Beyond Hydrogen: The Multigeneration Potential of Waste Gasification for Multiple Value-Added Products

Abating excessive greenhouse gas emissions from fossil fuel combustion and implementing sustainable waste management strategies are two critical contemporary environmental challenges. Hydrogen has gained considerable attention as a prospective clean energy source over the past few decades. In this regard, generating hydrogen from various types of waste provides a unique opportunity to divert waste from landfills and convert it into sustainable hydrogen, offering a solution to both aforementioned environmental concerns. The concept of multigeneration is a further advancement of waste-to-hydrogen, allowing the integration of different processes with a waste-to-hydrogen system, producing multiple usable utilities such as space cooling and heating, electricity, freshwater, hot water, or methane in addition to hydrogen. This study expands on previous assessments and proposes a novel multigeneration waste-to-hydrogen gasification scenario. Municipal solid waste is subjected to gasification at a rate of 10,000 kg per hour, producing 1093 kg of hydrogen per hour. An organic Rankine cycle using R-245fa as the working fluid recovers thermal energy from the resultant effluent gas stream. As a result, electricity and low-pressure steam are produced at a rate of 13.1 kW and 2000 kg per hour. The cradle-to-gate life cycle assessment yielded that incorporating the organic Rankine cycle into gasification can reduce global warming by approximately 40%. The economic evaluation revealed reductions in the levelized cost of hydrogen between 1 and 3% under different scenarios of increasing carbon taxes. This evaluation offers valuable insights to investors, engineers, and other key stakeholders for informed decision-making regarding the successful establishment of waste-to-hydrogen gasification facilities.