Coil-wound heat exchanger for hydrotreatment or hydroconversion

A process comprising hydroconversion or hydrotreatment of a hydrocarbon feedstock, comprising:

• preheating and directly distributing a portion of the hydrocarbon feedstock and optionally a hydrogen stream or a hydrocarbon feedstock/hydrogen stream mixture to a reactor inlet furnace (F-1) of a hydrotreatment or hydroconversion reaction section (R-1) by a single coil-wound heat exchanger (S-1);
• directly distributing via a bypass a portion of the hydrocarbon feedstock or a portion of the hydrocarbon feedstock/hydrogen stream mixture from the inlet of the coil-wound heat exchanger (S-1) to the outlet of the coil-wound heat exchanger (S-1);
• mixing the hydrocarbon feedstock with the hydrogen stream, said mixing taking place before or after preheating;
• cooling reaction effluent from the hydrotreatment or hydroconversion reaction section (R-1) by means of the coil-wound heat exchanger (S-1), said coil-wound exchanger being a single-pass heat exchanger formed by a vertical chamber in which one or more bundles of tubes are helically wound around a central core, as numerous superposed layers;
• heating and distributing preheated hydrocarbon feedstock/hydrogen stream mixture to the hydrotreatment or hydroconversion reaction section (R-1) by means of the reactor inlet furnace (F-1);
• hydrotreating or hydroconverting the hydrocarbon feedstock in the hydrotreatment or hydroconversion reaction section (R-1) comprising at least one reactor comprising at least one catalyst comprising at least one element of Group VIII of the Periodic Table;
• separating at least one portion of the cooled reaction effluent in a high-pressure cold separator (B-2) in order to distribute a first liquid effluent comprising at least one light fraction and a first gaseous effluent comprising hydrogen;
• and
• separating the first liquid effluent comprising at least one light fraction in a separation column (C-1) in order to distribute a bottoms liquid and an overhead effluent.