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 a focus on gasification of coal into syngas, syngas cleanup, and syngas conversion. Clean syngas enables highly efficient and low carbon footprint power generation, and is ideal for fuels or chemicals production, or combinations thereof (i.e. polygeneration). Improved reactors and processes for gasification, syngas upgrading and cleanup, and conversion of syngas into fuels or power will enable integrated systems with higher availability, reliability, efficiency, and flexibility, resulting in lowered costs of production and excellent environmental performance.
Fields of investigation under Process Intensification for Syngas & Hydrogen currently include:
Current reactor design (including coal gasification reactors) is based on a long legacy of industrial use, 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 much more precision and control in these reacting systems, and which can be developed more quickly and inexpensively.
The Gasification Systems Program will pursue development in promising areas of advanced gasification technologies to lower costs and increase efficiency of modular coal syngas production and syngas conversion to value-added products. 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 coal-particle behavior during coal conversion processes, and breakthroughs in advanced manufacturing to significantly drop the capital costs for small-scale reactors and modular plants.
Modular gasifier technology
Staged Opposed Multi Burner (OMB) for Modular Gasifier/Burner—A University of Kentucky team is making innovative burner modifications of their pilot-size staged-opposed multi-burner entrained flow gasifier (utilizing coal slurry as a feed for high temperature gasification) and testing to evaluate improvements in performance. Although OMB gasification is commercialized at full scale, the University of Kentucky OMB pilot gasifier is a one ton-per-day unit (a small fraction of the commercial unit size), so that it can serve as a test bed for small-scale modularization of an entrained flow gasifier outfitted with a novel burner configuration, enabling investigation of advanced modular gasifier performance and optimization.
Small Scale Engineered High Flexibility Gasifier—Southern Research Institute is developing a novel, cost-effective, radically engineered modular gasifier having applications to 1-5-MW energy-conversion systems, such as combined heat and power (CHP). The gasifier is pressurized, oxygen-blown, and uses a simple small-scale modular design. This approach targets flexibility to optimize fuel throughput and thermal efficiency, to manipulate coal conversion, and to produce syngas of a desired composition while producing negligible tar. The potential is for reduction of cost of coal conversion via an optimized, factory-built modular system to allow scale-up via modular expansion and deployment at remote sites.
Experimental Validation of Coal Gasification with Neutron Imaging—Oak Ridge National Laboratory (ORNL) is developing neutron imaging techniques in order to view coal pyrolysis and gasification reactions/behavior in situ. This would be a powerful diagnostic tool in developing novel modular gasifiers and gasification technology.
Modular syngas cleanup
Syngas cleanup processes remove contaminants present in raw syngas (these include hydrogen sulfide, ammonia, hydrogen chloride, and carbonyl sulfide, as well as various forms of trace metals, including arsenic, mercury, selenium, and cadmium) to extremely low levels demanded by stringent regulatory limits on air emissions, and to prevent the harmful effects of these contaminants on downstream equipment components and processes. Although conventional technologies exist to perform syngas cleanup, they rely on chemical or physical absorption processes operated at low temperature, which causes a significant efficiency penalty. Highly efficient, advanced processes that operate at moderate to high temperatures, referred to as warm syngas cleanup, will provide multi-contaminant control to meet the highest environmental standards and performance demands of gas turbines for electricity generation, and of downstream processes for fuels and chemicals synthesis.
Advanced Syngas Cleanup for Radically Engineered Modular Systems (REMS)— Research Triangle Institute (RTI) is developing modular designs for the cleanup of warm syngas with reduced costs, emissions, and improved thermal efficiency, enabling 1-5-MW REMS-based plants to be cost competitive with large state-of-the-art commercial plants using abundant domestic coal reserves. RTI recently completed a successful demonstration of their High Temperature Desulfurization Process, which is a so-called warm syngas cleanup technology operating at relatively high syngas temperatures for removing hydrogen sulfide and carbonyl sulfide. In this demonstration, they cleaned a 50 MWe slipstream of coal-derived syngas down to a total sulfur level of less than one part per million. For further information, see Recently Completed Projects below.
Warm Gas Multi-Contaminant Removal System—TDA Research Inc. is developing a warm gas multi-contaminant removal system to be used after the bulk warm gas sulfur removal such as that developed by RTI. Their high-capacity, low-cost sorbent targets removal of anhydrous ammonia (NH3), mercury (Hg), and trace contaminants from coal- and coal/biomass-derived syngas.
Modular gasification systems market applications
Field studies are underway for pilots in Alaska and eastern Kentucky to spearhead new coal industry growth in specific market applications, utilizing advanced modular gasifier systems technology:
Making Coal Relevant for Small Scale Applications: Modular Gasification for Syngas/Engine CHP Applications in Challenging Environments—The University of Alaska-Fairbanks is preparing a Front-End Engineering and Design (FEED) study for a modular, air-blown fixed-bed gasifier providing clean coal-derived syngas to an existing diesel engine generator, resulting in capital and operating-cost estimates for power generation using small-scale, modular, coal gasification units coupled with readily obtained diesel infrastructure, suitable for deployment at remote sites and providing a way to obtain fuel locally utilizing Alaska’s indigenous coal resources instead of importing diesel fuel at high cost.
Gasification CHP from Coal Fines—The University of Kentucky is working on a FEED study for a 5-MW-electrical-equivalent polygenerating unit located in Hazard, eastern Kentucky, using waste coal fines and biomass (sawdust from the lumber industry) as exceptionally low-cost feedstocks. The idea is to develop a cross-industry synergy in a rural, remote area that could serve as a model for future economic development in depressed regions.
Onsite NETL Research—Process and Reaction Intensification
NETL’s R&IC is focused on developing new reactors and reaction pathways that enable process intensification and/or reduce the overall cost of small-scale energy conversion. The initial focus is to investigate new reactors and reactions such that a techno-economic analysis can be performed to determine the benefit of the technology and provide R&D guidance on technology goals. Later, the focus will shift to determining realistic goals and refining the pathway to achieve those technology specific goals. The technological areas under investigation are as follows:
Onsite NETL Research—Virtual Reactor Optimization
NETL’s R&IC is focused on the creation and validation of advanced computational toolsets for design and optimization of novel reactor systems. These toolsets will be based on the use of multiphase computational fluid dynamics (CFD) to predict reactor performance, and the simulation-based optimization that use these predictions to meet optimal performance criteria. In this work, the elements support process intensification for syngas:
National Carbon Capture Center
Transport Reactor Integrated Gasification (TRIG™), originally developed by Kellogg, Brown, and Root (KBR) based on the company's fluidized catalytic cracking technology, has been enhanced through extensive testing by Southern Company at the Power Systems Development Facility in cooperation with NETL. Testing corroborated that the gasifier effectively handles low-rank coals (e.g., Powder River Basin lignite), which account for half of the worldwide coal reserves but are often considered uneconomic as energy sources due to high moisture and ash contents.
Some projects hosted by the NCCC:
NETL continues preparing and maintaining baseline studies to provide unbiased comparisons of competing energy conversion system technologies, determining the best way to integrate process technology steps, and predicting the economic and environmental impacts of successful development.
Other key technologies within Gasification Systems include the following: