Many functions of eukaryotic cells take place in membraneless compartments, which are biomolecular condensates concentrating proteins and nucleic acids. In order to perform such functions, compartments biogenesis, maintenance and disassembly must be finelly controlled. Understanding which physico-chemical drivers are involved in this processes and how they work, have attracted interest in biologists and physicist community. In the recent years liquid-liquid phase separation (LLPS) has been discovered to be the main driver of compartments assemble and maintenance. In this work we propose a different approach to the phenomenon, based on reaction-diffusion equations, that we call diffusion-controlled phase separation (DPCS). This model will describe the same phenomenology of the LLPS, and a comparison between the two models will show that DCPS is as valid as LLPS in capturing the physics of the phase separation phenomena..