Browsing by Subject "Targeting"
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Item A Systems-Integration Approach to Optimizing the Water-Energy Nexus in Energy Surplus Processes(2014-10-02) Gabriel, Kerron JudeThe objective of this research was to develop novel tools for systematically optimizing the benefits of the water-energy nexus in processes with surplus energy. The developed approach consists of the following problems: (1) screening of the processes to identify potential for cogeneration of water and power, (2) development of a flexible water generating process, (3) synthesis of the integrated water and power facility and (4) thermoeconomic analysis of the integrated process. In the screening problem, a targeting and benchmarking approach was used to identify the limits of the process for producing water and power from surplus energy. Various designs of the process were explored to compare the effects of process change on the overall targets for water and power generation. For the water generating process problem, a new mathematical formulation was proposed for the thermal desalination of saline water. The new formulation consisted of a mass flowrate decoupling approach that reduced the overall mass and energy balances to a linear programming (LP) problem. This approach was used to develop novel and flexible Multi-effect distillation with thermo vapor compression (MED-TV C) processes that balanced the tradeoff between economics and thermal efficiency. In the synthesis problem, an integrated water and power generating facility was developed based on the excess heat sources from the process. The synthesis approach incorporated the use of four building blocks: (a) Total site analysis to identify appropriate steam level connections in the process, (b) heat exchange network synthesis for producing steam and boiler feed water utilities from excess process heat, (c) turbine network development for power generation and (d) water generation and integration via direct recycle. In thermoeconomic analysis, the integrated facility from the synthesis approach was evaluated and optimized to maximize the intrinsic balance of the water-energy nexus. The analysis utilized extensive literature sources, fundamental chemical engineering practices as well as mathematical programming techniques to yield insightful conclusions. The Gas-to-liquids process was strategically used as the case study to demonstrate the developed methodologies due to its ability to produce not only fuels and synthetic lubricants but potable water and power as part of its commodity portfolio.Item Algebraic approaches to resource conservation via process integration(Texas A&M University, 2005-11-01) Almutlaq, Abdulaziz M.The primary objective of this dissertation is to introduce several algebraic procedures to the targeting of material recycle networks. The problem involves the allocation of process streams and fresh sources to process units (sinks) with the objective of minimizing fresh purchase and waste discharge. In the case of composition-limited sinks, allocation to process sinks is governed by feasibility constraints on flowrates and compositions. A systematic non-iterative algebraic approach is developed to identify rigorous targets for minimum usage of fresh resources, maximum recycle of process resources and minimum discharge of waste. These targets are identified a priori and without commitment to the detailed design of the recycle/reuse network. The approach is valid for both pure and impure fresh resources. The devised procedures also identifies the location of the material recycle pinch point and addresses its significance in managing process sources, fresh usage, and waste discharge. The dissertation also addresses the targeting of material-recycle networks when the constraints on the process units are described through flowrates and properties. This property-integration problem is solvedusing a non-iterative cascade-based algebraic procedure. Finally, for more complex cases with multiple fresh sources and with interception networks, a mathematical-programming approach is developed. Because of the nonlinear non-convex characteristics of the problem, the mathematical model is reformulated to enable the global solution of the problem. Several case studies are solved to illustrate the ease, rigor, and applicability of the developed targeting technique.Item Resource conservation and allocation via process integration(Texas A&M University, 2004-09-30) Harell, Dustin AshleyThroughout the process industry, the conservation and allocation of mass and energy resources plays a pivotal role in the site wide optimization of a plant. Typically, raw materials are transformed into products, byproducts and wastes through pathways involving heating/cooling, pressure changes, mixing, reactions and separations. These pathways often require the addition or removal of energy from the system. The optimal management of such a system therefore requires conserving resources through the appropriate allocation of materials and energy. In a typical plant, there are both mass and energy objectives that require optimization. This dissertation will focus on optimizing the mass and energy resources present in a utility system. This will entail developing a novel framework of techniques to: target and design steam cogeneration networks while minimizing fuel requirements, identifying and utilizing sources of waste heat and incorporating heat pipes to enhance heat exchange networks. Additionally, a specific case of waste recovery will be examined when properties are the primary concern.Item Targeted nanoparticle formulation for a poorly water soluble Gemcitabine derivative and its in vivo and in vitro anti-tumor activity(2012-08) Sandoval, Michael Anthony; Cui, Zhengrong; Williams, Robert O; Walkow, Janet CCancer is a collection of over one hundred different types of diseases and is responsible for the leading cause of death in the United States. More strikingly, cancer mortality rates have remained relatively unchanged for the past several decades, indicating significant clinical demand for improved cancer therapy. Gemcitabine, known clinically as Gemzar®, is used to treat a variety of human cancers, however, clinical efficacy is modest due to it’s brief blood circulation, rapid clearance, manifestation of tumor-drug resistance, and lack of drug specificity. This thesis sought to develop a solid lipid nanoparticle-based platform to passively and actively target a gemcitabine lipophilic derivative, 4-(N)-stearoyl gemcitabine, into tumor cells over-expressing epidermal growth factor receptor (EGFR) after intravenous injection. Considering gemcitabine is hydrophilic and the core of the nanoparticle is solid (hydrophobic), we lipophilized gemcitabine by conjugating a stearoyl group to its N-terminus to form 4-(N)-stearoyl gemcitabine. Second, we incorporated stearoyl gemcitabine into lecithin-based nanoparticles. The nanoparticle formulation was prepared from lecithin/glyceryl monostearate-in-water emulsions. Third, we grafted the gemcitabine nanoparticles with polyethylene glycol chains with reactive end groups that are capable of conjugating with a targeting moiety on the surface to actively target tumors that over-express EGFR. Taken together, the overall objective of the research presented in this thesis is to develop, characterize, and evaluate the anti-tumor performance in vitro as well as in mice against both human and mouse tumor models.