Drag Reduction in the Flow of Aqueous Solutions of a Mixture of Cocamidopropyl Betaine and Cocamide DEA

Abstract

The study presents results of rheological tests and measurements of pressure drops occurring during the flow of aqueous solutions of a mixture of drag reducing surfactants: cocamidopropyl betaine (CAPB, zwitterionic surfactant) and cocamide DEA (nonionic surfactant) through straight pipes. Tests were carried out at different CAPB/DEA weight ratios and different total concentrations of surfactants in the solution. Rheological measurements demonstrate the formation of a shear-induced structure (SIS) in the temperature range below 10 °C, which provides evidence for the presence of wormlike micelles in CAPB/DEA solutions. Drag reduction was observed during the flow of CAPB/DEA solutions in the temperature range from 3 to 45 °C, however, above 25 °C the degree of drag reduction was markedly decreased. The lower temperature limit at which drag reduction occurs depends on the CAPB and DEA weight ratio in the solution. In the range of higher temperatures, during the flow of CAPB/DEA solutions (similarly to flexible-chain polymer solutions) the onset of drag reduction is noted above a certain critical value of the Rec,0 number, whose value depends on the temperature of the solution, diameter of the pipe and the weight ratio of surfactants. At the same time, the critical value of wall shear stress τw,c0 corresponding to the critical value of Rec,0 is approximately independent of pipe diameter. The critical value of the Rec,0 number has been linked to the clouding of CAPB/DEA solutions.

Pressure drops during the flow of solutions of cocamidopropyl betaine and cocamide DEA mixtures with the addition of ethylene glycol

“…Model tests were carried out using two experimental stands adapted to work in the temperature range from -5 o C to 70 o C (stand 1) and from 15 o C to 20 o C (stand 2). The diagrams and detailed descriptions of the experimental stands are presented in an earlier paper 14 . The fl ow of the fl uid in the stand 1 was generated by a Grundfos UPE 25-60B centrifugal pump.…”

Drag Reduction Using Additives in Smooth Circular Pipes Based on Experimental Approach

“…Low concentrations will have an effect when the flow is turbulent. Research on non-ionic surfactants with cationic surfactants can be distinguished in the study [103], where zwitterionic CAPB (Cocamidopropyl betaine) showed a higher drag reduction of 65% than cationic surfactant in turbulent flow with a composition of 0.12% DEA in the combined CAPB-DEA. It also adds a perspective of the effectiveness against cationic surfactants, which are insignificant in a turbulent flow.…”

Bio-based synthesis of a sustainable Nano drag reducing agent for sprinkler irrigation systems

“…Therefore, surfactants were used to lower frictional drag since they are less susceptible to thermal, mechanical, and chemical deterioration. But, they simply experience impermanent deterioration when a specific crucial wall shear stress is surpassed [4]. Scientists reported recently the utilization of Nano fluid in the drag reduction process.…”

“…The critical Reynolds number of drag reduction for aqueous Nano silicate solution was quantified as 96000. 4.…”