H
Catalyst
Triglycerides
Para ns CO H O
H
Catalyst
Free fatty acids
Para ns CO H O
only partially absorbs COS. Figure 3 compares data for commodity amines (MDEA and DEA) versus formulated solvents. Managing CO₂ from renewable feedstocks Renewable feedstocks generate substantial CO₂ as an inherent consequence of the deoxygenation pathways as per the reactions reported in Scheme 1 (see Figure 4 ). The resulting increase in CO₂ concentration within the recycle gas stream places additional demand on the absorber and may surpass the CO₂ removal capacity of MDEA-based systems. The deoxygenation unit can produce a gas stream containing up to 15 mol% CO 2 . Since MDEA is a tertiary amine with a significantly higher reaction rate towards H₂S than CO₂, its interaction with CO₂ is kinetically limited. As a result, a portion of the CO₂ remains unabsorbed and ‘slips’ through the treating sys - tem. When CO₂ generation exceeds the MDEA capability, alternative amine formulations or solvent blends may be required to maintain stable operation and ensure adequate treating performance. Circuit-specific solvent strategy Every refinery has a distinct configuration, different process units, gas characteristics, amine unit design, and even dif- ferent levels of renewable feed integration. As a result, a single solvent strategy (such as using MDEA everywhere) is, in most cases, not optimal. In many cases, MDEA performs effectively. However, there are also numerous cases where its performance is inadequate. In any refinery amine treating unit, the primary and most critical objective is to reliably meet the required gas/LPG quality specifications. While this objective may appear straightforward, it can be highly challenging in prac- tice, especially when the removal target extends beyond H₂S to include CO₂ and organic sulphur compounds. Traditional amines often struggle to consistently achieve these multi-component specifications. However, meeting the specification is only part of the challenge. A truly optimised gas treating operation must also maintain high energy efficiency, minimal solvent deg- radation and losses, and robust corrosion control. These factors directly impact operating costs, unit reliability, and overall refinery performance. Even refineries that do not suffer from frequent product specification failures may still operate inefficiently without realising it. This is why amine selection is absolutely critical. The solvent is not just a consumable; it is a core process Figure 4 Renewable feeds deoyxgenation pathways towards CO₂ production
GRABNER FPV PRO The Ideal Choice for ASTM D7094 Jet Fuel Testing
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PTQ Q4 2026
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