarheid wat voor 1541 geskep is. Vakuum pirolise is ‘n termo-chemiese omskakelings tegniek waarin biomassa afgebreek word na bio-olie, houtskool en nie-kondenseerbare gasse. Die doelwit van hierdie werk was om die chemiese en fisiese eienskappe van houtskool, wat geproduseer is deur die vakuum pirolise van swart wattel, jaarlikse wingerd snoeisels, en suikerriet bagasse, vir hulle potensiaal vir grond verbetering en adsorpsie toepassings te ondersoek. Die vakuum pirolise van swart wattel, jaarlikse wingerd snoeisels, en suikerriet bagasse (pirolise temperatuur: 460°C, druk: 8kPaabs, verhittingstempo: 17°C/min) het houtskool opbrengste van 23.5%, 31.0% en 19.7% op massa basis, respektiewelik tot gevolg. Die tipe biomassa het ‘n beduidende effek op die opbrengs van die produkte. Hoë as-inhoud, gekombineer met hoë lignien inhoud, lei tot hoër houtskool opbrengste vir wingerd snoeisels. Die hoogste oppervlak suurheid is gevind vir suikerriet bagasse (2.3 mmol/g), terwyl die laagste waarde gevind is vir die wingerd snoeisels (1.67 mmol/g). Gevolglik, is die pH van die houtskole in die volgorde van: wingerd (10.43) > swart wattle (9.74) > suikerriet bagasse (6.56). Die katioon uitruiling vermoë (CEC) van die houtskole was 122 cmol/kg, 101 cmol/kg and 65 cmol/kg vir suikerriet bagasse, swart wattel en wingerd snoeisels respektiewelik. Die elektriese konduktiwiteite (EC) is gekorreleer met die eienskappe van die biomassas. Die Ca en K ryke wingerd snoeisel houtskool het die hoogste EC waarde (0.83 dS/m) tot gevolg, terwyl die EC waardes vir swart wattel en suikerriet bagasse bepaal is as 0.67 dS/ 0.16 dS/m respektiewelik. Die houtskole het groot hoeveelhede plant-beskikbare voedingstowwe bevat, terwyl dit laag was in toksiese anorganiese stowwe (Pb, As, Cd). Die BET oppervlak areas van suikerriet bagasse, swart wattel en wingerd snoeisels was 259 mª/g, 241 mª/g en 91 mª/g respektiewelik. Daar is gevind dat die adsorpsie kapasiteit toeneem met toenemende kontak tyd met die aanvanklike oplossing. Die eksperimentele ewewigs tye is gevind as 350 min, 1350 min en 150 min vir die adsorpsie van ‘n 20 mg/L metileen blou oplossing vir wingerd snoeisels, swart wattel en suikerriet bagasse, respektiewelik. Die ewewigs data het die Langmuir en Freundlich isoterme goed gepas. Die maksimum adsorpsie kapasiteite is gevind as 15.15 mg/g, 14.9 mg/g en 19.23 mg/g vir wingerd snoeisels, swart wattel en suikerriet bagasse wanneer dit gemodeleer is met Langmuir isoterme. Daar is bevind dat die adsorpsie kinetika ‘n pseudo-tweede orde kintika model volg. In opsomming, houtskool van suikerriet bagasse is ‘n veelbelowende adsorpsie middel vir die verwydering van basiese kleurstowwe, as gevolg van die hoë oppervlak area en mikroporie-struktuur van hierdie houtskool. Dié houtskool kan gebruik word op effense suur gronde vir voedingstof behoud en uitruiling. Aan die ander kant, houtskole van swart wattel en wingerd snoeisels wat hoë hoeveelhede voedingsstowwe bevat, is potensiële grond verbeterings middels. Houtskool afkomstig van swart wattel is meer voordelig as die van wingerd snoeisels, as gevolg van die hoër oppervlak area, mikroporositeit en katioon uitruilings vermoë van die swart wattel houtskool.

Biochars have been created and characterized from a variety livestock manure biomass including poultry, dairy, and swine. However, no research has been conducted on the physical and chemical makeup of biochar pyrolyzed from horse muck. Two horse muck derived biochars containing either straw (HS) or woodchip (HW) bedding were pyrolyzed at 700°C and characterized for their physical and chemical properties. Tests revealed both biochars had high alkalinity, moderate specific conductivity, and low surface area as compared to other biochars in the literature. HS contained more mineral structures than HW. Scanning electron microscopy presented differences in particle shape, size, and presence of xylemic structures. The chemical makeup of both biochars was similar, while HW contained about 23% more C than HS while HS contained more calcium and magnesium. The effect of biochar-amended soils on the transport of two Escherichia coli isolates was studied using saturated soil columns. The results show that HW significantly reduced the transport of isolate SP2B07 over the Soil control, and reduced the transport of isolate SP2B07 more than isolate SP1H01. Horse muck biochars may show promise in reducing bacterial transport though agricultural soils.

Marken är en viktig faktor att ta hänsyn till i dagens hårda klimat för våra stadsträd. Allra helst för de träd som skall stå i det mest utsatta delarna av staden, så som på torg, längs med tungt trafikerade vägar eller omringade av bara hårdgjorda ytor. En lösning är skelettjord som används i många städer i Sverige men även i andra länder. I ett projekt i Stockholm testas just nu en vidareutveckling av skelettjordar där AMA-jorden har bytts ut mot biokol. Fördjupningen i denna uppsats kommer därför att handla om hur biokol används rent praktiskt i trädens växtbäddar och vilka effekter detta har på trädens utveckling.   Syftet med denna uppsats är att få en inblick i hur biokol i stadsträdens växtbäddar används med exempel från Stockholm Biochar Project. Syftet är också att undersöka vilka parametrar som används för att mäta biokolets effekt på trädens tillväxt, samt att bedöma vilka effekter biokol har på träd.   Arbetet har genomförts som en intervjustudie som sedan kompletterats med faktasökning i vetenskapliga artiklar och böcker. Intervjupersonen är verksam inom området och arbetar som trädspecialist på trafikkontoret Stockholm stad och är delaktig i Stockholm Biochar Project. Fakta har sökts i olika databaser där sökorden biochar, biokol, terra preta, urbana stadsträd och trädinventering har använts.   Uppbyggnaden av växtbädden med biokol i Stockholm stad har visat sig vara snarlik den gamla modellen men skillnaden kan ses i att AMA-jorden har blivit utbytt mot biokol och även att dimensionerna på makadamen i skelettjorden är något ändrade.   De parametrar som används i Stockholm stad för att mäta trädets tillväxt är stamomkrets. Det finns andra parametrar som går att användas för att bedöma träds tillväxt och dessa skulle även kunna appliceras för att undersöka biokolets effekt på träd.   I en jämförelse av träds tillväxt, där träd av samma art hade växt i liknande förhållanden men i tre olika växtbäddar, visade resultatet att träden som planterats i biokol inte hade den största tillväxten. / The ground is an important factor to consider in today's tough climate for our urban trees. Especially for the trees that shall live in the most vulnerable parts of the city, such as the square, along heavily trafficked roads or surrounded by only paved surfaces. One solution is structured soils which is used in many cities in Sweden but also in other countries. An interesting new development of structured soils where AMA-soil has been replaced with biochar is now being tested in a project in Stockholm. The focus in this paper will therefore be on how biochar is used practically in the tree plant beds and the effects this has on the trees' development.   The purpose of this paper is to get an insight on how biochar in urban tree plant beds are used with examples from Stockholm Biochar Project. And also to examine the parameters used to measure the effect biochar have on tree growth, and to assess the impact of biochar has on the trees.   The work of this paper was carried out as an interview study and was then also combined with research in scientific books and articles. The interviewee is active in the area and works as a tree specialist at the traffic office,Stockholm city and complicit in Stockholm Biochar Project. Researched have been done in various databases where the keywords biokol, biochar, terra preta, urban city trees and tree inventory have been used.   The construction of the plant bed with biochar in Stockholm city has proved to be similar to the old model, but it differs in that the AMA-soil has been exchanged for biochar and also in that the dimensions of the macadam instructured soil is changed.   The parameters used in the Stockholm city to measure tree growth are stem circumference. But there are also other parameters that could be used to measure growth and these could also be applied to assess effect of the biochar on the tree.   In a comparison of tree growth, where tree of the same species had grown in similar conditions but in three different types of plant beds, the results showed that the trees planted in biochar did not have the best growth.

Ett av riksdagens miljömål är att minska övergödande faktorer. En källa till övergödning är kväveutsläpp från avloppsreningsverk. Arvidstorps avloppsreningsverk i Trollhättan väntar en ökad inkommande belastning på grund av befolkningsökning i området samt skarpare krav på utgående halt utsläppt kväve. Detta innebär att planer på att bygga en ny anläggning har satts i verket för att kunna hantera den ökande belastningen. Eventuellt kommer den nya anläggningen inte bli klar innan de nya kraven kommer. Detta gör att reningsverket utreder andra alternativ för att reducera kväve ur avloppsvattnet som kan tas i drift innan den nya anläggningen är klar. Ett alternativ till kväverening är att använda rejektvattenrening eftersom denna avloppsström innehåller höga koncentrationer kväve. Ett annat problem som reningsverket står inför är att kostnaderna för att hantera det avvattnade slammet förväntas öka. Reningsverket utreder därför alternativ för att minska slamvolymen. En biokolsanläggning där biokol tillverkas av det avvattnade slammet skulle kunna vara ett alternativ. Fördelen är att slamvolymen minskar samt att biokol kan användas som vattenrening då det har förmågan att adsorbera ämnen. I detta arbete har två olika tekniker för att rena kväve ur rejektströmmen på Arvidstorps reningsverk studerats. Dessa är dels en beprövad teknik som kallas deammonifikation där kväve renas med bakterier, och dels biokolsadsorption som kvävereningsmetod vilket inte är en lika etablerad reningsteknik på kommunala reningsverk. Deammonifikationsprocessen finns som flera olika tekniker där den som valts för detta arbete är ANITA Mox. ANITA Mox finns som två tillämpningar där den ena är MBBR (Moving Bed Biofilm Reactor) och den andra är IFAS (Integrated Fixed Film Activate Sludge). Målet med detta arbete var att göra en investeingskalkylering för att bedöma hur ekonomiskt försvarbart det är att installera ANITA Mox MBBR eller ANITA Mox IFAS samt uppskatta kvävereningskapaciteten för alternativet med biokolsadsorption. Inga ekonomiska aspekter togs hänsyn till för det senare alternativet.  För beräkningarna byggdes modeller i Excel och två olika experiment utfördes. Pyrolysering av rötrest till biokol och adsorption, samt ett luftningsförsök för att bestämma faktorer som krävs vid beräkning av luftbehov för deammonifikationsprocessen. ANITA Mox MBBR ha de lägsta årskostnaderna, trots att IFAS kan reducera mer kväve och därmed har lägre driftkostnader. IFAS kräver dessutom en mindre volym total sett med reaktor och sedimenteringsbassäng inräknat, men anledningen till den högre kostnaden är de extra instrument och komponenter som krävs till sedimenteringsbassängen med slamretur och den kortare livslängden på dessa komponenter som ger den högre årskostnaden. Biokol som reningsmetod är inte en lämplig metod då det krävs 66 gånger mer rötrest för att producera den mängd biokol som krävs för att rena rejektvattnet. Den rötrest som kommer produceras i en framtida anläggning kan endast reducera 1,5 % av kvävemängden. / One of the environmental goals for the Swedish parliament is to reduce eutrophic factors. A source of eutrophication is nitrogen emissions from waste water treatment plants. Arvidstorp's waste water treatment plant in Trollhättan expects a population increase and sharper requirements for outgoing nitrogen emissions. This means that plans to build a new plant have been put into operation in order to handle the increasing load. The new facility may not be ready before the new requirements come. The waste water treatment plant is therefore investigating other options for reducing nitrogen from the wastewater. An alternative to nitrogen removal is to use reject water purification since this sewage stream contains high concentrations of nitrogen. Another problem facing the waste water treatment plant is that the costs of handling the dewatered sludge is expected to increase. The treatment plant is therefore looking for alternatives to reduce the sludge volume. A biomass pyrolysis plant where biochar is produced by the dewatered sludge could be an alternative since the advantage is that the sludge volume is reduced and that biochar can be used as water purification as it has the ability to adsorb substances. In this work, two different techniques to remove nitrogen from the reject stream at Arvidstorp's treatment plant has been studied. One is a proven technique called deammonification where nitrogen is purified with bacteria, the other one is biochar adsorption as a nitrogen removal process, however not an equally established purification technique on municipal waste water treatment plants. Several different techniques exists as deammonification processes. The one chosen for this work is ANITA Mox. ANITA Mox is available as two implementations where one is MBBR and the other is IFAS. The goals of this work was to make an investment calculation to assess how economically justifiable it is to install either ANITA Mox MBBR or ANITA Mox IFAS and to estimate the nitrogen removal capacity of the alternative with biochar adsorption. No economic aspects were taken into account for the latter option. For the calculations, models were built in Excel and two different experiments were performed. Pyrolysis of digestion residue for biochar production and adsorption, as well as an aeration test to determine the factors required when calculating the air demand for the deammonification process. ANITA Mox MBBR has the lowest annual costs, even though IFAS can reduce more nitrogen and thus have a greater impact on operating costs. IFAS also requires a smaller reactor volume. The reasons for the higher cost are the extra instruments required for the sedimentation basin and the shorter life span of these components which gives the higher annual cost. Biochar as a purification method is not a suitable method as it requires 66 times more sludge to produce the amount of biochar required to purify the reject water. The sludge that will be produced in a future plant can only reduce 1.5% of the nitrogen load.