A novel design of microstructured membrane reactor with micro-channels formed between closely packed catalytic filaments is reported. The system comprises filaments of 7 gm in diameter and has a laminar flow with a short radial diffusion time. This leads to low pressure drop and to a narrow residence time distribution (RTD) during reactor operation. The latter device in combination with a membrane permeable to hydrogen is used in non-oxidative propane dehydrogenation. The catalytic filaments of Pt/Sn on alumina were active/selective and sustained periodic regeneration. This innovative micro-reactor system allowed to control the selectivity to propene due to a narrow RTD. At propane conversions exceeding equilibrium, selectivities towards propene up to 97% were attained.