Enhancing refinery profitability through reduction of coke make Technological interventions that reduce the yield of petcoke from the delayed coking unit can play a significant role in mitigating downstream CO 2 emissions
Satyen Kumar Das, Pradeep PR, RK Kaushik Singha, and Alok Sharma Indian Oil Corporation Ltd, R&D Centre
W ith the growing focus on reducing the carbon footprint of petroleum refineries, there is a renewed interest in identifying opportunities for mitigating carbon dioxide (CO₂) emissions within refinery operations. One such opportunity lies in addressing the production of fuel-grade petcoke – a high-sulphur, low-value byproduct from the delayed coking unit (DCU) – which is widely used as a fuel in boilers and in the steel and cement industries. Since the combustion of petcoke at the consumer end leads to significant Scope 3 CO₂ emissions, reducing its production can directly contribute to emission reduction goals. Technological interventions that lower petcoke yield from the DCU can therefore play a vital role in mitigating downstream carbon emissions. Moreover, the high sulphur content of fuel-grade petcoke also results in considerable oxides of sulphur (SOx) emissions during combustion, further compounding environmental concerns. The challenge is exacerbated by declining crude quality and increasing residue volumes, making coke reduction an operational and environmental priority. In response to stricter environmental regulations on high-sulphur petcoke combustion, a modified reaction scheme – termed Ind-Coker AT technology – has been developed. This innovation enables a reduction of approximately 4-5 wt% in coke yield compared to conventional DCU operations. After successful validation in a 1 barrel/day thermal cracking pilot plant, the technology was demonstrated at commercial scale in a 3 million metric tonnes per annum (MMTPA) DCU at a 15 MMTPA Indian refinery. A demonstration run for
the Advanced Coker technology was carried out using a vacuum residue (VR) feedstock of ~23 wt% Conradson carbon residue (CCR) while ensuring product quality met specifications. Significant yield benefits were observed in comparison with the conventional DCU, such as the following: • Reduction in coke yield by 5.2 wt% and corresponding Scope 3 CO2 emission reduction by ~17 wt% by preventing petcoke burning. • Improvement in the middle distillate yield by ~3 wt%. • Liquefied petroleum gas (LPG) yield improvement by 1 wt%. • Additional benefits compared to conventional 3 MMTPA DCU: ~75 million $/yr. “ Since the combustion of petcoke at the consumer end leads to significant Scope 3 CO₂ emissions, reducing its production can directly contribute to emission reduction goals ” The technology can be easily implemented in both existing DCUs and new grassroots units globally. It offers new hope for conventional petroleum refiners to improve their bottom lines by alleviating the perennial issue of petcoke disposal while progressing on the path to net zero. Introduction Global industries, including petroleum refineries, are increasingly committed to reducing their carbon footprint, as carbon emissions account for approximately 81% of total greenhouse gas
Refining India
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