| 摘要 |
In a process for hydrocarbon steam reforming, a primary reformed gas is produced from a mixed gas of hydrocarbon and steam with use of a primary reforming means including an external combustion type of reforming furnace. A secondary reforming reaction of the primary reformed gas is carried out in the presence of air and/or oxygen. A burner assembly of the reforming furnace comprises burners for heating reforming tubes of the furnace and regenerators for preheating a combustion air flow to the burners. Combustion exhaust gas of the reforming furnace heats the second regenerator for preheating the combustion air to the second burner, while the first burner is in firing operation, whereas the combustion exhaust gas heats the first regenerator for preheating the combustion air to the first burner, while the second burner is in firing operation. The flow passage for the combustion exhaust gas is so controlled as to be switched to either of first and second flow passages in a predetermined time interval. A part of the combustion exhaust gas, which is 10% to 30% by weight relative to the total combustion exhaust gas of the reforming furnace, is introduced from an internal area of the furnace to first and second heat-exchangers, so that hydrocarbon feedstock, mixed gas of hydrocarbon and steam, and air and/or oxygen are heated by the heat-exchangers. Reformed gas produced in such a system is fed to a third heat-exchanger to heat the mixed gas of hydrocarbon and steam, and thereafter, it is delivered to a reformed gas delivery line. According to the process or method of these arrangements, high and economical energy efficiency and production efficiency can be achieved. <IMAGE> |
