Micro-reactor technology has found increasing usage in the synthesis of several organic compounds and pharmaceutical chemicals in the last decade. The main advantages of micro-reactors are good mixing characteristics, less hold-up volume of reagents and better control as compared to traditional batch reactors. Micro-reactors have recently been used in the laboratory to study the underlying reactions and develop a kinetic models. Further, it is possible to monitor reactions using in-situ spectroscopy in micro-reactors, and collect spectral data at different residence time. In this work, we propose a calibration-free method to analyse spectral data obtained from micro-reactors to identify reaction kinetics. Then, the proposed method can be applied to spectral data directly to identify the parameters of the proposed reaction kinetic model. The method is illustrated using a numerical case study of base catalyzed Knoevenagel condensation reaction system. © 2018 Elsevier B.V.