Estimation of energy consumption during cross-flow membrane filtration of oil/water emulsion

Abstract

s: Pressure driven membrane filtration has been widely adopted for oil and water recovery from oil/water emulsion. The technology offers numerous economic and environmental advantages. However, specific energy consumption remains a critical factor for its economic assessment. The specific energy consumption depends on several factors, among which is the fouling filtration period/time. Therefore, the fouling filtration time indirectly affects the overall economic viability of the system. Herein, the effect of fouling filtration time on the specific energy consumption during cross-flow filtration of 1000 ppm oil/water emulsion was evaluated. During the first 20 min of oil/water emulsion filtration, the energy consumption was found to be 0.0225 KWh/m3. While the filtration was continued to 90 min, the system requires 0.0301 KWh/m3 energy input. The tradeoff between fouling filtration time and energy consumption was found to be just before 30 mins. Suggesting that at 30 mins fouling filtration time, clean water flushing/backwashing would restore significant hydraulic performance and thus, less increase in energy input would be required. At the tradeoff point 0.0254 KWh/m3 energy was required to drive the filtration. This represents up to ∼19 % energy saving compared to the straight nonstop 90 min fouling filtration time. The overall results demonstrated that fouling filtration time affects the overall economics of cross-flow membrane filtration.