quickly detect and resolve discrepancies between planning models and AIO targets. Optimisation models also offer significant value beyond real-time control. Offline analysis can identify active con - straints and quantify the economic benefit of relaxing them, guiding maintenance priorities and informing capital invest- ment decisions. What-if simulations allow teams to explore the impact of process changes without affecting live produc- tion, enabling more proactive and informed decision-making. These tools also help identify new variables that may be valuable to bring into closed-loop, continuously expanding the system’s optimisation potential. When used strategically, these insights ensure that optimisation efforts remain closely aligned with evolving operational and economic conditions. Reducing margin leakage is as much an organisational challenge as it is a technical one (see Figure 1 on p7). By combining technical excellence with strong ownership, cross-functional alignment, and operator engagement, plants can fully realise the value of their optimisation sys- tems and ensure they continue to evolve and deliver value long after initial implementation. A Arvind Chaturvedi, Director Process Optimisation, Transcend Solutions, LLC, arvind.chaturvedi@trnsnd.com In modern refineries, strategies for margin optimisation are not just limited to process efficiency and market alignment, but also to rigorous contamination control. Contamination, whether from particulates, water, corrosion products, or chemical incompatibilities, has a profound and often under - estimated impact on energy consumption, equipment reli - ability, and unplanned downtime, which together cause more than half of the potential margin leakage experienced by refiners. Contaminants such as fouling agents (for example, iron sulphides, salts, and organic sludge) lead to heat exchanger fouling, compressor, turbine and fired heater inefficien - cies, hydrotreater bed plugging, and consequent increased hydrogen recycle compression. Contaminants can also cause direct damage to critical assets, such as pumps, compressors, valves, bearings, and seals. If left unchecked, this can further lead to catalyst poi - soning in FCC units, hydroprocessing, or reformer units. An accumulation of these issues leads to earlier than planned turnarounds, catalyst changeouts, and emergency repairs. A rigorous feedstock quality control system is the first step in preventing the ingress of external contaminants in the pro - cess. It often gets the desired attention from the operators by way of advanced crude assays, desalters, online moni - toring, and tighter acceptance specifications for opportunity crudes. The downstream processes are generally where the issues arise, through a combination of traditional practices, as follows: • Licensors focus on the key processes to a much greater extent than on the separation of critical solid and liquid con - taminants. As a result, most licensors leave separations out of their scope of critical supply. • Engineering, procurement and construction (EPC) compa - nies rely on the vendor claims for efficiency and sealing. Once they have the vendor claims, the EPC firms make a choice
based on the lowest cost. In case study after case study, we have shown that there are many companies that provide poorly performing separators for solid and liquid removal. • End users typically have no leverage during the detailed design process once the contract is signed, and these kind of contaminant-related operating issues typically only rear their head after the performance warranty period. In the context of these practices, some of the strategies for preventing margin leakages can be summarised as follows: • Identify the high-risk separations in the process. For these areas, end-customer, EPC, and licensor should strongly con - sider working with those that have the technology expertise, along with the manufacturing capability to provide the nec- essary separation equipment. • Install high-efficiency coalescers and particulate separa - tors, designed to the appropriate size for current and future predicted fluid flows. • Monitoring heat exchanger performance closely and using predictive models could provide a possible indication of future fouling. • Conducting a detailed analysis of process fluids after any failure may help in identifying the root cause and lead to pre- vention at the source of contamination. These may include particle counts, elemental analysis, and FTIR. • Linking contamination sensors like filter dP heat exchanger fouling to predictive maintenance platforms may help trigger early warnings. • Establish baseline contamination surveys in critical opera- tions and regularly perform contamination surveys to moni- tor system health. In an environment where every dollar of margin counts, contamination control is not just a maintenance issue; it is a margin strategy. By integrating robust contamination pre- vention, detection, and mitigation practices, refineries can unlock significant gains in energy efficiency, uptime, and long-term reliability. Q What valuable side streams can be co-produced with SAF production technology? A Woody Shiflett, Ph.D., Blue Ridge Consulting LLC, blu- eridgeconsulting2020@outlook.com Optimally, one needs to define ‘valuable side streams’ for each current process. Hydroprocessed esters and fatty acids (HEFA) processes currently dominate the SAF scene, and side streams produced are well known (for example, renew - able diesel, naphtha, propane, and light ends). The main side stream is renewable diesel, which, depend - ing on local regulatory structure and markets, can be more or less valuable than SAF. Depending on unit design, cata - lyst system, and operating mode, the jet yield can vary from about 15% to about 55%, with resultant diesel yield about 75% and 25%, respectively, with renewable naphtha and light ends making up the balance (see Figure 1 on p10). In the US, renewable diesel produces more RIN credits than SAF by about 6%. However, the latest variant of tax credits under 45Z provides added credits for SAF. In the EU, the process is driven by mandates and emis - sion trading schemes. ReFuelEU Aviation legislation places
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PTQ Q4 2025
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