Energy Case Studies

Case Study 122: LNG Conversion Industry Sector: Energy • Vaporizer Control System

Process or Machine Automated: submerged combustion vaporizer control systems

New Technology Applied:

  • GE Fanuc 90-30 series PLC
  • GE QuickPanel HMI
  • Wonderware Intouch SCADA

Project Description:
Staneco Corporation designed controls for multiple liquefied natural gas vaporizers for use in a re-gasification process at a peak shaving facility. Each vaporizer contained a large burner that heated a water bath for the evaporation process. Two PLC systems were utilized for control of each vaporizer; one system for burner management as required per the NFPA and one system for other process controls. All units had automatic ignition and bath temperature control. In addition to the gas control required to operate under normal conditions, interlocks were added to safely handle alarm conditions. Each control system provided feedback to the plant DCS.

Project Outcome:
The addition of these peak shaving units enabled the plant to meet the critical requirements of peak consumption periods. Operators praised the ease of use provided by the control system and the ability to make adjustments to ensure optimal performance.

Case Study 102: Ethanol Plants Industry Sector: Energy • Regenerative Thermal Oxidizers

New Technology Applied:

  • Allen Bradley CompactLogix
  • Allen Bradley PanelView Plus HMI

Project Description:
Staneco designed controls for two thermal oxidizers used at a corn-to-ethanol plant to remove organic chemicals from discharged air. The oxidizers consisted of multiple gas burners which heated combustion chambers containing ceramic pellets. When the process gas is passed through the pellets, the organic chemicals are oxidized, neutralizing them. In order to prevent overheating of the ceramic pellets, a series of dampers were switched based on either time or chamber temperature. As the chambers were switched, some gas escaped unprocessed. To remove these gases, a purge operation was included to re-circulate the untreated gasses. The motors were controlled over Devicenet which included two VFDs. Temperatures and operation of the valves are monitored and alarmed. Data was made available to the plant DCS system.

Project Outcome:
System met and exceeded the required emission acceptable limits. The process also helped minimize fuel consumption.