DMDS Evolution® E2 for hydrotreatment catalyst sulfiding


Arkema is the only company to manufacture DMDS Evolution® E2, the most performant sulfiding agent, and provide direct turn-key catalyst sulfiding services worldwide with Carelflex®.

DiMethy Disulfide, DMDS Evolution® E2 is the most effective sulfiding agent to be used for insitu hydroprocessing catalyst activation during startup of the unit. Hydrotreating (HDT) catalysts must be converted to the “Sulfide” forms to get the desired activity. DMDS Evolution® E2 is easy to pump, fully soluble in any hydrocarbon and has a high sulphur content to minimize delivered quantity and be cost effective.

Reach the highest catalyst activity

Arkema was the first company to introduce the “Efficient Sulfur” concept, in which all the sulfur present in the sulfiding agent DMDS (68 % sulfur) is efficiently converted to H2S on the hydrotreating catalyst under standard sulfiding conditions. Indeed, coking phenomena can interfere with the catalyst activation as it creates a physical barrier to actives sites and reduces catalyst activity. The choice of the sulfiding agent structure plays a key role to the catalyst life cycle.

As a result, DMDS Evolution® E2 has become the most widely used catalyst sulfiding chemical globally for hydroprocessing catalysts in-situ sulfding.

In parallel, Arkema offers its expertise with Carelflex® service which includes top quality equipment and dedicated and flexible teams to handle and inject DMDS . Carelflex® provides refineries with the benefits of an optimal on time sulfidings with DMDS Evolution® E2.

DMDS Evolution® E2 properties

  • Liquid over a wide range of temperature: DMDS remains liquid in a large range of temperature (from -85 °C to 109 °C) 


  • The highest sulfur content on the market: With a sulfur content of 68w % DMDS Evolution® E2 is the the most efficient sulfur carrier for your sulfidings and for your operations optimization. This reduces the operation logistic and costs, as well as provides a better control of the sulfiding operation 


  • High solubility: DMDS evolution® E2 shows the best solubility in hydrocarbons for an easy injection and perfect dispersion, allowing the homogenous reaction on all hydrogenation catalysts. 


  • Clean and ideal decomposition profile for sulfiding: DMDS Evolution® E2 provides early decomposition to H2from 180 °C, and fully decomposes at 230 °C and above. The H2S released reacts immediately with catalyst. Moreover, the DMDS converts to methane and avoids any coke deposition on the catalyst.


  • Outstanding performance with superior scent: DMDS Evolution® E2 is a breakthrough formulation for outstanding odor control and safe handling operations. It provides a pleasant fragrance.  



DMDS Evolution® E2 benefits for hydroprocessing catalysts activation

More fluid injection over a wide range of process temperature

Reduces operation logistics, minimize costs and provides better sulfidings operation control with less sulfiding agent to be ordered and handle at the refinery

Improves the user experience thanks to DMDS Evolution® E2 outstanding scent 

Minimizes coke formation on the catalyst for long life cycles 

Maximizes hydroprocessing catalyst activity thank to ideal decomposition profile into H2S at low temperature. DMDS shows the best catalyst activation levels and improves hydroprocessing units' profitability

Approved by all catalyst manufacturers and technology licensors. With more than 300 sulfiding operations per year, DMDS Evolution® E2 references are available for any unit type and technology


Geographic availability



  • Oil and gas
    • Refineries
    • Refining


  • Hydrocracking catalyst activation
  • Hydrodesulfurisation catalyst activation
  • Hydrotreatment catalyst activation