Analysis of the characteristics and interrelationships of industrial energy consumption and waste generation for selected Tennessee industries

This study focused on determining the characteristics and interrelationships among selected manufacturing facility parameters and production efficiency as measured by energy usage and hazardous waste generation. The types and quantities of hazardous waste generated for facilities in Standard Industrial Classifications 34, 36, and 37 were obtained from the 1991 Tennessee Annual Hazardous Waste Report (THWR). Energy consumption rates and facility characteristics for the same plants were collected with a direct-mail survey.

Characterization of the survey data using the JMP 3.02 Statistical Software Package revealed that most respondents were medium-sized companies with only one reportable hazardous waste stream. Furthermore, the waste quantities generated tended to correlate with the specific processes used in the plant. Among companies in the targeted SIC categories, most waste was produced from operations involving either metal-plating, solvent-based painting, and parts cleaning. As a result, the study determined the prevalent waste types to be corrosive or ignitable in character.

An initial investigation into the relationship between energy usage and waste generation was also performed using globalized data from the 1988 Manufacturing Energy Consumption Survey and the 1988 Toxic Release Inventory. The results demonstrated an overall proportional relationship between energy usage and waste generation.

Finally, analysis of combined data from the 1991 THWR and direct-mail survey revealed that hazardous waste production was unrelated to the quantity and type of energy used. But, when the quantity of hazardous waste generated was normalized with facility size, a significant relationship with energy usage was found.

These results confirm the overall importance of considering the linkages between industrial energy use and waste generation. Such relationships may be useful in designing industrial processes for improving manufacturing efficiency.