In this study the use of available agro-industrial and forest residues, in Alagoas, were evaluated for use in ceramic furnaces to energy generation. At first, a survey of various types of biomass in Brazil and in Alagoas was made, followed by a investigation of the main permanent and temporary crops that could generate agro-industrial residues. Later, studies of the forms of use of agro-industrial residues as well as a quantitative assessment and energy that can be generated from the agro-industrial residues from major crops of Alagoas were conducted. The main agro-industrial residues next to the bigger five ceramics, located in adjacent municipalities of Alagoas were characterized in terms of physical-chemical parameters, comparing energy demands with their possible use in furnaces. The process of manufacturing of briquettes was also subject to a case study involving such a process on laboratory scale. The economic evaluation of the use of agro-industrial residues considering the preparation, transportation and energy consumption in furnaces and one simulation, considering various scenarios for the use of agro-industrial residues, with reference to a ceramic Arapiraca were made. In addition, the case of utilization of eucalyptus wood for energy generation was assessed using economic and financial study, simulating the culture of this crop in a rural settlement. The various aspects investigated here showed that the agro-industrial residues from the processing of agricultural production in the State of Alagoas could be used in ceramic and can completely replace the fuel currently used in furnaces, for one ceramic located in the Arapiraca region, where these kind of residues are available. In the case of ceramics located in regions where the availability of agro-industrial residues is limited, an alternative of renewable fuel, would be the culture of energy forests with native or exotic species, such as the eucalyptus. / Nesse estudo foi avaliada a utilização de resíduos agroindustriais e florestais do Estado de Alagoas, para utilização em fornos cerâmicos para geração de energia. Inicialmente, foi realizado um levantamento dos diversos tipos de biomassa existentes no Brasil e em Alagoas, seguido de um levantamento das principais culturas agrícolas permanentes e temporárias que poderiam gerar resíduos agroindustriais. Após, foram efetuados estudos das formas de utilização dos resíduos agroindustriais assim como uma avaliação quantitativa e da energia que pode ser gerada, a partir dos resíduos agroindustriais provenientes das principais culturas agrícolas de Alagoas. Os principais resíduos agroindustriais dos municípios limítrofes as cinco principais cerâmicas de Alagoas foram caracterizados, do ponto de vista físico-químico, comparando-se demandas energéticas com a possível utilização desses em fornos ou fornalhas. O processo de fabricação de briquetes também foi alvo de um estudo de caso envolvendo tal processo em escala laboratorial. A avaliação econômica do aproveitamento dos resíduos agroindustriais considerando a preparação, o transporte e o consumo energético em fornalhas e fornos cerâmicos foi alvo de investigação e uma simulação, considerando vários cenários para o aproveitamento de resíduos agroindustriais, tomando como referência uma cerâmica em Arapiraca. Complementarmente, a hipótese de utilização da lenha de eucalipto para a geração de energia foi avaliada através de estudo econômico e financeiro, simulando o plantio dessa cultura em um assentamento rural. Os vários aspectos aqui investigados apontaram que os resíduos agroindustriais provenientes do beneficiamento da produção agrícola do Estado de Alagoas poderiam ser usados nos fornos cerâmicos sem processamento ou adensados e poderiam substituir totalmente os combustíveis atualmente utilizados nos fornos ou fornalhas, de cerâmicas localizadas na região de Arapiraca, privilegiada nesses tipos de resíduos, pela alta produção agrícola. No caso de cerâmicas, localizadas em regiões onde exista pouca disponibilidade de resíduos agroindustriais, uma alternativa em termos de combustível renovável, seria o plantio de florestas energéticas com espécies nativas ou exóticas como, por exemplo, o eucalipto.

Este trabalho tem como objetivo preparar membranas compostas de α-alumina recobertas com paládio usando a técnica de deposição química electroless plating associada ao método sol-gel. Foram realizados tratamentos térmicos a 1450°C nos suportes cerâmicos em 6, 12, 18, 24 e 30 h visando verificar a influência do tempo na porosidade do mesmo. Foram preparadas membranas compostas, alumina-Pd com uma, duas e três camadas de paládio na superfície externa do suporte cerâmico, em que o suporte e as membranas foram caracterizados por: análise morfológica realizada por Microscopia Eletrônica de Varredura (MEV) e Microscopia Eletrônica de Varredura de Emissão de Campo (FESEM), porosidade avaliada pelo Método de Brunauer, Emmet e Teller (BET), Método de Barret-Joyner-Halenda (BJH) e porosimetria de mercúrio, quantificação de paládio em solução por Espectrometria de Massa com plasma indutivamente acoplado (ICP-MS) e a permeabilidade e seletividade dos gases mensurada a partir de um equipamento em escala de bancada. O aumento do tempo durante a sinterização não promoveu mudanças significativas na porosidade do suporte, mostrando que o tempo de 6 h de tratamento térmico é suficiente para atingir a menor distribuição de tamanho de poro do material. A formação da camada de paládio foi realizada sem e com a associação do método sol-gel, apresentando uma camada mais homogênea com o uso do método, no entanto a análise de ICP-MS indicou maior quantidade de metal paládio na deposição electroless plating. A análise morfológica indicou espaços vazios menores de acordo com o número de camadas formadas. O suporte cerâmico sem e com camada de paládio apresenta variação na permeabilidade aos gases N2, CH4 e CO2 nas pressões de 100 a 400 kPa e quanto mais espessa a camada de paládio formada, menor é a permeabilidade dos gases. / Within this context, this work aims to prepare membranes composed of α-alumina coated with palladium using the electroless plating technique associated with the sol-gel method. To achieve the objectives of the paper, analyzes of porosity of the ceramic support with and without heat treatment of 1450°C for 6; 12; 18; 24 and 30 h, the formation of one, two and three layers of palladium on the external surface of the ceramic support, the effect of the sol-gel method, the chemical and physical properties, permeability and selectivity of the gases were performed. Morphological analysis were performed by Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscope (FESEM), the membrane porosity was evaluated by the Brunauer, Emmet and Teller (BET) theory, Barret-Joyner-Halenda (BJH) method and by mercury porosimetry, the palladium quantification in solution was given by mass spectrometry with inductively coupled plasma (ICP-MS) analysis and gas permeability and selectivity were measured by a bench scale equipment. The time increase during the sinterization did not promote representing changes in the support porosity, which shows that the 6 h time of heat treatment is sufficient to achieve the lowest porosity of the material. The palladium layer formation was realized without and with the combination of the sol-gel method, presenting a more homogeneous layer with the use of the method. However, the ICP-MS analysis indicated a greater amount of palladium deposition without sol-gel method. The morphological analysis showed smaller empty spaces according to the number of layers formed. The ceramic support without and with palladium layer showed variation in permeability to N2, CH4 and CO2 gases at pressures of 100 to 400 kPa and the higher the palladium layer formed, the smaller the gas permeability

Algae offer as much as 30 times greater biomass productivity than terrestrial plants, and are able to fix carbon and convert it into a number of interesting products. The numerous challenges in algae production and use extend across the entire process chain. They include the selection of suitable algal phyla, cultivation (which takes place either in open ponds or in closed systems), extraction of the biomass from the suspension, through to optimal use of the obtained biomass. The basic suitability of aquatic biomass for material use and energy supply has been demonstrated in a large number of studies. Numerous research projects are concerned with identifying the optimal processes to enable its widespread implementation. [... aus der Einleitung]

The objective of this study is to develop a model to evaluate the economic feasibility of biofuels production, and in particular to isolate the variables crucial to feasibility. The model constructed to define these variables is unique in its ability to accommodate a variety of plants and to integrate all portions of the production process; it was tested on a case study of a Euphorbia lathyris industry. The model minimizes costs of production to determine the best configuration for the industry. Total cost equals the sum of costs incurred in each segment of the process: growth, harvest, transport, and extraction. The solution is determined through a non-linear transportation- transshipment algorithm which describes production as a series of nodes and links. Specific application of the model was analysis of E. lathyris biofuel production in Arizona. Simulations were run examining the sensitivity of biocrude cost to changes in input parameters. Conclusions are summarized as follows. * No change in any single element can reduce final cost sufficiently to enable competitive production in the near future. * The major factor necessary to bring cost into range is improvement in biological yield. Two components of equal importance are tonnage produced per acre and percentage extractables recovered in processing. * Lowering cropping costs provided the most effective improvements of economic inputs. Perennial crops significantly reduced farm costs. * Transportation costs outweighed economies of scale in extraction; extractor location close to crops is more efficient than centralized. The cost minimization model was successfully used to isolate the critical factors for an E. lathyris industry in an arid region. Results determine that this industry would not be competitive in Arizona without dramatic improvements in yields and moderate changes in a combination of input costs. Viability is critically dependent on improvements in tonnage yield produced per acre and percent extractables recovered.

Recent years have seen an unprecedented global increase in the production and use of biofuels. This has been driven primarily by government support for biofuel industries. Soybeans are the only field crop produced in sufficient quantities in the province of KwaZulu- Natal (KZN) that the South African (SA) industrial biofuel strategy identifies as a potential biodiesel feedstock. Thus, this study is an evaluation of the economic feasibility of producing biodiesel on farms from soybeans in the main soybean-producing regions of KZN, using batch processing biodiesel plants. A mixed integer linear programming model was developed to simulate observed agricultural land rental rates (estimated at 4.48% of the market value of land) and cropping behaviour of commercial crop farms in the study regions. The model incorporates various alternative crops, crop rotations, tillage techniques, arable land categories and variance-covariance matrices to account for risk in production. All data are on a real 2009/10 basis. The model is used to predict possible farmer investment behaviour and determine the minimum biodiesel subsidy required to stimulate soybean-based biodiesel production in the study areas. Results suggest that biodiesel production is currently not an economically viable alternative to fossil fuel, and that the incentives and commitments outlined by the current industrial biofuel strategy are inadequate to both establish and sustain a domestic biodiesel industry. Under baseline assumptions, a realistic minimum implicit subsidy of R4.37 per litre of biodiesel is required to draw soybean-based biodiesel production into the optimum solution for commercial farms. The economic feasibility of on-farm biodiesel production is highly dependent on the soybean price (i.e., the feedstock input cost) and the soybean oilcake price (i.e., the highest valued byproduct). Thus, future promotion of biodiesel ventures could primarily target a reduction of feedstock costs through the development of new technologies which increase yields of available feedstocks and/or permit the use of lower cost alternatives. Higher subsidy levels are anticipated for: (i) small-scale initiatives (particularly in the absence of a rental market for cropland); (ii) soybean-based biodiesel production in areas with less suitable growing conditions for cultivating soybeans; and (iii) using sunflower and/or canola as biodiesel feedstock. To the author’s knowledge no other previous studies have attempted to quantify the minimum level of support needed to stimulate biodiesel production in South Africa. The SA industrial biofuels strategy promotes a development-oriented strategy with feedstock produced by smallholders and processed by traditional producer-owned cooperatives. However, traditional cooperatives suffer from a myriad of institutional problems that are associated with ill-defined property rights. As such, it is argued that these initiatives will fail to attract the capital and expertise needed to process biodiesel. This research, therefore, highlights the need for South Africa’s current Cooperatives Act to be amended. Accordingly, this also infers a need to revise the proposed SA industrial biofuels strategy. It is concluded that smallholder participation in biodiesel ventures would require a rental market for cropland, co-ownership of the processing plant in a non-traditional cooperative or investor-owned firm, information and training, and a high level of government subsidy. This research advocates that government consider promoting soybean oil extrusion ventures as a means of stimulating rural development for small-scale farming initiatives rather than soybean-based biodiesel production, as they will likely require less government assistance, whilst potentially combating the food versus fuel debate against biofuels. This is compounded by the fact that South Africa has historically been a net importer of both soybean oilcake and soybean oil. Importantly, however, the proliferation of such initiatives should not be based on the current notion of traditional cooperatives. The need for government to play a proactive role in such ventures through facilitating the development of appropriate business models which stimulate private investment in feedstock and processing facilities is clearly evident. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Seed-oil based biodiesel production particularly biodiesel production from the nonedible oil seed bearing plant - Jatropha curcas L. - is a key strategic direction outlined in the biofuels strategy of the Government of Ethiopia. The main objective underlying the strategy include substitution of imported diesel oil used in the road transport sector while at the same time contributing to the local and global greenhouse gasses (GHG) reduction efforts. In this study the environmental benefits and costs of production and use of Jatropha biodiesel in the road transport sector of Ethiopia is assessed using a life cycle analysis (LCA) methodology. The analysis focused on determining the potential environmental impacts and net non-renewable energy saving potential of biodiesel from Jatropha oil-seeds using the following metrics: (i) Net Greenhouse Gas (GHG) reduction, and (ii) Net Energy Balance (NEB) relative to diesel oil. The study shows that the net GHG emissions reduction potential of Jatropha Methyl Ester (JME) is highly influenced by the magnitude of initial carbon loss occurring in the process of conversion of different land uses to Jatropha plantation, and less so on other unit processes of JME production system analysed. The NEB of JME relative to use of diesel oil per functional unit of one GJ is less sensitive to impacts of land use change and is generally positive. Where no land use change impacts is considered, or where Jatropha is grown on lands with low carbon stock such as grasslands, substitution of diesel oil with JME in Ethiopia can provide GHG emission reduction of about 43%, and for each MJ of JME produced the nonrenewable energy requirement will be 0,38 MJ. Production of JME by converting lands with high above ground, below ground and/or soil carbon stocks such as shrub lands or well stocked forest lands will result in net loss of carbon and require ecological carbon payback time of 50 to hundreds of years. The impact of introducing and use of JME-diesel oil blends by Anbassa City Bus Services Enterprise (ACBSE) bus fleets shows that, displacement of diesel oil with JME that have positive GHG reduction potential, will also contribute to the reduction of air pollutants and improvement of ambient air quality in Addis Ababa. Two key recommendations of this research work are that to ensure environmental sustainability of biodiesel production from Jatropha seeds (i) land availability and land suitability assessment for estimating the potential available land for Jatropha (and other oil-seed bearing plants) shall be conducted, and (ii) minimum requirements on GHG reduction and NEB requirements on biodiesel shall be established. / Environmental Sciences / M. Sc. (Environmental Management)

Thesis (MScEng)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: Through many years of research, a number of production schemes have been developed for converting lignocellulosic biomass into transport fuels. These technologies have been assessed through a number of techno-economic studies for application in a particular context in terms of the technical and economic feasibility. However, previous studies using these methods have tended to lack vigour in various aspects. Either the energy efficiency of the processes were not maximised through adequate heat integration, or a competing technology which existed was not considered. From an economic perspective, the financial models would often lack the vigour to account for the risk and uncertainty that is inherent in the market prices of the commodities. This phenomenon is especially relevant for the biofuel industry that faces the full fledge of uncertainties experienced by the agricultural sector and the energy sector. Furthermore, from an environmental perspective, the techno-economic studies had often ignored the environmental impacts that are associated with biofuel production. Thus, a comparative study could have favoured an option due to its economic feasibility, while it could have had serious environmental consequences. The aim of this study was to address these issues in a South African context, where biofuels could be produced from sugarcane bagasse. The first step would be to modify an existing simulation model for a bioethanol scenario that operates with a Separate Hydrolysis and Fermentation (SHF process) configuration into a second processing scenario that operates with a Simultaneous Saccharification and Fermentation (SSF process) configuration using reliable experimental data. The second step was to ensure that the maximum energy efficiency of each scenario was realised by carrying out pinch point analysis as a heat integration step. In contrast to these biological models is the thermochemical model that converts bagasse to gasoline and diesel via gasification, Fischer-Tropsch synthesis and refining (GFT process). While there were no significant advances in technology concerning this type of process, the energy efficiency was to be maximised with pinch point analysis. The GFT process obtained the highest energy efficiency of 50.6%. Without the affects of pinch point technology, the efficiency dropped to 46%, which thus emphasises the importance of heat integration. The SSF had an efficiency of 42.8%, which was superior to that of the SHF at 39.3%. This resulted from a higher conversion of biomass to ethanol in the SSF scenario. Comparing the SHF model to an identical model found in literature that did not have pinch point retrofits, this study showed lower efficiency. This arose because the previous study did not account for the energy demands of the cold utility systems such as the cooling tower operation, which has been shown in this study to account for 40% of the electrical energy needs. The economic viability of all three processes was assessed with Monte Carlo Simulations to account for the risks that the fluctuations in commodity prices and financial indices pose. This was accomplished by projecting the fluctuations of these parameters from samples of a historical database that has been transformed into a probability distribution function. The consequences were measured in terms of the Net Present Value (NPV) and Internal Rate of Return (IRR) for a large number of simulations. The results of these variables were aggregated and were then assessed by testing the probability that the NPV<0, and that the IRR recedes below the interest rate of 12.64%. The investment was thus deemed unfeasible if these probabilities were greater than 20%. Both biological models were deemed profitable in terms of this standard. The probabilities were 13% for the SSF and 14% for the SHF. The GFT process however was deemed completely unfeasible because the probability that the NPV<0 was 78%. Given that the GFT process had the highest energy efficiency, this result arises mainly because the capital investment of 140,000USD/MWHHV of biomass energy input is to enormous for any payback to be expected. The environmental footprint of each process was measured using Life Cycle Assessments (LCAs). LCAs are a scientifically intricate way of quantifying and qualifying the effects of a product or process within a specified boundary. The impacts are assessed on a range of environmental issues, such as Global Warming, Acidification, Eutrophication and Human toxicity. Furthermore, if the project under concern has multiple output products, then the impacts are distributed between the output products in proportion to the revenue that each generates. The impacts were either relative to the flow of feedstock, which was 600MW of bagasse, or to the functional unit, which was the amount of fuel required to power a standard vehicle for a distance of 1 kilometre. In either case, the GFT scenario was the least burdening on the environmental. This was expected because the GFT process had the highest energy efficiency and the process itself lacked the use of processing chemicals. Relative to the feedstock flow, the SSF was the most environmentally burdening scenario due to the intensive use of processing chemicals. Relative to the functional unit, the SHF was the most severe due to its low energy efficiency. Thus, the following conclusions were drawn from the study:  The GFT is the most energy and environmentally efficient process, but it showed no sign of economic feasibility. iv  There is no significant difference in the economic and environmental evaluation of the SSF and SHF process, even though the SSF is considered to be a newer and more efficient process. The major cause of this is because the setup of the SSF model was not optimised. / AFRIKAANSE OPSOMMING: Deur baie jare van navorsing is ‘n aantal produksie-skemas vir die omskakeling van lignosellulose biomassa na vloeibarebrandstof ontwikkel. Hierdie tegnologië is geassesseer ten opsigte van die tegniese en ekonomiese haalbaarheid deur middel van tegno-ekonomiese studies in bepaalde tekste. Tog het hierdie vorige studies besliste beperkings gehad. Of die energie-doeltreffendheid van die proses is nie gemaksimeer deur voldoende hitte-integrasie nie, of 'n mededingende tegnologie wat bestaan is nie oorweeg nie. Vanuit 'n ekonomiese perspektief, was die finansiële modelle dikwels nie die omvattend genoeg om rekening te hou met die risiko en onsekerheid wat inherent is in die markpryse van die kommoditeite nie. Hierdie verskynsel is veral relevant vir die biobrandstof bedryf wat die volle omvang van onsekerhede ervaar waaraan die landbousektor en die energiesektoronderhewig is. Verder het die tegno-ekonomiese studies dikwels die omgewingsimpakte wat verband hou met biobrandstofproduksie geïgnoreer. Dus kon ‘n opsie deur die ekonomiese haalbaarheid bevoordeel word, ten spyte van die ernstige omgewingsimpakte wat dit kon inhou. Die doel van hierdie studie was om hierdie kwessies aan te spreek in 'n Suid-Afrikaanse konteks, waar biobrandstof uit suikerriet bagasse geproduseer kan word. Die eerste stap was om 'n bestaande simulasiemodel vir 'n bio-scenario wat met Afsonderlike Hidroliese en Fermentasie (SHF proses) stappe werk, te modifiseer vir 'n tweede verwerking scenario wat met 'n gelyktydige Versuikering en Fermentasie (SSF proses) konfigurasie werk. Die verandering is gedoen deur die gebruik van betroubare eksperimentele data. Die tweede stap was om te verseker dat elke scenario die maksimum energie-doeltreffendheid het, deur 'n hitte-integrasie stap, wat gebruik maak van “pinch-point” analise. In teenstelling met hierdie biologiese modelle, is daar die thermochemiese roete waar petrol en diesel van bagasse vervaardig word via vergassing, Fischer-Tropsch-sintese en rafinering (GFT proses). Daar was geen betekenisvolle vooruitgang in tegnologie vir hierdie proses nie, maar die energie-doeltreffendheid is gemaksimeer word deur energie-integrasie. Die GFT proses toon die hoogste energie-doeltreffendheid van 50,6%. Sonder die invloed van energie-integrasie het die doeltreffendheid gedaal tot 46%, wat dus die belangrikheid van hitte-integrasie beklemtoon. Die SSF het 'n effektiwiteit van 42,8% gehad, wat beter was as dié 39,3% van die SHF opsie. Hierdie hoër effektiwiteit wasas gevolg van die hoër omskakeling van biomassa na etanol in die SSF scenario. Die energie doeltreffendheid vir die SHF-model was laer as met 'n identiese model (sonder energie-integrasie) wat in die literatuur gevind wat is. Dit het ontstaan omdat die vorige studie nie 'n volledig voorsiening gemaak het met die energie-eise van die verkillingstelselsnie, wat tot 40% van die elektriese energie behoeftes kan uitmaak. Die ekonomiese lewensvatbaarheid van al drie prosesse is bepaal met Monte Carlo simulasies om die risiko's wat die fluktuasies in kommoditeitspryse en finansiële indekse inhou, in berekening te bring. Hierdie is bereik deur die projeksie van die fluktuasies van hierdie parameters aan die hand van 'n historiese databasis wat omskep is in 'n waarskynlikheid verspreiding funksie. Die gevolge is gemeet in terme van die netto huidige waarde (NHW) en Interne Opbrengskoers (IOK) vir 'n groot aantal simulasies. Die resultate van hierdie veranderlikes is saamgevoeg en daarna, deur die toets van die waarskynlikheid dat die NPV <0, en dat die IRR laer as die rentekoers van 12,64% daal, beoordeel. Die belegging is dus nie realiseerbaar geag as die waarskynlikhede meer as 20% was nie. Beide biologieseprosesse kan as winsgewend beskou word in terme van bostaande norme. Die waarskynlikhede was 13% vir die SSF en 14% vir die SHF. Aangesien die NHW van die GFT-proses onder 0 met ‘n waarskynlikheid van 78% is, is die opsie as nie-winsgewend beskou. Gegewe dat die GFT-proses die hoogste energie-doeltreffendheid het, is die resultaat hoofsaaklik omdat die kapitale belegging van 140,000 USD / MWHHV-biomassa energie-inset te groot is, om enige terugbetaling te verwag. Die omgewingsvoetspoor van elke proses is bepaal deur die gebruik van Lewens Siklus Analises (“Life Cycle Assessments”) (LCAS). LCAS is 'n wetenskaplike metodeom die effek van ‘n produk of proses binne bepaalde grense beide kwalitatief en kwantitatief te bepaal. Die impakte word beoordeel vir 'n verskeidenheid van omgewingskwessies, soos aardverwarming, versuring, eutrofikasie en menslike toksisiteit. Voorts, indien die projek onder die saak verskeie afvoer produkte het, word die impakte tussen die afvoer produkte verdeel, in verhouding tot die inkomste wat elkeen genereer. Die impak was met of relatief tot die vloei van roumateriaal (600MW van bagasse), of tot die funksionele eenheid, wat die hoeveelheid van brandstof is om 'n standaard voertuig aan te dryf oor 'n afstand van 1 kilometer. In al die gevalle het die GFT scenario die laagste belading op die omgewing geplaas. Hierdie is te verwagte omdat die GFT proses die hoogste energie-doeltreffendheid het en die proses self nie enige addisionele chemikalieë vereis nie. Relatief tot die roumateriaal vloei, het die SSF die grootse belading op die omgewing geplaas as gevolg van die intensiewe gebruik van verwerkte chemikalieë. Relatief tot die funksionele eenheid, was die SHF die swakste as gevolg van sy lae energie-doeltreffendheid.

Thesis (PhD(Agric))--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The energy paradigm shift from fossil fuels to renewable energy sources is driven, among others, by a growing sustainability awareness, necessitating more sophisticated measurements in terms of a wider range of criteria. Technical efficiency, financial profitability, environmental friendliness and social acceptance are some of the factors determining the sustainability of renewable energy systems. The resulting complexity and conflicting decision criteria, however, constitute major barriers to processing the information and decision-making based on the information. Seeking to implement local bioenergy systems, policymakers of the Cape Winelands District Municipality (CWDM), South Africa, are confronted with such a problem. Following a case study approach, this study illustrates how life-cycle assessment (LCA), multi-period budgeting (MPB) and geographic information systems (GIS) can aid the decision-making process by providing financial-economic, socio-economic and environmental friendliness performance data in a structured and transparent manner, allowing for a comparison of the magnitude of each considered criterion along the life-cycle. However, as the environmental impacts cannot readily be expressed in monetary terms on a cardinal scale, these considerations are given less attention or are omitted completely in a market economy. By measuring the various considerations on an ordinal scale and by attaching weights to them using the multi-criteria decision analysis (MCDA) approach, this study, illustrates how to internalise externalities as typical market failures, aiding policymakers of the CWDM to choose the most sustainable bioenergy system. Following the LCA approach, 37 lignocellulosic bioenergy systems, encompassing different combinations of type of harvesting and primary transport, type of pretreatment (comminution, drying, and fast pyrolysis) and location thereof (roadside or landing of the central conversion plant), type of secondary transport from the roadside to the central conversion plant, and type of biomass upgrading and conversion into electricity, were assessed against five financial-economic viability criteria, three socio-economic potential criteria and five environmental impact criteria. The quantitative performance data were then, as part of the MCDA process, translated into a standardised ‘common language’ of relative performance. An expert group attached weights to the considered criteria using the analytical hierarchy process (AHP). The ‘financial-economic viability’ main criterion received a weight of almost 60%, ‘socio-economic potential’, nearly 25% and ‘lowest environmental impact’, the remainder of around 16%. Taking the prerequisite of financial-economic viability into consideration, the preferred option across all areas of the CWDM (despite various levels of productivity) comprises a feller-buncher for harvesting, a forwarder for primary transportation, mobile comminution at the roadside, secondary transport in truck-container-trailer combinations and an integrated gasification system for the conversion into electricity. / AFRIKAANSE OPSOMMING: Die energie paradigma verandering van fossielbrandstowwe na hernubare energiebronne word gedryf deur ‘n groeiende klem op volhoubaarheid, wat ook meer gesofistikeerde meting in terme van ‘n wyer verskeidenheid maatstawwe vereis. Tegniese doeltreffendheid, finansiële winsgewendheid, omgewingsvriendelikheid en sosiale aanvaarbaarheid is sommige van die faktore wat die volhoubaarheid van hernubare energie stelsels bepaal. Die verskeidenheid oorwegings bring egter kompleksiteit en konflik mee by die verwerking van inligting en die besluitneming wat daarop berus. Beleidmakers van die Kaapse Wynland Distriksmunisipaliteit wat ten doel het om plaaslik bio-energie stelsels te implementeer, word met hierdie probleem gekonfronteer. Hierdie ondersoek illustreer aan die hand van ‘n gevallestudie benadering hoe lewensiklus analise, multiperiode begroting en geografiese inligtingstelsels besluitneming kan ondersteun deur die voorsiening van finansieel-ekonomiese, sosio-ekonomiese (indiensneming) en omgewingsvriendelikheid prestasie data op ‘n gestruktureerde en deursigtige wyse. Dit maak die vergelyking van die waardes van al die kriteria by elke fase van die lewensiklus moontlik. Aangesien die omgewingseffekte nie geredelik in monetêre terme op ‘n kardinale skaal gemeet kan word nie, kry hulle binne die markekonomie minder aandag of word selfs buite rekening gelaat. Deur hierdie verskeidenheid kriteria op ‘n ordinale skaal te meet en gewigte met behulp van multikriteria besluitneming aan hulle toe te ken, toon hierdie ondersoek hoe om eksternaliteite as tipiese markmislukkings te internaliseer om beleidmakers van die Kaapse Wynland Distriksmunisipaliteit in staat te stel om die mees volhoubare bio-energie stelsel te kies. Met behulp van lewensiklus analise is 37 lignosellulose bio-energie stelsels geïdentifiseer as verskillende kombinasies van oes van die bome, primêre vervoer van houtstompe, vooraf verwerking (verspaandering, droging, vinnige pirolise), die ligging van hierdie aktiwiteite (langs ‘n plantasie of by ‘n sentrale omsettingsaanleg), tipe sekondêre vervoer van houtspaanders vanaf die plantasie na die sentrale omsettingsaanleg en tipe biomassa opgradering en omsetting van die houtspaanders na elektrisiteit. Die verskillende stelsels is gemeet aan die hand van vyf finansieel-ekonomiese kriteria, drie indiensneming potensiaal kriteria en vyf omgewingsimpak kriteria. Die kwantitatiewe metings is deur middel van multikriteria besluitneming omgeskakel na ’n gestandaardiseerde “gemeenskaplike taal” van relatiewe prestasie. Lede van ‘n ekspertgroep het gewigte is aan die onderskeie kriteria met behulp van die analitiese hierargie proses toegeken. Aan die finansieel-ekonomiese lewensvatbaarheid hoof kriterium is ‘n gewig van by die 60% toegeken, aan die indiensnemingspotensiaal bykans 25% en aan omgewingsvriendelikheid sowat 16%. Die voorkeur kombinasie vir al die areas van die Kaapse Wynland Distriksmunisipaliteit sluit in ‘n saag-bondelaar vir die oesproses, ‘n plantasie-vragmotor vir primêre vervoer, mobiele verspaandering langs die plantasie, ‘n vragmotor-skeepshouer-treiler kombinasies vir die sekondêre vervoer van houtspaanders en ‘n geïntegreerde vergassingstelsel vir die omsetting van houtspaanders na elektrisiteit.

石化能源逐漸耗竭引人關注，再加上「京都議定書」對溫室氣體排放之全球性管制，促使世界各國重視各種新能源與替代性能源，並積極投入應用與研究開發。生質燃料已成為全球許多國家的戰略性資源，其發展除可開發自產綠色能源，提高能源自主比例，並能結合能源、農業、環保、產業等共同發展。面對全球生質燃料產業急速成長，台灣自不能自外於節能減碳的永續發展趨勢。 為驗證政府推動生質燃料政策的環境條件及業界投入狀況，本研究以次級資料分析方法進行國內、外之發展現況及趨勢分析；透過學者、專家、政府業務執行主管及業者之深度訪談，藉由訪談之資料歸納國內發展情形，對照現有生質燃料政策推動目標之發展模式，並以五力分析架構及SWOT評估方法評估生質燃料產業發展之競爭力。 本研究的主要發現包括：1.影響我國生質燃料的發展，最主要的關鍵要素是料源成本、價格補貼及市場保證；2.在推廣生質燃料的策略作法上，絕大多數主張應依政府政策規劃目標循序漸進推動；3.業者在發展生質燃料過程中，面臨最大的困難在於政策的不確定及原料的掌握不足；4.產業發展初期仍應以國內產製優先，不足部分再開放進口；5.生質柴油料源中，目前以廢食用油最具價格競爭力，麻瘋果油次之，藻類則是長期看好的料源。生質酒精部分，依國內廠商最可行技術而言，以甘蔗酒精較具價格競爭力，狼尾草居次，纖維素作物則是長期看好者。6.現階段的政策目標，在生質柴油部分的推廣比例仍以B2為佳，生質酒精則以E3為國產料原的最大量。長期來看，生質燃料產業的擴展，一定要以非糧食作物為優先，關鍵環節在於纖維酒精技術及藻類開發技術有突破，推廣比例及市場規模才有再擴張的空間。 就研究分析所得，提供下述政策建議：1、政府需訂定明確的政策目標；2.成立再生能源國家型計畫，加速推動生質燃料發展；3.政府率先投資第二代生質燃料產業；4.需建構生質燃料永續發展的制度性設計；5.確立以本國產製為優先之政策宣示；6.強化節能減碳教育宣導，讓消費者建立信心並接受。在業界策略上建議：1.必須提升料源掌握度與開發多元料源，並降低生產成本；2.業者須加強與通路商籌組供油策略聯盟；3.生質酒精業者可採合資或合作生產方式切入市場，取得先占地位；4.積極參與第二代生質燃料的研發與技術銜接。 / Petrochemical energy shortage is an issue that has been gradually gaining attention. Global regulation of greenhouse gases emission set by the Kyoto Protocol has also called attention to new and alternative energy sources, as well as the active involvement of individual countries in new energy application and research development. Biofuel has now become a strategic resource in many countries. Additional development of alternative energy can not only help increase the amount of domestic green energy and its ratio to traditional energy, synergy is also created causing the equal development of energy, agriculture, environmental production, and industrial growth. In face of the rapid growth of the biofuel industry worldwide, Taiwan must not exclude itself from the trend of sustainable development in energy conservation and CO2 reduction. To access the conditions of government policy in biofuel promotion and industry involvement, this study used secondary data analysis methods to analyze the current trend and status of national and international development. Through information gathered from in-depth interviews with academics, experts, government executives, and industry members, current domestic developments are compared to existing models of biofuel policy, promotion, and objectives. The competitiveness of biofuel industry development is further evaluated using SWOT assessment and Five Power Analysis. The main findings of this study include the following: 1) The key elements affecting national biofuel development are raw material costs, price subsidies, and market guarantees. 2) In biofuel promotion strategies, a vast majority should be made gradually and according to government policy planning objectives. 3) In biofuel development, the biggest challenges the industry faces are policy uncertainties and the lack of raw materials. 4) In initial industry development, domestic production should be a priority, allowing imports only when in demand. 5) In raw materials for bio-diesel, recycled oils are currently the most competitive in value, followed by Jatropha oil, while algae is seen as having long-term potential. According to the most viable technology offered by domestic manufacturers, sugarcane ethanol is the most competitive in value for bio-ethanol, followed by Chinese Pennisetum, while agricultural waste is seen as having long-term potential. 6) In the current stage of policy objectives, B2 is still more adequate in the promotion of bio-diesel, and E3 is the main domestic raw material for bio-ethanol. In the expansion of biofuel industry in the long run, priority must be given to non staple crops, while the key lies in cellulosic ethanol and algae oil development technology. Only then can there be room for further expansion in promotional proportion and market scale. The following policy recommendations are provided based on analysis of the study: 1) Clear policy goals must be set by the government. 2) Establish nation-wide plans for renewable energy, and accelerate the promotion of biofuel development. 3) Government must take initiatives in second-generation feedstock investments. 4) A systematic design must be built for the sustainable development of biofuel. 5) Policy declarations must be made to ensure the priority of domestic production. 6) Strengthen education in energy conservation and CO2 reduction, and build consumer confidence and acceptance. Recommendations for industry strategies: 1) It is essential to increase control of raw materials, develop multi-source materials, and lower production costs. 2) The industry must strengthen its strategic alliances with distributor in oil supply. 3) The biofuel industry may partake in joint ventures or cooperative efforts to get a head start when entering the market. 4) Actively participate in the research and development and technology adaptation of second-generation feedstock.

Avec l'épuisement des ressources naturelles, notamment les sources d’énergies fossiles, les énergies renouvelables sont à nouveau considérées comme une alternative réelle pour la transition énergétique des pays industrialisés.Les moteurs à apport de chaleur externe comme le Stirling et son « cousin » le moteur Ericsson peuvent valoriser de multiples sources -renouvelables ou non- d'énergie thermique. Le moteur Ericsson est ainsi particulièrement bien adapté pour la conversion de l’énergie solaire ou de la biomasse en électricité dans des applications de microcogénération.Cette thèse s’inscrit dans la continuation des travaux théoriques et expérimentaux sur le moteur Ericsson réalisés au LaTEP de l'Université de Pau et des Pays de l'Adour. Dans ce travail, nous nous sommes principalement intéressés auxtransferts thermiques entre le fluide de travail et les parois des cylindres de compression et de détente du moteur. Un premier modèle, global, a permis de déterminer dans quelles conditions ces transferts thermiques peuvent améliorer les performances du système énergétique considéré. Un second modèle, ‘intracycle’, a permis d’évaluer les transfertsthermiques instantanés dans les cylindres à partir des corrélations habituellement utilisées dans les moteurs à combustion interne. Le prototype de moteur Ericsson a alors été équipé de différents capteurs de pression et de températures, ces derniers étant constitués de micro-thermocouples. Les relevés de température instantanée dans lecylindre de compression sont présentés commentés et comparés aux résultats obtenus par le modèle « intracycle ». / With exhaustion of natural resources, in particular the fossil energy sources, renewable energies are again regarded as a real alternative for the needed energy transition of the industrialized countries. The "hot air engines" like the Stirling engine and his “cousin” the Ericsson engine, can use multiple thermal sources - renewable or not -. The Ericsson engine is thus particularly well adapted for solar or biomass energy conversion in electricity or for microcogeneration purposes. This thesis is a continuation of the theoretical and experimental work on the Ericsson engine realized in the LaTEP of theUniversity of Pau (France). In this work, we are mainly interested in the - in-cylinder - heat transfer between the working gas and the walls of the compression and expansion cylinders of the Ericsson engine. A first original model made possible to determine under which conditions these heat transfers can improve the performances of the energy system considered. A second model, “intracycle”, allowed to evaluate the instantaneous heat transfers in the cylinders starting from the correlations usually used in the internal combustion engines, reciprocating compressors and pneumatic springs. The Ericsson prototype was then equipped with various pressure and temperature gauges, the latter consisting of K-type microthermocouples of 25 and 12,5μm wires. The results of instantaneous temperature measurements in the compression cylinder are presented, commented and compared with the results obtained by the “intracycle” model.