Industrial & Engineering Chemistry Research, Vol.59, No.29, 13143-13159, 2020
Hybrid Regeneration Network for Flowback Water Management
As global exploration of shale gas reserves increases, there is a need for an accurate and efficient approach to proper water management, which is one of the vital problems related to shale gas production. This study looks at the effect of using multiple or hybrid treatment technologies in maximizing hydraulic fracturing wastewater reuse while ensuring the sustainability of the process in terms of energy and associated cost. The study considers ultrafiltration and membrane distillation processes as possible pretreatment and desalination technologies for flowback water management. It also considers the possibility of supplying the electrical and thermal energy requirements of these regenerators using flared gas. Two different scenarios are considered based on the flowback water composition in hydraulic fracturing in terms of salinity. Application of the proposed model to a case study leads to a 24.13% reduction in the quantity of water needed for fracturing. In terms of energy requirements, the approach yields a 31.6% reduction in the required thermal energy in membrane distillation and 8.62% in energy requirement for ultrafiltration. For flowback water with moderate total dissolved solid concentration, 93.6% of wastewater reuse comes from pretreated water by ultrafiltration and 6.4% from membrane distillation. However, as the flowback water salinity becomes higher, the percentage of pretreated reusable water reduces to 81.1% and the percentage supply through membrane distillation increases to 18.9%. In all cases, the results indicate that the decision to allow the pretreated water to pass through desalination technology strictly depends on the quantity of water required by a wellpad and the salinity of the wastewater.