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Hydrogen economy is capitalizing the decarbonization of transport and industrial sectors. Ammonia is an attractive intermediate to store and transport hydrogen, due to its low production cost, well developed storage and transportation infrastruc- ture, high hydrogen density in its liquified form (for transportation) and the potential production from renewable energy sources. Although there have been significant ad- vancements in catalyst development for ammonia decomposition, the potential of this technology cannot be fully exploited until significant process development is made. In this sense, catalytic membrane reactors show promising features and performances. In this work, ammonia decomposition has been studied using the following ap- proach: (1) Catalytic Packed Bed Reactor (CPBR) and kinetic modeling, (2) Cat- alytic Packed Bed Membrane Reactor (CPBMR) modeling and (3) CPBMR scale-up. Stage (1) was performed using Ru-K/CaO and Co-Ce catalysts over a wide range of experimental conditions (including pressures up to 16 bar). Stage (2) includes 1-D and 2-D models that were further validated experimentally, also using different software to tackle the stage (3), which aims to give the optimized geometry and properties of a CPBMR for a production of 5 N m3 h−1 of high purity H2 . The results presented in this Thesis enabled to: (1) obtain a reliable kinetic model capable of describing the ammonia decomposition under a wide range of operating conditions, using Ru-K/CaO and Co-Ce catalysts. (2) identify a range of operat- ing conditions where the CPBMR performs better than the CPBR in terms of NH3 conversion, H2 recovery and H2 purity. This range includes: reaction temperature between 250◦C and 500◦C; reaction pressures between 1 and 16 bar; space times be- tween 1 and 15 gcat h mol−1 and H2 permeate pressure higher than the atmospheric pressure (up to 5 bar). (3) scale-up the CPBMR for ammonia decomposition at a pilot scale, encountering that a pilot plant for a production of 5 N m3 h−1 of pure H2 ( >99.99%) could be obtained with a relatively small multitubular arraignment, that might be even smaller than the needed for the same product using other technology.

No description available.

No description available.

Spent nuclear fuel is received at a storage facility in heavily shielded casks transported by either rail or by truck. Once at the storage facility, the casks are inspected, emptied, decontaminated, and reshipped. Allied-General Nuclear Services' (AGNS) nuclear fuel reprocessing plant in Barnwell, South Carolina, is constructed but not yet licensed for spent nuclear fuel storage or reprocessing. Recently, however, AGNS was granted funds by the Department of Energy to prepare the necessary procedural and regulatory paperwork in order that the Fuel Receiving and Storage Station (FRSS) of the plant can be licensed by 1985. In this paper, the activities involved in the receiving an unloading of casks at the Barnwell FRSS is simulated by computer using IBM's program software package, General Purpose Simulation System (GPSS). The GPSS model is developed and verified, and steady-state output statistics are achieved. Also, several sensitivity analyses are performed such as, changes in expected arrival schedules and decision policies, and changes to the physical characteristics of the existing FRSS to monitor the effect of these changes in the existing system.

Since the first observation of antineutrinos from beta decay of the fission products inside a nuclear reactor in 1956, the design and operating experience of antineutrino detectors near reactors has increased to the point where monitoring the reactor's power level and progression through its burnup cycle has become possible. With the expected increase in world nuclear energy capacity, including the dissemination of reactor technologies to non-nuclear states, the need for safeguards measures which are able to provide continuous, near-real-time information about the state of the core, including its isotopic composition, in a tamper- and spoof-resistant manner is evident. Near-field (~20 m from the core) antineutrino detectors are able to fulfill this demand without perturbing normal reactor operation, without requiring instrumentation which penetrates the reactor vessel, and without displacing other plant structures. Two sodium-cooled long-life fast reactors that are characteristic of next-generation reactors which are attractive for installation in non-nuclear states, one large and one small power rating, have been modeled throughout their reference burnup cycles using MCC-3 and DIF3D/REBUS. Various diversions of fissile material from the core designed to obtain weapons-usable material for the purpose of nuclear proliferation were studied as perturbed core states. The difference in detector event rates between the reference and perturbed states was used to determine the probability that a particular diversionary activity would be apparent before the material could be converted into a weapon. These data indicate which types of diversion antineutrino safeguards are particularly strong against and how the technology might be implemented in current and future international policies concerning nuclear proliferation.

<p>In this bachelor thesis we focus on how to controlling different machines that would be used in the Bio-gas production processes. By useing the Labview program, we can do controlling, detecting, data storing and other jobs all together.</p><p>The whole project is just a blueprint for the following work, as for there are too many components and units that we haven't seen yet. What we have done is to design a program that could be used in reality base on the principle of the whole bio-gas producing processes. Actually we did a quite good job on designing the limited machines that we have in hand, like the Pt-100 unit and the circulation pump are working as well as we had imagined.</p><p>Hopefully, this thesis and the program I designed can give a direction for the following work on the project, and the most important part--temperature checking and controlling can work well in reality as we expected.</p>

This study investigated the heat transfer within the anode material moving through and heated by an electric arc. The arc was a low current (< 16 A) atmospheric electric discharge between a carbon rod cathode, and a moving carbon felt anode. The carbon arc was a low current(<16 A) electric discharge between a cathode constructed of a carbon rod, and a moving carbon felt anode. The thermal profile within the anode material was predicted by a system of differential algebraic equations, adapted from the model developed by (Stark and Fricke, 1993). This set of equations was run using the software MATLAB R2011b, using a numerical integrator with consideration taken for sparsity. The change in degree of graphitisation was then predicted using the thermal profiles developed. This indicated that while the graphitisation of the surface of the felt exposed to the arc increased (from about 10% to about 99%) this effect did not penetrate far into the felt. At a depth of 0.3 mm there was very little increase in graphitisation (about 7% increase at slow movement rates, negligible at standard rates), indicating that this gaphitisation degree was unlikely to explain the improvement of battery cells produced using this material compared to non–arc treated material. Vaporisation of carbon due to the arc was then investigated as a possible explanation. With a similar activation energy to graphitisation a similar profile was obtained.

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No description available.