Sewage Sludge: a Fascinating Feedstock for Clean Energy

Sewage sludge is composed of organic and inorganic materials. The organic portion of the sludge is predominantly composed of C, H, ti, and S. On a dry-basis, the heating value of sludge is greater than that of oil shale or tar sand. The volatile matter content of dry sludge can be higher than that of the high volatile bituminous coal. Available correlations in the literature, developed for coals, were applied to predict the experimentally determined heating values. In addition, the sludge compositional data (C, H, S, and ash) were used to develop a new correlation specifically for raw sewage sludge. Compared to the models tested, the new correlation developed in this study for sewage sludge provided a better fit between the measured and predicted values.