Introduction to Chemical Process Design

Process Design Basics A chemical process can be defined as a set of unit operations that are needed in a manufacturing or processing facility. The design process involves determining what equipment is needed to accomplish a set of processing objectives and the associated cost of purchasing and operating the equipment.

Process Design Basics Chemical process design requires knowledge and integration of various areas of study including: Material Balances Energy Balances Thermodynamic Data and Correlations Kinetic Data & Reactor Design Fluid Mechanics Heat Transfer Mass Transfer Staged Separations Process Control Material Science Engineering Economics

Process Design Basics Process simulators such as Aspen Plus and Hysys are tools which can be used to help design the chemical process. Not all process equipment can be designed with the simulator. It is likely that some aspects of the process design will require information from the literature.

Common Process Equipment Pumps Compressors and Turbines Heat Exchangers and Interchangers Furnaces / Fired Heaters Process Vessels Reactors Packed Bed Stirred Tanks Fluid Beds Columns Distillation Absorption & Stripping Extraction Storage Tanks

Conceiving and Defining a Project Understand the processes under consideration Literature review Define Conditions and Capacities Project statement Use common sense, intuition and previous experience where possible

Basic Steps in the Feasibility Evaluation of a Process Design Develop the conceptual flowsheet for the process to be developed including production rate required. Design the individual equipment required to operate the process including mass and energy balances. Calculate the capital and operational investment needed to build and run the plant. Perform an economic analysis and calculate the return on investment. Compare the rate of return (ROR) on the investment with other investment options Perform a sensitivity analysis of key economic parameters