Data Reconciliation, Mass. Heater, Energy Balance, Yield Accounting

ChemPlant Technology는 1991년 설립되어 정유, 석유화학 공정의 Consulting, Plant Information System (Data Reconciliation, Balancing, Yield Accounting), 공정 데이터 분석, 플랜트 테스터, 최적화 (Optimization), VOC 방출 감시 및 최소화 등의 활동을 하고 있습니다.
Chem Plant의 창립자인 Dr. Frank Madron는 수학 및 통계학의 대가로써 1977년부터 Data Reconciliation / Yield Accounting에 대한 논문 발표 및 개발을 주관하였습니다. SimSci의 DATACON 개발을 주관하였으며 Aspentech 제품 개발 시에도 Consultanting을 하였습니다.
현재 Data Reconciliation에 대한 논리적이고 체계적인 교육을 주관하고 있으므로 관심 있으신 분들은 연락 주시기 바랍니다.

또한 일반적인 Tool 및 Package로 해결하기 어려운 Data Reconciliation 또는 Balancing /Accounting 부분에 대해서는 별도의 Consulting Service도 제공하고 있습니다.
ChemPlant의 Staff들은 공정 데이터 분석 방법론에 대하여 50개 이상의 논문 및 2권의 책을 발행 하였습니다.

주요 제품 및 서비스 부분은 하기와 같습니다.

IBIS : Information Balancing and Yield Accounting System

RECON : Mass and Heat Balancing with Data Reconciliation

VOC : Emissions Monitoring and Minimization

Reconciliation Training Course

APIS : Advanced process Information System

TIS : Technology Information System

RETRO : Retrofitting of Heat Exchange Systems

IBIS는 대규모 프로세서 공장 내에 있는 Mass (Material), Utility (Energy), Reaction (Component)의 Balancing 및 Yield Account를 위한 소프트웨어 Package입니다. 또한 Mass와 Energy Flow에 대한 정보를 수집하고 평가하는 것이 중요한 Refineries, Chemical, Electrical networks, Pipeline systems등에서효율적으로 사용할 수 있습니다.

Capabilities

Setting up regular (e.g.daily) mass and energy balances
Data input is manual via keyboard or automatic from existing control and information systems
Reconciliation of redundant data
Automatic calculation of unmeasured flows and inventories from a balance model
Automatic generation of some unmeasured flows on the basis of so-called reference streams
Protection of results against human and measurement gross errors
Easy merging of balances of subsystems into the balance of whole plants or companies
Setting up balances in longer time intervals
Automatic generation of tables and reports

Characteristic features

Flexibility
The user can easily and with great freedom configure the system according to changing needs.

Balance model
IBIS does not form only database of measured quantities, but automatically sets up and solves the system of balance equations. On the basis of thus formed balance model it calculates unmeasured quantities.

Hierarchy of balancing
IBIS is distributed and hierarchical. It is supposed that input data can be entered at many sites (production units, plants) simultaneously. After a preliminary treatment of data at this lower level, data are sent to one or more higher levels, where the data processing continues.

Speed of calculation
Balance calculations are based on new fast algorithms developped by authors. This results in the fact that balances of even largest complexes can be solved on standard personal computers (the computing time even for large companies in tens of seconds).

Data reconciliation
IBIS is equipped with so-called statistical reconciliation of redundant data, so that consistent (in the sense of balance laws) results are obtained. Reconciliation improves precision of results.

Gross errors elimination
The daily use of mass and energy information system in process industries can be called "a fight against gross errors" (human errors, malfunction of measurement instruments). IBIS is therefore rich in gross errors detection, identification and elimination methods which facilitates obtaining really reliable results.

Database and reporting facilities
IBIS has its own optimized database for comfortable managing of data files. It also contains a generator of tables and reports for efficient presentation of results (yield tables, surveys of expedition of products, inventories of products and intermediate products etc.).

Compatibility

Results can be exported in files readable by other text editors, spreadsheets and database systems.

IBIS enables one to form balances in longer time intervals (decades, months etc.) on the basis of short-term balances.

IBIS is based on more than 15 years experience with plant data processing systems. It incorporates the newest theoretical development in this field and at the same time also long-term practical experience.

Installation

There are many ways how to install IBIS, for example:

Installation on a single PC
Installation on LAN PCs
Hybrid installation, for example combination of a network with isolated PCs. Data transfer via modems or diskettes
Communication with distributed control systems via data files prepared by process computers

The flexibility of installation makes possible an instant implementation of IBIS on existing hardware with perspective of smooth creation of balance information system of a whole plant or a company.

RECON serves for reconciliation of sigle/multi-component material and heat balance of complex proceses.

What is reconciliation?

Reconciliation is a method for extracting all information present in plant data. Reconciliation is based on statistical adjustment of redundant process data to obey laws of nature (mass and energy conservation principles). As a result, new consistent set of data is obtained. Moreover, reconcilation serves as a basis for other important activities:

finding confidence intervals of results (error propagation analysis)
detection and elimination of gross measurement errors
measurement planning and optimisation.

RECON can be used to treat measured data before it is used for other purposes (simulation, optimisation, control,...)

Features

RECON is PC oriented software with user friendly facilties (menus, screens, etc.). Problems are defined interactively in the graphical user interface. Results can be viewed either on the screen, printed or saved as the output file. Manual contains brief survey of reconciliation theory.

Problem definition

Problem is defined by the following basic elements:

the list of nodes (process units)
the list of streams
the list of components
the list of temperatures
the list of chemical reactions
the list of heat exchangers
presence of individual reactions in nodes
the structure of the flowsheet

All process variables must be classified as

measured
unmeasured, or
fixed (are not changed during reconciliation)

The user must set also

values of measured and fixed quantities
estimates (guesses) of unmeasured variables (for nonlinear problems only)
maximum errors or standard deviations of measured quantities

Capabilities of RECON

calculation of unmeasured variables
reconciliation of redundant measured variables
analysisis of input data as concerns their consistency
confidence intervals of results
statistical analysis (detection and identification of gross measurement errors)
detailed classification of variables (redundant - nonredundant, observable -nonobservable).
instrumentation design and optimisation

Hardware requirement

The software can be installed on any IBM compatible PC operating under MS Windows 95/98/2000/NT with Pentium processor. The minimum recommended RAM is 32 MB.

Volatile organic compounds (VOC)

Organic compounds whose vapor pressure at 20 캜 exceeds 0.13 kPa are referred to as Volatile Organic Compounds. VOC have been implicated as a major precursor in case of production of photochemical smog, which causes atmospheric haze, eye irritation and respiratory problems. Some VOC's are cancerogenic. VOC emissions are typical for oil processing, petrochemical and chemical plants.
There are two main types of VOC emissions:

emissions from point sources - storage tanks and filling stations vents
fugitive emissions - process equipment leaks

Emissions from storage tanks

Emissions from storage tanks can be either measured (for fixed roof tanks) or can be calculated (for all tank types) by means of the U.S. EPA AP-42 method.
The calculation is based on

tank construction data
stored liquid volatility data
meteorological data
annual turnovers of the liquid stored. The validity of calculated results may be controlled by means of direct emission measurement.

TEMS (Tank Emissions Monitoring System)
Software TEMS based on EPA's AP-42 equations was developed for tanks emissions calculations. The program uses metric units of data entered. The tank construction data, liquid data and meteorological data are in most cases permanent. Annual number of turnovers of the stored liquid changes often and must be regularly updated by. The best way of updating turnovers is the linking of TEMS to a process information system containing data about tank levels.

TEMS allows to obtain emission database and create an emission report easily and rapidly even for large tank farms. TEMS helps the user to be in compliance with ever more stringent legislation requirements on emission recordkeeping and reporting.

Fugitive emissions data

Sources of fugitive emissions are leaking components of process equipment such as flanges, valve stem packings, pump and compressor sealings, etc. Total emission rate from these sources depens especially on the age of the equipment and on maintenance routine in the plant.

LDAR Program (Leak Detection And Repair)
All the accessible equipment is monitored by means of the EPA's reference method 21. Leaking components are tightened (the first attempt to repair) or repaired during the next shutdown. The correlations between measured VOC concentration near the source and the real emission rate developed by EPA allows to evaluate total emission rate (production losses) due to leaking component and achievable savings due to repairs of leaking components.

LDAR Program

improves a maintenance routine
saves both money and environment,
helps to comply with the environmental laws

We offer:

data consulting in area of VOC monitoring and minimization

implementation of TEMS

monitoring of fugitive emissions as a part of LDAR

Course overview

Basics

Mathematical models

Statistics

Measurement errors

Reconciliation

Usually more data is measured than necessary. Reconciliation makes redundant data consistent with the mathematical model. Moreover, unmeasured parameters of the model are estimated on the maximum likelihood principle. Reconciled data are generally more accurate than the measured ones. In general, reconciliation is a method for optimum estimation of model's parameters. Moreover, reconciliation represents basis for other activities related to validation of plant data - especially to elimination of gross measuring errors and to optimisation of the overall measurement process.

Propagation of measurement errors

Results of data processing are usually of different accuracy. In practice we can meet in some cases with errors in hundreds of per cents of real values. Information about accuracy of results (confidence intervals) should accompany all values important in further decisions.

Data analysis

Confront your data with the model. A bad fit can be caused either by gross measurement error, or by a model error. Both discrepancies can devalue your results.

Detection and identification of gross measurement errors

Reconciliation provides powerful tools for detection of gross errors presence and also for finding sources of gross errors (gross errors identification).

Model errors

Sometimes are discrepancies between data and model caused by model's inadequacy (neglecting process dynamics, unmeasured leaks, too simplified models of unit operations, etc.). Reconciliation represents an efficient method of model building, to incorporate more complex features in the model.

Measurement optimisation

Even advanced methods of data processing can't substitute for a bad measurement plan. Reconciliation provides methods for either optimising existing instrumentation system, or designing a new one.

Case studies

The most important fields of reconciliation will be covered: mass, component and energy balancing reconciliation of non-linear models

heat exchangers (identification of heat fluxes and heat transfer coefficients)

distillation columns (identification of plate efficiency as a prelude to modeling)

mass and energy accounting in a large plant (reconciliation as a part of plant information system)

optimal design of measurement placement

Course features

computer workshops with professional reconciliation software

possibility to solve user-specific problems possibility to tailor the course according to user needs

every participant will acquire a software needed for solving basic reconciliation tasks

course text is an unique reconciliation minibook comprising the most important techniques of reconciliation

Who should attend?

IT managers

managers and technologists of operating plants

staff of optimisation, retrofitting and debottlenecking groups

control engineers, especially dealing with advanced control.

Characteristics of the system

APIS is a comprehensive information system for process industries (refinery, petrochemistry, inorganics etc.). APIS fills the gap between raw process data and a financial (accounting) system of a company.
APIS is based on data reconciliation technology which provides data which are consistent with chemical-engineering and accounting models (conservation of mass and energy, models of unit operations, etc.).

Other advanced features of APIS:

Estimation of model's parameters

Detection, identification and elimination of gross errors

Confidence intervals of results

Measurement system optimization.

APIS is built on PC platform under local area PC network.

Basic components (subsystems) of APIS

APIS consists of several mutually connected information systems and programs. All these subsystems can be used independently. Anyway, their efficient use is promoted in the framework of APIS. APIS is the platform which enables one to analyze the input data, run the individual applications and present final results.

Architecture of APIS

APIS consists of the core and applications. The core is formed by

Software for data gathering

Relational databases of primary data

Maintenance, browsing and analysis of primary data.

Above the core are applications which serves to APIS clients.

TIS
TIS is a database of process variables logged in regular time intervals. Process variables can be directly measured quantities (flows, temperatures, lab data, etc.), time of some activities, and text variables (names of products, comments, etc.).
Database of TIS can be viewed in two ways - table or graphical form (on process flowsheets). Basic features:

hierarchy of process units (up to six levels)

basic statistical techniques

exports of data to commercial spreadsheets and databases

reporting facilities

visualization of trends

IBIS
IBIS is a comprehensive PC software for mass and energy balancing in process plants and utility distribution systems. IBIS automatically sets up and solves the system of balance equations. Redundant data are reconciled and statistically analyzed.

Basic capabilities of IBIS:

setting up regular mass and energy balances (flows and inventories)

automatic calculation of unmeasured flows and inventories from the balance model

automatic generation of some unmeasured flows on the basis of so-called reference streams

protection of results against human and gross measurement errors

data can be exported to commercial spreadsheets and database programs

reporting facilities.

RECON
serves for reconciliation of process data. RECON makes single/multi-component material and heat balancing of complex processes with reconciliation of redundant data

COMA
reconciliation of data described by implicit nonlinear algebraic models.

MODEL
A comprehensive PC software package for analysis and interpretation of data obeying non-linear implicit algebraic mathematical models (mostly chemical-engineering models at steady state). User must supply model equations.

EXPE
Database of expedition of products. Supporting program for system IBIS.

VOC emissions
Information system about Volatile Organic Compounds emissions from tanks based on US EPA method No. AP-42. Program files and reports emissions of VOC required by authorities.

System description

TIS is a PC based information system for process data collected from a single plant up to a compex production. TIS can be efficiently used on PC networks.
The basis of TIS is a database of process variables logged in regular time intervals (e.g. every hour). Process variables can be directly measured quantities (flows, temperatures), time of some activities, and text variables (names of products, comments, etc.). Data input is either manual via keyboard or imported from ASCII or DBF files. System can also import data directly from process computers.

There are the following basic functions of TIS:

presenting database in two ways - table or graphical form (on process flowsheets)

selection of variables is either according the place in the plant or according to prepared lists of variables

basic statistics

daily averages

monthly averages

printing

exports to standard databases and spreadsheets

Browsing the TIS database

There are two basic variants:

according to a location

according to a list
In the first variant the process is viewed as a tree. The system is branched, for example from a company, to plants, process units, etc. There are up to six levels of branching. Every branch represents some place (area) in the company.
The second variant are lists of variables which are either common for all TIS users or specific for individual TIS user. Variables in lists are not limited to specific location in a company.
Database can be browsed either in table form or in graphical form (on process flowsheets prepared by the user). Trends of variables can be also visualised in graphical form.

Derived (secondary) variables

Besides the directly measured (primary) variables the user can define also a set of derived variables which are automatically calculated from primary variables on the basis of user defined formulas.
Typical examples here are

compensated flows

simple heat balances

efficiencies of furnaces

etc.

Data exports

Possibilities include export of data in ASCII form according to a location or a list. Output can be to screen printer to a disk in the form of ASCII file or exports to other databases and spreadsheets (format DBF)