The objective of the present work is to evaluate the pyrolysis process mixing corn and coconut crop residues in CO2 atmosphere and to compare the result of the solid product obtained in the starting biomass. For this research, the feedstock was characterized by proximate analysis, Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The pyrolysis process was carried out in a fixed bed reactor with a CO2 flow at a temperature of 450°C and for a time of 2 hours (2.77*10-4m3/s). The results show that the calorific value of the carbonaceous residues from the pyrolysis is increased by 59.7% compared to the original raw material, the FTIR of the solid demonstrates the transformation of the original carbonyl and hydroxyl groups that are part of the condensable gases and products.