Tag refinery

A refinery hydrotreating reactor showing the catalyst activation process with sulfur-containing agents such as DMDS, TBPS, and DTBPS under controlled conditions.
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What is sulfiding in refineries?

by Manufacturers, Producers, Suppliers

What is sulfiding in refineries?

Sulfiding is the activation process for hydrotreating and hydrocracking catalysts. Fresh catalysts are manufactured in oxide form and must be converted into their active sulfide form before they can remove sulfur, nitrogen, and other impurities from fuels. The process involves feeding a sulfur-containing compound (sulfiding agent) with hydrogen into the reactor to form hydrogen sulfide (H₂S), which reacts with the catalyst to create the active sulfide phase.

A refinery hydrotreating reactor under controlled sulfiding conditions, symbolizing catalyst activation with sulfur compounds such as DMDS and TBPS
Sulfiding Agent

What Sulfiding Agents Do Refineries Use?

by Manufacturers, Producers, Suppliers

To activate hydrotreating and hydrocracking catalysts, refineries use sulfiding agents — specialized sulfur compounds that convert metal oxides (like CoMo or NiMo) into their active sulfide forms.

The most widely used sulfiding agents today are:

Sulfiding AgentChemical NameSulfur ContentCommon AliasKey Advantages
DMDSDimethyl Disulfide68%—High sulfur content, cost-effective, stable decomposition profile
TBPSTertiary Butyl Polysulfide54%Also known as DTBPS (Di-tert-Butyl Polysulfide)Lower decomposition temperature, suitable when “methane make” is an issue
DTBPSDi-tert-Butyl Polysulfide56%Also known as TBPS or Tertiary Butyl PolysulfideHigh-purity grade, safer handling, stable sulfur release

Note:
In refinery practice, TBPS and DTBPS are often used interchangeably. DTBPS (Di-tert-Butyl Polysulfide) is a high-purity variant of TBPS, offering greater thermal stability and a smoother sulfiding profile.

Why Refineries Choose These Agents

  • DMDS is preferred globally due to its higher sulfur concentration and cost efficiency.
  • DTBPS (or TBPS) is selected where lower sulfiding temperatures or improved safety and odor control are priorities.

Both are crucial in ensuring complete and controlled activation of hydrotreating catalysts — a key step for producing ultra-low sulfur fuels.