Patent DE-102007027397-A1 (DE)
Title: Cooling hydrogen and water vapor contained in process gas that is produced in hydrogen extraction plant, comprises cooling process gas at temperature below condensation temperature and simultaneously separating occurring process condensate
Inventor: TROTHA THILO VON
IPC: C01B3/02
Filed: 2007-06-11
Abstract: The method for cooling hydrogen and water vapor (4) contained in a process gas (5), which is produced in a hydrogen extraction plant by vapor reforming process, comprises cooling the process gas at a temperature below the condensation temperature and simultaneously separating the occurring process condensate, utilizing the enthalpy of the process condensate by re-conducting the process condensate into the vapor reforming process or by heating a material flow, subjecting the process gas in a contact apparatus (9) with a coolant, and condensing a part of the water vapor. The method for cooling hydrogen and water vapor (4) contained in a process gas (5), which is produced in a hydrogen extraction plant by vapor reforming process, comprises cooling the process gas at a temperature below the condensation temperature and simultaneously separating the occurring process condensate, utilizing the enthalpy of the process condensate by re-conducting the process condensate into the vapor reforming process or by heating a material flow, subjecting the process gas in a contact apparatus (9) with a coolant, and condensing a part of the water vapor separated from the process gas by direct cooling and then separating with the coolant. The process condensate, additives contained in an aqueous system, water/glycol mixture or aqueous salt solution is used as coolant water. A liquid used for direct cooling is led in a cooling circuit (10). The liquid in the cooling circuit is drawn-off from the contact apparatus, cooled in a heat exchanger and then supplied again into the contact apparatus. The occurring condensate is removed from the cooling circuit for further use during the direct cooling. The condensate is removed over a separation step, in which inorganic or organic additives are separated for leading into the cooling circuit. The enthalpy taken from the liquid by the heat exchanger is used for vapor production or for heating combustion air (2) or a heat carrier. The quantity of the process condensate from the cooling circuit occurring in the contact apparatus is removed by condensation and is used in the vapor reforming process. The process condensate is degassed before re-conducting into the vapor reforming process. The process gas produced in the vapor reforming process is pre-cooled by indirect heat exchanger before entering into the contact apparatus at 70[deg] C, which is larger than the condensation temperature of the water vapor. A boiler feed water for the vapor reforming process is heated through pre-cooling. The process gas is cooled in a further cooling step at 20-50[deg] C following the direct cooling in the contact apparatus. The condensate, which occurs in the further cooling step, is removed and is led back as a coolant into the contact apparatus for direct cooling. The process gas is led by several contact apparatuses one after each other, in which the process gas is subjected with the coolant and is separated by direct cooling of water vapor through condensation. The contact apparatuses are arranged to the cooling circuit in each case. The condensate is used as the coolant into the upstreamed contact apparatus. The liquid drawn-off from the first contact apparatus is led into the cooling circuit, which connects the first contact apparatus with the upstreamed contact apparatus.