AP Consultoria e Projetos undertook a project to implement a new diesel hydrotreatment unit (HDT) with a capacity of 10,000 m3/d (U-5283), in order to adapt REPLAN's refining scheme. This increased the production of S-10 diesel and QAV-1 and aimed to meet the specifications and volumes demanded by the future market, economically, without compromising operational safety or the environment. For the proper operation of the new HDT (U-5283) the implementation of a new hydrogen recovery unit (U-6241) and adaptations in several existing process units in the refinery were foreseen.