Development of quantitative SHE index for waste to energy selection

Abstract

Municipal solid waste (MSW) conversion to energy through waste-to-energy technologies (WtE) is promising in offering sustainable and environmentally friendly answers to MSW disposal problems. This paper proposes a quantitative safety, health and environmental (SHE) index for WtE selection. This technique compares WtE technologies according to SHE hazards posed by the chemicals produced. Scores representing the level of hazards expected is assigned to SHE parameters through the implementation of the logistic function. These scores are then added to produce a single score representing the technologies called the Safety, Health and Environmental Total Score (SHETS). Technologies with a lower score are more preferable than a higher score. This technique was applied to a case study of landfill gas recovery system, incineration, gasification, and anaerobic digestion. Incineration is evaluated as the least preferred technology with SHETS value of 54.74 mainly due to the existence of sulfur dioxide which has high atmospheric toxicity and acidification potential while gasification is the most preferred waste-to-energy technology with SHETS value of 50.82. The developed index provides insight on SHE hazards of the chemicals produced allowing the adoption of preventive measures for the development of WtE technology that is efficient in energy production, safer, healthier and environmentally friendlier.