Transport sector is an essential driver of economic development and growth, and at the same time, one of the biggest contributors to climate change, responsible for almost a quarter of the global carbon dioxide emissions. The sector is 95 percent dependent on fossil fuels. International Energy Agency (IEA) scenarios present different mixes of fuels to decrease both dependence on fossil fuels and emissions, leading to a more sustainable future. The main alternative fuels proposed in the Blue map scenario, presented in the Energy Technologies Perspective 2008, were hydrogen and second-generation ethanol. An assessment of these fuels was made using the tools SLCA (Sustainability Life Cycle Assessment) and SWOT Analysis. A Framework for Strategic Sustainable Development (FSSD) is the background used to guide the assessment and to help structure the results and conclusions. The results aim to alert the transport sector stakeholders about the sustainability gaps of the scenario, so decisions can be made to lead society towards a sustainable future. / <p>Phone number 0708293568</p>

Due to the shortage of oil and the current environmental pollution problems, there is a growing need for alternative energy sources. Compressed or liquefied natural gas is shown as a prospective fuel. For LNG, consumption of 100 million Nm3/year is predicted by 2030. This work aims to prepare a pre-feasibility study for the production of LNG in the Czech Republic, which would be able to cover this predicted demand. The economic concept of the chemistry-engineering approach provides comprehensive information about the topic. The results show that the planned plant will unfortunately not be profitable, as compared to the current LNG price imported to European seaports, the price of the produced product in the factory considered would be roughly twice as high.

Global energy demands are constantly increasing and fossil fuels are a finite resource. The shift towards alternative, more renewable and sustainable fuels is inevitable. Furthermore, the increased emissions of greenhouse gases have forced a pressing need to find cleaner, more environmentally friendly sources of fuel. Biomass energy is a promising alternative fuel because it offers several important advantages. It is a renewable energy form, it comes from many sources and produces biogas (CH4 and CO2). Furthermore, it can have a zero carbon footprint; this is due to the fact that the carbon produced is from the same carbon used to make the biomass. In addition, by replacing fossil fuels, the emissions of CH4 and CO2 (both greenhouse gases) is reduced. Biomass-derived syngas (H2 and CO) can be utilized as a feedstock for many important industrial processes such as methanol synthesis, ammonia synthesis and Fischer-Tropsch synthesis (FTS) to produce long chain hydrocarbon fuels. Municipal solid waste (MSW) biomass is considered as the source of the biomass for this dissertation work. MSW accounts for 20% of man-made methane emissions making it an attractive source for utilization. However, methane reforming to synthesis gas (H2 and CO) typically occurs at temperatures higher than 600°C making it economically challenging at the smaller scale of MSW conversion processes. This dissertation effort focused on formulating low precious metal loaded heterogeneous catalysts that can reform methane at low temperature (T<500°C) making the process more industrially viable. The effect of select contaminants (siloxanes) in the biogas on the reforming catalysts was studied through accelerated poisoning. Finally, the syngas ratio was improved by combining low temperature dry reforming with steam reforming (termed bi-reforming). The catalyst system used for this dissertation study was comprised of 1.34wt%Ni- 1.00wt%Mg on a Ceria-Zirconia oxide support (0.6:0.4 ratio respectively). The catalysts were doped with platinum (0-0.64% by mass) and compared to palladium doped catalysts (0-0.51% by mass). The ratio chosen for the support, Ce0.6Zr0.4, was determined to be the best ratio in terms of activity and surface area by previous studies done in this group [1]. Nickel has been widely studied as methane reforming catalyst [2-6]. Alone, nickel atoms are prone to carbon deposition especially during methane decomposition, however, coupling NiO with MgO helps to reduce carbon deposition by reducing agglomeration of Ni crystallites, thereby improving catalyst lifetime [2, 7]. Furthermore, addition of small amounts of noble metals such as Pt or Pd help to drive the reduction of the catalyst to lower temperatures and enhance catalytic activity. Different metal loadings of Pt and Pd were tested to determine the optimum catalyst that will reform methane at low temperatures, is resistant to deactivation and produces a high syngas ratio (~2:1) which is necessary for processes such as FTS. Preliminary results have shown that in general Pt is superior in this catalyst system for low temperature reforming of methane. It consistently had syngas ratios near the desired ratio compared to Pd, it did not deactivate with extended time on stream and overall had higher turnover frequencies. This catalyst system has potential to make industrial reforming of methane from biomass feedstock more economically viable.

According to the current governmental regulations, all diesel buses will be replaced in the United States and the European market within the next ten years. There are over 60,000 buses in the United States and each year over 3,000 new buses of approximately 40 feet in length are purchased. The bus market has a growth rate of four to five percent per year over the last two years. The improvements in technology offered by United States companies prove unsatisfactory in terms of bus performance and the emissions of new buses. The energy crisis in the United States and concern over the health hazards of the diesel fuel exhaust gases and particulates, alternative fuel vehicles are in great demand in the transit market world wide.

The field of this diploma thesis is characteristic of cement used in road infrastructure building. In cooperation with the cement plant Horné Srnie, was made previously produced road cement matrix, according to the original recipe. This Diploma thesis is focused on the following characteristics of the cement: the compressive strength, the stiffening process, the volume stability and the development of the hydration heat. The research of the hydration process was analyzed by X-ray diffraction and differential thermal analysis

Master’s thesis deals with comparsion and rating the compressed natural gas as an aircraft piston engine fuel. An information search of conventional fuels and differences of the fuel systems for AVGAS and CNG is included. Next part describes the aircraft and its engine on which is the mathematic model based. After that perfomance and consumption data are calculated for both fuels and the results are then compared. At the end of the thesis, a design of the CNG fuel system with components selection is described.

Reducing CO2 emission in air transport is the main theme of this master´s thesis. As the public interest in aviation and climate change is world´s growing it could be consider as a hot topic. As a response to public interest was the creation of contracts, standards and limits of carbon dioxide emissions. The master´s thesis is divided into several parts. The first is mapping of global air traffic and carbon dioxide emissions. The second part deals with European approach to solving problems of reducing CO2 emissions follows by description of ICAO Aeroplane CO2 emissions standard. The part of the thesis is the overview of the use of biofuels in aviation and their price. The conclusion summarizes all knowledge learned while working on this thesis.

This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...

Three troublesome issues concerning residential curbside collection (RCC) and municipal solid waste (MSW) management systems in the United States motivated this research. First, reliance upon inefficient collection and scheduling procedures negatively affect RCC efficiency, greenhouse gas (GHG) emissions, and cost. Second, the neglected impact of MSW management practices on water resources. Third, the implications of alternative fuels on the environmental and financial performance of waste collection where fuel plays a significant rule. The goal of this study was to select the best RCC program, MSW management practice, and collection fuel. For this study, field data were collected for RCC programs across the State of Florida. The garbage and recyclables generation rates were compared based on garbage collection frequency and use of dual-stream (DS) or single-stream (SS) recyclables collection system. The assessment of the collection programs was evaluated based on GHG emissions, while for the first time, the water footprint (WFP) was calculated for the most commonly used MSW management practices namely landfilling, combustion, and recycling. In comparing alternative collection fuels, two multi-criteria decision analysis (MCDA) tools, TOPSIS and SAW, were used to rank fuel alternatives for the waste collection industry with respect to a multi-level environmental and financial decision matrix. The results showed that SS collection systems exhibited more than a two-fold increase in recyclables generation rates, and a ~2.2-fold greater recycling efficiency compared to DS. The GHG emissions associated with the studied collection programs were estimated to be between 36 and 51 kg CO2eq per metric ton of total household waste (garbage and recyclables), depending on the garbage collection frequency, recyclables collection system (DS or SS) and recyclables compaction. When recyclables offsets were considered, the GHG emissions associated with programs using SS were estimated between -760 and -560, compared to between -270 and -210 kg CO2eq per metric ton of total waste for DS programs. In comparing the WFP of MSW management practices, the results showed that the WFP of waste landfilling can be reduced through implementing bioreactor landfilling. The WFP of electricity generated from waste combustion was less than the electricity from landfill gas. Overall, the WFP of electricity from MSW management practices was drastically less than some renewable energy sources. In comparing the WFP offsets of recyclables, the recycling of renewable commodities, e.g. paper, contributed to the highest WFP offsets compared to other commodities, mainly due to its raw material acquisition high WFPs. This suggests that recycling of renewable goods is the best management practice to reduce the WFP of MSW management. Finally, the MCDA of alternative fuel technologies revealed that diesel is still the best option, followed by hydraulic-hybrid waste collection vehicles (WCVs), then landfill gas (LFG) sourced natural gas, fossil natural gas and biodiesel. The elimination of the fueling station criterion from the financial criteria ranked LFG-sourced natural gas as the best option; suggesting that LFG sourced natural gas is the best alternative to fuel WCV when accessible. In conclusion, field data suggest that RCC system design can significantly impact recyclables generation rate and efficiency, and consequently determine environmental and economic impact of collection systems. The WFP concept was suggested as a method to systematically assess the impact of MSW management practices on water resources. A careful consideration of the WFP of MSW management practices and energy recovered from MSW management facilities is essential for the sustainable appropriation of water resources and development.

Autoignition and oxidation of two Methane (CH4) and Dimethyl Ether (CH3OCH3 or DME) mixtures in air were studied in shock tubes over a wide range of equivalence ratios at elevated temperatures and pressures. These experiments were conducted in the reflected shock region with pressures ranging from 0.8 to 35.7 atmospheres, temperatures ranging from 913 to 1650 K, and equivalence ratios of 2.0, 1.0, 0.5, and 0.3. Ignition delay times were obtained from shock-tube endwall pressure traces for fuel mixtures of CH4/CH3OCH3 in ratios of 80/20 percent volume and 60/40 percent volume, respectively. Close examination of the data revealed that energy release from the mixture is occurring in the time between the arrival of the incident shock wave and the ignition event. An adjustment scheme for temperature and pressure was devised to account for this energy release and its effect on the ignition of the mixture. Two separate ignition delay correlations were developed for these pressure- and temperature-adjusted data. These correlations estimate ignition delay from known temperature, pressure, and species mole fractions of methane, dimethyl ether, and air (0.21 O2 + 0.79 N2). The first correlation was developed for ignition delay occurring at temperatures greater than or equal to 1175 K and pressures ranging from 0.8 to 35.3 atm. The second correlation was developed for ignition delay occurring at temperatures less than or equal to 1175 K and pressures ranging from 18.5 to 40.0 atm. Overall good agreement was found to exist between the two correlations and the data of these experiments. Findings of these experiments also include that with pressures at or below ten atm, increased concentrations of dimethyl ether will consistently produce faster ignition times. At pressures greater than ten atmospheres it is possible for fuel rich mixtures with lower concentrations of dimethyl ether to give the fastest ignition times. This work represents the most thorough shock tube investigation for oxidation of methane with high concentration levels of dimethyl ether at gas turbine engine relevant temperatures and pressures. The findings of this study should serve as a validation for detailed chemical kinetics mechanisms.