(545aw) Technoeconomic Optimization of Emerging Technologies for Regulatory Analysis: NH4HCO3 Forward Osmosis for Power Plant Wastewater Treatment

The regulatory design process requires the use of tools that can rapidly assess the cost and performance of potential compliance technologies. Performing technoeconomic assessments of emerging treatment options for integrated, sustainable technologies is particularly challenging as models of full-scale performance do not yet exist (for emerging technologies) or highly nonlinear and with greater uncertainty (for integrated processes). In this talk, we demonstrate the use of gray-box optimization to inform process assessment during the development of regulations. We do this with the Effluent Limitation Guidelines for flue gas desulfurization wastewater discharges as a case study. We build a set of computationally lean meta-models of ammonia-bicarbonate forward osmosis (NH₄HCO₃ FO) – an emerging process that can be integrated with the power plant steam cycle or waste heat. Using these meta-models, we perform technoeconomic optimization of NH₄HCO₃ FO and crystallization to assess the capital and operational costs. We compare these NH₄HCO₃ FO costs to the costs for mechanical vapor recompression and crystallization, the EPA identified best available technology for achieving zero liquid discharge. We estimate that the NH₄HCO₃ FO treatment train would reduce zero liquid discharge costs by $0.30-$1.20/m³ or $20-$70 million nationwide annually. This work highlights the opportunities and challenges associated with deploying gray-box optimization techniques for the rapid assessment of emerging technologies in policy analysis.