THE USE OF MOBILE DEVICES IN PROCESS COMPUTATION Mordechai Shacham Ben Gurion University of the Negev Beer-Sheva Michael B. Cutlip University of Connecticut Storrs, CT Michael Elly Intel Corp., Qiryat Gat.

Smart phones – the Latest Addition to the Engineers’ Computational Toolbox *PolyMathLite is an Android app produced by PolyMath Software. (http://www.polymathlite.com)

Presentation Outline Review of the process design and problem solving tools available for (chemical) engineers: 1965 – 1980 Manual calculations and mainframe based process simulators 1980 – 2015 PC based mathematical software packages 2015 - ? Mathematical software packages for mobile devices. 2. The advantages and disadvantages of mobile devices (smart phones, tablets etc.) for process computational use. 3. Simulation of a semi-batch reactor (exothermic reaction) to investigate possible outcome of the change of the operating conditions to prevent temperature runaway.

Chemical Engineer’s Problem Solution Techniques – 1965-85 Analytical solutions, including Model simplification by neglecting less important terms Model manipulation to bring it into a solvable form Short-cut solution techniques Replacing the problem with a simpler one that can be solved Graphical solutions Trial and error solution techniques Numerical solution, including Computer language programming, flow-sheeting programs

The Emerge of the Mathematical Software packages for the PC Use of a PLATO based mathematical software package for solving a system of ordinary differential equations (ODE) representing material and energy balances on a tubular reactor. C2H6 → C2H4 + H2 z – conversion T – Temp (°R) *Shacham and Cutlip, Computers Chem. Engng., 6(2), 79-95(1982)

Pre-assigned variable names. Solution of the Tubular Reactor Balance Equations using the PLATO Software Package The user enters the problem, the package takes care of the technical details of the solution. Limited problem size. Pre-assigned variable names. *Shacham and Cutlip, Computers Chem. Engng., 6(2), 79-95(1982)

Solution of the Tubular Reactor Balance Equations using the Polymath Software Package The user enters the problem, the package takes care of the technical details of the solution. No limits on the problem size. Meaningful variable names.

A “Paradigm Shift” in Engineering Problem Solving* Numerical Solution: After the mathematical model of the problem is formulated it is solved directly by a numerical software without any further manipulation *Fogler H. S., “An Appetizing Structure of Chemical Reaction Engineering for Undergraduates”, Chem. Eng. Ed., 27(2), 110(1993)

A List of POLYMATH Solutions in Fogler’s Textbook* *Fogler H. S., Elements of Chemical Reaction Engineering, 4th Ed., Prentice Hall 2006

Mathematical Software Package Recommendation* *Himmelblau DM and Riggs JB, Basic Principles and Calculations in Chemical Engineering, 7th Ed, Pearson Education, 2004.

POLYMATH Site Licenses, 2015 *Number of Institutes of Higher Education

What Can be the Role of the Smartphone in Process Computation? It has been shown that numerical solutions (using the PC) have replaced the traditional methods (analytical, short cut etc.) in process calculations. The advantage of the mobile devices over the PC is the 24/7 availability. The disadvantage lies in the difficulties associated with the program development and/or major program modifications in such devices. It is recommended to use the PC for program development and testing, to load the well tested program in the mobile device and to change only limited amount of numerical data for specific calculations, simulations etc.

Create Your Own Sophisticated Calculator for Future Value and Constant Annual Payment Calculations File name Comment Save the problem specification and change the parameters: loan amount, interest rate and number of periods as needed

Create Your Own Sophisticated Calculator for Temperature Dependent Physical Properties Calculations Calculates heat of vaporization, liquid density, vapor pressure, liquid thermal conductivity and liquid viscosity as function of temperature. Source of correlations is the DIPPR database.

Create Your Own Sophisticated Calculator for Temperature Dependent Physical Properties The Solution Report contains the numerical values of the variables at the solution, the problem specification (including units and uncertainties) and a complete MATLAB program. The report can be exported to other applications, stored and e-mailed

Solving the Example Problem with PolyMathLite Full results are presented for all the variables in tabular form

Process Simulation - Nitric Acid oxidation of 2-octanol in a Semi-Batch Reactor Presents from start Added continuously A - 2- octanol, P - 2-octanone , X – undesired oxidation products B - nitrosonium ion, causes an autocatalytic behavior

The 2-octanol reacts to form 2-octanone and carboxylic acid. Nitric Acid oxidation of 2-octanol in a Semi-Batch Reactor (van Woezik and Westerterp*) In the semi-batch reactor aqueous nitric acid is initially present, and 2- octanol (A) is added at a constant rate until a desired molar ratio of the reactants is reached. The 2-octanol reacts to form 2-octanone and carboxylic acid. Under normal operating conditions, the temperature in the reactor does not exceed the limit of ~ 0 °C. If the temperature at any time exceeds ~ 5 °C, runaway conditions develop, which may lead to a maximal temperature of over 200 °C, and conversion of all of the 2-octanone to carboxylic acid. *Chemical Engineering and Processing, 39, 521(2000) and 41, 59(2001).

PolyMathLite Model of the of the 2-octanol Oxidation Reactor– Mole Balance Equations

PolyMAthLite Model of the of the 2-octanol Oxidation Reactor– Energy Balance Equations

2-octanol Oxidation Reactor –Safety Related Parameters Potential Causes of Temperature Runaway Increase of coolant inlet temp. Reduction of coolant flow rate Shortening of dosing time Increase of dose volume Increase of nitric acid concentration Reduction of effective heat transfer rate

2-octanol Oxidation Reactor– Simulation Results Normal operating conditions Desired product Temperature runaway Maximal temp. (K)

Reactor’s Temperature - Normal Operation and Temperature Runaway Simulation of 20 hours of operation of the reactor with PolyMathLite on a smart phone takes 5 seconds

Conclusions It has been shown that mathematical software packages associated with mobile devices can complement such packages installed on PCs, because of their 24/7 availability and very short execution times. The program development and testing should be done, preferably, on a PC. The tested program can be installed on the mobile device to enable the user to carry out parametric runs, whenever necessary. A potential application of PolyMathLite was demonstrated by calculating temperature dependent properties and parametric study of the operation of a semi-batch, multi-phase reactor in which two consecutive, highly exothermic reactions are carried out.

The Predicted Future of Mathematical Software Packages (1990) To Mordechai, You are going to bring about a paradigm shift in the way we not only teach chemical reaction engineering, but all chemical engineering through your development of POLYMATH. Scott 8/27/90

Chemical Equilibrium Computation with POLYMATH * *Kyle BG, Chemical and Process Thermodynamics, 3rd Ed, Prentice Hall, 1999

The PolyMathLite App* *PolyMathLite is an Android app produced by PolyMath Software. (http://www.polymathlite.com)

Product Distribution - Normal Operation and Temperature Runaway 2-octanone – desired product Carboxylic acid - undesired product Temperature runaway Plots can be obtained by the Plotim free app.

Example - Additional Causes of Temperature Runaway Increase of coolant inlet temp. ≥ 266 K Reduction of coolant flow rate ≤ 12 Shortening of dosing time ≤ 7.5 h Increase of dose volume ≥ 0.81 m3 Increase of nitric acid concentration ≥ 0.64 Reduction of effective heat transfer rate ≤ 81%