Process synthesis is an act of determining the optimal interconnection of processing units as well as the optimal type and design of the units within a process system. When the performance of the system is specified, the structure of the system and the performance of the processing units are not determined uniquely. The task is to select a particular system out of a large number of alternatives which meet the specified performance. In this thesis, separation system and heat exchanger network of 2,6-Xylenol process are designed. The optimal design of separation system is performed by using heuristics and comparing internal mass flow rate in a sequence of simple distillation. The optimal pressures of columns are found from simulation using ASPEN PLUS and Pro II. The optimal design of heat exchanger network is accomplished by using pinch technology. The proposed heat exchanger network reduces utility cost by almost 50 \% with a slight increase in the capital cost compared to the process without heat integration. Increase in the annualized capital cost is 10 \% of the utility saving.