Life cycle assessment of end of life strategies for waste from petroleum production

Abstract

The waste treatment and disposal of oil refining industry sector are one of the significant aspects of environmental concerns. Because they are not only generated in substantial amounts, but also contained with various hazardous substances such as waste oils, spent catalysts, and mercury-contaminated materials. This study aimed to develop and evaluate the waste management strategies, from waste generator (WG) to waste processors (WP), using the material flow analysis (MFA, STAN v.2.6.601) and life cycle assessment (LCA, SimaPro v.8.3.0.0) as an assessment tool. The functional unit is the amount of waste generated from six refineries in the year 2015. The waste management schemes for hazardous (HZW) and non-hazardous (Non-HZW) were developed; the base case or existing operation (Option 1), zero waste to landfill and reduce burning in incinerators (Option 2) and enhancing recycling method (Option 3). The MFA results indicated that most of the HZW were disposed to produce energy, while the sorting method was the favorable option for Non-HZW. For the impact assessment, the base case and zero wastes to landfill and reduce burning in incinerators showed no significant difference for all of the impacts, but the enhancing recycling option indicated a decrease in the impacts for both HZW and Non-HZW. For global warming potential (GWP), the least impact value was the enhancing recycling, about 3.2958x10⁸ kg CO₂ eq for HZW and 1.4095x10⁷ kg CO₂ eq for Non-HZW. Therefore, the enhancing recycling is an appropriate method for waste utilization in order to reduce the environmental impacts. The MFA can be used as an assessment tool regarding the material balances and stock of the waste flow, while LCA can be used to evaluate the environmental impacts of the oil refinery waste management.