Innovative grassroots CDU-VDU configuration: Pioneering energy efficiency and net-zero pathways in modern refineries

Srivardhan G is an Assistant General Manager in R&D at Engineers India Ltd. (EIL), New Delhi, and has more than 15 yrs of experience in computational fluid dynamics (CFD), coal-to-liquids (CTL), refinery and petrochemical technology development, and energy efficiency improvement studies. His work also extends to biomass valorization and sustainable process development. He has played a key role in developing several high-impact process innovations, including a novel CDU-VDU configuration delivering nearly 50% reduction in VDU steam consumption and a single-column SWS unit, achieving ~30% lower energy consumption with complete H2S-NH3 separation. He is credited with more than 20 patent applications, 10 of which have been granted, and has been published in many international publications. A BEE-certified energy auditor, Srivardhan is a recipient of the Ambuja Young Researcher Award and the National 2nd Runner-Up prize in the NHRDN Business Simulation Competition (2016). He has actively contributed to more than 50 national and international conferences, including the World Petroleum Congress held in Istanbul, the U.S. and Canada. He holds a postgraduate degree in chemical engineering from IIT Kanpur. The author can be reached at srivardhan.g@eil.co.in.

Ramanayya Gorle is a Senior Manager at Engineers India Ltd. and has more than 15 yrs of experience in process design, development and commissioning for the oil and gas and refining sectors. His expertise spans mass transfer equipment, column hydraulics, desalters, heat exchangers, fired heaters and heater treaters, with a strong focus on energy efficiency and process intensification. Gorle has led several high-impact innovations, including patented CDU-VDU configurations achieving a nearly 50% reduction in VDU steam consumption, a novel single-column sour water stripper (SWS) with ~30% lower energy use and complete hydrogen sulfide (H₂S)-ammonia (NH3) separation, advanced AC-DC crude desalting technology, syngas scrubbing systems and 2G bioethanol distillation processes. He is credited with more than 15 patent applications. Gorle has contributed extensively to digital twin development, real-time optimization and deployment of EIL’s proprietary technologies such as indDiesel®, indDSK® and indJet®, improving refinery operability and sustainability. His project experience includes refinery process optimization, CDU reflux drum innovation, desalter revamps for BPCL, IOCL, BORL and CPCL, and heater treater design for ONGC. As a certified energy manager and auditor, he holds a B.Tech degree in chemical engineering from Andhra University and is proficient in PRO-II, ASPEN, FRI and HTRI. The author can be reached at g.ramanayya@eil.co.in.

Narendra Kumar Paladugu holds an MS degree in technology in chemical engineering from NIT Tiruchirappalli and has been associated with Engineers India Ltd. for more than 19 yrs. His professional expertise spans process simulation, in-house software development, coal gasification and renewable energy systems. Paladugu has been actively involved in the development and deployment of indigenous process tools and technologies, contributing to both conventional hydrocarbon processing and emerging energy transition domains. He has also represented EIL at several national and international technical conferences, sharing insights on process innovation and sustainable engineering solutions. His long-standing experience and cross-domain proficiency continue to support EIL’s efforts in advancing efficient, reliable and future-ready process technologies. The author can be reached at pnarendra.kumar@eil.co.in.

Anil Kumar is the Executive Director (Technical) at Engineers India Ltd. (EIL), New Delhi, with more than 31 yrs of experience in process design, technology development and plant commissioning across the oil and gas, refining and petrochemical sectors. His career has been rooted in translating refinery concepts into operating assets, with a strong grounding in both design fundamentals and operational realities. Kumar’s expertise spans crude oil distillation, hydrotreating, hydrocracking and complex refinery configurations, with particular strength in refinery configuration studies and LP-based optimization modeling to evaluate feedstock flexibility, product slate optimization and energy efficiency. He has served as Group Lead and Technical Authority for several large and complex projects, including Dangote Refinery, HMEL, GAIL, etc., contributing across the full project lifecycle from early configuration studies to commissioning support. Kumar heads the R&D Division at EIL, leading indigenous technology development, process innovation and intellectual property creation, with a focus on improving refinery performance and addressing emerging energy-transition challenges. He earned a B.Tech degree in chemical engineering from Banaras Hindu University. The author can be reached at akumar@eil.co.in.