Greenness index evaluation of fracking chemicals using SDS (safety data sheet) information

Abstract

The fracking industry faces various challenges although technologies have been advanced in the hydraulic fracturing and horizontal drilling. Treatment for the water used after the fracking process is one of the key issues preventing hydraulic fracturing from being widely implemented. Especially the chemicals that are used for various purposes during fracking remain in the water that flows back to the surface. Reports have been seen that the problematic chemicals used in the fracking process cause HSE (Health, Safety and Environment) issues. Before any chemical used in the fracking is eliminated or replaced with alternatives, its greenness should be evaluated.A tool called Greenness Index was used in this study to evaluate several typical chemicals used in the current fracking process. SDS (Safety Data Sheet) information was used by Greenness Index to assess the chemicals. It was found that with similar amount of SDS information available, citric acid is relatively greener than ammonium persulfate. SDS information of guar gum is less than that of citric acid and ammonium persulfate, but the evaluation for guar gum still indicates that it is a green chemical based on the limited data from its SDS. When more information with respect to how they behave during the fracking process is available, Greenness Index can provide more comprehensive evaluations.