Fuel flow sheet

Zabunoglu, O.H. Ozdemir, L. Purex co-processing of spent LWR fuels Flow sheet, Ann. Nucl. Energy 32 (2005) 151-162. 

Furthermore, 60—100 L (14—24 gal) oil, having sulfur content below 0.4 wt %, could be recovered per metric ton coal from pyrolysis at 427—517°C. The recovered oil was suitable as low sulfur fuel. Figure 15 is a flow sheet of the Rocky Flats pilot plant. Coal is fed from hoppers to a dilute-phase, fluid-bed preheater and transported to a pyrolysis dmm, where it is contacted by hot ceramic balls. Pyrolysis dmm effluent is passed over a trommel screen that permits char product to fall through. Product char is thereafter cooled and sent to storage. The ceramic balls are recycled and pyrolysis vapors are condensed and fractionated. 

By contrast, HLW from LWR fuel reprocessing is stored ia cooled, well-agitated, stainless steel tanks as an acidic nitrate solution having relatively few sohds. Modem PUREX flow sheets minimise the addition of extraneous salts, and as a result the HLW is essentially a fission-product nitrate solution. Dissolver soHds are centrifuged from the feed stream and are stored separately. Thus the HLW has a low risk of compromising tank integrity and has a favorable composition for solidification and disposal (11). 

Utilities These include steam, cooling water, process water, electricity, fuel, compressed air, and refrigeration. The consumption of utilities can be estimated from the material and energy balances for the process, together with the equipment flow sheet. 

Once a decision has been made to recover materials and/or energy, process flow sheets must be developed for the removal of the desired components, subject to predetermined materials specifications. A typical flow sheet for the recovery of specific components and the preparation of combustible materials for use as a fuel source is presented in Fig. 25-63. The light combustible materials are often identified as refuse-derived fuel (RDF). 

FIG. 25-63 Typical flow sheet for the recovery of materials and production of refuse-derived fuels (RDF). [Adapted in pait from D. C. Wilson (ed.). Waste Management Planning, Evaluation, Technologies, Oxford Univei-sity Press, Oxford, 1981.]... 

Figure 4.13 Schemaiic flow sheet of lire-to-fuel proce is.

Np, and fission products. The Thorex solvent extraction process is generally used to reprocess spent Th-based fuels. As in the Purex process, the solvent is TBP diluted in an appropriate mixture of aliphatic hydrocarbons. Figure 12.9 shows the Thorex process flow sheet used by Kuchler et al. [41] for reprocessing high-burn-up thorium fuel. 

Many of these drawbacks were circumvented in a process developed at Chalmers University, which was successfully demonstrated in continuous operation using the old high-level raffinate concentrate from Purex processing of low burn-up fuel. Although operation was very easy and stable, the process flow sheet was complicated using bromoacetic acid, HDEHP, TBP, and lactic acid [57-59]. 

Figure 6, Flow sheet of the 12,5 kW United Technologies fuel cell tested by...

Figure 8, Flow sheet of the 40-kW fuel cell under development at United Technologies...

C. 2008. Towards an optimized flow-sheet for a SANEX demonstration process using centrifugal contactors. ATALANTE 2008 Nuclear Fuel Cycles for a Sustainable Future, May, Montpellier, France. 

Figure 10.15 shows the simulated temperature distribution in the electrolyte for the single-cell stack model. In this calculation, the cell operating voltage is set at 0.16 V at which the electrolyte sheet cracked in the internal heat evolution test. In Figure 10.15, it can be observed that the temperature is almost 1273 K outside the anode/electrolyte/cathode area where heat is generated. Near the fuel inlet at the channel, the temperature increases steeply and the maximum temperature spreads over a wide area to the downstream of the fuel flow the maximum temperature difference in the electrolyte is around 60 K. 

Kivisaari, T. Van der Laag, P. C. Ramskold, A. Benchmarking of chemical flow sheeting software in fuel cell application, Journal of Power Sources, 94, (2001), 112-121. 

Various authors consider appropriate flow sheets for fuel cell systems. Fellows [5] proposes to employ a cascade of fuel cells, operating at different cell voltages, to increase the overall electric power output. According to this concept the exhaust gas... 

Transport and technological flow sheets for management of spent nuclear fuel from nuclear submarines under utilization in the north-west region and the far east region of Russia problems and solutions... 

The MTU MCFC provides catalysed 600 °C anode reform capability, with flat anode temperature distribution. In contrast the 1000 °C SOFC encounters difficulties with anode reform, in which excessive reaction rates lead to unacceptable, thermally stressed, local anode cool zones. The title direct fuel cell (DFC) is used, to highlight the absence of a separate combustion-heated 800 °C reformer and its pre-reformer. The balance of plant flow sheet is shown in Figure 5.3. 

The work reported by Ralph etal. (2003) is a well-rounded, self-contained essay on the DMFC. (See DMFC flow sheet in Figure 6.6.) Moreover, because Ballard/Johnson Matthey did not contribute on fuel cells at the Palm Springs Fuel Cell Seminar in 2002 (see below), Ralph etal. (2003) is the current information source, additional to the patents in the list of references. Note that the methanol-water mixture presents to the fuel electrode its associated methanol vapour pressure. The DMFC does not have an incompressible fuel. The cell needs circulators. It is incomplete. 

The equilibrium of a hydrogen or carbon monoxide fuel cell operating at high temperature and pressure is defined using a flow sheet, which connects the cell to a fuel store at standard conditions, and to the environment, via combined isentropic and isothermal circulators and a Carnot cycle. 

The flow sheet in Figure A.6 then requires the addition of isothermal concentration cells to give their contribution to the power, and increase the Nernst potential difference. These would be immediately adjacent to the fuel cell in the methane and oxygen supply lines. The rearranged flow sheet is shown as Figure A.7. 

In the absence of developed components, the performance of the flow sheet cannot be calculated. It shows the problems which need to be tackled before the fuel cell industry can exploit its full potential. 

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