We describe the design and operation of a microstructured steam-methane reformer in which the heat transfer area and reaction volume demands for the reforming process are decoupled to yield a high degree of process intensification relative to conventional tubular reformer design. The plant design incorporates intensive process integration without steam export. With 80% hydrogen recovery from the syngas in a PSA, and use of the PSA offgas as the only fuel source, the reformer system has a fuel energy efficiency of 78.6% as designed, corresponding to a hydrogen production rate of 2.69 mol H(2) per mol NG. Based on printed-circuit heat exchanger techniques, the demonstration plant incorporates 17 stages of reforming at nominally 15 bar. Heating for the individual adiabatic stages is provided by combustion stages and by flue-gas heat recovery. The plant incorporates design features to minimise potential for carbon deposition and metal dusting. It displays intrinsic autoregulation over a wide range of turn-down, from 34% to 125%. Start-up is very rapid, approximately 2 h from cold to syngas production at full rate. With these features, this process and plant design is well suited for standalone operation, for example to substitute for merchant hydrogen delivery in small or isolated facilities. While the present plant has a capacity of 5 Nm(3) H(2) h(-1), the multichannel printed circuit architecture is scalable without loss of precision to very large throughputs. (C) 2011 Elsevier B. V. All rights reserved.