ARKS CK - software for evaluation of concentration-based Kinetic models

Purpose of the program 

The ARKS CK (Descriptive concentration-based kinetics) software is intended for creation of complex multi-stage descriptive concentration-based kinetic models on the basis of available sets of experimental data generated by methods of thermal analysis, adiabatic and reaction calorimetry. In addition the program provides fast and reliable simulation of processes in a well stirred BATCH, semi-BATCH, continuous stirred (CSTR) and plug-flow (PFR)  reactors. Kinetics evaluation is implemented by employing the state-of-the-art nonlinear optimization method. The group or mutually complementary robust numerical integration methods allows accurate integration of the stiff system of ordinary differential equations that represent a model.

It should be specifically noted that the most appropriate data for creation of concentration-based models can be obtained by applying reaction calorimetry ((Mettler RC1, HEL Simular, ChemiSens CPA 102, 202 and many others), which provides accurate information about heat generation by a reaction coupled with data on variation of mixture composition.

The convenient project-oriented interface facilitates ARKS CK application. ARKS CK is addressed to those who are interested in reaction kinetics, to chemical engineers involved in design of chemical processes, to specialists in thermal hazard assessment of processes, etc.

ARKS CK comprises two main modules – Simulation and Estimation. The access to these modules is provided by the ARKS CK suite shell which makes use of the package more convenient and vivid.

The unique feature of the software is that it uses the specialized method of statistical analysis for estimation of the quality of a model created.

The ARKS CK software inherits the best qualities of its predecessor DesK and has many new features - new interface, revised and improved algorithms, completely reworked documentation,  etc. ARKS CK is supported by videotutorils which help in mastering software: 

CK Tutorial 1 working with properties
CK Tutorial 2 evaluating kinetics from adiabatic data,
CK Tutorial 3 evaluating kinetics from RC data
CK Tutorial 4 process simulation

Loading data

ARKS CK allows handling multi response data containing integral and/or derivative responses: heat, gas generation, pressure and concentrations of species.

ARKS CK provides direct access to experimental data stored in ARKS-AC  and ARKS TA  databases for importing data.

Note that in the case of data from reaction calorimetry there is no need in data transfer of any kind between ARKS CK and  ARKS RC - they use common data base. 

The possibility is also envisaged to paste responses from clipboard.

Storing data

ARKS CK stores original and processed data into internal database. Database consists of data volumes. Every data volume includes number of data sets; each data set may represent results of separate run, simulated results, conditions of an experiment, and kinetic model created.

ARKS CK allows saving estimation projects. Every project includes all the information prepared for estimating kinetic parameters - kinetic model, initial guess on parameters and their limits, references to experimental data sets, etc.

Physical properties

ARKS CK supports two sources of physical properties necessary for simulation:

• The simplified built-in database that is replenished by the User. The additive rules are applied for calculation of properties of multi-component mixtures
• The MIXTURE software capable of accurate calculation of properties of non-ideal multi-component mixtures

Type of kinetic models

ARKS CK supports application of complex multi stage descriptive kinetic models that are based on concentrations as state variables and obey the generalized Law of Mass Action. Creation of a model is implemented by defining the stochiometric scheme of a reaction. No programming is required. See CISP Newsletter N6 for more details

Reactor’s model

A chemical reaction is considered to proceed in a continuous stirred tank reactor (CSTR) which can operate under the following thermal modes:

• adiabatic mode - no heat exchange with environment;
• forced temperature mode - reactant temperature is equal to the environment temperature;
• general mode - heat exchange between reactant and environment obeys Newtonian law;
• NEW. Possibility to take into account temperature dependencies for heat capasities of reacting substance and material of a reactor in adiabatic and general mode (variable thermal inertia);
• fire impact which can be defined either as a temperature ramp or as external time-depecndent heat flux;
• operating conditions (environmental temperature, heat transfer coefficient, inlets and outlet flows) can be defined as tabular functions on time;
• a reactor can have several multi component inlets. Composition of a mixture and its temperature can be defined separately for every inlet.
• a reactor may have jacket and several cooling coils, every cooling tool can be characterized by the unique set of parameters (surface of heat exchange, heat exchange coefficient, cooling agent temperature). In addition to simple heat exchange with the jacket/coil based on Newton equation ARKS CK supports more precise balance-based calculation of heat exchange.

Simulation module provides modeling of a reaction's behavior. The following possibilities are envisaged:

• loading the complete kinetic data set;
• loading kinetic model from database or creating a new model;.
• manual inspection of the impact of variation of kinetic parameters of a model;
• manual inspection of the effect of controls variation;
• loading conditions from database or defining original conditions;
• loading existing responses and conditions;
• defining parameters of numerical integration method;
• simulating a process; calculation of pressure in a reactor void volume including pressure of gas products, pad gas and vapor pressure either by using the equilibrium data for every species or calculating the overall vapor pressure defined by the Antoine equation
• determining adiabatic Time to Maximum Rate (TMR) and Total Energy Release (TER) for a reaction course under adiabatic conditions
• analyzing thermal stability of a substance;
• viewing results of simulation in tabular and graphic form in selectable axes;
• saving simulated responses as pseudo experimental ones into the database.

Estimation module is used for estimation of kinetic parameters when evaluating chemical kinetics. The following possibilities are envisaged:

• loading experimental data from database;
• loading kinetic model from database or creating a new model. The unique feature supported by ARKS CK is generation of the lists of key species. The key species denote the minimal set of species which concentrations must be measured in order to provide the uniqueness of a kinetic model. Information provided by this unique procedure allows a researcher more realistic estimate of the problem which is to be solved
• manual inspection of the impact of variation of kinetic parameters of a model and easy way for selecting appropriate initial values of kinetic parameters;
• loading complete project;
• simultaneous processing of several data sets obtained under different conditions and/or by different experimental methods;
• editing data;
• applying set of non linear optimization methods for estimating parameters;
• NEW. Visulal representation of the parameters estimation course,
• scanning of hyper surface of the objective function;
• viewing original data and simulated responses in graphic form; one can export data (all data used for estimation or some selected data sets) into the Excel just by selecting the menu option; at that both experimental and simulated responses will be transferred;
• NEW. Statistical assessment of the quality of the kinetics created using the coefficient of determination,
• saving results into database.

Installation

Requirements: CPU: Intel Pentium 1200 MHz and faster; Memory: 1024 MB; Disk space: 50 MB, CD-ROM: present
                        OS: MS Windows 7, 8, 10, 11.

ATTENTION!

​1. When installing ARKS CK under Windows 7 and higher we strongly recommend to use the default path
    C:\Users\[username]\CISP\ARKS CK

2. When installing TSS-ARKS applications one can meet the problem with Anti-virus tools you use.
    Some of them may suspect that TSS-ARKS programs are hazardous ones. Please don't worry. This may  happen 
    due to new powerful protection system (provided by  the Enigma Protector - one  of the world  leaders in this
    area) which sometimes causes alarm because anti-virus tools cannot look  inside the protected code. As a
    result the application will be blocked.  To avoid such problem ask your IT service to exclude
    Users\[username]\CISP folder from virus  check.
    CISP guarantees that TSS-ARKS is 100% clean, which means its applications do not contain any form
    of malware, including but not limited to: spyware, viruses, trojans and backdoor.

Be aware - even if you are the licensed user of TSS or TSS-ARKS software with valid guarantee or maintenance when you upgrade DesK to ARKS CK  you will have to get new registration key. Please email us the request and don't forget to indicate your company and your name  

IMPORTANT! Be aware that on the expiration of the Warranty/maintenance Period the License on any TSS or TSS-ARKS application remains valid for the version last updated during maintenance Period. Therefore if your maintenance has expired you wouldn't be able to use new updates. If you nevertheless download the setup of new version and replace your working version with new one it won't work and you will lose working program! To avoid such situation check please whether you have valid maintenance before downloading any TSS-ARKS program.