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Used Fe catalyst containing about 30% total C as carbide, coke, or wax is treated with a mixture of H2 and steam (5-40 vol. %) at 900°-1,400° F. The regeneration takes place in fixed bed with pelleted catalyst and in fluid bed with fluid bed with fluid catalyst. The time required will vary with the operation but will ordinarily be 2-20 hr. In continuous operation 5-85% of the volume of catalyst maintained in the reactor may be regenerated in a separate zone and recycled to the reactor after being cooled to synthesis temperature, or about 20% of the catalyst may be treated batchwise for about 5 hr. at 1,000°-1,100° F. Regeneration may take place in 2 or more stages, with progressively increasing temperature. The 1st stage for C removal may be at 900°-1,000° F., the subsequent stages for coke and wax removal may be 1,100°-1,400° F. In general, the proportions of H2 and steam and the temperature of the treating step can be correlated in terms of the equation: Maximum % H2O=10+0.05 (T °F., 700). T is the regeneration temperature in °F. 6 United States patents cited. |