A laboratory scale mini-pilot plant is successfully designed and built to carry out research in the liquid-phase methanol synthesis process in a impinging stream reactor, the reactor has good heat transfer and mass transfer performance, because the catalyst slurry is atomized into fine drop when it goes through the pressure-flow nozzles, the mass transfer between gas phase and liquid-phase is promoted. Sustained operating conditions of temperatures approximately at 230 degrees C, space velocity at 10,000h(-1), high slurry recirculation flow rate and two or four opposed nozzles represent a major extension of the operating range for this type of reactor. A high slurry recirculation flow rate is benefit to the inter-phase mass transfer because the inter-phase disturbance is enhanced, and the catalyst slurry after atomized impacts each other when the opposed nozzles are used, this promotes the inter-phase interfusion and distribution so as to increase the gas-liquid mass transfer. (c) 2007 Elsevier B.V. All rights reserved.