Optimization of Coal Waste/Biomass Gasification for Hydrogen Production

Decades of coal use in the United States has resulted in large amounts of waste coal materials produced from coal preparation plants. Currently, these coal wastes are stored in piles and ponds, and many are causing environmental problems such as acid mine drainage. Technologies must be developed that can utilize these coal waste materials. Gasification of coal waste combined with biomass has the potential to produce hydrogen in a process that is carbon neutral and carbon negative. This SBIR project is aimed at developing tools that can be utilized to overcome challenges associated with waste coal and biomass materials in gasification technologies to produce hydrogen. A major challenge is that the impurities in the coal waste and biomass can produce problematic ash materials that can impact plant performance and reliability. The tool will predict the impacts of waste coal and biomass blends on gasifier performance relative to ash-related issues such as slag flow and fouling. The key benefits of the technology include improved methods for efficient usage of challenging feedstocks such as waste coal and biomass, well-informed decision making and advanced response planning. The tool can improve performance by matching feedstock properties with optimal gasifier technologies, sorting and blending feedstocks to optimize feedstock properties prior to gasification, and adjusting gasifier operations to accommodate current and projected fluctuations in feedstock properties in order to maximize efficiency and reliability. In Phase I, samples will be obtained and chemical/physical analysis will be performed to determine slag flow, fouling, and agglomeration behavior. The impacts of feedstock blends on ash behavior will be modeled. Optimal gasifier technologies for utilizing coal waste/biomass blends for hydrogen production will be identified, and the sensitivity of gasification costs to changes in gasifier availability will be modeled. The impacts of feedstock quality fluctuations on availability will be calculated in order to calculate the cost savings provided by the feedstock properties management tool. The feedstock properties management tool will be used in gasifiers to maximize the efficiency and reliability of hydrogen production from waste coal/biomass feedstock blends, supporting the hydrogen economy and providing economic opportunities for priority energy communities affected by the downturn of the coal industry. The need for the tool is anticipated to grow as more gasification-based hydrogen production plants that use challenging feedstocks are developed in the US to meet the goal of the decarbonization Net-Zero by 2050.