Typical specific energy consumption can vary between 3,500 to 8,000 kcals/kg (6,300 to 14,500 Btu/lb) of product ethylene. Cracking furnaces typically contribute between 45 to 65% of energy consumption in an ethylene plant. The remainder is contributed by recovery section, including main compressors.
The level of energy consumption and variability of split is dictated by many factors. The main ones include:
- Feedstock and cracking severity
- Feed and product conditions
- Level of integration, both hydrocarbons and utilities
- Steam/power system integration has significant impact
- Process technology and age of facility
- Operation and maintenance approaches and practices
- Asset utilization including reliability and availability
Generic benchmarks may provide directional indication about the relative comparison to peers in the grouping, it is normally an insufficient approach for determining the viability and success of the programs to either strategic approach for digital transformation or to achieve environmental/energy efficiency and sustainability targets. Another weak area for external and internal benchmarks is understanding and determination of asset capability. A simplistic approach that a facility could only produce as much as it has done historically can lead to an underestimation and underutilization of its capability, therefore influencing not only the benchmarks but also operating and maintenance discipline. A systematic approach based on understanding of all aspects of process technology/design, main equipment limits/performance, plant data along with operation/maintenance approach etc. can not only provide a meaningful baseline but also determine the strategic approach for energy and digital transformation.
We, at Apex PetroConsultants, have a successful track record of helping ethylene plants in not only determining the baseline but also help develop strategic approaches for a successful outcome. We work together with owner teams to turn these ambitious goals and objectives into reality.