Lithium Chloride In Water Research Articles

Energy analysis of lithium bromide-water and lithium chloride-water based single effect vapour absorption refrigeration system: A comparison study

The present research article discussed; a detailed energy analysis for single effect vapour absorption refrigeration system using two working pairs Lithium bromide-water (LiBr–H 2 O) and Lithium chloride-water (LiCl–H 2 O) under different operating climate conditions. The performance parameters of the both the systems like coefficient of performance (COP), solution concentration, heat load at different components and optimum operating generator temperature have been investigated for both the systems. The capacity of the systems is fixed as 300 kW. The present work has been simulated for the evaporator temperatures of 5, 10 and 15 °C while the condenser temperatures of 25, 30 and 35 °C. Result shows, the maximum COP of LiBr–H 2 O system comes out to be in the range of 0.741–0.902, whereas in case of LiCl–H 2 O system it is to be in the range of 0.809–0.926. The minimum load at the generator for LiBr–H 2 O system is 382.573 kW, while for LiCl–H 2 O as 370.787 kW. Comparison shows that the LiCl–H 2 O system has better COP and minimum generator load as compared to LiBr–H 2 O system, especially at lower evaporator temperatures. The optimum operating generator temperature has been observed 54.56 °C for LiBr–H 2 O system and 56.25 °C for LiCl–H 2 O system.

Energy and Exergy Analysis of an Absorption and Mechanical System for a Dehumidification Unit in a Gelatin Factory

In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liquid desiccant system in an industrial gelatin conveyor dryer. The working fluid is a binary solution of lithium chloride (LiCl) in water. Dry air is used in order to decrease the amount of liquid in the gelatin. Therefore, the environmental air must have its absolute humidity reduced from about 12 g/kg to the project target, which is 5 g/kg. The process is a cycle using an absorption desiccant unit (LiCl in water), where the weak solution absorbs water vapor from the air. In the regenerator, condensation of the solution (desorption) from the moist air occurs. As a result, the steam consumption of the desorber and electrical power used for the vapor compression chiller (with ammonia, NH, as working fluid) are the primary sources of cost for the factory. To improve the plant’s energy and exergy behaviors, the process is evaluated using a mathematical model of the system processes. In addition, we evaluate the substitution of the vapor compression chiller by an absorption unit (lithium bromide (LiBr) in water). The performance indicators of the compression vapor systems showed the best results. Even when using the condenser’s energy to pre-heat the solution, the installed system proved to be more effective.

Performance Enhancement in LiCl–H2O and LiBr–H2O Absorption Cooling Systems Through an Advanced Exergy Analysis

This research study compares the thermodynamic performance of 10[Formula: see text]kW lithium chloride–water (LiCl–H2O) and lithium bromide–water (LiBr–H2O) absorption cooling systems through first and second law of thermodynamics. Further, the exergy degradations happening in each component have been split into unavoidable and avoidable exergy degradations as well as endogenous and exogenous exergy degradations through advanced exergy analysis. Pressure–temperature–concentration ([Formula: see text]–[Formula: see text]–[Formula: see text] diagrams are drafted to clarify the real, ideal, and unavoidable cycles for LiCl–H2O and LiBr–H2O absorption cycles. Moreover, this paper exhibits the sensitivity of various system components towards the generator, condenser, and absorber temperature for both pairs. Energetic observation proves that LiCl–H2O pair is 10% more efficient as compared to LiBr–H2O pair. Exergetically, LiBr–H2O cycle struggles with additional (nearly 13.45%) exergy destruction than LiCl–H2O cycle. The major contribution (around 70% to 80%) of irreversibility comes from the generator and absorber. Comprehensively, the parametric partitions of irreversibility rate in each component provide broad indications to prioritize the system components for enhancements.

Theoretical and Experimental lnvestigation on the Absorption Refrigeration Systems.(Dept.M)

In the present work, a theoretical model is developed to study the single-effect absorption refrigeration cycle from the thermodynamic point of view for lithium bromide-water pair und lithium chloride-water pair. The effect of different operating (temperatures on the coefficient of performance (COP) and low ratio (FR) (the weak solution mass flow rate with reference to the refrigerant 113ss low rule) are investigated. This generation process in cui absorption refrigeration cycle using lithium chloride-Water solution is the working pair is experimentally studied. From the theoretical study, it is found that the COP increases an within increases in generation temperature until a certain value, then it decreases slightly. The COP increases with an increase in evaporator temperature and decrease in condenser or absorber temperatures. The rule of decrease in FR is higher at higher condenser and absorber temperatures. The data obtained for lithium bromide-water pair is compared with lithium chloride-water pair it is found that the COP is higher for lithium chloride-water pair than that for lithium bromide-water pair and the FR is lower for the lithium chloride-water pair. The experimental results are plotted to illustrate the effect of generation temperature on the coefficient of performance. low ratio and output variables. Also, the effect of the inlet solution temperature, inlet solution low rate and generator pressure on the generated water Vapor is discussed. A minimum generation temperature must be chosen to boil oil this water from the lithium chloride-water solution. from the measured data a maximum coefficient of performance of 0.812 can be obtained for it single stage system.

A COMPARATIVE STUDY ABOUT LITHIUM BROMIDE-WATER AND LITHIUM CHLORIDE-WATER SOLUTIONS IN PUMPLESS ABSORPTION SOLAR COOLING SYSTEMS IN IRAQI CIRCUMSTANCES

A comparative study between two solutions which they usually work as a working pairs in pumpless absorption cooling system is achieved analytically with aid of ESS (Engineering Equation Solver) 9.43 software. The pump in this system is replaced by a vertical pipe (lift tube) to ensure the pressure difference between the condenser and the evaporator. These working pairs are Lithium Bromide-Water and Lithium Chloride-Water. The study intends Iraqi summer weather as an ambient circumstance. A thermodynamics model is designed to find the energy and Energy loss in each of system components. By solving the thermodynamic model, and assuming the same generator, absorber, condenser and evaporator temperatures in each case. It’s found that the system coefficient of performance is relatively the same while the probability of agglomeration in case of Lithium Bromide-Water system is higher because of the large salt concentration. It’s concluded that the Lithium Chloride-Water is most suitable in Iraqi circumstances in spite of high values of total energy loss which is obtained in case of Lithium Chloride-Water system if it is compared with the energy loss value in case of Lithium Bromide-Water system.

Energy and Exergy Analysis of LiBr-aq and LiCl-aq Liquid Desiccant Dehumidification System

In this study, energy and exergy analysis of experimental results obtained from a dehumidification system using LiBr-aq (lithium bromide-water) and LiCl-aq (lithium chloridewater) as desiccant was made. In dehumidifier and regenerator columns polycarbonate sheets, which have not been used before, were used as packing material to increase contact area in purposed liquid desiccant dehumidification system. In the analysis, variation of electrical coefficient of performance and exergy efficiency with airflow rate for different solution mass flow rates were investigated. Because of investigation, maximum values of electrical coefficient of performance and exergy efficiency were calculated approximately as 2.8 and 18%, respectively.

Integrated theoretical model for performance evaluation of flat-sheet membrane-based absorptive dehumidification module using lithium chloride-water solution

This paper presents an integrated theoretical model to evaluate the performance of a flat-sheet membrane-based absorptive dehumidification module with different flow arrangements (i.e., cocurrent, countercurrent, and cross-flow configurations) using an aqueous lithium chloride desiccant. The model results showed good consistency with experimental data, with a maximum relative error of approximately 7%. The performance of the flat-sheet dehumidification module was evaluated for various air and solution channel heights ranging from 1 to 5 mm at a constant Reynolds number in both channels, in terms of sensible, latent, and total effectivenesses. The sensible effectiveness increased with a decrease in the air channel height and an increase in the solution channel height; in particular, the effect of the solution channel height was more pronounced in the cocurrent flow configuration. In addition, the latent effectiveness increased with a decrease in both channel heights. Thus, there was a trade-off between the effects of the solution channel height on the sensible and latent effectivenesses; consequently, the effect of the solution channel height on the total effectiveness was mitigated. The total effectiveness was observed to decrease in the order of countercurrent, cross-, and cocurrent flow configurations; here, its value in the countercurrent flow configuration was approximately 0.788 when both channel heights were 1 mm.

Performance analysis of a solar heat driven organic Rankine cycle and absorption cooling system

In this study, a solar based organic Rankine cycle and an absorption cooling system is proposed for Jodhpur, Rajasthan, India. Energy and exergy analyses are done to evaluate system performance during February, May, August and November. In the organic Rankine cycle, five different working fluids (Isopentane, R245ca, Neopentane, R245fa and Butane) are considered for comparison. The maximum net power (1.74 MW) was obtained with R245fa during February with a simultaneous cooling of 4.82 MW produced from the water-lithium chloride based absorption cooling system. The power output, although was the minimum (1.62 MW), but maximum cooling (6.00 MW) was obtained from the cooling system with Neopentane as ORC working fluid. The overall system energy output (power and cooling together) and efficiency were however more with Neopentane than with R245fa. For all the ORC working fluids, maximum power and cooling was obtained during February while the lowest during August. In an additional case considering all the year months, it was found that actually it is July in which the power and cooling output are minimum. In the cooling system, with fixed evaporator (5 °C) and equal condenser and absorber temperatures (31 °C), slightly more cooling was obtained with relatively high COP, low irreversibility and high exergy efficiency at 63 °C generator temperature compared to those at 66 °C. From exergy analysis, it was found that maximum irreversibility occurs in the parabolic trough solar collector, followed by total irreversibility of the organic Rankine cycle and the absorption cooling system.

Effect of Ejector Location in Absorption Refrigeration Cycles Using Different Binary Working Fluids

In this study, three novel modifications of ejector-absorption refrigeration cycles (E-ARC) are investigated to evaluate the effect of ejector location on cycle performances. In the first modification (triple pressure level absorption refrigeration cycle TPL-ARC), the ejector is located at the evaporator inlet. In the second modification (double ejector absorption refrigeration cycle DE-ARC), two ejectors are used; one is located at the evaporator inlet and the other at the absorber inlet, which are coupled to each other. In the third modification (low pressure condenser absorption refrigeration cycle LPC-ARC), the steam ejector is installed at the downstream of the vapor generator discharging line. An additional flow splitter is integrated to the steam ejector outlet and part of the vapor is extracted and returned to the absorber at a pressure equal to the diffuser pressure. Effect of ejector location on thermodynamic performances are evaluated considering three different working fluids, namely ammonia–water solution (NH3–H2O), lithium bromide-water solution (H2O–LiBr), and lithium chloride–water solution (H2O–LiCl). Even though all three configurations enhance the conventional absorption refrigeration cycle (C-ARC) performances, the LPC-ARCs work at high temperature and improve the cycle performance. The TPL-ARC proves to improve the COP and exergy efficiency up to 9.14% and 7.61%, respectively, presenting the highest thermodynamic performance enhancement and lowest operating temperature.

Comments on “Multi-objective optimization of double effect series and parallel flow water–lithium chloride and water–lithium bromide absorption refrigeration systems” by Konwar et al. [Energy Convers. Manage. 180 (2019) 425–441

The paper, “Multi-objective optimization of double effect series and parallel flow water–lithium chloride and water–lithium bromide absorption refrigeration systems” by Konwar et al. [Energy Convers. Manage. 180 (2019) 425–441], presented a genetic algorithm based multi-objective optimization tool along with its applications, which are found highly erroneous and conveying wrong information. Such issues are explained here in detail in order to prevent readers from misleading.

Reply to Comment on Multi-objective optimization of double effect series and parallel flow water-lithium chloride and water-lithium bromide absorption refrigeration systems“ [Energy Convers. Manage. 2019;180:425–441] by Konwar et al.

Reply to Comment on Multi-objective optimization of double effect series and parallel flow water-lithium chloride and water-lithium bromide absorption refrigeration systems“ [Energy Convers. Manage. 2019;180:425–441] by Konwar et al.

Multi-objective optimization of double effect series and parallel flow water–lithium chloride and water–lithium bromide absorption refrigeration systems

In this study, multi-objective optimization of the series and parallel flow type double effect absorption refrigeration systems is presented. Genetic algorithm is used to find the optimal solutions and the Pareto-optimal fronts. First, a thermodynamic model is developed to simulate the double effect series and parallel flow configurations with water–lithium chloride and water–lithium bromide solution pairs. Energy and exergy balances are applied to evaluate coefficient of performance, exergy efficiency and irreversible losses in the system components separately for the two working fluid pairs. Next, optimization is done considering coefficient of performance, exergy efficiency and the total system irreversibility rate as objective functions. The low and high pressure generator temperatures are taken as decision variables in the series configuration while for the parallel system; additionally the distribution ratio is also taken as a decision parameter. The optimization is done for four different cases of fixed evaporator, absorber and condenser temperatures. For each case, the optimal decision parameter values are determined for both the water–lithium chloride and water–lithium bromide operated double effect series and parallel configurations. The optimized coefficients of performance were found slightly lower for water–lithium chloride. Contrary to this, the optimal exergy efficiencies were more and the total system irreversibility were less for water–lithium chloride. Further, the optimal performances of the double effect water–lithium chloride systems were obtained comparatively at lower generator temperatures than those of the water–lithium bromide systems.

Energy and exergy analysis of advanced absorption power cycles using salt-water mixtures as working fluids

In advanced absorption power cycles (AAPCs), a jet ejector is installed at the absorber inlet and serves for two main functions; it assists pressure recovery, and improves the mixing between the weak solution and the vapour coming from the turbine. These effects enhance the absorption of the vapour into the solution resulting in a better performing power cycle. The influence of the jet ejector on the energy and exergy efficiencies of an AAPC is evaluated, and the thermodynamic efficiencies of the AAPC are compared to those of conventional absorption power cycle (APCS) using three different working fluids, namely ammonia-water solution (NH3-H2O), lithium bromide-water solution (LiBr-H2O), and lithium chloride-water solution (LiCl-H2O). Five cases are studied that represents the improvement in the AAPCS efficiencies as results of jet ejector integration in the cycle. Results of parametric studies depict that LiCl-H2O exhibits the highest energy and exergy efficiencies used in AAPC.

Quantitative analysis of the hydration of lithium salts in water using multivariate curve resolution of near-infrared spectra

The hydration process of lithium iodide, lithium bromide, lithium chloride and lithium nitrate in water was analyzed quantitatively by applying multivariate curve resolution alternating least squares (MCR-ALS) to their near infrared spectra recorded between 850 nm and 1100 nm. The experiments were carried out using solutions with a salt mass fraction between 0% and 72% for lithium bromide, between 0% and 67% for lithium nitrate and between 0% and 62% for lithium chloride and lithium iodide at 323.15 K, 333.15 K, 343.15 K and 353.15 K, respectively. Three factors were determined for lithium bromide and lithium iodide and two factors for the lithium chloride and lithium nitrate by singular value decomposition (SVD) of their spectral data matrices. These factors are associated with various chemical environments in which there are aqueous clusters containing the ions of the salts and non-coordinated water molecules. Spectra and concentration profiles of non-coordinated water and cluster aqueous were retrieved by MCR-ALS. The amount of water involved in the process of hydration of the various salts was quantified. The results show that the water absorption capacity increases in the following order LiI < LiBr < LiNO3 < LiCl. The salt concentration at which there is no free water in the medium was calculated at each one of the temperatures considered. The values ranged between 62.6 and 65.1% for LiBr, 45.5–48.3% for LiCl, 60.4–61.2% for LiI and 60.3–63.7% for LiNO3. These values are an initial approach to determining the concentration as from which crystal formation is favored.

Lithium and boron isotope effects in extraction systems

Extraction characteristics of chloroform-water system were studied using lithium chloride and tetrafluoroborate as extracted salts and benzo-15-crown-5 as an extractant. Single-stage isotope separation factors (α) for lithium isotopes at different concentrations of lithium chloride in water were measured and multiplication of isotope effect was made by extraction chromatography. The magnitude of α for Li6-Li7 pair was 1.036 for chloride and 1.030 for tetrafluoroborate. Light lithium isotope is concentrated in organic phase. Extraction chromatography experiments were conducted in 1,1,7-trihydrododecafluoroheptanol-water extraction system for boron isotope separation using boric acid as extracted compound and trioctylamine as an extractant as well as in chloroform-water system with lithium tetrafluoroborate as extracted compound and benzo-15-crown-5 as an extractant. The upper assessment of α values for B10-B11 boron isotopes was found to be not larger than 1.005 for both systems.

Neutron scattering studies of the hydration structure of Li+.

New results derived from the experimental method of neutron diffraction and isotopic substitution (NDIS) are presented for the hydration structure of the lithium cation (Li(+)) in aqueous solutions of lithium chloride in heavy water (D2O) at concentrations of 6, 3, and 1 m and at 1.5 m lithium sulfate. By introducing new and more-accurate data reduction procedures than in our earlier studies (I. Howell and G. W. Neilson, J. Phys: Condens. Matter, 1996, 8, 4455-4463), we find, in the first hydration shell of Li(+), ∼4.3(2) water molecules at 6 m, 4.9(3) at 3 m, 4.8(3) at 1 m in the LiCl solutions, and 5.0(3) water molecules in the case of Li2SO4 solution. The general form of the first hydration shell is similar in all four solutions, with the correlations for Li-O and Li-D sited at 1.96 (0.02) Å and 2.58 (0.02) Å, respectively. The results resemble those presented in 1996, in terms of ion-water distances and local coordination, but the hydration number is significantly lower for the case at 1 m than the 6.5 (1.0) given at that time. Thus, experimental and theoretical results now agree that lithium is hydrated by a small number of water molecules (4-5) in the nearest coordination shell.

Reentrant condensation of lysozyme: Implications for studying dynamics of lysozyme in aqueous solutions of lithium chloride.

Recent studies have outlined the use of eutectic solutions of lithium chloride in water to study microscopic dynamics of lysozyme in an aqueous solvent that is remarkably similar to pure water in many respects, yet allows experiments over a wide temperature range without solvent crystallization. The eutectic point in a (H2O)R(LiCl) system corresponds to R ≈ 7.3, and it is of interest to investigate whether less-concentrated aqueous solutions of LiCl could be used in low-temperature studies of a solvated protein. We have investigated a range of concentrations of lysozyme and LiCl in aqueous solutions to identify systems that do not show phase separation and avoid solvent crystallization on cooling down. Compared to the lysozyme concentration in solution, the concentration of LiCl in the aqueous solvent plays the major role in determining systems suitable for low-temperature studies. We have observed interesting and rich phase behavior reminiscent of reentrant condensation of proteins.

An Experimental Study of Simultaneous Heat and Mass Transfer in Falling Film and Bubble Mode Absorbers

In this study we investigated the lithium chloride–water vapor absorption process for falling film and bubble column absorbers under the same operating conditions. The results obtained were used to analyze the transfer process during the absorption of water vapor in an aqueous solution of LiCL. The performance of both absorbers was investigated for various solution flow rates and various gas flow rates. The results showed that bubble absorber is superior to the falling film mode for mass and heat transfer. Increasing the solution flow rates rarely affected the mass transfer but improved the heat transfer. As the gas flow rate increased, channels were formed in the film, which decreased the mass transfer in the falling film. But in the bubble column, increasing the gas flow rate influenced the boundary layer and therefore enhanced mass transfer. To evaluate the performance of mass and heat transfer, experimental results obtained were plotted as Nusselt and Sherwood numbers versus operating conditions for falling film and bubble modes, respectively, and the following empirical correlations were proposed: • For falling film mode: • For bubble mode:

The development of an NMR spectrometer for the precision determination of the ratio of the resonance frequencies of nuclei

A nuclear magnetic resonance (NMR) spectrometer for determining the resonance frequencies of various nuclei at a magnetic field induction of 2.142 T is described. The spectrometer enables the NMR frequency of a nucleus to be recorded simultaneously with the frequency of the signal from a comparison nucleus and enables the magnetic field to be stabilized using the NMR signal from a third nucleus. The ratios of the resonance frequencies of protons and of the lithium-7 nuclei: F(H 2 O)F( 7 Li) = 2.573041789(3) are obtained for a solution of lithium chloride in water, and also the ratio for protons and deuterons of an isotopic solution of water: F(H 2 O)/F(D 2 O) = 6.514399603(2). Methods of determining the systematic errors which occur when there are quadratic gradients of the magnetic field in the sample when processing spectral numerical data matrices are discussed.

Chronic Lithium Impairs Skin Tolerance to Ischemia in Random-Pattern Skin Flap of Rats

Despite its apparent anti-apoptotic effect, lithium impairs endothelium-dependent vasorelaxation in various tissues. In this study, we assessed the effect of lithium treatment on ischemic skin flap survival and its interaction with nitric oxide pathway. Seventy-six male Sprague-Dawley rats were randomly assigned into 13 groups. For skin flap surgery, dorsal skin flap measuring 8 × 2 cm was elevated on the midline. After local injections (if needed), the cranial pedicle was cut and flap was sutured back. Flap survival was assessed after 7 d. Animals in the chronic lithium group received lithium chloride in tap water for 4 wk preoperatively and 7 d postoperatively. Acute lithium groups received 3 nmol, 10 nmol and 3 μmol/flap lithium locally. In another experiment, interaction with nitric oxide synthase inhibitor L-NAME as well as nitric oxide precursor L-arginine was studied, and the effect of ischemic preconditioning on skin flap survival in lithium treated rats was investigated. Chronic lithium group had mean flap survival value of 32.6% ± 5.2% (mean ± SD), which was significantly lower than normal subjects (52.7% ± 6.1%, P < 0.001), while acute local lithium treatment had no effect. In chronic lithium group, systemic L-NAME (10 mg/kg, 30 min before flap elevation) failed to significantly decrease the survival, while sub-effective systemic L-arginine (100 mg/kg) and ischemic preconditioning significantly increased flap survival (P < 0.001 and P < 0.01, respectively). We conclude that long-term lithium treatment impairs the skin tolerance to ischemia in rats, which seems to be nitric oxide mediated. This effect is prevented by ischemic preconditioning or L-arginine treatment. The results suggest that skin-involving interventions should be applied more cautiously in patients who are on lithium treatment.