The economics of pure clean fuel hydrogen produced by steam reforming of hydrocarbons in an earlier suggested novel autothermal circulating fluidized-bed membrane reformer (ACFBMR; Chen, Z.; Elnashaie, S. S. E. H. Chem. Eng. Sci. 2004, 59 (18), 3965 - 3979; Chen, Z.; Elnashaie, S. S. E. H. AIChE J. 2005, 51 (5), 1467-1481) is evaluated. A detailed autothermal reforming pilot plant is suggested and used for the determination of the specifications and costs of the main units/equipments. Using statistical correlations and cost factors, the total capital investment is determined. The economical analysis data show that the hydrogen production cost decreases with an increase of the plant size in the region of 100-100 000 kg of H-2/day. Above this region, the effect of the plant capacity becomes insignificant. For a small pilot plant with a 100 kg of H2/day capacity, the hydrogen cost in the industrial steam methane reforming process is $9.10/kg of 112, while using this novel autothermal technology, the costs are $2.05/kg of H-2 for the methane feed and $2.22/kg of H-2 for the heptane feed. The cost reductions are 77.5% and 75.6%, respectively. For a typical large industrial plant with 214 286 kg of H-2/day (equivalent to 100 000 Nm(3) of H-2/h; Scholz, W. H. Gas Sep. Purif 1993, 7 (3), 131-139), the reported industrial hydrogen production cost by steam methane reforming is $0.74-0.97/kg of H-2, while using this autothermal technology, the hydrogen production costs are $0.66/kg of H2 from heptane and $0.50/kg of H-2 from methane, respectively. The cost reductions are 10.8-32.0% and 32.4-48.5%, respectively. The comparison of hydrogen production costs over a wide range of plant sizes shows that this novel ACFBMR can be a more efficient and more economical pure hydrogen producer.