Engineering Lifecycle applied to Ethanol Plant – Process Design Study, Process Analysis & Operator Training Simulator (OTS) System!
A Proprietary Process for producing Ethanol was focused on applying the concept of Process Engineering Lifecycle for improving the process efficiency, validating the new control schemes, and to train the plant operators on the new process.
The above came with the challenge of minimal plant information regarding H&MB, equipment data & the understanding-handling of process thermodynamics due to the azeotropic phenomenon.
The Process facility covered a ‘ fermented wash processing unit’ for producing Extra Neutral Alcohol ( ENA ) continuously with complex heat integration. The ethanol in feed was at around 12 vol%. The utility systems consist of cooling water, steam & vacuum.
The steady-state model was focused to execute the process engineering efficiency analysis while the full plant dynamic model focused on control system validation & helping plant engineers-operators in understanding the process intricacies involved in the plant & thereby empowering the operator to handle the upset situations in a quicker, efficient and safest manner.
Modeling the unit:
All the relevant datasheets, process descriptions, PFD, P&ID, standard & emergency operating procedures, and drawings were analyzed for the data requirement.
The model had 10 distillation columns for the separation of impurities to achieve ethanol purity of 96.0 vol%.
The DCS console was created to mimic an actual DCS with all the DCS control functionalities e.g. process PID Controllers, pump on/off. On the FOD console, all the Field Operated Devices (FOD) like valves, pushbuttons, pump on/off switch were modeled.
The integrated model was configured & tested to:
- Achieve proper control response
- Take startup & shutdown of the plant as per client’s procedure
- Check operator response to various malfunctions e.g. pump failure, heat exchanger leak, indicator value offset, etc
- Check the performance of the Evaporator section at various operating conditions of temperature & flow
- Check & compare various operating strategies to enhance the ethanol purity e.g. changing recycle of side-cut draw flow
Some of the important check points were to match:
- Removal of Aldehyde in Aldehyde Column
- Ethanol composition in ‘Spent Lees’
- Removal of Methanol in Polishing Column
A team of client engineers and operators performed an actual startup & shutdown of the plant successfully, as part of the Model Acceptance Test & Factory Acceptance Test.
Application Profile: Engineering Model & OTS of an Ethanol Plant
Challenge:
- To improve Process Efficiency
- To validate the New Process Control System
- To build an OTS to meet the operator training needs
Solution:
Develop a detailed steady-state & dynamic model of the complete plant including:
Analyzer Column | Degasifying Column | Aldehyde Column | Recovery Column | Pre-Rectifier Column | ENA Column | Extractive Distillation | Polishing Column | Fuel Oil Column | Purifier Column | 1st & 2nd stage evaporator
The steady-state model was used for engineering analysis while the dynamic model was used for validating process controls & for operator training needs.
Learning:
- The separation efficiency is very sensitive to column operating pressure & evaporator performance
- The complex heat integration presents challenges during startup
Benefits:
- Replica of an existing plant for operator training e.g. startup, shutdown, malfunction, emergency procedures
- Using the model to identify capacity expansion bottlenecks
We make perfect models
Equinox Software & Services Pvt. Ltd. (EQNX) is a global provider of IT-enabled process engineering and plant performance improvement solutions & services, which help customers, simulate, and optimize their equipment, plants, and business processes.
EQNX specializes in building state of the art model-centric decision support systems. With “Models” being the core technology, it is applied in the areas of:
- Engineering Design & Analysis
- Manufacturing Execution Systems (MES)
- Supply Chain Management
EQNX’s Over the Top (OTT) applications and services have been developed specifically for companies in the process industries, including the energy, chemicals, and engineering and construction industries.
With a global clientele of blue-chip companies, the company is breaking new grounds in developing and applying “MODELS” of all hues for Creating Value and Sustaining Value, through Innovative Solutions.
