Capturing Heat from Spent Nuclear Fuel

ME450 Capstone Design and Manufacturing Experience: Winter 2021Spent Nuclear Fuel can be placed in dry cask storage, where it emits waste heat into the atmosphere. Our sponsor, Dr. Marianna Coulentianos, identified an opportunity to capture this heat for a beneficial application. Our team evaluated the feasibility of our sponsor’s previously proposed solutions and designed a system that could transfer heat from the dry cask. We focused specifically on quantifying the amount of heat that would be available for a therothecial application. In order to determine how much heat would theoretically be available, we constructed both mathematical and computational simulations of heat transfer through a duct system. The system we propose includes a square funnel feature at the cask interface, connected to a round, rigid duct system extending over the perimeter fence. It was observed that the outlet temperature of our proposed system is around 36-65℃, which we determined is most suitable for a greenhouse application. We calculated a return on investment of 5 years by growing tomatoes in a greenhouse of 1800 ft2. We are confident that our design is feasible and does not violate any regulations set forth by the Nuclear Regulatory Commission. However, more analysis is needed to further examine discrepancies between field data and our assumptions, as well as the scalability of our proposed solution. We also considered the social context of this solution. Eating fruits and vegetables grown on a nuclear site is likely to cause skepticism around our solution. While we believe that the radiation levels of this waste heat are too low to realistically affect horticultural applications, all food that is intended for human or animal consumption in the United States must register with the FDA before beginning these activities.Dr. Marianna Coulentianos: UM Mechanical Engineering Departmenthttp://deepblue.lib.umich.edu/bitstream/2027.42/167636/1/Team_17-Capturing_Heat_from_Spent_Nuclear_Fuel.pd

Covalent modification of reduced graphene oxide with piperazine as a novel nanoadsorbent for removal of H2S gas

In the present research, piperazine grafted-reduced graphene oxide RGO-N-(piperazine) was synthesized through a three-step reaction and employed as a highly efficient nanoadsorbent for H2S gas removal. Temperature optimization within the range of 30–90 °C was set which significantly improved the adsorption capacity of the nanoadsorbent. The operational conditions including the initial concentration of H2S (60,000 ppm) with CH4 (15 vol%), H2O (10 vol%), O2 (3 vol%) and the rest by helium gas and gas hour space velocity (GHSV) 4000–6000 h−1 were examined on adsorption capacity. The results of the removal of H2S after 180 min by RGO-N-(piperazine), reduced graphene oxide (RGO), and graphene oxide (GO) were reported as 99.71, 99.18, and 99.38, respectively. Also, the output concentration of H2S after 180 min by RGO-N-(piperazine), RGO, and GO was found to be 170, 488, and 369 ppm, respectively. Both chemisorption and physisorption are suggested as mechanism in which the chemisorption is based on an acid–base reaction between H2S and amine, epoxy, hydroxyl functional groups on the surface of RGO-N-(piperazine), GO, and RGO. The piperazine augmentation of removal percentage can be attributed to the presence of amine functional groups in the case of RGO-N-(piperazine) versus RGO and GO. Finally, analyses of the equilibrium models used to describe the experimental data showed that the three-parameter isotherm equations Toth and Sips provided slightly better fits compared to the three-parameter isotherms