CASE STUDY

Technical Pre-Bid support for Ethanol Production from Off-Gas of HGU at IOCL

IOCL is planning for a new unit for production of Ethanol from off-gas of Hydrogen Generation Unit (U-76/77) at Panipat Refinery. The Ethanol plant is to produce 33.5 KTPA ethanol (Anhydrous Ethanol for Use in Automotive Fuel conforming to Bureau of Indian Standards IS-15464:2004) considering 8000 hrs of operation.

All Emergency and some operational relief from the plant are to be routed to Quench drum package to separate condensable vapours and liquid.

The relief stream to quench drum is fed into the drum below the baffles. DM Water is introduced into the drum above the baffles at a rate that depends on the temperature and the amount of material being fed to the quench drum. The water spilling over the baffles desuperheats and condenses the vapor, knocks out entrained hydrocarbon liquid and cools down the hydrocarbon liquid collected in the bottom of the drum. The water at the vessel bottom is recycled via pump and cooled prior to routing to quench drum. The uncondensed vapor and any steam formed pass up the drum and enter flare system.

The scope of the project consists of providing complete design and supply of the relief system package including all process and utilities required and interconnections inside the package.

The project objectives were as follows:

  1. Preparation of Quench drum process data sheet as per API 521 guidelines and process details covering maximum gas, maximum liquid, gas with maximum condensable ethanol and continuous flow from control valves and vacuum pump cases.
  2. Preparation of process datasheet for Cooler (Shell & Tube heat exchanger).
  3. Preparation for process datasheet for Pump (Horizontal centrifugal pump).
  4. Equipment list preparation based on the requirement.
  5. Preparation of Instrument datasheets.
  6. Process flow diagram preparation.
  7. Piping & Instrument Diagram and legend preparation.
  8. Utility summary preparation.
  9. Bill of Quantity preparation.