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The world is about to shift from fossil fuel dependency to independency. The national agenda of Sweden has put forth future goals of becoming a zero net greenhouse gas emitter by the year 2045 and before that, having an 80 % fossil fuel independent transportation fleet by 2030. In order to achieve these goals, the form of energy used in the transport sector needs to be changed into a more renewable solution. Biogas could be part of the solution. The aim of this report has been to review earlier research regarding the future biogas potential in Sweden and to examine how realistic and practically feasible these are. Three of the substrates that has shown the highest future potential according to earlier research; energy crops, manure and black liquor has been chosen for investigating their future potential. Interviews was made with biogas researcher in Sweden as well as government employees working with biogas and other biofuels. Scenario building was another method used were the report have created four future scenarios with varying optimistically future economic and technical outcomes using more practical limitations and restrictions. The result was a combined future potential of between 0,42 – 77,54 TWh/annually from all three substrates using the values and information gathered from the interviewers regarding how to calculate the potential. The result shows that depending on how lucrative the future financial support systems and subsidies as well as how efficient the technical breakthroughs will be, biogas can become a large contributor to the transport sectors transition in becoming less fossil fuel dependent.

Biofuels, including ethanol and biodiesel, are important components of energy policy in the U.S. and abroad. There is a long history of ethanol production from corn (maize) in the United States and from sugarcane in Brazil. However, there has been a push for greater use of next-generation biofuels (including those derived from cellulosic feedstocks) to mitigate many of the environmental and potential food system impacts of large scale biofuel production. Farmer willingness to grow biomass crops and ensuring adequate feedstock supply are two important challenges impeding large scale commercialization of next-generation biofuels. The costs of transporting bulky, low density biomass will be substantial. Consequently, in the near term, the economic success of next-generation biofuels will hinge on the supply of locally available biomass. As such, agricultural contracts are expected to be an important tool in overcoming the feedstock acquisition challenge. The broad objective of this study is to understand the effect of contracting for non-food energy crops (cellulosic feedstocks) on the agricultural landscape via the displacement of commodity (food) crops on productive cropland. We develop an analytical framework for evaluating the design and use of two different contract structures for securing cellulosic feedstock in a representative supply chain with a biorefinery and farmer. We study the dynamics of scarce land and indirect competition from commodity market production on a biorefinery's equilibrium pricing strategy and the resultant supply of cellulosic biomass. And we consider its sensitivity to various production characteristics and market conditions. We develop a method for quantifying the biorefinery's tradeoff between profit margins and competing for land in order to secure the requisite feedstock for biofuel production. And we characterize the loss of efficiency in the decentralized system, relative to a vertically integrated system, that can be attributed to the need to compete for the farmer's scarce land resource versus that which results from the biorefinery's desire to make a profit. Then we extend our framework to consider multi-year contracts for biomass production and evaluate the importance of land quality, yield variability and contract structure on a farmer's willingness to accept a contract to produce cellulosic feedstock as well as the resulting impact on the agricultural landscape through the displacement of commodity crops. Using switchgrass production in Tennessee as a case study, we develop feedstock supply curves for each contract structure considered and evaluate the conditions and contract prices at which land devoted to various field crops would be displaced by switchgrass based on field trials of switchgrass production in Tennessee and recent USDA data on crop prices and production.

Thesis (M.S.)--Mississippi State University. Department of Agricultural Economics. / Title from title screen. Includes bibliographical references.

Agriculture started the new way, instead of the food crops is icreased growing of energy crops. Thesis {\clqq}Production potencial and specificity of energy plant growing`` deals with evaluation of suitability of selected energy crops in field trials and theire needs of soil, clima and agrotechnology. The growth ability, health were evaluated during vegetation period and production potencial in harvest time in choosed group of energy crops. The thesis content also the seed quality, field germination and initial growth evaluated in conditions of anthropogenic soils.

Since the launch of the Biofuels Industrial Strategy in 2007 by the South African government, only a few smallholder farmers have adopted biofuels for production. The government hopes to stimulate economic development and alleviate poverty by targeting areas that were previously neglected for agriculture by the apartheid government. However, there still appears to be a lack of a clear and comprehensive policy framework for the development of a South African biofuel industry, because the proposed initiatives have not been implemented to date. There are also concerns among stakeholders that government policy is taking too long to formulate, compounding existing uncertainty in the industry. This study therefore aims to identify barriers and incentives that influence the potential adoption of biofuel crops in selected areas in the Eastern Cape Province, South Africa. The study utilised a semi-structured questionnaire to record responses from 129 smallholder farmers that were identified through a snowballing sampling technique. Descriptive statistical analysis and a Heckman two-step model were applied to analyse the data. Analysis was done using SPSS 21 and EViews 8. Results obtained showed that the variables: arable land, incentives offered, challenges faced, labour source and farm experience were statistical significant at 5 or 10 percent p value to awareness of farmers to biofuel crops. Adoption of biofuel crops was statistically related to gender, qualification, membership to association and household size. The study recommends that the Biofuels Industrial Strategy Policy be revisited in order to have a mechanism of including smallholder farmers that it aims to empower with employment and improvement in their livelihoods. The government can help smallholder farmers by addressing the challenges they face in improving their output. Furthermore, it recommends that a national study on barriers and incentives that influence the adoption of biofuel crops be carried out in order to identify other factors that may hinder the Biofuels Strategy Policy aims in empowering the disadvantaged farmers.

The cellulosome is a multimeric enzyme complex that has the ability to metabolise a wide variety of carbonaceous compounds. Cellulosomal composition may vary according to the microbe’s nutritional requirement and allows for the anaerobic degradation of complex substrates. The complex substrates of interest in this research study were sugarcane bagasse and pineapple fibre waste, as they represent two important lignocellulosic, South African agricultural crops. The effective degradation of complex plant biomass wastes may present a valuable source of renewable compounds for the production of a variety of biofuels, for example bioethanol, and a variety of biocomposites of industrial importance. The identification of renewable energy sources for the production of biofuels is becoming increasingly important, as a result of the rapid depletion of the fossil fuels that are traditionally used as energy sources. An effective means of completely degrading lignocellulose biomass still remains elusive due to the complex heterogeneity of the substrate structure, and the fact that the effective degradation of the substrate requires a consortium of enzymes. The cellulosome not only provides a variety of enzymes with varying specificities, but also promote a close proximity between the catalytic components (enzymes). The close proximity between the enzymes promotes the synergistic degradation of complex plant biomass for the production of valuable energy products. Previous synergy studies have focused predominantly on the synergistic associations between cellulases; however, the synergy between hemicellulases has occasionally been documented. This research project established the synergistic associations between two Clostridium cellulovorans hemicellulases that may be incorporated into the cellulosome and a cellulosomal endoglucanase that is conserved in all cellulosomes. This research study indicated that there was indeed a synergistic degradation of the complex plant biomass (sugarcane bagasse and pineapple fibre). The degrees of synergy and the ratio of the enzymes varied between the two complex substrates. The initial degradation of the bagasse required the presence of all the enzymes and proceeded at an enhanced rate under sulphidogenic conditions; however, there was a low production of fermentable sugars. The low quantity of fermentable sugars produced by the degradation of the bagasse may be related to the chemical composition of the substrate. The sugarcane contains a high percentage of lignin forming a protective layer around the holocellulose, thus the glycosidic bonds are shielded extensively from enzymatic attack. In comparison, the initial degradation of the pineapple fibre required the action of hemicellulases, and proceeded at an enhanced rate under sulphidogenic conditions. The initial degradation of the pineapple fibre produced a substantially larger quantity of fermentable sugars in comparison to the bagasse. The higher production of fermentable sugars from the degradation of the pineapple fibre may be explained by the fact that this substrate may have a lower percentage of lignin than the bagasse, thus allowing a larger percentage of the glycosidic bonds to be exposed to enzymatic attack. The data obtained also indicated that the glycosidic bonds from the hemicellulosic components of the pineapple fibre shielded the glycosidic bonds of the cellulose component. The identification of the chemical components of the different substrates may allow for the initial development of an ideal enzyme complex (designer cellulosome) with enzymes in an ideal ratio with optimal synergy that will effectively degrade the complex plant biomass substrate.

Heavy metals are part of us life for many centuries. Some of them are for living organism neccessary, but in large amount they have toxic effects. So we should decrease amount of heavy metals in the Environment. We have many way to do it. A relatively new way are the phytoremediation. If we would use the phytoremediation, we should know, what they do in plants. We must use specific plants, which are tolerant to certain heavy metal. If we would select a suitable plant, we have to try, how heavy metals in soil solution are toxic to plants. Zinc is no expection, although it is important part of many proteins. In plants it make rusty leaves and reduct aboveground and root biomass production. In hydroponic experiment I investigated that mallow Malva verticillata was very sensitive to low additon of Zn(NO3)2. The toxic efect appeared in 2 weeks. In sorghum Sorghum bicolor zinc show expressive toxic effect at concentration 1 mmol/l. I studied six cultivars of Sorghum bicolor, DSM 14-535, Expres, Honey Graze BMR, Nutri Honey, Sucrosorgho 506 and Sweet Virginia. According EC50 I as- sessed that the most sensitive was Sucrosorgho 506 and very tolerant were Nutri Honey and Sweet Virginia. Cultivar Nutri Honey was characteristic. It had the highest ratio concentration in shoot to concentration in root. I studied...

Bioenergy is expected to play an increasingly significant role in the global energy budget. In addition to the use of liquid energy forms such as ethanol and biodiesel, electricity generation using processed energy crops as a partial or full coal alternative is expected to increase, requiring large-scale conversions of land for the cultivation of bioenergy feedstocks such as cane, grasses, or short rotation coppice. With land-use change identified as a major contributor to changes in the emission of biogenic volatile organic compounds (BVOCs), many of which are known contributors to the pollutants ozone (O3) and fine particulate matter (PM2.5), careful review of crop emission profiles and local atmospheric chemistry will be necessary to mitigate any unintended air-quality consequences. In this work, the atmospheric consequences of bioenergy crop replacement are examined using both the high-resolution regional chemical transport model WRF/Chem (Weather Research and Forecasting with Chemistry) and the global climate model CESM (Community Earth System Model). Regional sensitivities to several representative crop types are analyzed, and the impacts of each crop on air quality and climate are compared. Overall, the high emitting crops (eucalyptus and giant reed) were found to produce climate and human health costs totaling up to 40% of the value of CO2 emissions prevented, while the related costs of the lowest-emitting crop (switchgrass) were negligible.