Heuristic Reactor Design for Clean Synthesis and Processing - Separative Reactors

EPA Grant Number: R825370C055
Subproject: this is subproject number 055 , established and managed by the Center Director under grant R825370
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: EERC - National Center for Clean Industrial and Treatment Technologies (CenCITT)
Center Director: Crittenden, John C.
Title: Heuristic Reactor Design for Clean Synthesis and Processing - Separative Reactors
Investigators: Mullins, M. E. , Zhang, Huidong
Current Investigators: Mullins, M. E. , Kline, Andrew A. , Rogers, Tony N.
Institution: Michigan Technological University
EPA Project Officer: Klieforth, Barbara I
Project Period:    
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Clean Industrial and Treatment Technologies (CenCITT) , Targeted Research

Objective:

This project intends to develop a prototype Heuristics and Reactor Design (HARD) system to aid engineers in the conceptual design and engineering of clean chemical processes. There are two core tasks in the initial phase of the effort both aimed at separative reactor processes: the development of mathematical models (1) for the reactive distillation process, and (2) for catalytic membrane reactors. The resulting models can be used as a screening tool to determine the suitability of a given reaction for these processes. The completed models will be integrated into an expert system resource along with other existing models for chemical reactor design.

Approach:

Our modeling approach is to consider the packed reactor column as a series of discrete stages, and model it the same way as a tray column. In this way, the resulting model equations are a set of non-linear algebraic equations. The composition and temperature profiles can be obtained after solving these equations simultaneously. Due to the small liquid hold-up in trays (pseudo-trays), the chemical reactions are assumed to reach equilibrium. Hence, we adopted a rigorous, non-equilibrium stage model which assumes vapor-liquid phase equilibrium is only established at the interface rather than over the whole stage.

The equations of Mass balance, Energy balance, Rate of mass and energy transfer, and eQuilibrium (so called MERQ model) are written for each phase separately. The Newton-Raphson method will be used to solve the equations, and the technique of line search and backtracking is incorporated into the algorithm to achieve global convergence. Therefore, the solution of the model does not totally depend on the initial estimate, which compensates for a major drawback of the Newton-Raphson method.

We will first develop this model with C++, and a Graphic User Interface (GUI) will be constructed afterwards. Basically, the model consists of four classes: a thermodynamic class which is designed to calculate all thermodynamic properties; a matrix class which does block matrix manipulation; a solver class which implements the Newton-Raphson method with line search and backtracking techniques; and a main program which simply incorporate other classes.

Rationale:

Currently there are no existing design models for catalytic membrane reactors; and although commercial software from several simulation companies is available for distillation related modeling, they are not specifically tailored to reactive distillation process. Therefore, it is important to construct a model based on the unique features of reactive distillation in a packed column.

Reactive distillation is a unit operation which combines a chemical reaction with a multistage distillation in one step simultaneously. This technique has two important advantages compared with conventional reaction and distillation processes: (1) energy savings and (2) reduction of capital investment. With reactive distillation, the heat generated by chemical reaction can be utilized directly for the separation of products. At any point in the reactive zone, the reaction heat will cause additional mass transfer between vapor and liquid phases.

Another benefit of this process is to reduce both hardware investment and operation costs. Combining the reactor and distillation column in one vessel, one process step is eliminated along with its associated pumps, piping, and instrumentation. In some situations, this elimination results a 30 - 40% reduction of hardware investment. Unfortunately, not all industrial processes are suitable for reactive distillation. One of the drawbacks of reactive distillation is that the temperature control in reactive zone is more difficult than conventional distillation, and it is also difficult to modify the process after it has been designed.

Publications and Presentations:

Publications have been submitted on this subproject: View all 2 publications for this subprojectView all 157 publications for this center

Supplemental Keywords:

RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Sustainable Industry/Business, cleaner production/pollution prevention, Sustainable Environment, Chemistry, Technology for Sustainable Environment, Monitoring/Modeling, Civil/Environmental Engineering, computing technology, Civil Engineering, New/Innovative technologies, Engineering, Environmental Engineering, cleaner production, clean technologies, reactors, clean technology, modeling, membrane reactors, computer simulation modeling, Heuristics and Reactor Design (HARD) system, chemical processing, mathematical models, pollution prevention


Main Center Abstract and Reports:

R825370    EERC - National Center for Clean Industrial and Treatment Technologies (CenCITT)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825370C032 Means for Producing an Entirely New Generation of Lignin-Based Plastics
R825370C042 Environmentally Conscious Design for Construction
R825370C046 Clean Process Advisory System (CPAS) Core Activities
R825370C048 Investigation of the Partial Oxidation of Methane to Methanol in a Simulated Countercurrent Moving Bed Reactor
R825370C054 Predictive Tool for Ultrafiltration Performance
R825370C055 Heuristic Reactor Design for Clean Synthesis and Processing - Separative Reactors
R825370C056 Characterization of Selective Solid Acid Catalysts Towards the Rational Design of Catalytic Reactions
R825370C057 Environmentally Conscious Manufacturing: Prediction of Processing Waste Streams for Discrete Products
R825370C064 The Physical Properties Management System (PPMS™): A P2 Engineering Aid to Support Process Design and Analysis
R825370C065 Development and Testing of Pollution Prevention Design Aids for Process Analysis and Decision Making
R825370C066 Design Tools for Chemical Process Safety: Accident Probability
R825370C067 Environmentally Conscious Manufacturing: Design for Disassembly (DFD) in De-Manufacturing of Products
R825370C068 An Economic Comparison of Wet and Dry Machining
R825370C069 In-Line Copper Recovery Technology
R825370C070 Selective Catalytic Hydrogenation of Lactic Acid
R825370C071 Biosynthesis of Polyhydroxyalkanoate Polymers from Industrial Wastewater
R825370C072 Tin Zeolites for Partial Oxidation Catalysis
R825370C073 Development of a High Performance Photocatalytic Reactor System for the Production of Methanol from Methane in the Gas Phase
R825370C074 Recovery of Waste Polymer Generated by Lost Foam Technology in the Metal Casting Industry
R825370C075 Industrial Implementation of the P2 Framework
R825370C076 Establishing Automated Linkages Between Existing P2-Related Software Design Tools
R825370C077 Integrated Applications of the Clean Process Advisory System to P2-Conscious Process Analysis and Improvement
R825370C078 Development of Environmental Indices for Green Chemical Production and Use