Visualization and control of the process of formaldehyde production at National Aerochem, Faisalabad, Pakistan

Located in Faisalabad, Pakistan, National Aerochem is a chemical plant that produces formaldehyde (CH₂O). The plant’s production capacity is 140 tons per day.

By the cracking of methanol, formalin is produced – it is 37 weight percent of formaldehyde in water. Formaldehyde and urea are used to make urea-formaldehyde resins, which are used as adhesives and binders for chipboard and plywood.

In 2015, Alpha Engineering installed a SCADA-based control system at the plant.

Control system

The system consists of a control cabinet, which houses a Siemens S7-1200 PLC, and the Reliance SCADA/HMI system, which provides an overview of the production process. The Siemens PLC collects and controls the process parameters and communicates with Reliance over Ethernet.

The Reliance 4 system is used as front-end SCADA software. Bringing some new features, it is a replacement for the existing DCS system.

The Reliance SCADA system provides monitoring and control of the following:

• Graphics-oriented operator screens displaying important information obtained from different transducers with the remote control of valves, motors, etc.
• Status and important parameters of all parts of the production process
• Real-time and historical trending of all the important parameters
• Archiving of reports, alarms/events, and trends

Example of a visualization window

This screen displays all the important parameters, different temperatures and pressures, flow meters, and PID control valves including a temperature trend at the bottom (from this window, all the pumps, burners, and valves can be monitored and controlled).