The Challenges of Renewable Feedstocks and Opportunity Crudes: Why Real-Time Analysis is the Refinery’s New Lifeline

As global energy priorities shift toward decarbonization and circular economy principles, the refining industry is undergoing a transformation in how it sources and processes feedstocks. Increasingly, refineries are turning to renewable feedstocks—including vegetable oils, used cooking oil, animal fats, pyrolysis oil, and crude tall oil—as alternatives or supplements to traditional petroleum crude. In parallel, opportunity crudes—lower-cost, unconventional crude oils such as heavy or high-sulfur blends—are also being integrated to improve economics.

While these feedstocks enable operational diversification and improve environmental performance, they bring with them significant processing challenges. Issues such as unstable emulsions, high sulfur and salt content, corrosive behavior, and inconsistent chemical profiles can result in poor product quality, increased maintenance costs, and reduced equipment reliability. In this evolving environment, real-time feedstock quality measurement becomes indispensable.

Renewable Feedstocks: A Sustainability Imperative with Processing Complexity

The global push to decarbonize energy systems has spurred increased demand for renewable liquid feedstocks, especially in regions with progressive emissions regulations. Vegetable oils and animal fats, for example, are valued for their low net greenhouse gas emissions. Likewise, pyrolysis oils—derived from plastic waste or biomass—and crude tall oil, a byproduct of paper production, present sustainable, circular options for refinery input.

However, these materials present major variability in composition and physical properties:

• Vegetable oils and animal fats have elevated oxygen content and acid numbers, which can cause thermal instability and accelerated corrosion.
• Pyrolysis oils are highly heterogeneous, with varying levels of aromatics, acids, water, and contaminants depending on feedstock and production method.
• Used cooking oils can include degradation products and emulsifiers that complicate separation and hydrotreating processes.

Processing these feedstocks safely and efficiently requires rigorous, continuous quality control, especially during blending with conventional crudes.

Opportunity Crudes: Economic Advantage Meets Operational Risk

Opportunity crudes—those that are discounted due to their higher impurity content or difficult processing characteristics—can boost refinery margins but come with hidden costs. Typically, these crudes exhibit:

• High sulfur levels, contributing to equipment corrosion and catalyst deactivation.
• Elevated metal content (e.g., vanadium, nickel), which can poison catalysts and degrade distillation performance.
• High salt and water content, which increase fouling risk in heat exchangers and cause pressure drop in desalters.

When mixed with renewable feedstocks, the complexity increases exponentially. The result is an unpredictable blend that can compromise unit stability, product yields, and compliance with emissions regulations unless precisely monitored.

See also: The Oil and Gas Industry: A Pillar of Global Energy

The Critical Role of Real-Time, On-Line Analysis

To address the inherent variability and risk of modern feedstocks, refineries must implement real-time analytical systems capable of capturing dynamic changes in feedstock composition. Manual sampling and laboratory analysis—while accurate—are too slow and labor-intensive for today’s requirements, where processing conditions must be adapted in real time.

Enter the Modcon MOD-4100 crude oil analyzer—a factory-calibrated, modular solution designed for continuous on-line analysis of both conventional and non-traditional feedstocks. Integrated directly into process pipelines or feedstock headers, this analyzer delivers high-frequency, ASTM-correlated data across a broad range of critical parameters.

Key Parameters Measured by the MOD-4100 Analyzer

The MOD-4100 Crude Oil Analyzer enables fast, accurate measurement of several vital quality attributes:

• Distillation Curve (ASTM D2892, D86)
  Determines boiling point distribution—key for assessing compatibility with unit operating conditions and optimizing product yields.
• Salt Content (ASTM D3230)
  High salt levels are a leading cause of heat exchanger fouling and corrosion in atmospheric distillation units.
• Water Content (ASTM D4928, D4006)
  Excess water can lead to phase separation, hydrotreater issues, and emulsion problems in desalters.
• Total Sulfur (ASTM D2622, D4294)
  Monitoring sulfur is essential for meeting clean fuel regulations and avoiding catalyst poisoning in hydroprocessing units.
• Emulsion Stability (ASTM F3045, D4007, D3707)
  Helps optimize separation efficiency in desalters, particularly critical when processing used oils and fats.
• Viscosity (ASTM D445, D2501)
  Affects pumping performance and blending strategy; particularly important for highly viscous animal fats and tall oils.

Each of these parameters directly affects refinery uptime, throughput, emissions, and profitability.

Seamless Integration and Operational Reliability

The MOD-4100 analyzer is designed for fast commissioning, with all modules factory-tested and pre-calibrated. Its robust construction allows for continuous operation in harsh environments, reducing the risk of sampling errors and delayed quality response. The modular design enables refineries to tailor the system to specific feedstock blends or operational needs.

Moreover, correlation with ASTM methodologies ensures data validity for regulatory compliance, enabling refiners to meet product specifications and environmental targets with confidence.

The Value Proposition: From Compliance to Profitability

Deploying on-line crude analyzers such as the MOD-4100 offers tangible returns:

• Operational Efficiency: Real-time insights allow operators to make timely adjustments in distillation cut points, catalyst usage, and blend ratios.
• Asset Protection: Early detection of corrosive or unstable feedstocks reduces unplanned downtime and maintenance costs.
• Environmental Compliance: Reliable sulfur, salt, and water monitoring ensures regulatory adherence and helps avoid penalties or reprocessing.
• Product Quality Assurance: Continuous measurement prevents off-spec batches and improves blending accuracy.

In an era where feedstock variability is the norm rather than the exception, these capabilities are no longer optional—they are critical.

Conclusion: Future-Proofing Refining with Analytical Precision

The transition to sustainable energy systems does not mean abandoning liquid fuels—it means adapting to new inputs. Renewable feedstocks and opportunity crudes represent both a challenge and an opportunity for forward-looking refineries.

However, processing them efficiently demands next-generation analytical infrastructure. The MOD-4100 crude oil analyzer, with its capability to deliver real-time, ASTM-aligned quality data, is a key enabler of this transformation.

By investing in robust on-line measurement technologies, refineries can unlock the economic value of unconventional feedstocks while preserving equipment life, product quality, and environmental performance. As feedstock diversity grows, so does the importance of measurement—and the future belongs to those who can see their feedstock in real time.