Effect of Glycolic Acid Ethoxylate Lauryl Ether (GAL) Surfactant Solutions among Low and High Concentrations on Drag Reduction to Progress Flow in the Pipeline Networks Using RDA

In the pipeline networks field, GAL surfactant can reduce drag forces relatively using a small quantity part per million (ppm). Accordingly, the drag reduction (DR) enhancement is highly recommended in many industrial applications specifically the crude oil transportation aspect. GAL solution was experimentally investigated at various concentrations. The experiments were performed at low concentrations range from 50 to 300 ppm, and high concentrations range from 1000 to 2000 ppm. The rotating disk apparatus (RDA) was used at various speeds range from 50 to 3000 rpm in all experiments. Torque values of the GAL solutions were compared with water alone. The results clearly show that the different concentrations of the Glycolic Acid Ethoxylate Lauryl Ether (GAL) are good drag reduction agents (DRAs), with clear and high torque reading differences. Further, GAL solutions have the same tendency at all concentrations. The torque finding was enhanced with increasing concentration.


Introduction
In interior fluid flow such as pipes, conduits, and channels, mechanical energy is dissipated and turned to friction losses in the path of flow due to fluids resistance.
The friction caused by adjacent boundary layers is termed friction drag while friction caused by disconnected boundary layers of the wall is termed form drag. Form drag or This work is licensed under a Creative Commons Attribution 4.0 International License. pressure drag can arise due to a difference in the pressure drops, additionally; the flow under turbulent conditions, drag forces will develop dramatically due to the formed eddies. Therefore, the highest drag force is translated into the greatest energy pumping requirement and increased energy costs then. To overcome the drag forces problems; a minor minute of additives that add to the fluid could be substantially decreasing the friction loss in the turbulent flow inside the pipeline. The drag Reduction (DR) phenomenon is known as "drag reduction", by drag reduction technique could be made a huge difference in the power saving that is used to transfer liquid in pipelines. In 1948, Toms [1] is the first pioneer noticed decreasing in the friction losses when he adds a small concentration of high molecular weight of the polymer in the turbulent flow. Forrest et.al [2] studied the pulpwood suspended in water solution were observed decreasing in pressure losses in the turbulent flow. Mysels [3] applied aluminum soap as drag reduction additives. Lumley [4] has been described the DR phenomenon as turbulent drag reduction which is decreasing skin friction in stormy flow less than the solution individual. Mysels [5] studied the surfactant effect on reducing drag performance. The surfactant agents were classified by Mysels into three categories namely: zwitterionic, nonionic, and ionic. The onset of researchers who study nonionic surfactant is Zakin and Chang [6] applied triple types of non-ionic surfactants to study the effect of temperature, concentration, and shear stress on the drag reduction efficiency. The results indicated that the micelles geometric form can be changed due to the impact of the molecule structure of nonionic surfactants. In addition, the drag reduction efficiency is going to increase in these conditions. Zakin and Ge [7] stated that the activity of nonionic surfactants has a limited range only in the concentration and temperature. Zakin et al. [8] employed the cationic surfactant Cetyltrimethylammonium bromide (CTAB) to study its effect on drag-reducing. The CTAB-naphthol was mixed in various concentrations. the highest drag-reducing obtained is around 70%. Further, the shear-thinning features were examined at the same component to predict its drag reduction potential. They found the drag reduction of the mixture solution discontinuous at Re increase, which follows the same behavior of anionic surfactant solution. Suksamranchit and Sirivat [9] used a complex solution of polymer PEO and cationic surfactant. The linking between the polymer and surfactant micelles could be changing the velocity of the solutions. The complex component has a great benefit such as decrease the optimization of polymer concentration and modification the drag reduction efficiency by decreasing the critical polymer molecular weight [10]. Mysels [5] one of the pioneers who employ an anionic aluminum soap with the gasoline in the pipe flow. Savins [11] applied the anionic surfactants to study drag reduction in aquatic solution in wide experimental attempts.
The ammonium soaps and alkali metal about 0.2% in salt or ester of oleic acid solutions were used. The results revealed that the rod-like shape is formed when adding (KCl) to the solution due to the quicken union of the soap molecules. Further, the drag reduction is increased during the growth of the shear stress until a critical point, after this critical point the drag reduction is decreased with any more increasing in shear stress. This means the micelles bundles will be destroyed after the critical point of shear stress and this case reverses when the shear stress becomes below the critical point. In other words, the micelles will fix themselves. Eman et al. [12] investigated the impacts of biopolymer and surfactant additives on the features of DR, as well as the performance of (Chitosan, SLES) individually and their complex solution in different concentrations by RDA. The results showed the highest drag reduction performance of about 47.75% came with a mixed solution at 3000 RPM of RDA. Yunqing Gu et al. [13] studied the mechanism of additives and drag reduction properties. Further, they have discussed the factors that caused the decay and antidecay in polymer and surfactant, respectively. The results revealed that the mixture solution has properties to resist a high shear and the drag reduction effected directly with increase Re. In previous studies were used one or more polymer or surfactants materials, where polymers are generally degraded after a certain time which driving the flow to lose their stability. Weili Liu et al. [14] have conducted a numerical and practical study to assess the drag reduction efficiency for electronic pipes. They have suggested a new surface form for pipes using narrow grooves to reduce the pressure gradient of liquid transportation. The comparative tests were achieved in a water tube.
The results revealed that the eddy "cushioning" and "driving" impacts generated via eddies in narrow grooves were very important for drag drop. Paul et al. [15] a revision and investigation were achieved on the effect of additives on the drag using the flat The morphological test has been done employing scanning electronic microscopy (SEM) technique.

Drag Reduction
In hydrodynamics science, drag is defined as a kind of frictional or fluid resistance force which is working reverse to the proportion motion of anybody regarding an ambient liquid. Drag is generally classified to four categories namely: form drag, skin friction, interference drag, lift-induced drag. The drag improver was remarked first in 1943 by Toms. It was observed when he added a minute amount of polymer to the pipeline in the turbulent flow that in (ppm) could give distinguish results through decreasing the friction force and flow resistance [19].
Recently, the drag reducers had significant value as a new process for decreasing power consumption in the fluid transportation field, especially power saving in pump stations. In other words, drag improver can considered as a substitutional trajectory to decrease the power losses in the pumps, which occur through a fluid transition by a pipeline system. This could occur by adding one or more drag improvers inside the fluid flow in the pipeline system, that leads to power saving, and reducing the cost that spends to update pieces equipment of pumping [20].

Surfactant
The surfactant is called surface-active agents, which is decreasing the surface tenseness in liquids and interfacial tenseness between twin immiscible liquids, particularly if used in minute amounts. The surfactant has a unique property which is the capability to form a remarkable structure called micelles, which can rejuvenate their basic shape after being deformation or exposed to high stresses due to self-repair.
The formative groups of micelles shapes were named According to the solvent and the system situation, such as cylindrical, disk-like, ball shape, thread-like, and vesicle.
Also, surfactants can change their form to another form. Mostly, surfactants have been used in moisturization products, detergent products, and emulsifying or separating  [21]. In general, the surfactants are categorized into two groups; the first group is called hydrophilic or head group. The second group is called hydrophobic or tail group, in case the solvent is water the structure of surfactants can be categorized chemically into two parts namely: 1-Polar (ionic) part, which is usually called a hydrophilic head group, that in an aqueous environment is attracted to water. Also, is widely used due to their ability to form hydrogen bonds.
2-Nonpolar part, which is usually called hydrophobic tail group, that in an aqueous environment is often interacting with water, that reason make the hydrophobic molecules combined with hydrocarbon atoms to avoid interaction with water. Also, is available and cheaper enough in different sources such as petroleum industry products and agriculture [22], [23], [24].

Experimental Set up
The rotating disk apparatus was used to test the rheology characteristics and the resistance of the solutions to maximum levels of turbulence as shown schematically in

Glycolic Acid Ethoxylate Lauryl Ether (GAL)
The surfactant of Glycolic acid ethoxylate lauryl ether (GAL) commercially is called Laureth-4 carboxylic acid. GAL is classified from the anionic surfactant group.
Also, it does not cause any risk and is environmentally friendly. Figure (3) shows GAL, and its chemical structure. Material employed in this study was supplied by Sigma Aldrich, USA, and used as a liquid without any additional treatment.

Preparing Solutions
The desired concentration was dissolved in a container with de-ionized water, then dispersed by a mechanical stirrer at a low speed for five hours, until the additive solutions become homogenous. The homogenous solution and water were poured into the main tank frequently and kept stirring for a certain period and the moment that stirring was completed, the additive solutions were covered to avoid water drying up.
The solution was relaxed for one day or more before doing the tests. All solutions were operated at low concentrations ranging between (50-300 ppm) and at high concentrations ranging between (1000-2000 ppm). Further, the rotational speeds of RDA were ranging from (50-3000 rpm) and the tests were conducted at room temperature. All these procedures were repeated in the individual solutions at each concentration.

Experimental Calculation
Drag reduction percentage calculates using the following equations: (1) Where: T a is the torque values after adding GAL (water alone) (N.m) T b is the torque values before adding GAL (N.m).

NRe= (2)
Where: µ is a viscosity of a fluid ρ is a density of a fluid R is a radius of the disk ω is an angular velocity N R e >= 1 x10 5 (turbulence because of using the rotational disk apparatus speed range 0-3500) The major variables investigated are: Speeds: RDA was used at different rotational speeds ranged (0-3000) and the torque value was calculated, which adopted with the dimensionless Reynolds number (Re).

Effect of GAL Enhancer on Viscosity
The effect of GAL additives on viscosity at different shear rates is illustrated in   The experimental work has been validated by comparing torque behavior after adding a GAL agent using RDA with previous experimental works at the same conditions. Where it found a good agreement with Edward's study [29] as shown in