Title : Discovery of mercaptan selective scavengers for streams containing hydrogen sulfide
Abstract:
Hydrogen sulfide (H2S) is typically the primary sulfur contaminant of concern in oil and gas operations because of its extreme toxicity, corrosivity, and the stringent specifications required for pipelines. Mercaptans also pose significant challenges, as they create persistent odors, accelerate corrosion, reduce product stability, and can lead to off spec fuels. . Most commercially available scavengers, including hexahydrotriazines and oxazolidines, react preferentially with H2S, leaving mercaptans insufficiently treated or requiring excessive chemical dosing, which increases operating costs and fouling risks. In this work, we report the identification of hyperbranched scavengers that are selective for mercaptans in the presence of H2S. A rapid Raman-based pre-screening methodology was developed to evaluate a series of commercially available compounds based on the emergence of the characteristic C–S-C Raman band following reaction with ethyl mercaptan. Promising candidates were subsequently assessed for mercaptan specificity under low-pressure conditions using an experimental setup designed to simulate multiphase continuous chemical injection in the presence of H2S. The results demonstrate that these hyperbranched chemistries can selectively target mercaptans in mixed sulfur systems. This enables lower chemical consumption, greater operational reliability, and improved compliance with tightening odor and sulfur limits.
