(290e) Deploying Intensified, Automated, Mobile, Operable, and Novel Designs “Diamond” for Treating Shale Gas Wastewater

Authors: 
Sengupta, D., Texas A&M Engineering Experiment Station
Carlberg, P., US Clean Water Technology
Camacho, L. M., Texas A&M University-Kingsville
Brennecke, J. F., University of Texas at Austin
Stadtherr, M., University of Texas at Austin
Khanna, V., University of Pittsburgh
Freeman, B. D., University of Texas at Austin
Vidic, R., University of Pittsburgh
El-Halwagi, M., Texas A&M University
The DIAMOND project is aimed at developing integrated design and operating approaches of modular systems that can be deployed for treating flowback and produced water resulting from shale gas production. Because of the highly distributed nature and variable characteristics of shale-gas wastewater (SGWW), there is a unique opportunity to deploy modular systems. There is also a major challenge in developing tailored designs for each source of wastewater. An integrated theoretical-experimental project is proposed to: (1) Assess, screen and integrate commercially-viable conventional and emerging technologies for wastewater treatment, (2) Develop computer-aided modeling, design, operation, scheduling, and costing approaches for non-recurring engineering needed to deploy the SGWW treatment systems, and (3) Demonstrate proof-of-concept via applications to a broad range of SGWW samples. A combination of systems engineering approaches and experimental/pilot-scale work will be used to generate commercially viable design and operational strategies with significant impact on intensification metrics.

A dynamic model will be developed to describe the flow rate and TDS concentration of flowback and produced water from fractured wells. These models will be validated against experimental data available from the literature. Based on this, a computer tool will be developed to run detailed complex models according to modular/intensified process alternatives, obtained from superstructure optimization. An engineering study will be performed to provide techno-economic and controllability analysis.

Based on the characterization of available samples, a combination of experimental/pilot scale work will be conducted. USCWT technology uses electromagnetic fields and electrocoagulation to clean shale gas wastewater by removing, oxidizing, or precipitating contaminants. Bench and pilot scale units will be used to demonstrate this technology with waters from gas fields studied in this project.

Membrane distillation laboratory experiments will be carried out using simulated and real SGWW to identify membranes that are resistant to very high TDS concentrations. Simulated samples will be created by preparing brines with total dissolved solids (TDS) concentration between 50,000 ppm and 150,000 ppm. Parameters such as turbidity and total suspended solids (TSS), as well as SGWW-contained minerals ions as well as heavy metals, will be included in the study. Both lab-scale and pilot-scale experiments will be conducted to validate operating parameters and system performance.

Ionic liquids (ILs) have the potential to extract salts, as well as some organics, from SGWW. The key is to prevent back contamination of the wastewater with the IL. Manufacture, test and model polymeric membranes will be designed to allow transport of the SGWW contaminants through the membrane, but prevent the IL from entering the cleaned aqueous phase.

The technical and economic feasibility of membrane distillation (MD) and counterflow reverse osmosis (CFRO) for treatment of shale gas wastewater (SGWW) will be evaluated. Lab and pilot scale data will be used to inform and develop optimization-based technoeconomic models for SGWW treatment using MD and CFRO technologies.

In conclusion, all these processes will be used to build the framework for assessing, screening and integrating commercially-viable conventional and emerging technologies for wastewater treatment.