Quantifying life cycle environmental benefits from the reuse of industrial materials in Pennsylvania

Local reuse of waste materials from industrial processes has many potential environmental benefits, but these have been difficult to aggregate and measure across industries on a broad geographic scale. Nonhazardous industrial waste is a high volume flow principally constituted of wastewater with some solid materials. The state of Pennsylvania produced some 20 million metric tons of these residual wastes in 2004. An innovative reporting requirement for industrial generators implemented and compiled by the Pennsylvania Department of Environmental Protection has resulted in a rich database collected since 1992 of residual waste generation, detailing the fate of more than 100 materials. By combining these records with life cycle inventory (LCI) data, the current and potential environmental benefits of residual waste use have been assessed. Results for Pennsylvania indicate a savings in 2004 of 13 PJ of primary energy, 0.9 million metric tons of CO2eq, 4300 tons of SO2eq, and 4200 tons of NOx emissions from reuse of residual wastes. While these energy savings constitute less than 1% of total industrial primary energy use in the state, it is a greater quantity of energy than that generated by the state's renewable energy sector. The framework and constraints surrounding reuse of residualwaste in Pennsylvania are discussed.