Sustainable Waste Management: An Unheralded Source of Low Carbon Hydrogen Production

Sustainable waste management is a global challenge, and demand for it is increasing as the production of waste increases. Global waste generation is expected to reach 6 million tons/day by 2025 assuming a global population growth rate of 1.18% each year. Conventional waste management practices rely on landfills and incineration that have limited energy efficiencies and adverse environmental impacts. Landfill-based waste management emits massive amounts of methane, accounting for approximately 14% of global methane emissions in 2019. An alternative to landfill and incineration is to convert waste material to hydrogen.  

What Is Waste-to-Hydrogen?

Thermochemical and biochemical processing are the two main methods by which waste can be converted to hydrogen. In general, thermochemical processes (i.e., gasification and pyrolysis) are faster than biochemical processes (e.g., fermentation) and have higher hydrogen yields and conversion efficiencies and shorter reaction times. Nonetheless, biochemical processes are less energy intensive as they operate under moderate energy conditions.        

Which Companies Are Active in this Space?

The production of hydrogen from waste is viewed as an alternative to green hydrogen production and has attracted the attention of multiple stakeholders. Ways2H, a California-based startup, converts municipal solid waste and hazardous medical waste into hydrogen. To achieve this conversion, the company first pretreats the waste, then feeds it into a gasification vessel that operates at 1000°C. During this process, organic waste is converted into hydrogen and a stream of methane. This methane is further steam treated to increase the hydrogen yield. The resultant syngas is cleaned, and through a separator, hydrogen is recovered and residual carbon emissions are captured. It is reported that every ton of dry waste can produce approximately 40 kg-50 kg of hydrogen through this process. Based on this technology, the company is planning to build commercial projects in California, Japan, and South America for the conversion of waste-to-hydrogen for possible end usage in hydrogen-fueled mobility. 

Boson Energy is another waste-to-hydrogen company, based in Luxembourg. The company has a goal to produce carbon-negative green hydrogen from nonrecyclable waste using its plasma-assisted gasification process. The company aims to have its first commercial plant fueled by nonrecyclable waste to be operational by 2023 in Europe.      

Waste-to-hydrogen projects are also active in Germany and France. In Wuppertal, a waste-to-energy plant is used for producing hydrogen to power 20 public buses with a goal of reaching 70 buses by 2025. Similarly, a waste-to-energy plant in Créteil, Paris, is expected to begin production and distribution of 500 kg H2/day by the end of 2022. The hydrogen produced is planned for use fueling buses and household waste trucks. 

What Challenges Does Waste-to-Hydrogen Face?

Although there is strong potential in the conversion of waste to produce hydrogen, there are certain limitations that need to be addressed. One such limitation is the pretreatment of the waste. Pretreatment involves drying and contaminant removal that are essential to improve the energy density of the waste. This requires energy, transport, and separation facilities. Another limitation related to infrastructural constraints is the storage of the waste and the subsequent storage of the hydrogen produced. These limitations can be addressed through the growth of the hydrogen economy. As demand for green hydrogen outstrips its production, there will be a need for alternate low carbon hydrogen production methods that would provide the impetus to waste-to-hydrogen projects and their development.