Industrial decarbonization is a daunting challenge given the relative lack of low-carbon options available for “hard to decarbonize” industries such as iron and steel, cement, and chemicals. Hydrogen, however, offers one potential solution to this dilemma given that is an abundant and energy dense fuel capable of not just meeting industrial energy requirements, but also providing long-duration energy storage. Despite the abundance and potential of hydrogen, isolating it and utilizing it for industrial decarbonization remains logistically challenging and is, in many cases, expensive. Industrial utilization of hydrogen is currently dominated by oil refining and chemical production with nearly all of the hydrogen used in these applications coming from fossil fuels. The generation of low-carbon or zero-carbon hydrogen for industrial applications requires new modes of hydrogen production that either intrinsically produce no carbon emissions or are combined with carbon capture technologies. This review takes a sociotechnical perspective to examine the full range of industries and industrial processes for which hydrogen can support decarbonization and the technical, economic, social and political factors that will impact hydrogen adoption.

Industrial decarbonization via hydrogen: A critical and systematic review of developments, socio-technical systems and policy options

Plasma gasification can be a viable technology for converting municipal solid waste (MSW) into value for the circular economy. However, in its current state, plasma gasification is mostly limited to lab or pilot scales as there are various challenges associated with it; there exist knowledge gaps which need attention and research for its successful future commercialisation. The present study critically reviewed the current status of plasma gasification for waste-to-value processing. Various traditional techniques for MSW disposal and processing available in the literature were discussed and were compared with plasma gasification in terms of cost, service life, energy comparison, and environmental impact comparison. After the review, knowledge gaps were identified, challenges associated with the plasma gasification technology were discussed, and a possible roadmap for the successful future commercialisation of plasma gasification for waste-to-value processing was suggested. Furthermore, various strategies to cope with challenges associated with plasma gasification were discussed. The successful commercialisation of plasma gasification can be achieved by reducing its costs by generating revenue or value in the form of synthesis gas or fuels from MSW, energy can be saved or reused using insulation, process integration, and process intensification, the technology and community readiness levels can be improved with better communication between relevant stakeholders and adding extra layers of safety, and process understanding can be improved by conducting extensive fundamental studies, as well as plasma gasification technology being standardised by establishing standards and standards organisations.

Plasma gasification of municipal solid waste for waste-to-value processing

Hydrogen sourced from energy recovery processes and conversion of waste materials is a method of providing both a clean fuel and a sustainable waste management alternative to landfill and incineration. The question is whether waste-to–hydrogen can become part of the zero-carbon future energy mix and serve as one of the cleaner hydrogen sources which is economically viable and environmentally friendly. This work critically assessed the potential of waste as a source of hydrogen production via various thermochemical (gasification and pyrolysis) and biochemical (fermentation and photolysis) processes. Research has shown hydrogen production yields of 33.6 mol/kg and hydrogen concentrations of 82% from mixed waste feedstock gasification. Biochemical methods such as fermentation can produce hydrogen up to 418.6 mL/g. Factors including feedstock quality, process requirements and technology availability were reviewed to guide technology selection and system design. Current technology status and bottlenecks were discussed to shape future development priorities. These bottlenecks include expensive production and operation processes, heterogeneous feedstock, low process efficiencies, inadequate management and logistics, and lack of policy support. Improvements to hydrogen yields and production rates are related to feedstock processing and advanced energy efficiency processes such as torrefaction of feedstock which has shown thermal efficiency of gasification up to 4 MJ/kg. This will affect the economic feasibility and concerns around required improvements to bring the costs down to allow waste to viewed as a serious competitor for hydrogen production. Recommendations were also made for financially competitive waste-to-hydrogen development to be part of a combined solution for future energy needs.

Mike Cairns-Terry

Papers

Production of biohydrogen from gasification of waste fuels: Pilot plant results and deployment prospects.