(74c) Hydrogen Enhanced Conversion of Municipal Solid Waste to Methanol Using Natural Gas Pyrolysis: Potential Net GHG Reduction Impacts

Avoiding methane emissions from landfilling of municipal waste and the need for low-carbon liquid fuels and chemicals are two important needs for decarbonization of methane emitting practices and the transportation and chemical industry sectors. Converting municipal solid waste (MSW) into renewable fuel can provide a means to avoid release of methane emissions from landfills into the atmosphere and as well a means to use MSW and hydrogen to provide clean liquid fuels/chemicals with lower carbon intensity than fossil fuel. We have analyzed the potential lifecycle greenhouse gas (GHG) reductions from conversion of MSW to methanol (MeOH) using gasification with hydrogen enhancement where the hydrogen is produced by electrolysis or by natural gas pyrolysis. Hydrogen enhanced MSW conversion increases the amount of methanol produced from a given amount of MSW by around a factor of two. We have given particular emphasis to the use of natural gas pyrolysis because of its potential for providing lower costs and its substantially reduced dependence on renewably-sourced electricity. MSW is pretreated to Refused Derived Fuel (RDF) before being fed to an illustrative case of entrained fluidized gasifier. A lifecycle analysis (LCA) is performed for this illustrative MSW gasification and methanol production process and the associated landfill methane avoidance. For the case of pyrolytic H₂, these results are for an illustrative fugitive methane emissions level of 1 %. The net GHG emissions impact of varying levels of fugitive methane emissions on net greenhouse gas emissions is analyzed and illustrates the importance of minimizing these emissions.