# Direct Contact Membrane Distillation: A Critical Review of Transmembrane Heat and Mass Transfer Models

## TL;DR

This paper reviews models for heat and mass transfer in membrane distillation, focusing on practical applications for water desalination.

## Contribution

The paper compiles and evaluates data and correlations relevant to Direct Contact Membrane Distillation for practical model development.

## Key findings

- Existing correlations for transmembrane heat and mass transfer are summarized for MD applications.
- The review emphasizes physical properties of saltwater and their impact on MD performance.
- Suitable data for hollow fiber designs in DCMD is highlighted for model development.

## Abstract

The present review summarizes a vast body of literature on the subject of Membrane Distillation (MD), with a special emphasis on the existing results and correlations for the transmembrane transport of heat and mass. The issue of saltwater physical properties is also discussed in depth, whereas the advective transport of heat and salt concentration in the feed and permeate compartments is only briefly mentioned but is beyond the scope of this review. The paper does not aim to provide a complete treatment of the subject of MD, which can be found in other publications. Rather, it suggests the data and correlations most suitable for the range of operating conditions typically expected in actual units implementing Direct Contact Membrane Distillation (DCMD), including hollow fiber designs, with a view to assist model development. The focus is on MD for water desalination, although some results may apply well to other fields.