Calculators
Sulfiding Balance Calculator
Sulfur requirement and sulfiding agent (DMDS / TNPS) injection rate for hydroprocessing catalyst activation. Computes total sulfur required from catalyst mass and target S uptake, agent volume needed, and a 3-phase injection schedule with running S-on-catalyst percentage.
Method: Catalyst mass = volume × bulk density. Target S = mass × wt% S uptake × overshoot. DMDS (CH3SSCH3) decomposes with H2 to 2 H2S and 2 CH4; H2S sulfides the metal oxides (MoO3 + 2 H2S + H2 → MoS2 + 3 H2O). Sulfur mass delivered per phase = rate · density · S wt%-fraction · duration. Typical target is 100–110% of stoichiometric. References: Speight, The Desulfurization of Heavy Oils and Residua; Topsoe, Clausen, Massoth, Hydrotreating Catalysis.
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