Thermal Safety Software (TSS) series

Transcription

1 Ready-solutions Thermal Safety Software (TSS) series 各種の反応危険性評価ソフト The subset for adiabatic calorimetry ( 断熱測定データ解析ソリューション ) 断熱熱量計 (ARC VSP DEWAR) 等は 化学反応の熱的危険性評価に有効であることが知られています このソリューションは 断熱下で測定した熱量データを多目的に解析するために CISP 社が提供する TSS の中から選ばれた最適組み合わせセットです ADPro, ForK および / または DesK と各種の反応危険性を評価する ThermEx, ReRank, ConvEx と BST パッケージで構成されています ARC 等を利用した断熱測定データ 測定データ変換と解析 反応速度解析 簡易シミュレーション 反応危険性の評価 ADPro ARC 等の断熱熱量計のデータを TSS を使用して解析するための変換ソフトです 温度データ 圧力データのスムージング等の機能があります 反応速度を解析するソフトには ForK と DesK が準備されています ForK DesK シンプルな反応モデルを組み合わせて反応速度を解析するソフトです 変数は反応率となり物質を特定する必要はありません 濃度を変数として反応速度を解析するため 反応式を定義する必要があります 反応プロセス全体についての反応性を評価します 反応危険性評価パッケージは 以下のソフトで構成されています ThermEx 固相 ( 高粘性液体 ) の温度分布を熱伝導シミュレーションし熱暴走に至る限界条件を計算します ConvEx ReRank BST 液体中の温度分布をシミュレーションし熱暴走に至る限界条件を計算します 対象化学物質の反応性指数を決定します このパッケージは バッチ反応を想定して熱暴走をシミュレーションできる他 放散口の設計も可能です 反応危険性を評価する組み合わせパッケージは 研究目的に合わせて変更可能です 物質の反応危険性の評価 ランク付けには 基本となる ThermEx, ConvEx, ReRank が適していますが これら 3 ソフトに加え BST(The Batch Stirred Tank) も強力な評価ツールとなります 1

2 図 1 20%DTBP( ジ -tert- ブチルペルオキシド ) トルエン溶液の熱分解挙動 TDPro と ForK によるシミュレーションと測定値を比較 図 2 ConvEx を用いたシミュレーション 図 3 BST を用いたシミュレーション ( 出典 ; 住友化学 2001-Ⅰp.67) 2

3 Kinetics-based simulation How can this approach help when assessing reaction hazard? Introduction Reaction hazard of a chemical process, along with toxic and fire hazards, is one of the main aspects of the general problem of safety in chemical industry. The term thermal (or reaction) hazard covers variety of hazards dealing with heat evolving in a chemical process. Improper choice of operational conditions or accidental deviations from the normal course of an exothermic process may result in development of runaway (thermal explosion) and cause severe consequences. As far as thermal hazard of a chemical product is concerned, the main aim of hazard assessment is the choice of safe conditions of storage, transportation and use of a product. As usual, there is no other way to get data necessary for assessing thermal hazard rather than by experimental study. Typical technique, which is used in this area, is calorimetric data of various kinds. Kinetics-based simulation Principal solution of the scale-up problem Of course almost all experiments, especially when hazardous materials are investigated, are carried out in the laboratory small scale. At the same time the key problem that has to be solved is the scale-up problem. Among various methods that are used for scaling there is only one almost universal method that allows prediction of reaction course under any conditions of interest. This is kinetics-based simulation. It involves 3 main steps. In the first step: necessary series of calorimetric experiments is carried out. In the second step: the mathematical model of a reaction is created. Finally: the created model is incorporated into the model of a process and the practical target is achieved by using numerical simulation. Is this approach simple? We have to admit that this method is quite complex. In practice the presented procedure turns out to be iterative rather than the plain one. Today this can be resolved by the problem oriented tools that would be convenient for researchers. CISP has designed a problem-oriented system and corresponding software is now available: Thermal Safety Software series (TSS). 3

4 Example 1. Verification of the software for ERS design Reaction: Isopropanol + Propionic anhydride Isopropyl Propionate + Propionic Acid Experiment: Adiabatic Calorimetry (Phi-tech); simultaneous use of 2 data sets: To =25 o C & 35 o C Reactor: Vertical tank, V = 312 liters; U = 270 W/m2/K, S = 1.53 m2 with 1.5 bar vent system The created model was incorporated into the model of a BATCH reactor and the runaway scenario has been simulated. The results are in good accord with the results of the pilot-scale experiment(hse Round-Robin test) 2. Designing Inherently Safer Semi-Batch Process Reaction: Isopropanol + Propionic anhydride Isopropyl Propionate + Propionic Acid Reactor: Vertical tank, V = 312 liters; U = 270 W/m2/K, S = 1.53 m2, operating in a semi-batch mode Optimization criterion - Inherent Safety: Max { MPT(Maximal Permissible Temperature) MTSR(Maximal Temperature of Synthesis Reaction)} Initial Mode (Before optimization) Feed rate is assigned as 10 identical pulses with f = 1.65 dm 3 /min and duration = 10 min each. PA T 125 C, t 60 min max max unsafe Safe Mode Feed rate is optimized to f PA = f PA (t) T max 106 C, t max 67 min Inherent Safety is provided 4

5 Thermal Safety Software (TSS) series ChemInform St. Petersburg (CISP) has been created in 1994 on the basis of the research department of the Russian Scientific Center Applied Chemistry and inherits more than 40 years of experience in investigation of thermal safety of propellants, explosives and other energetic chemicals as well as study of chemical processes and products of general purpose. The CISP achievements in methodology for research of reaction hazards and creation of the problem-oriented software are recognized worldwide. Assessing Thermal Hazards of Chemical Processes and Products From experimental study of a reaction through creation of a kinetic model to the mathematical modeling of a process TSS covers the entire spectrum from processing of experimental data to simulation of chemical reactors and runaways of various kinds TSS gives general solution of the crucial challenge of hazard assessment the scale-up problem TSS applications are addressed to: R&D Centers of Chemical and Pharmaceutical Companies Chemical Engineering Departments of Universities R&D Centers and laboratories dealing with assessment of reactive hazards of dangerous goods Flowchart of the TSS series 5

6 Main Features of the TSS components Applications for data processing ADPro, TDPro, and RCPro ADPro, TDPro and RCPro are powerful tools for processing of experimental data for kinetics evaluation. These tools implement CISP proprietary data processing methods. ADPro, TDPro and RCPro can be used as the standalone programs in such fields as kinetics of chemical processes, study of thermal decomposition, and study of physical properties. Features ADPro TDPro RCPro Type of experiment supported Unique data processing methods Pseudo-adiabatic calorimeters (Accelerating Rate Calorimeter (ARC), VSP, RSST, DEWAR, and others.) Non-adiabatic calorimeters with pressure response Consideration of thermal expansion of a sample bomb and its contents Consideration of temperature dependent sample and bomb heat capacities when calculating thermal inertia and heat production Processing of nonadiabatic data containing pressure response Determining vapor pressure (choice between August and Antoine equations); calculating gas production Various thermo-analytical experiments (DSC, TDA, TG, combined technique, etc.) Deconvolution of DSC data (correction of dynamic distortions due to thermal inertia) Reconstruction of correct sample temperature Statistical analysis of results of parallel runs Determination of thermal conductivity of liquid substances Reaction calorimetry, data can include: - thermal responses (heat, heat release rate, temperature) - pressure - concentration responses Deconvolution of heat release rate data (correction of dynamic distortions due to thermal inertia) Determining vapor pressure (choice between August and Antoine equations); calculating gas production Processing of concentration responses 6

7 Applications for Kinetics evaluation ForK, DesK and IsoKin ForK and DesK are unique state-of-the-art programs that allow: 1. Creation of a kinetic model of a chemical reaction on the basis of experimental data. 2. Simulation of a process or product s behavior. General characteristics: Use of the non-linear optimization methods for estimating parameters of complex multi-stage reaction models Highly efficient numerical methods for integration of differential equations and nonlinear optimization Simultaneous use of several experimental data sets for kinetics evaluation; each data set may correspond to its own type of experiment and temperature mode Analysis of the uniqueness of the found set of kinetic parameters Import of experimental data from ADPro/TDPro/RCPro, manual load Automated determination of adiabatic Time to Maximum Rate (TMR) and Thermal Stability Analysis Features ForK DesK Reactors supported Well stirred BATCH Continuous stirred tank; BACTH, semi-batch and Plug Flow reactors are available. Thermal modes Adiabatic, Heat exchange with the environment (with time-dependent parameters) Forced temperature mode (sample and environment temperatures coincide) Type of a kinetic model Model design Properties required Conversion-based complex multi-stage formal models Concentration-based complex multi-stage multi-component descriptive kinetic models Friendly method for creation of complex multi stage models doesn t require programming Cp(T), Antoine equation for vapour P Molar mass, Cp (T), density (T), Antoine equation for vapour P. Internal property data bases Link to MIXTURE software New original model is available in the latest version of ForK. It allows taking into account slow reaction in the solid substance, its melting and appearance of liquid phase in which reaction is much faster and proceeds till completion. As opposed to the conventional methods of melting simulation the model of the melting stage used in ForK is based on the physical model of the event. Recently new member of TSS had been added. This is the IsoKin program designed for creation of the so-called model-free kinetics. IsoKin may be useful for preliminary analysis of thermo-analytical data as well as for fast approximate solution of some practical problems 7

8 Applications for explosion simulation ThermEx and ConvEx ThermEx and ConvEx are the unique analog-free program packages intended for analyzing the possibility of thermal explosions at production, application, storage, or transportation of unstable chemical products. ThermEx and ConvEx help in prediction, assessment and monitoring of thermal hazards by direct numerical simulation. They provide: Determination of critical conditions (package size, ambient temperature, induction period.) for complex reacting systems Automated search of Critical Temperature and Self Accelerating Decomposition Temperature (SADT) Analysis of accidental scenarios (a fire, etc.) Features ThermEx package ConvEx package Substance Solid Liquid Heat transfer Thermal conductivity Thermal conductivity and natural convection Type of a kinetic model Geometry Simulation of pressure rise Formal models, imported from ForK Formal models, imported from ForK Possibility is foreseen for manual creation of formal or descriptive models Infinite cylinder, slab and sphere Barrel, variety of lids Rectangular box, stack of boxes Complex User-defined geometry Shell (container) and inert partitions Available for a barrel and a box; pressure of gas products is estimated Descriptive models; imported from DesK Sphere; Barrel tank-track (tank-wagon) Shell is available Total pressure of vapour and gas products is calculated Time-dependent boundary conditions (BC) can be set on each surface of a container separately: BC of the 1st kind (Surface temperature) BC of the 2nd kind (Heat flux on a surface) BC of the 3rd kind (Heat exchange with the environment) One of the unique features of ThermEx is that the time-dependent heat power can be assigned to any inert or reactive zone thus allowing simulation of such events as functioning of a heater within the container with the unstable product and so forth. 8

9 Software for Runaway simulation and Vent sizing - BST The batch stirred tank program, BST, is designed for simulation of physical and chemical processes in well-stirred batch tanks utilizing emergency relief systems. With simulation of accident dynamics, BST helps in selection of proper size of a vent system that prevents tank bursting in case of a runaway reaction. BST is based on DIERS methodology of gas-liquid mixture flowing out of the tank. BST modeling facilities are: Complex multi stage formal or descriptive kinetic models imported from ForK or DesK Tanks of various shapes: sphere, vertical and horizontal cylinder Time-dependent heat exchange with environment Multi sectional vent system (up to 256 elements) Vent type: rupture disk or valve; vent position: top or bottom; pipe inclination can be defined Flow models: tank: bubble, churn turbulent, or foam; vent system: one phase; two-phase homogeneous equilibrium or frozen for nozzle; homogeneous equilibrium or nonequilibrium for pipes. BST is linked to the MIXTURE software, which provides reliable calculation of properties of ideal and non-ideal liquid and gas mixtures depending on their compositions and temperature. BST is the main part of the BST program package which comprises also MIXTURE and VENT Software for evaluation of physical properties - MIXTURE MIXTURE is a powerful and convenient tool for evaluation of physical properties of liquid and gas multi- component non-ideal mixtures. Non-ideality of liquid mixtures can be taken into account during calculation of vapor pressures. Component activity coefficients are determined by the modified UNIFAC method. MIXTURE has an internal data base containing properties of 400 substances. Complete compatibility with other TSS applications (DesK-Pro, ConvEx, BST, InSafer) MIXTURE provides access to data from commercial databases such as DIPPR 801 and PPDS. 9

10 Software for design of inherently safer Processes InSafer InSafer is intended for optimization and design of inherently safer chemical processes. The software doesn t have any commercial analogs. The optimization is aimed at finding an operational mode that ensures an inherently safer process, i.e. a process which is as safe as possible under normal operating conditions and in case of an accident. The most efficient numerical methods for integration and non-linear optimization The choices of different criteria that take into account both process safety and feasibility. Simple methods for defining control variables that are to be optimized and can be applied in practice. CISP proprietary unique method for stability analysis of operation mode of a non-stationary process Software for calculation of two-phase flow along the pipeline VENT VENT is designed for calculation of steady -state two- phase flow along a multi-segment pipeline. The pipeline can contain up to 256 hydraulic elements; Straight pipes, Elbows, expanders, contractors, Valves and rupture disks. Every element is described by the appropriate set of parameters. VENT supports two types of flow models in a pipeline: One- or two-phase homogeneous equilibrium or frozen for nozzle; Homogeneous equilibrium or non-equilibrium for pipes VENT is linked to the MIXTURE software which provides calculation of necessary physical properties of gas-liquid mixtures. VENT can be used as the module of the BST package and as the standalone application Software for Reactivity Rating - ReRank ReRank is the first commercial software intended for Reactivity Rating of individual substances and mixtures. General features: お問合せ先株式会社住化技術情報センター TEL: FAX: 担当者 : 岡本弘 okamotoh5@sc.sumitomo-chem.co.jp 10