Resource Assessment and Carbon Footprint Analysis of the Pyrolysis of Municipal Solid Waste (MSW) in Mexico
Data from the Mexican Institute of Statistics and Geography and U.S. Energy Information Administration database were consulted for the resource assessment. The life cycle assessment methodology was applied to estimate the GHG emissions of two proposed pathways (âorganicsâ and âpolyolefinesâ), using a functional unit of one MJ of fuel produced. Both pathways comprised the stages of collection, separation, feedstock transportation, size reduction, fast pyrolysis, fuel distribution, and vehicle operation. Stages of hydroprocessing and avoided landfill emissions were considered only in the âorganicsâ pathway. The emission factors for each stage were obtained from research papers and the Ecoinvent database available in the software SimaPro. The results showed that in Mexico 4.2 million metric tons of hydrocarbon fuels can be produced through MSW pyrolysis. This amount can contribute with 7.1% of the current national fossil fuel consumption. According to the carbon footprint analysis the proposed âorganicsâ pathway produced savings of -9.5 g CO2 eq. per MJ of fuels mainly due to avoided emissions from landfill disposal. The proposed âpolyolefinsâ pathway generated 88.0 g CO2 eq. per MJ which is a value 7.8% lower compared to emissions from fossil fuel production and use (95.5 g CO2 eq. per MJ). Finally, these results were used to estimate a mixture that produces an advance biofuel (60% savings compared to the fossil fuel production). This mixture was comprised of 78.8% (wt) âorganicsâ and 21.2% âpolyolefinsâ. These findings point the waste-to fuel pathway as an interesting research area for the production of pyrolysis-derived fuels.