At present, in a region of the plant where LPG (Petroleum Liquefied Gas) is synthesized and unloaded, we find a control system pending renewal, both in hardware and in software, as well as an error in the values of downloaded material about 10% and 15%. Considering these conditions, the project focuses on an improvement of the process control system, so two clear objectives can be described: The first one would be the migration to a new control system, including the PLC hardware, the communication system, the SCADA system and the PLC programming and configuration software, providing a better longevity and reliability to the LPG synthesis and unloading process. In the other side, the process had to be improved, through changes in the instrumentation architecture of the infrastructure to reduce product unload errors.