Energy Efficiency of a PRO Process

Energy strength of a professional ProcessIntroductionThe global qualification use up is expeditiously increasing due to rapidly expanding population and their improved alert standard. Although fossil fuels be mostly contributing to fulfilling this demand, the consumption has already exceeded the condenser of sustainable button production (Efraty, 2013)(Yip et al., 2011). It is often claimed that we bring forth enough militia of coal, gas, and oil man the real scenario is dissimilar. Environment scientists reported that vim reserves atomic number 18 decreasing with prison term, which would be diminished within few decades (Figure 1). The liveliness of these reserves would be elongated slightly if new reservoirs fag end be identified. Disc all overing new wells is becoming harder day-by-day and if it is discovered, the amounts of fuels would be significantly lower than the ones that lease been found in the past1.Figure 1 The trends of global fossil fuels reserves1Th e raise cleverness demand and limited reserves of fossil fuels have prompt to re searchers for exploring alternatives sources of renewable efficacy. Researchers have already discovered dissimilar sources of life force while wind, solar, tidal and bio good deal have been used for sustainable vim production (Straub, Deshmukh, Elimelech, 2015). However, costly equipment and high school introduction cost coupled with the uneven distribution of energy throughout the year have prevented them from being used widely (Sharif, Merdaw, Aryafar, Nicoll, 2014). newly, a newly emerging source of bonnie energy called osmotic supply has attracted much attention to the researcher, which derived from common salt gradients found worldwide where ii sources of wet with different salinities be available next to individually new(prenominal) (Y. C. Kim Elimelech, 2013). The approachability and predictability of osmotic spring are much greater than the intermittent renewables bid wi nd and solar.Salinity gradient is the difference in salt minginess mingled with two dissolvers. The enormous amount of energy released from the mix of two firmness of purposes of different salinities and this amount rises for higher concentration difference between the solutions. venial investigations have been done for the mixing of freshwater system and saltwater, which reported that 2.6 MW energy produced for a flow of 1m3/s freshwater when mixed with seawater (Veerman, Saakes, Metz, Harmsen, 2009). some(prenominal) technologies are being used to harvest osmotic fountain such as reverse electrodialysis ( ablaze(p)) (Achilli Childress, 2010) (Yip Elimelech, 2012), pressure mentally retarded osmosis ( professional) (Altaee Sharif, 2015)(Thorsen Holt, 2009)(Norman S., 2016), capacitive mixing (CAPMIX) (Reuters News Agency, n.d.), and hydrogel mixing (J. Kim, Jeong, Park, Shon, Kim, 2015). Among the technologies, RED and master are more advanced and demonstrated at pilot scale and both converts chemical authorisation to useful cypher by the controlled mixing of two solutions of different salt concentration (Achilli Childress, 2010)(Yip Elimelech, 2014).RED is a membrane-establish technology, which is pay offn by the Nernst potential, a manifestation of chemical potential difference. It uses a mound of altering ion ex spay membranes that selectively allows ion permeation crossways the membranes. The net ion res publica of flux across the membranes is converted directly to electric real (Norman S., 2016)(Pattle, 1954). The process is very efficient for advocate times but economically inefficient. The cost prices of available RED membrane is out of range, and recent investigations have showed that the price has to be reduced a hundred times to understand the technology affordable (Post et al., 2010). The development of such type of membranes is very time consuming and difficult to achieve (Turek Bandura, 2007). Also, The operati ons of the RED process is decomposable and highly sensitive to the process parameters, which requires elaborate control system (Altaee Sharif, 2015). as well reverse electrodialysis, PRO is also a membrane-based technology, but the difference is, PRO uses a single(a) salt-rejecting semipermeable membrane instead of a stack of ion-exchange membranes. It utilizes the saltiness gradient as osmotic mogul difference to drive the water permeation across the membrane from low salinity persist solution to high salinity draw solution. The expanding muckle of draw solution flows through a hydro-turbine that generates useful mechanical and electrical works 1819. The visualise and operations of PRO are much simpler, and it does not depend excessively much on operational parameters except operating pressure of membrane at draw solution side. The recent analysis shows that PRO can achieve both greater efficiencies and designer densities than RED and other alert technologies 14.Most of the PRO studies have been focused on the mixing of seawater and freshwater, but this mixing scheme has been found to be unfeasible due to the lower condition densities. Researchers agree that more study is indispensable to treasure the feasibility of processes based on streams of higher salinity. One of such processes is the energy recovery from desalination units by taking advantages of the mixing of dis charged saltwater and seawater. Another process is the mixing of seawater with high salinity produced water from oil and natural gas exploration. However, the main problems of these process are concentraion polarisation and salt leakage, which limit the PRO performance by reducing the operate force across the membrane. Before investigations to establish a viable PRO process for the large-scale operation, have focused on developing high-performance membrane and setting up suitable conditions to increase the energy yields.Several thermodynamic properties are necessary to set up appropriate conditions to measure out the performance of PRO process. The first of them is the Gibbs free energy of mixing because it provides the swiftness limit to the shaft power that is possible to recover from a mixing process, which occurs at constant temperature and pressure. Another property is osmotic pressure, which in necessary to establish operating pressure at different parts of the plant. Entropies and enthalpies are privationful to evaluate the mechanical power of the rotary equipment involved. This work demonstrates a thermodynamic fabric to evaluate all of them in order to maximize the power recovery from PRO process. The Q-electrolattice equation of (EOS), which extends a lattice-based fluid perplex for electrolyte solutions, is adopted. The model also includes recently developed equations for PRO that considers concentration polarization reverse salt permeability, and membrane fouling to predict water and salt flux across the membrane.In addition, most PRO models are based on solutions of Na+ and Cl ions only, whereas, in practice, saline water contains other ions in addition to these two. This work reports simulations of PRO processes that consider the presence of quintuple ions in solutions (Na+, K+, Mg2+, Ca2+, Cl- and SO42-). The existing model mostly uses different platforms to foreshadow osmotic power, power density, and flux across the membrane (e.g. OLI-software is used to calculate osmotic power and another program for flux and power density), that increase the gap of getting erroneous value because all these are inter-dependent. On the other hand, this model constantly and accurately determines all of them by a single program.Initial investigations have been done for freshwater+sewater and seawater+brine systems with single-stage PRO configuration. The predicted osmotic pressure, water flux across the membrane and recoveries of mechanical power are in very good agreement with experimental books info. This set of result s suggests that the Q-electrolattice EOS is a suitable model for the calculation of thermodynamic properties needed to assess the performance of PRO plants. Now, it is planning this model for very high salinity solutions with quaternate stage configurations. A techno-economic analysis will be done for the feasibility study of PRO process implementing at industrial scale.Aim and Objectives The aim of this work is to develop a thermoynamic model based on Q-electrolattice equation of state for PRO process, and implement it to predict different thermodynamic properties in order to caltulate water and salt flux across the membrane and power densities. The various objectives associated with this aim are delineated at a lower place weapon Q-electrolattice equation of state for the solutions of multiple salts to calculate osmotic power and verify the results with literature experimental data.Implement recently developed mass and salt flux equations, which considered concentration polariza tion, reverse salt flux and fouling of membrane.Implement basic thermodynamic relations for PRO units to determine entropies and enethalpies accurately.Develop the model for freshwater-seawater system with single stage configuration and extended it for higher salinity system with multiple stage configuration.Implement the cost equations to determine the dandy cost for installation of the PRO units.Literature ReviewQ-elctrolattice equation of stateThe elctrolattice equation of state (EOS) was developed using the equal methodology presented by Myers et al. (Myers, Sandler, Wood, 2002), based on the Helmholtz energy approach. The residual Helmholtz energy at a given temperature and volume is calculated by the addition various contributions on a hypothetical path. These contributions consist of ion-solvent and solvent-solvent interaction over the short range, solvation effects, and ion-ion interactions over the long range.The total process is shared into four steps along a thermody namic path( a. Zuber et al., 2013)Step-1 It is assumed that a reference mixture consisting of charged ions and molecules is in a hypothetical ideal gas state at temperature T and volume V. In the first step, the charges on all ions are removed. The change in Helmholtz energy is accounted by the Born equation for ions in a vacuum, Step-2 The short-range attractive dispersion and repulsive forces due to excluded volume are turned on. Also, self-association of solvent molecules can occur. The MTC EOS is used to calculate the change in Helmholtz energy for this step,.Step-3 The ions are recharged. The change in Helmholtz energy is accounted for by the Born equation for ions in a dielectric solvent, Step-4 The long-range interactions among the ions in solution are taken into account using the Mean globose Approximation (MSA), and the corresponding change in the molar Helmholtz free energy is denoted by .The residual Helmholtz energy for forming an electrolyte solution is thus given bywh ereinSo,To model electrostatic interactions, a single salt electrolyte solution is divided into five regions three for solvent (D, , and ), one for cation (C) and one for anion (A).To determine the MTC Helmholtz energy change, the model uses seven parameters to represent pure solvents. The model assumes that the region-region interaction (except for -) are dispersion interactions, which are temperature dependent. In addition, it also assumed that the short-range interactions between the and region are zero. This is summarized belowIn addition, hydrogen bonding interactions are taken to be temperature independent.It is assumed that the interaction between the solvent and each charged species is equal short-range interaction between opposite ions and same charge are neglected altogether. This is summarized belowThe Q-electrolattice equation of state is an extended version of the EOS in which an explicit MSA term is used which allows for unequal noggin diameters (which are ultimatel y regressed using experimental data).PRO principlesBasic theoryReferenceAchilli, A., Childress, A. E. (2010). Pressure retarded osmosis From the tidy sum of Sidney Loeb to the first prototype installation Review. Desalination, 261(3), 205-211. https//doi.org/10.1016/j.desal.2010.06.017Altaee, A., Sharif, A. (2015). Pressure retarded osmosis advancement in the process applications for power generation and desalination. In Desalination (Vol. 356, pp. 31-46). Elsevier B.V. https//doi.org/10.1016/j.desal.2014.09.028Efraty, A. (2013). Pressure retarded osmosis in closed electrical circuit a new technology for clean power generation without need of energy recovery. Desalination and piddle Treatment, 51(40-42), 7420-7430. https//doi.org/10.1080/19443994.2013.793499Kim, J., Jeong, K., Park, M. J., Shon, H. K., Kim, J. H. (2015). Recent advances in osmotic energy generation via pressure-retarded osmosis (PRO) A review. Energies, 8(10), 11821-11845. https//doi.org/10.3390/en81011821Ki m, Y. C., Elimelech, M. (2013). electromotive force of osmotic power generation by pressure retarded osmosis using seawater as feed solution Analysis and experiments. Journal of Membrane Science, 429, 330-337. https//doi.org/10.1016/j.memsci.2012.11.039Myers, J. a., Sandler, S. I., Wood, R. H. (2002). An equality of State for Electrolyte Solutions Covering round-eyed Ranges of Temperature, Pressure, and Composition. Industrial Engineering Chemistry Research, 41(13), 3282-3297. https//doi.org/10.1021/ie011016gNorman, S. L., S., R. (2016). osmotic role Plants Author ( s ) Sidney Loeb and Richard S . Norman. Science, 189(4203), 654-655.Pattle, R. E. (1954). Production of Electric Power by mixing snotty-nosed and Salt Water in the hydroelectric Pile. Nature.Post, J. W., Goeting, C. H., Valk, J., Goinga, S., Veerman, J., Hamelers, H. V. M., Hack, P. J. F. M. (2010). Towards implementation of reverse electrodialysis for power generation from salinity gradients. Desalination and Water Treatment, 16(1-3), 182-193. https//doi.org/10.5004/dwt.2010.1093Reuters News Agency. (n.d.). Norway Opens Worlds First Osmotic Power Plant. Retrieved January 17, 2013, from http//www.reuters.com/article/2009/11/24/us-nor way-osmotic-idUSTRE5A-N20Q20091124Sharif, A., Merdaw, A., Aryafar, M., Nicoll, P. (2014). Theoretical and Experimental Investigations of the Potential of Osmotic Energy for Power Production. In Membranes (Vol. 4, pp. 447-468). https//doi.org/10.3390/membranes4030447Straub, A. P., Deshmukh, A., Elimelech, M. (2015). Pressure-retarded osmosis for power generation from salinity gradients is it viable? Energy Environ. Sci. https//doi.org/10.1039/C5EE02985FThorsen, T., Holt, T. (2009). The potential for power production from salinity gradients by pressure retarded osmosis, 335, 103-110. https//doi.org/10.1016/j.memsci.2009.03.003Turek, M., Bandura, B. (2007). Renewable energy by reverse electrodialysis. Desalination, 205(1-3), 67-74. https//doi.org/10.1016/j.d esal.2006.04.041Veerman, J., Saakes, M., Metz, S. J., Harmsen, G. J. (2009). stamp out electrodialysis Performance of a stack with 50 cells on the mixing of sea and river water. Journal of Membrane Science, 327(1-2), 136-144. https//doi.org/10.1016/j.memsci.2008.11.015Yip, N. Y., Elimelech, M. (2012). Thermodynamic and energy might analysis of power generation from natural salinity gradients by pressure retarded osmosis. environmental Science and engineering science, 46(9), 5230-5239. https//doi.org/10.1021/es300060mYip, N. Y., Elimelech, M. (2014). Comparison of Energy force and Power Density in Pressure Retarded Osmosis and Reverse Electrodialysis (7th Editio).Yip, N. Y., Tiraferri, A., Phillip, W. A., Schiffman, J. D., Hoover, L. A., Kim, Y. C., Elimelech, M. (2011). Thin-film building complex pressure retarded osmosis membranes for sustainable power generation from salinity gradients_. environmental Science and Technology, 45(10), 4360-4369. https//doi.org/10.1021/es1043 25zZuber, A., Figueiredo, R., Castier, M. (2014). politic figure Equilibria Thermodynamic properties of aqueous solutions of single and multiple salts using the Q-electrolattice equation of state. Fluid Phase Equilibria, 362, 268-280.Zuber, a., Checoni, R. F., Mathew, R., Santos, J. P. L., Tavares, F. W., Castier, M. (2013). Thermodynamic Properties of 11 Salt Aqueous Solutions with the Electrolattice comparison of State. Oil Gas Science and Technology Revue dIFP Energies Nouvelles, 68(2), 255-270. https//doi.org/10.2516/ogst/2012088This work focuses on developing a thermodynamic model to analyse the energy efficiency of a PRO process in order to maximize the power recovery. It uses Q-electrolattice equation of state (developed for mixtures with mixed electrolytes) that can accurately determine various thermodynamics properties such as vapor pressure, osmotic coefficient, osmotic pressure, entropy and heat content at different conditions of concentration temperature and pres sure (A. Zuber, Figueiredo, Castier, 2014). The model is implemented to XSEOS outperform tool to calculate these thermodynamic properties. Moreover, it does not have any limitations to calculate osmotic pressure and other properties for very high concentraion solution containing multiple salts at extreme high temperation and pressure conditions.Achilli, A., Childress, A. E. (2010). Pressure retarded osmosis From the vision of Sidney Loeb to the first prototype installation Review. Desalination, 261(3), 205-211. https//doi.org/10.1016/j.desal.2010.06.017Altaee, A., Sharif, A. (2015). Pressure retarded osmosis advancement in the process applications for power generation and desalination. In Desalination (Vol. 356, pp. 31-46). Elsevier B.V. https//doi.org/10.1016/j.desal.2014.09.028Efraty, A. (2013). Pressure retarded osmosis in closed circuit a new technology for clean power generation without need of energy recovery. Desalination and Water Treatment, 51(40-42), 7420-7430. https/ /doi.org/10.1080/19443994.2013.793499Kim, J., Jeong, K., Park, M. J., Shon, H. K., Kim, J. H. (2015). Recent advances in osmotic energy generation via pressure-retarded osmosis (PRO) A review. Energies, 8(10), 11821-11845. https//doi.org/10.3390/en81011821Kim, Y. C., Elimelech, M. (2013). Potential of osmotic power generation by pressure retarded osmosis using seawater as feed solution Analysis and experiments. Journal of Membrane Science, 429, 330-337. https//doi.org/10.1016/j.memsci.2012.11.039Myers, J. a., Sandler, S. I., Wood, R. H. (2002). An Equation of State for Electrolyte Solutions Covering Wide Ranges of Temperature, Pressure, and Composition. Industrial Engineering Chemistry Research, 41(13), 3282-3297. https//doi.org/10.1021/ie011016gNorman, S. L., S., R. (2016). Osmotic Power Plants Author ( s ) Sidney Loeb and Richard S . Norman. Science, 189(4203), 654-655.Pattle, R. E. (1954). Production of Electric Power by mixing Fresh and Salt Water in the Hydroelectric Pile. Nature.Post, J. W., Goeting, C. H., Valk, J., Goinga, S., Veerman, J., Hamelers, H. V. M., Hack, P. J. F. M. (2010). Towards implementation of reverse electrodialysis for power generation from salinity gradients. Desalination and Water Treatment, 16(1-3), 182-193. https//doi.org/10.5004/dwt.2010.1093Reuters News Agency. (n.d.). Norway Opens Worlds First Osmotic Power Plant. Retrieved January 17, 2013, from http//www.reuters.com/article/2009/11/24/us-nor way-osmotic-idUSTRE5A-N20Q20091124Sharif, A., Merdaw, A., Aryafar, M., Nicoll, P. (2014). Theoretical and Experimental Investigations of the Potential of Osmotic Energy for Power Production. In Membranes (Vol. 4, pp. 447-468). https//doi.org/10.3390/membranes4030447Straub, A. P., Deshmukh, A., Elimelech, M. (2015). Pressure-retarded osmosis for power generation from salinity gradients is it viable? Energy Environ. Sci. https//doi.org/10.1039/C5EE02985FThorsen, T., Holt, T. (2009). The potential for power production from salinity gradients by pressure retarded osmosis, 335, 103-110. https//doi.org/10.1016/j.memsci.2009.03.003Turek, M., Bandura, B. (2007). Renewable energy by reverse electrodialysis. Desalination, 205(1-3), 67-74. https//doi.org/10.1016/j.desal.2006.04.041Veerman, J., Saakes, M., Metz, S. J., Harmsen, G. J. (2009). Reverse electrodialysis Performance of a stack with 50 cells on the mixing of sea and river water. Journal of Membrane Science, 327(1-2), 136-144. https//doi.org/10.1016/j.memsci.2008.11.015Yip, N. Y., Elimelech, M. (2012). Thermodynamic and energy efficiency analysis of power generation from natural salinity gradients by pressure retarded osmosis. Environmental Science and Technology, 46(9), 5230-5239. https//doi.org/10.1021/es300060mYip, N. Y., Elimelech, M. (2014). Comparison of Energy Efficiency and Power Density in Pressure Retarded Osmosis and Reverse Electrodialysis (7th Editio).Yip, N. Y., Tiraferri, A., Phillip, W. A., Schiffman, J. D., Hoover, L. A., Kim, Y. C., Eli melech, M. (2011). Thin-film composite pressure retarded osmosis membranes for sustainable power generation from salinity gradients_. Environmental Science and Technology, 45(10), 4360-4369. https//doi.org/10.1021/es104325zZuber, A., Figueiredo, R., Castier, M. (2014). Fluid Phase Equilibria Thermodynamic properties of aqueous solutions of single and multiple salts using the Q-electrolattice equation of state. Fluid Phase Equilibria, 362, 268-280.Zuber, a., Checoni, R. F., Mathew, R., Santos, J. P. L., Tavares, F. W., Castier, M. (2013). Thermodynamic Properties of 11 Salt Aqueous Solutions with the Electrolattice Equation of State. Oil Gas Science and Technology Revue dIFP Energies Nouvelles, 68(2), 255-270. https//doi.org/10.2516/ogst/20120881 All fossil fuel reserve and consumption data from CIA World Factbook