9 pages.-- PACS numbers: 05.40.-a, 82.39.-k, 82.40.-g.-- Final full-text version of the paper available at: http://dx.doi.org/10.1103/PhysRevE.76.031139.An autocatalytic reacting system with particles interacting at a finite distance is studied. We investigate the effects of the discrete-particle character of the model on properties like reaction rate, quenching phenomenon, and front propagation, focusing on differences with respect to the continuous case. We introduce a renormalized reaction rate depending both on the interaction radius and the particle density, and we relate it to macroscopic observables (e.g., front speed and front thickness) of the system.We have benefited from a MEC-MIUR joint program (Italy-Spain Integral Actions). C.L. acknowledges support from FEDER and MEC (Spain), through project CONOCE2 (FIS2004-00953). A.V. and D.V. acknowledge support from PRIN-MIUR project "Dinamica Statistica di sistemi a molti e pochi gradi di libertà"
