(158a) Development and Application of Plant-Wide Process Modeling in Shale Produced Water and Petroleum Wastewater Treatment

Wastewater generated from the oil production is of increasing concern as it threatens to significantly harm human health and the environment. Produced water which is wastewater emerging from the well after production begins, needs to be treated before recycling/reuse, discharging, and disposal. Regardless of the fate of produced water, produced water treatment (PWT) is expensive, complex, and an energy intensive process. We have developed mathematical models targeting technologies used for different stages of PWT and petroleum wastewater treatment. Process modeling is a very useful and inexpensive tool that can be used for plant design, evaluating various operation strategies, and training of process engineers and operators. The plant-wide model developed considers biological and physio-chemical reactions specific to produced water and petroleum waste. The biology considers different aerobic/anaerobic heterotrophic and autotrophic microbial pathways targeting VFA, BTEX, MTBE, Alcohols, PHAs, Amines, Phenolic, Sulfur compounds, and dissolved Oils removal. The physio-chemical model considers the Surface Complexation Model concept for heavy metal removal and other precipitation reactions (forming ACP, calcium carbonate, struvite, vivianite).

Major process units developed for physio-chemical treatment are listed below -

• Reverse/forward osmosis, ultrafiltration, and nanofiltration
• Electrodialysis and evaporators
• Continuous stirred tanks, plug flow reactors, moving bed biofilm reactors, and membrane bioreactors
• Primary, secondary settlers, dissolved air flotation, thickeners, centrifuges, cyclone, dewatering, filters, etc.
• Pumps, bypass weirs, channels

The developed models show potential application in improved process design, and optimisation of different stages of treatment. It helps identify potential strategies for saving capital and operational costs. Case studies comparing different treatment trains will be presented as part of the full paper.