DCU Revamp for Capacity and Efficiency Increase

Presented By

Hardeep Sigh - Bharat Oman Refining Ltd. Bina Refinery

Conference: Mumbai 2016

Courtesy of CB&I and BORLThe Delayed Coker Unit at Bharat Oman Refinery Limited (BORL) licensed by Chevron Lummus Global (CLG) was originally designed to process 170,000 kg/h (24,710 BPSD) of Vacuum Residue from high sulfur crude using a two-drum configuration. The unit was commissioned in January 2011.

After successful operation of the DCU at design levels, BORL noted the potential to further enhance the capacity of the unit. CLG was engaged for conducting a feasibility study. The main objective of the study was to increase the unit throughput by 30% of its original design capacity while maximizing use of the existing equipment.

In developing the revamp study, an accurate simulation model was necessary. Therefore, a test run at 115% plant throughput was conducted on the existing DCU. Data obtained from the test run validated the CLG yield model. The model was then used to generate the revamp case product yields and heat and material balances.

To achieve the main objective of increasing the unit capacity, several innovative solutions were considered. One of these was the addition of a new coke drum with the existing pair of drums. Aside from improving the distillate yield from the unit, this three-drum configuration will vastly increase operational flexibility. A DCU capacity revamp with a three-drum configuration will be the first of its kind in India.

The Coker heater was also rated for the revamp conditions. The wall-thickness of the tubes was made thinner by upgrading the metallurgy to SS-347. This resulted in a heater coil pressure drop less than the allowable for the revamp conditions and also increased heater run length. Other proposed modifications included adding a new Wet Gas Compressor in parallel to the existing one, and recommending a Liquid Ring Compressor on the Blowdown Overhead Receiver vent gas circuit.

Based on the results of the feasibility study, BORL has decided to further pursue the revamp of the unit. CLG has prepared the revamp case Basic Engineering Design Package (BEDP), and detailed engineering activities are currently on-going.

Hardeep Singh has been working with Bharat Oman Refineries Limited for the past 8 years accumulating vast experience in refinery commissioning, operations, and technical services. In his current role as Asst. Vice President, he supports the refinery expansion project. Prior to joining BORL, Mr. Singh has worked as Asst. Manager in a fertilizer firm in Rajasthan. He holds a Bachelor’s degree in Chemical Engineering from Panjab University, Chandigarh.

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