Types of H2S Scavengers Explained: Triazine vs Non-Triazine & More
There are four main types of hydrogen sulfide scavengers: liquid triazines, non-triazine liquids, solid iron-oxide media, and specialty formulations. This guide explains each type, compares triazine vs non-triazine treatment, and reviews scavenger performance in crude oil.
Vasudev Chemo Pharma Technical Team
ISO 9001:2015 Certified Manufacturer of Industrial & Specialty Chemicals
The Main Types of Hydrogen Sulfide Scavengers
Hydrogen sulfide scavengers fall into four practical categories. Liquid triazines (MEA and MMA triazine) are amine-based, water-soluble chemicals with the highest capacity per litre and a fast, irreversible reaction — the industry default for continuous injection. Non-triazine liquids include glyoxal-based products and formaldehyde-donor chemistries such as EDDM (CAS 3586-55-8); these avoid amine pH shift and are chosen for specific downstream-compatibility reasons. Solid scavengers use fixed beds of iron oxide (iron sponge) or proprietary iron media that adsorb H2S until exhausted, then require media change-out. Specialty and hybrid formulations blend chemistries or add corrosion inhibitors, defoamers, or solvents for difficult streams. Choosing among them is not about brand loyalty; it is about matching chemistry to the stream, the equipment, and the operating risk.
- Four types: liquid triazine, non-triazine liquid, solid iron-oxide, specialty/hybrid
- Triazine: highest capacity, clean dithiazine by-product, possible pH/odour
- Glyoxal: non-triazine, low-H2S niche, 20–40% price premium
- EDDM: non-triazine, no pH shift, no scaling, catalyst-friendly
- Crude-oil performance depends on phase behaviour and contact, not just capacity
Triazine vs Non-Triazine for H2S Treatment
The triazine vs non-triazine decision usually comes down to by-product behaviour and downstream sensitivity. Triazine (amine-based) offers the lowest chemical volume, fast ambient reaction, and clean water-soluble dithiazine by-product — but it can raise pH, contribute an amine odour, and, if over-reacted, form dithiazine solids. Non-triazine options avoid amine chemistry: glyoxal reacts through a different pathway and suits lower-H2S duties at a 20–40% price premium, while EDDM is a formaldehyde donor that does not shift pH, does not precipitate salts, and does not poison refinery catalysts — advantages in offshore, high-scaling, or catalyst-sensitive service. For most cost-driven bulk gas and crude applications, triazine wins on economics; where its by-products or pH behaviour cause a specific problem, a non-triazine chemistry is the better engineering choice. Our dedicated comparison page walks through the selection logic in depth.
Performance of Different H2S Scavengers in Crude Oil
Crude oil is a demanding scavenging environment because H2S partitions between oil, water, and vapor phases, and contact between a water-soluble scavenger and oil-phase H2S is limited. In crude and multiphase service, liquid triazines perform well when adequate mixing and residence time are provided, and they are widely used for vapor-phase control in crude stabilisation and storage tanks. However, in heavily oil-continuous systems, a water-soluble triazine may under-perform because it cannot readily reach H2S dissolved in the oil phase — here, oil-dispersible or non-triazine chemistries can improve contact. Solid scavengers are generally unsuited to crude because of fouling and plugging. The practical lesson is that crude-oil scavenging performance depends less on the nominal capacity of the chemical and more on phase behaviour and contact design; a bench test on the actual crude is the only reliable predictor.
Quick Comparison Table (Prose)
Capacity per litre: liquid triazine is highest; glyoxal moderate; iron sponge is a solid, rated per kg of bed. Reaction speed: triazine is fast at ambient and faster when warm; glyoxal moderate; iron sponge depends on bed contact. By-products: triazine yields water-soluble dithiazine; glyoxal yields thiazolidine-type compounds; iron sponge yields spent iron-sulfide media needing disposal; EDDM yields water-soluble products without pH shift. Best fit: triazine for continuous gas/crude injection and contact towers; glyoxal for low-H2S niche or non-triazine preference; iron sponge for low-volume batch gas with existing vessels; EDDM for catalyst-sensitive, high-scaling, or offshore duty. Cost: triazine is typically the lowest cost per kg H2S removed; glyoxal carries a 20–40% premium; solid media add change-out and disposal cost.
How to Select the Right Scavenger Type
Selection follows the stream, not the sales pitch. Start with H2S concentration and mass load, then flow rate, phase (gas, liquid, multiphase), temperature, and any downstream sensitivity such as refinery catalysts, water-treatment limits, or scaling tendency. High-volume gas above roughly 500 ppm H2S usually favours continuous triazine injection; moderate low-H2S streams with spare vessels may favour solid media; catalyst-sensitive or high-scaling systems favour non-triazine EDDM. Total cost of ownership — chemical, logistics, labour, disposal, and downtime — should drive the decision, not headline chemical price alone. Because Vasudev Chemo Pharma manufactures triazine and non-triazine chemistries, we can run a like-for-like comparison on your stream rather than steering you to a single product.
There is no universally best H2S scavenger — only the best fit for a given stream, equipment set, and risk profile. The engineering skill is matching chemistry to conditions.
Related Products & Services
Understanding the types of hydrogen sulfide scavengers — and honestly comparing triazine against non-triazine and solid options — leads to lower cost and fewer operating surprises. For a stream-specific comparison across MEA Triazine, MMA Triazine, glyoxal, and EDDM, contact the Vasudev Chemo Pharma technical team. We will recommend the chemistry that fits your conditions and supply it directly with full documentation.
