The Process Intensification for Syngas & Hydrogen key technology area addresses control of chemical reactions in increasingly modular and intrinsically efficient reactors, allowing for smaller reactors and streamlined processes with well-coordinated unit operations, with a focus on gasification of biomass and carbonaceous wastes into syngas, syngas cleanup, efficient hydrogen and carbon dioxide separation, and syngas conversion. Clean hydrogen and syngas enable highly efficient and low carbon footprint power generation and serve as ideal feedstocks for fuels or chemicals production. Improved reactors and processes for gasification, syngas separations and cleanup, and conversion of syngas into hydrogen or other valuable products will enable integrated systems with higher availability, reliability, efficiency, and flexibility, resulting in lowered costs of production and excellent environmental performance with potential of net-zero and even net-negative carbon emissions for versatile solid feedstock-based energy systems.
Philosophy
Current reactor design (including traditional large-scale coal and petroleum coke fueled gasifiers, and small-scale biomass gasifiers) is characterized by simplistic geometries, limited control over reactants inside, and incremental advancements with surprisingly little significant change over time. However, advances in technology have resulted in tools that should allow development of more sophisticated reactor concepts that will allow more precision and control in these reacting systems, and which can be developed more quickly and inexpensively. Process intensification with well-integrated/coordinated unit operations and resulting synergies can help realize sustainable and cost-effective energy system processes.
Strategy
The Gasification Systems Program is pursuing development in promising areas of advanced gasification technologies to lower costs and increase efficiency of modular syngas production and syngas conversion to value-added products. By combining gasification of biomass and waste materials with carbon capture in these systems, net-zero and even net-negative carbon emissions performance is attainable to support ambitious long-term goals for decarbonization of the U.S. economy. The Program also plans to leverage ongoing technological advances to make rapid advances in reactor engineering and design. Notably, these include exponentially increasing computing power at lower costs, expected to allow increasingly realistic computer models to simulate feedstock conversion during gasification, and breakthroughs in advanced manufacturing to significantly drop the capital costs for small-scale reactors and modular plants.
In the biomass gasification field, moving bed or fixed bed gasifiers and fluidized bed gasifiers comprise the vast majority of gasifiers used, given their relative flexibility in handling varying feed streams and suitability to the sizes needed for typical applications. However, high-temperature, oxygen- or steam-blown, pressurized, entrained-flow gasification of biomass-containing feed streams has been advocated as an important area of focus for R&D, considering the higher efficiency and reaction intensity of entrained gasification. NETL has begun to make inroads into this area as it supports R&D of high-pressure modular gasifiers (mainly entrained flow type), high-pressure feeding of lower quality fuels including biomass/waste blends, lower cost air separation for modular systems, and so on. The R&D strategy is to continue pursuing gasifier technology for higher efficiency gasification of waste/biomass blends and reduction of those technology costs.
Biomass/wastes co-gasification
Several projects in the program are focusing on the co-gasification of coal/waste plastic/biomass feedstocks to produce syngas and clean hydrogen with greatly reduced CO2 emissions:
Fluidized-Bed Gasification of Coal-Biomass-Plastics for Hydrogen Production—Auburn University is studying gasification of coal/plastic/biomass mixtures in steam and oxygen environments, characterizing the thermal properties of ash/slag and investigating the interaction between slag/ash and refractory materials, and developing process models to determine the technology needed for syngas cleanup and removing contaminants for hydrogen production.
Enabling Entrained-Flow of Gasification of Blends of Coal, Biomass, and Plastics— The University of Utah is enabling entrained flow co-gasification of biomass and waste plastic by creating slurries of pulverized coal, biomass pyrolysis liquids, and liquefied plastic oil. Conventionally, high-pressure, slurry-fed, oxygen-blown entrained-flow systems are not generally amenable to waste and biomass gasification, but this approach is a novel and elegant solution to that problem. Challenges include formulating coal-biomass-plastic mixtures that produce a stable slurry suitable for pumping to high pressure, designing and testing a novel burner (“hot oxygen burner”) to effectively atomize the mixed feedstock slurry in a pressurized gasifier, and acquiring performance data using Utah’s one ton per day pressurized oxygen-blown gasifier.
Development and Characterization of Densified Biomass-Plastic Blend for Entrained Flow Gasification—The University of Kentucky has been developing and studying a coal/biomass/plastic blend fuel for oxygen-blown, slurry feed gasification. They have densified biomass and encapsulated biomass in plastic to improve gasification characteristics and have demonstrated viable coal/biomass/plastic solid fuel slurry for gasification in their versatile entrained flow gasifier.
Performance Testing of a Moving-Bed Gasifier Using Coal, Biomass, and Waste Plastics to Generate White Hydrogen— Electric Power Research Institute, Inc. (EPRI), is studying combinations of coal, biomass, and plastic waste blends in formulation of feedstock pellets for moving-bed gasification to produce hydrogen.
Machine Learning Enhanced LIBS to Measure and Process Biofuels and Waste Coal for Gasifier Improved Operation— Energy Research Company and Lehigh University are developing technology to measure biomass and waste coal gasifier feedstocks in-situ and in near real time, resulting in immediate and time sensitive fuel data that gasifier operators can use in a feedback or feedforward control scheme to maximize performance and avoid negative effects of ash in feedstocks.
Hydrogen separations
Modular Hydrogen Separation System for Biomass Gasification—TDA Research is developing a modular hydrogen separation process that can efficiently separate the carbon from the hydrogen in the synthesis gas generated by the gasification of coal fines and biomass to produce clean hydrogen that has negative carbon emissions. TDA’s proposed process uses next generation adsorbents to remove carbon dioxide and carbon monoxide (which can be sent for storage or utilization) to produce the high purity hydrogen in a modular pressure swing adsorption process.
Onsite NETL Research
NETL’s R&IC is developing innovative gasification technologies that enable process intensification and/or reduce the overall cost of small-scale energy conversion through improved methods, materials, and approaches. Currently, the technological areas under investigation are as follows:
Other key technologies within Gasification Systems include the following:
