A Liquid Heat Capacity Limit for Organic Compounds

The heat capacity of liquids is an important property when designing any chemical process. While there have been numerous methods developed for predicting the liquid heat capacity, all of these include some degree of uncertainty. When making capital investments, reducing uncertainty as much as possible is desirable and profitable. In this work, an upper limit for heat capacity using the n -alkane family was developed as a function of temperature and the critical temperature. While this limit is not intended as a standalone prediction method, it is useful for several common engineering problems such as data evaluation or early process design. This limit has been tested for hundreds of species and at several temperatures. We discuss the basis of this limit, family exceptions, and the applicability in industry and process design. Coupling this limit with traditional methods of estimating liquid heat capacity can give a chemical engineer a higher confidence in predicted values of liquid heat capacity and the tools to plan safer, more cost-effective processes.