The emulsion of hydrocarbon components in water is usually found in the wastewater of refineries. In this work, a mathematical modeling of the destabilization process of gas condensate droplets in water emulsions was constructed using the population balance equation, and the coalescence coefficient (agglomeration kernel) of different demulsifiers (KENON 20, KENON 4, KENON 2, CTAB, SDS, Span 80, Span 60, Polyamide, Polyacrylamide and an EO/PO block copolymer of dodecan-1-ol) was obtained. For modeling, it needs droplets size distribution before adding a demulsifier at time = 0 and after adding a demulsifier at time = 1 h and 2 h. For this purpose, the numerical method of Crank-Nicolson by MATLAB software was applied. Additionally, the growth of gas condensate droplets was modeled by the population balance, and the agglomeration kernel for each demulsifier with the help of two models (simple flow and sum of the volumes) was determined. Moreover, the dependency of the agglomeration kernel to time was obtained. The results showed that the accuracy of the sum of the volumes model was better than the simple flow model to describe destabilization of the emulsion with demulsifiers. Furthermore, the agglomeration kernel of demulsifiers increases with increasing the demulsification time.