TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractHydrogen sulfide (H 2 S), a corrosive and toxic gas, when present in produced fluids such as condensate, gas and water, poses serious health and operational hazards.Nonregenerable H 2 S scavengers have been in use for H 2 S removal from sour gas and condensate for over a decade. Selection of an appropriate non-regenerable chemistry is dictated by the downstream treatment processes that the gas or condensate will be subjected to after H 2 S removal is accomplished. Successful selection and application of non-regenerable H 2 S scavengers requires a thorough evaluation of operating conditions such as temperature, pressure, mixing, etc., that affect H 2 S removal from sour fluids. Most of the applications require on-site optimization to achieve maximum scavenging performance.This paper presents results and observations from a field trial for sweetening a large volume of sour condensate held in a 70,000 bbl storage tank using a water-soluble triazine-based scavenger.Mode of application of the triazine-based scavenger was found to be one of the most important factors for successful reduction of H 2 S in liquid hydrocarbons held in large tanks. Another important factor affecting H 2 S scavenger performance was the presence of sulfide species other than H 2 S in the sour fluid. Experiences gained from the trial illustrate the importance of a systematic approach required for effective sweetening in liquid hydrocarbons.