Salt Flow Research Articles

Large salt accumulations as a consequence of hydrothermal processes associated with ‘Wilson cycles’: A review, Part 2: Application of a new salt-forming model on selected cases

Abstract The new hydrothermal salt model predicts that salt may accumulate in the sub-surface by hydrothermal circulation of seawater and brines in locations of high heat-flow. Such conditions are primarily found along tectonic plate boundaries, with processes of subduction and rifting, associated with the Wilson cycles. Modern knowledge of the physicochemical and thermodynamic properties of salt solutions at elevated pressures and temperatures, allows numerical modeling of fluid behavior at relevant conditions in the deep crust. This modeling shows how seawater that migrates down towards hot magma bodies in a rift situation (e.g. in the Red Sea) is subject to phase transitions, where low-saline (distilled) water vapor migrates out of the system, while still saltier brine continues to migrate further down towards the heat source, until solid salt precipitates. Similarly, in a subduction situation, the seawater confined in the subducting oceanic plate is subjected to an ever increasing pressure and temperature during the descent towards the mantle, which leads to similar phase behavior of the brine as in the rifting situation. The salts forming in the deep of a subduction zone are not readily transported up to the surface due to thick overburden of mantle- and crustal rocks. Hence, much of the salt formed during subduction remains hidden from human observation in the roots of the mountains. The formation of solid salt is therefore an inevitable process associated with the Wilson cycles, even without solar evaporation. Recent observations of thick carpets of mobile salt slurries on the Red Sea floor (Salt Flows) and huge accumulations of salts in the subsea/subsurface (Salt Walls and Salt Ridges), associated with topographic lows (Deeps), suggest that the Red Sea currently produces new volumes of brines and solid salts underground. The different solubilities of sea salts lead to a refining of the salt types. When reaching the seafloor, the warm brines are cooled down in brine pools, eventually becoming oversaturated with salts, which results in precipitation onto the seafloor. The dense brine layers protect seafloor salts from re-dissolution by normal seawater. Magmatic and volcanic processes associated with hydrothermal activity, e.g. connected to the subduction under the Andes Mountains are associated with enormous deposits of salts. The brines are transported hydrothermally up from the subduction zone and are venting out at 3500–4000 m above sea level. At the surface, the brines evaporate in the dry climate, which is also protecting the salt from re-dissolution. The brine feeding the hydrothermal systems above the subduction zone originates from dewatering of the subducting slabs. This water is causing fractional melting of the mantle wedge above, initiating volcanism. The hydrothermal water is also transporting salts to the surface, thus, explaining the close relationship between some types of volcanism and salt accumulations. It is assumed that this new understanding of hydrothermal salt formation will have a profound impact on interpretation of geological phenomena involving salt and salt formation, including the early development and behavior of salt basins.

The impact of base-salt relief on salt flow and suprasalt deformation patterns at the autochthonous, paraautochthonous and allochthonous level: insights from physical models

Abstract Salt is sensitive to the geometry of the substrate it flows across. We use physical models to investigate the impact of base-salt relief on deformation patterns. First, we investigate early-stage gravity gliding across base-salt relief. Salt flowing onto structural high blocks forms a zone of thickened salt and associated shortening owing to a flux mismatch. On the downdip edge of the basement high another flux mismatch generates a topographic monocline (ramp-syncline basin) with associated extensional and contractional hinges. With multiple base-salt high blocks, this structural pattern was repeated down the entire slope. Laterally discontinuous base-salt relief generated additional complexities such as major rotations of raft blocks and intervening diapirs as salt is channelled around and between base-salt relief. At the allochthonous level, regional dip, salt budget and base-salt relief influence flow patterns. Individual salt sheets spread sub-radially with streamlines skewed down the regional slope. As the canopy coalesced along allosutures, inward flow from the canopy peripheries dominated, driven by more vigorous flow from outer feeders owing to less competition for source-layer salt. Subsequent shortening returned flow patterns to grossly dip-parallel. However, salt flows fastest where it is thickest and thus chains of feeders channel rapid intracanopy flow.

Salt flow direction and velocity during subsalt normal faulting and syn-kinematic sedimentation—implications from analytical calculations

Salt flow direction and velocity during subsalt normal faulting and syn-kinematic sedimentation—implications from analytical calculations

Structural, micro-structural and kinematic analyses of channel flow in the Karmostaj salt diapir in the Zagros foreland folded belt, Fars province, Iran

One of the main characteristic of the Zagros foreland fold-and-thrust belt and the Zagros foreland folded belt are wide distributions of surface extrusion from the Hormuz salt diapirs. This study examines the structure and kinematic of channel flow in the Karmostaj salt diapir in the southwestern part of the Zagros foreland folded belt. This diapir has reached the surface as a result of the channel flow mechanism and has extruded in the southern limb of the Kuh-Gach anticline which is an asymmetric décollement fold with convergence to the south. Structural and microstructural studies and quantitative finite strain (Rs) and kinematic vorticity number (Wk) analyses were carried out within this salt diapir and its namakier. This was in order to investigate the structural evolution in the salt diapiric system, the characteristics and mechanism of the salt flow and the distribution of flow regimes within the salt diapir and interaction of regional tectonics and salt diaprism. The extruded salt has developed a flow foliation sub-parallel to the remnant bedding recorded by different colors, a variety of internal folds including symmetrical and asymmetrical folds and interference fold patterns, shear zones, and boudins. These structures were used to analyze mechanisms and history of diapiric flow and extrusion. The microstructures, reveal various deformation mechanisms in various parts of salt diapir. The measurements of finite strain show that Rs values in the margin of salt diapir are higher than within its namakier which is consistent with the results of structural studies. Mean kinematic vorticity number (Wm) measured in steady state deformation of diapir and namakier is Wm = 0.45–0.48 ± 0.13. The estimated mean finite deformation (Wm) values indicate that 67.8% pure shear and 32.2% simple shear deformation were involved; the implications of which are discussed. The vorticity of flow indicates that in the early stage of growth, Poiseuille flow was the dominate mechanism, especially in the core of diapir with higher pure shear component relative to simple shear component, whilst a Couette flow at the margins of diapir is the dominate mechanism with higher simple shear component relative to pure shear component. The obtained kinematic vorticity number reflects spatial partitioning of dominantly Poiseuille flow in core and Couette flow along edges of diapir. These two mechanisms reflect a persistent flow governed by a simultaneous combination of pure shear and simple shear in a hybrid Poiseuille-Coutte Flow.

Structural and microstructural analysis of K–Mg salt layers in the Zechstein 3 of the Veendam Pillow, NE Netherlands: development of a tectonic mélange during salt flow

AbstractIn fully developed evaporite cycles, effective viscosity contrasts of up to five orders of magnitude are possible between different layers, but the structures and mechanics in evaporites with such extreme mechanical stratification are not well understood. The Zechstein 3 unit in the Veendam salt pillow in the Netherlands contains anhydrite, halite, carnallite and bischofite, showing this extreme mechanical stratification. The Veendam Pillow has a complex multiphase salt tectonic history as shown by seismic reflection data: salt withdrawal followed by convergent flow into the salt pillow produced ruptures and folds in the underlying Z3-anhydrite–carbonate stringer and deformed the soft Z3-1b layerWe analysed a unique carnallite- and bischofite-rich drill core from the soft Z3-1b layer by macroscale photography, bulk chemical methods, X-ray diffraction and optical microscopy. Results show high strain in the weaker bischofite- and carnallite-rich layers, with associated dynamic recrystallisation at very low differential stress, completely overprinting the original texture. Stronger layers formed by alternating beds of halite and carnallite show complex recumbent folding on different scales commonly interrupted by sub-horizontal shear zones with brittle deformation, veins and boudinage. We attribute this tectonic fragmentation to be associated with a softening of the complete Z3-1b subunit during its deformation. The result is a tectonic mélange with cm- to 10 m-size blocks with frequent folds and boudinage. We infer that these structures and processes are common in deformed, rheologically strongly stratified evaporites.

Study on the coupled photon-thermal-stress integration method, characteristics with time and failure criterion in the solar molten salt cavity receiver

In this paper, the studies on the characteristics with time and failure criterion in the solar molten salt cavity receiver are carried out based on the coupled photon-thermal-stress integration method. Especially, the truly non-uniformed solar heat flux in the cavity receiver with different time are simulated using the optical simulation approach coupling the Monte Carlo ray tracing and Gebhart methods proposed by our team. Besides, the complex coupled heat transfer process of conduction, convection and radiative in the receiver are also comprehensively considered. Based on the integrally model, the solar flux, temperature and thermal stress on the absorber surfaces with different time are obtained. Then, the influences of different tube materials, flow layouts of molten salt on the coupling performances of photon-thermal-stress conversion process are discussed. Finally, the stress failure criterion in the molten salt cavity receiver is proposed based on the fracture mechanics theory. The results show that the temperature and thermal stress are influenced significantly by the non-uniformed solar flux, the distribution of temperature and thermal stress are also extremely non-uniformed. The solar flux and thermal stress change remarkably with different time, the peak heat flux and stress are maximum at 12:00 noon, and the peak thermal stress could increase by 11% and 10% compared with 11:00 and 13:00. It is also found that the peak thermal stress would be reduced effectively when the receiver tube with better thermal conductivity property and the molten salt flow layout which is from low-flux area to high-flux area are adopted. For example, compared with 800H receiver tube, the peak thermal stress of 316H tube could be reduced by 37%. Meanwhile, the peak thermal stress of flow layout which is from low to high flux area would be 20% lower than that with the opposite layout. The fracture toughness of receiver tube, which is influenced by the molten salt corrosion, is one of the key parameters to assess stress failure. Based on the stress failure criterion of critical solar flux proposed by this paper, the critical heat flux of stress failure would exhibit a decreasing trend when the fracture toughness degradation is serious in the molten salt receiver.

Novel thermosiphon-powered reverse osmosis: Techno-economic model for renewable energy and fresh water recovery

Recently, thermosiphon has been considered as an economically competitive approach for the withdrawal of thermal energy from molten salt. This feature of thermosiphon is particularly attractive for concentrated solar power (CSP) technology because molten salt can be used both as the direct receiver and thermal energy storage material, and pumping requirements can be minimized. However, the thermosiphon loop must be properly designed; otherwise the heated molten salt can flow in the reverse direction or solidify before heat exchange is fully carried out. In this paper, the dependence of important molten salt flow characteristics such as temperature, velocity and friction factor on the thermosiphon loop dimensions is theoretically investigated. The model is carried out for the withdrawal of 1MW of thermal energy from the molten salt. The economic assessment of the conversion of this energy to electricity for reverse osmosis desalination is also carried out. It is observed that by using the minimum possible value of leg length and maximum possible values of diameter and pressure head, the lowest decline of temperature and highest velocity of flow can be achieved along the loop. Fresh water production is more valuable than electricity and steam production by 460% and 480%, respectively.

Integrated model development for safeguarding pyroprocessing facility: Part I-model development and validation

Pyroprocessing is a method involving electrochemistry, thermodynamics, and transport theory. Driven by the current, nuclear materials redistribute between anode, electrolyte, and cathode to realize the desired separation. In the present study, a model for predicting the mass transport for the electrochemical process was developed. The model took into account the following key parameters: diffusion and mass transfer in both the electrode and electrolyte, the anodic dissolution and cathodic precipitation kinetics, the molten salt flow condition, and the solubility of species in molten LiCl-KCl and liquid cadmium. It was validated by available transport data between different pairs of the electrodes, namely liquid cadmium anode to solid cathode, solid anode to solid cathode, and solid anode to liquid cadmium cathode. Time for Pu depositing on the solid cathode as well as Zr dissolving from U-Pu-Zr alloy anode was precisely predicted. The potential and composition changes in various experiments were also well reproduced. The plausible explanation was given to explain the minor disagreement and future work was suggested to improve its capability. The model is useful to understand the reaction mechanisms and safeguard a pyroprocessing facility by monitoring the separation process and tracking the material flow.

Extensional flow of carboxymethylcellulose sodium salt measured on the opposed-nozzle device

ABSTRACTThe study presents results of the shear viscosity and apparent extensional viscosity measurements performed for semidilute solutions of carboxymethylcellulose sodium salt with two different average molecular weights and three different degrees of substitution, in distilled water and with the addition of NaCl. An increase in the weight average molecular weight of Na-CMC triggers a rapid increase in the apparent extensional viscosity and the Trouton ratio. Another finding was that the values of the apparent extensional viscosity and the Trouton ratio rose with a decrease in the degree of substitution, which can be attributed to the presence of interchain hydrogen bonds. The addition of NaCl to the Na-CMC solutions induces a reduction in the apparent extensional viscosity and the Trouton ratio, which can be linked to a change in the configuration of the polyelectrolyte chain.

Thermal management of a Sabatier reactor for CO2 conversion into CH4: Simulation-based analysis

Converting CO2-rich waste streams such as raw biogas, landfill gas and power plant flue gas into synthetic fuels and chemicals will reduce greenhouse gas emissions, providing revenue at the same time. One option is to convert CO2 into CH4 by hydrogenation via Sabatier reaction. This synthetic methane will be renewable if the H2 required for the reaction is generated via water electrolysis using solar and wind energy or hydroelectricity. However, to realize the potential of this approach, a number of technological challenges related to the Sabatier reactor design have to be resolved, including thermal management. The high exothermicity of the Sabatier reaction can lead to reactor overheating. High temperatures are unfavorable to the exothermic and reversible methanation process, resulting in low CO2 conversions. A simulation-based study of a Sabatier reactor was performed in order to optimize the removal of heat, while maximizing CO2 conversion and CH4 production. The heat-exchanger type packed bed reactor with internal cooling by a molten salt was simulated using a transient, pseudo-homogeneous mathematical model. Reactor performance was evaluated in terms of CO2 conversion and CH4 yield. The simulation results show that feed temperature, feed flow rate, and molten salt flow rate are the crucial parameters affecting the reactor performance. For the optimized operating conditions, the model predicts CO2 conversions and CH4 yields above 90% at high reactor throughputs, with space velocities up to 10,000h−1. A preliminary techno-economic evaluation is provided: opportunities and challenges are outlined.

SUSTAINABILITY ASSESSMENT OF A SPECIAL WATER MANAGEMENT PRACTICE IN A HUNGARIAN RIVERBASE

The purpose of the study is to assess the sustainability of the current water management practice of thermal water usage for bathing. The methodological approach is material flow analysis since it allows to achieve results without regular or online measurements. The current river base management plan recorded the quality status of certain reaches of river Kosely and its tributaries - the receiving water bodies of the used thermal waters - regarding salt content as good and moderate. The ecological status is recorded as moderate and weak, respectively. Since the Water Framework Directive prescribes to achieve the goal of good ecological status, water management measures must be implemented to meet this objective. Since there is no BAT for salt removal from used thermal waters, the possibility to reduce salt loads remain the only feasible measure. The purpose of the study in the frame of a PhD study was to assess with calculations the yearly variations of water and salt flow in river Kosely and its tributaries in order to assess the sustainability of the practice of thermal water management in the river catchment. The result of the calculations is a flow scheme provided with numerical data of yearly water- and salt flow and a subsequent calculation of necessary rate of reduction of usage and discharge of thermal water

Dynamic Sub-Thermoneutral Voltage Operation of Solid Oxide Electrolysis with Alternative Heat Addition

In this study, we experimentally evaluated electrolysis of water using a short stack of six solid oxide electrochemical cells (SOEC). A model of the SOEC stack was verified and used to evaluate thermal management of the stack operating above and below the thermoneutral voltage, which at these temperatures requires additional heat input into the stack to maintain the system operating temperature. High quality heat was supplied from a molten salt. Heat generated from concentrated solar power (CSP) can reach the required SOEC operation temperature through molten salts and can provide enough heat to sustain sub-thermoneutral voltage operation of an SOEC. The SOEC model is spatially and temporally resolved and was used to evaluate the dynamic performance of a system operating at sub-thermoneutral voltages with dynamic heat input. Dynamic results suggest high efficiency hydrogen generation can occur with external heat input under various conditions including variable power and salt flow.

Structure based classification for bile salt export pump (BSEP) inhibitors using comparative structural modeling of human BSEP

The bile salt export pump (BSEP) actively transports conjugated monovalent bile acids from the hepatocytes into the bile. This facilitates the formation of micelles and promotes digestion and absorption of dietary fat. Inhibition of BSEP leads to decreased bile flow and accumulation of cytotoxic bile salts in the liver. A number of compounds have been identified to interact with BSEP, which results in drug-induced cholestasis or liver injury. Therefore, in silico approaches for flagging compounds as potential BSEP inhibitors would be of high value in the early stage of the drug discovery pipeline. Up to now, due to the lack of a high-resolution X-ray structure of BSEP, in silico based identification of BSEP inhibitors focused on ligand-based approaches. In this study, we provide a homology model for BSEP, developed using the corrected mouse P-glycoprotein structure (PDB ID: 4M1M). Subsequently, the model was used for docking-based classification of a set of 1212 compounds (405 BSEP inhibitors, 807 non-inhibitors). Using the scoring function ChemScore, a prediction accuracy of 81% on the training set and 73% on two external test sets could be obtained. In addition, the applicability domain of the models was assessed based on Euclidean distance. Further, analysis of the protein–ligand interaction fingerprints revealed certain functional group-amino acid residue interactions that could play a key role for ligand binding. Though ligand-based models, due to their high speed and accuracy, remain the method of choice for classification of BSEP inhibitors, structure-assisted docking models demonstrate reasonably good prediction accuracies while additionally providing information about putative protein–ligand interactions.

Simplified model of a dual-media molten-salt thermocline tank with a multiple layer wall

Thermal ratcheting is a critical phenomenon associated with the cyclic operation of dual-media thermocline tanks in solar energy applications. To study this phenomenon, it is necessary to develop a comprehensive model of a thermocline tank that includes both the heterogeneous filler region and the composite tank wall. Because CFD models require a high computational cost to simulate a thermocline tank considering transient state operation, a simplified dual-phase model that includes the unsteady heat transfer through a multiple layer wall has been developed. The filler region consists of a rock bed with interstitial molten salt, and the tank wall is composed of a steel shell with two layers of insulation (firebrick and ceramic). In this simplified model, the fluid flow inside the tank is considered to be one-dimensional along the tank axis direction, whereas the heat conduction in the composite wall is considered to be two-dimensional. Therefore, a convective heat transfer coefficient from the bed to the wall is necessary to couple the molten salt flow with the heat transfer in the tank shell. In this work, the effects of both convective heat transfer from the bed to the wall and molten salt flow rate on the time-dependent thermal response of both the steel shell and molten salt have been analyzed. The simplified model is able to predict the temperatures of the molten salt, filler material and layer wall as well as the mechanical stress in the tank shell.

Bannu Basin, fold-and-thrust belt of northern Pakistan: Subsurface imaging and its implications for hydrocarbon exploration

The Trans Indus-Salt Range, located in northern Pakistan, is one of the most tectonically active fold-and-thrust belts and comprises three main regions: the Potwar-Salt Range, the Kohat-Surghar Range and the Bannu Basin-Khisor Range. Of these, the Bannu Basin is the least studied and only a handful of publically accessible datasets and publications are available. Recently made public 2D seismic profiles and well data from the Bannu Basin indicate the presence of salt as well as evidence for a main detachment surface which is Neoproterozoic in age. Our findings suggest that the Salt Range Formation could be the main detachment for the entire basin.Interpretation also shows a Miocene-Eocene basin-wide unconformity that marks the Himalayan orogenic event which separates the pre-Himalayan from the syn-Himalayan sedimentary units. On the basis of seismic reflection data, we conclude that the basin experienced three main tectonic settings. An early stage of pre-Himalayan passive tectonic environment is followed by the compressional Himalayan tectonics which resulted in uplifted areas sourcing the fluviatile fill of the subsided basin. During this time, sedimentation from the northern margin of the basin may have influenced the southward flow of salt. This is followed by a more recent stage of thrusting that produced folds and thrusts deforming all of the sedimentary units.Structural geometries suggest that prospective traps are developed mainly in the anticlines outlining the eastern and western boundaries of the Bannu Basin, as well as the southern zone of the basin. Furthermore, the presence of salt diapirism and transpression zones together with numerous oil seeps in and around the basin increase the probability of hydrocarbon accumulation and indicate great potential for future exploration.

Seismic interpretation and characterization of anhydrite caprocks in the Tromsø Basin, SW Barents Sea

The origin of anhydrite caprocks found in many evaporite basins is currently under debate. Existing models in the literature for anhydrite formation include rotated stratigraphic layering, rotated crestal caprock and diagenetic anhydrite. In this work, we interpret high-quality 2D seismic reflection data to understand the processes associated with anhydrite caprock formation. Our study focuses on anhydrite caprock formation in the Tromsø Basin, which represents one of several underexplored salt basins in the Arctic. We use well log data and seismic stratigraphic as well as seismic attribute analyses to characterize the ‘anhydrite’ layers associated with salt diapirs. Our results reveal that the anhydrite layers are high-amplitude reflections at the crests, which are often found close to the seabed and lateral caprocks on the flanks of salt diapirs. A third class of anhydrite layers is folded, faulted and boudinaged intrasalt stringers encased by the salt diapirs. Lateral caprocks in the Tromsø Basin are formed in response to rotated crestal caprock failure. The crestal caprocks are secondary in origin, occur at shallow depths, and are formed as insoluble residues from the dissolution of halite by the ingress of basinal fluids into the tops of diapirs. Anhydrite stringers, or floaters, originate from tectonic-related multi-dimensional salt flow. Salt diapirs in the Tromsø Basin are associated with varied anhydrite caprocks; their formation cannot be fully explained using a single model. Our work demonstrates from seismic reflection data the occurrence of caprock events that formed progressively on the flanks of salt diapirs due to local folding.

Thermal Performances of Two Stage Molten Salt Steam Generator

Abstract Thermal performances of two stage molten salt steam generator were experimentally investigated in this article. The two stage system consisted of primary U shape heat exchanger and secondary shell and tube heat exchanger, and its overall heat transfer coefficient, steam generation rate and thermal efficiency were further analyzed under different molten salt flow rates and water flow rates. According to the experimental results, the overall heat transfer coefficients of the primary and secondary heat exchanger both increase as the molten salt flow rising. As the water flow rate increases, the overall heat transfer coefficient of the primary heat exchanger first increases and then decreases, while that of the secondary heat exchanger gradually increases. As the molten salt flow rate and water flow rate increase, the steam generation rate and the thermal efficiency of the secondary heat exchanger both increase, while the thermal efficiencies of the primary heat exchanger and the whole system first increase, approaching their maximums with optimal molten salt flow rate and water flow rate respectively, and then begin to drop.

Development of a heat storage demonstration unit on the basis of Mg2FeH6 as heat storage material and molten salt as heat transfer media

The development and preliminary tests of a 5 kg Mg2FeH6 heat storage system which is useable for short and long-term storage applications at temperatures around 500 °C are described. The heat transfer for the heat storage process (dehydrogenation of the hydride Mg2FeH6) and heat release (hydrogenation of the hydride precursor 2Mg-Fe) is done by the flow of molten salt in appropriate heat exchangers serving as heat source or heat sink. The construction of the tube bundle reactor as a heat storage tank is presented. 1.6 kWh of heat could be released and 1.5 kWh of heat could be stored during the first experimental tests. Difficulties, which occured during the preliminary tests, are described.

Dissolution collapse of a growing diapir from radial, concentric, and salt-withdrawal faults overprinting in the Salinas de Oro salt diapir, northern Spain

AbstractA geomorphic investigation of the Salinas de Oro salt diapir in the Pyrenees reveals that the ring fracture pattern related to the karstic collapse of the diapir crest may vary significantly depending on the rates of dissolution and salt flow, and the rheology of the overburden. The salt diapir has well-developed concentric faults related to salt dissolution subsidence throughout the Quaternary. Roof strata accommodate subsidence by a combination of downward sagging and brittle collapse leading to the development of a ring monocline that is broken by 5 to 20 m throw conjugated normal faults and a 40 m throw, 9.5-km-long and 200-m-wide keystone graben. The salt diapir top has >100-m-long sinkholes that coalesce to form hollows >70 m deep. Up to 3-km-long radial grabens with a 70 to 90 m vertical throw overprint concentric-ring faulting and displace Quaternary deposits demonstrating active salt flow and diapir rise. Radial faults are linked with salt-withdrawal faults of the Andia Fault Zone (AFZ). Salt flow from the AFZ into the Salinas de Oro salt diapir causes brittle gravitational extension of limestone strata leading to a sequence of grabens and Quaternary faults >10 km long and several hundred meters deep.

Ionic Current Rectification in a Conical Nanopore: Influences of Electroosmotic Flow and Type of Salt

The influence of electroosmotic flow (EOF) on the behavior of the ionic current rectification (ICR) in a conical nanopore connecting two large identical reservoirs is investigated. In particular, the effect of the type of salt is examined by considering LiCl, NaCl, and KCl. We show that neglecting EOF is capable of influencing ICR both quantitatively and qualitatively. If EOF is neglected, the rectification factor at each level of the applied electric potential bias across the two reservoirs for the case of LiCl (KCl) is always the largest (smallest). However, if EOF is taken into account, the relative magnitude of the rectification factors for various salts depends upon the level of the applied electric potential bias. This behavior is consistent with the experimental observation in the literature and can be explained by the degree of ion enrichment/depletion in a nanopore.