Records with Keyword: Simulation
Space-constrained purification of dimethyl ether through process intensification using semicontinuous dividing wall columns
Sarah E. Ballinger, Thomas A. Adams II
June 12, 2018 (v1)
Keywords: Aspen Plus, Dimethyl Ether, Dividing wall column, Mobile Plant, Plant-on-a-truck, Process Intensification, Semicontinuous Distillation, Simulation
In this work, a distillation system is designed to purify dimethyl ether (DME) from its reaction by-products in the conversion of flare gas into a useful energy product. The distillation equipment has a size constraint for easy transportation, making process intensification the best strategy to efficiently separate the mixture. The process intensification distillation techniques explored include the dividing wall column (DWC) and a novel semicontinuous dividing wall column (S-DWC). The DWC and the S-DWC both purify DME to fuel grade purity along with producing high purity waste streams. An economic comparison is made between the two systems. The DWC is a cheaper method of producing DME however the purity of methanol, a reaction intermediate, is not as high as the S-DWC. Overall, this research shows that it is possible to purify DME and its reaction by-products in a 40-foot distillation column at a cost that is competitive with Diesel.
Modeling and simulation of an integrated steam reforming and nuclear heat system
Leila Hoseinzade, Thomas A. Adams II
June 12, 2018 (v1)
Keywords: Dynamic Modelling, Integrated Systems, Methane Reforming, Nuclear Heat, Simulation, Syngas
In this study, a dynamic and two-dimensional model for a steam methane reforming process integrated with nuclear heat production is developed. The model is based on first principles and considers the conservation of mass, momentum and energy within the system. The model is multi-scale, considering both bulk gas effects as well as spatial differences within the catalyst particles. Very few model parameters need to be fit based on the design specifications reported in the literature. The resulting model fits the reported design conditions of two separate pilot-scale studies (ranging from 0.4 to 10 MW heat transfer duty). A sensitivity analysis indicated that disturbances in the helium feed conditions significantly affect the system, but the overall system performance only changes slightly even for the large changes in the value of the most uncertain parameters.
Direct Steam Generation Concentrated Solar Power Plant with a Decalin/Naphthalene Thermochemical Storage System
Haoxiang Lai, Thomas A. Adams II
June 12, 2018 (v1)
This study presents the design and analysis of a new integrated direct steam generation (DSG) concentrated solar power (CSP) plant with a decalin/naphthalene thermochemical storage system. Model simulations were performed in accordance to historical hourly solar radiation data over a year, using a combination of Aspen Plus v10, MATLAB 2016b, and Microsoft Excel VBA. It was found that the proposed plant feasibly stored and discharged energy, based on the solar radiation and chemical storage availability, to maintain base-load power productions (250 MW or 120 MW) with an overall efficiency of 14.6%. The effectiveness of the designed storage system was found to be comparable to a molten salt storage system which is currently used in existing CSP plants. The proposed integrated DSG CSP plant with a decalin/naphthalene thermochemical storage system shows promise for being an alternative to existing CSP plants.
Biomass-Gas-and-Nuclear-To-Liquids Aspen Plus Simulations
Leila Hoseinzade, Thomas A. Adams II
June 12, 2018 (v1)
Aspen Plus simulation for eight different chemical processes. Each simulation corresponds to a process which convert biomass, natural gas, and in some cases, nuclear energy, into either dimethyl ether (DME) or Fischer-Tropsch liquids (synthetic gasoline and diesel). Some processes contain carbon capture and sequestration (CCS) steps.

The processes may include various technologies such as biomass gasification, steam methane reforming, integrated gasification and natural gas reforming, integrated high temperature gas-cooled reactors and natural gas reforming, water gas shift reaction, FT synthesis, DME synthesis, MEA or MDEA based carbon capture, gas combustion turbines, gas cleaning, and other processing steps. Nuclear energy, when used, is integrated into the system via a high temperature helium coolant as an energy carrier from certain kinds of Gen IV nuclear reactors.

The eight processes are: BGNTL-FT (biomass-gas-nuclear-to-liquids with FT synthesis), BGNTL-FT-CCS (the same w... [more]
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