Experimental adsorption water desalination system utilizing activated clay for low grade heat source applications

doi:10.1016/j.est.2021.103219

Journal of Energy Storage

Volume 43, November 2021, 103219

https://doi.org/10.1016/j.est.2021.103219 Get rights and content

Highlights

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Adsorption isotherms and kinetics of acid activated montmorillonite are studied.
•
Fitting the experimental results with famous equations is presented.
•
Building and testing adsorption desalination system is conducted.
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SDWP, SCP and COP are 4.4 m³/ton, 110 W/kg and are 0.41 at a driving temperature less than 100 °C.

Abstract

In the present study, benefits of utilizing acid activated montmorillonite as a proposed new adsorbent material in adsorption desalination-cooling systems- have been experimentally expressed. Montmorillonite is a natural clay mineral which is composed mainly of alumina-silicate. Effect of acid activation on montmorillonite has been illustrated using infra-red spectra analysis. Adsorption characteristics (isotherm and kinetic) of acid activated montmorillonite (with 2 mole of hydrochloric acid/water vapor pair have been expressed. Isotherms results have been fitted with Dubinin-Astakhov and Sun-Chakraborty models. An experimental adsorption desalination-cooling test rig has been erected to explore the adsorption desalination-cooling systems performance with montmorillonite /water pair and axial finned tube adsorption bed design. The experimental results indicates that the daily water production is about 4.4 m³/ton of montmorillonite, its specific cooling power is 110 W/kg and the coefficient of performance is 0.41 at a driving temperature less than 100 °C. Solar energy can drive adequately the investigated system. The experiment also illustrates that the ADCS is very significant in removing all forms of salts, as proven by the weighty drop of the total dissolved salt, TDS (measured by TDS analyzer), level from approximately 40,000 ppm in seawater intake to less than 30 ppm.

Introduction

Energy, fresh-water, and environment are inter-related features that infuse all our activities in the earth [1], [2], [3]. Utilizing renewable energy in desalination system has high interest from researchers. Adsorption desalination-cooling systems (ADCS) have been becoming a promising alternative to traditional cooling and desalination systems avoiding their common problems such as high energy consumption and global warming [4]. Unlike the traditional units, a sorption system utilizes low-grade heat from renewable sources or industrial wastes to produce freshwater and cooling effect [5], [6], [7]. These systems depend on the adsorbent materials characteristics represented in adsorption isotherms (Ad_iso) and adsorption kinetics (Ad_kin).

Disadvantage of the ADCS is its quite low performance [8]. Accordingly, the main concern of researchers in this field is to enhance the performance in several ways, one of which is to find new materials. Ferroaluminophosphate/water was presented as an adsorption pair for ADCS by Kim et al. [4]. Characteristics of adsorption were experimentally tested. The results reported that the equilibrium water uptake was five times higher than silica gel at 30 °C adsorption and 70 °C desorption. Kusgens et al. Metal-organic frameworks (MOF) was presented as new adsorption materials [9,10]. Table 1 illustrates a summary of a number of studies concerned about adsorption characteristics of different adsorption material with water vapor adsorbate.

Performance of ADCS had been investigated in many studies. Youssef et al. [11] investigated experimentally the performance of ADCS employing CPO-27(Ni). The results exhibited that in case of T_cond (from 5 to 30 °C) and T_eva (10 °C), specific daily water production (SDWP) and specific cooling power (SCP) were 3.2–7.5 m³/ton and 100–200 W/kg, respectively. Kim et al. [17] presented a new scheme for time-schedule of ADCS. The result illustrated that ADCS performance depended on the value of initial time lag. Elsayed et al. [22] present a mathematical analysis of the performance of ADCS employing (CPO-27(Ni), MIL-101(Cr) and aluminum-fumarate adsorption materials. The SDWP was 4.3 m³/ton for (CPO-27(Ni), 6 m³/ton for aluminum-fumarate and 11 m³/ton for MIL-101(Cr).

Montmorillonite is a natural clay mineral which is mostly composed of aluminosilicate. Egyptian clay found in the northern part of the Western Desert has the highest percentage of montmorillonite (60–90%) with the lowest impurities [23]. Abdel-Motelib et al. [24] analyzed a commercial clay product (smecta) produced by Amriya for Pharmaceutical Industries, Alexandria, Egypt. The XRD of smecta indicates that pure montmorillonite is the main constituent. Therefore, smecta is considered as a sample of montmorillonite in the present experiments. Acid activation of clays with HCl is described in many studies [25], [26], [27], [28]. It was concluded that the optimum concentration of HCl activation is 2 mole HCl for the highest surface area. Higher surface area is lead to higher adsorption capacity as reported in Ref. [29].

The present study investigates experimentally adsorption characteristics of water vapor onto acid activated montmorillonite for ADCS. A theoretical model has been developed to the investigated ADCS performance with utilizing AAM. An experimental adsorption desalination-cooling (ADC) test rig has been constructed to study the ADCS performance with montmorillonite/water vapor pair and axial finned tube adsorption bed design.

Section snippets

Material

Infra-red spectra, IR, is an adequate characterization technique for acid activated clays because it is very sensitive to clay structure modifications [30]. IR spectrum are obtained using Fourier transform-IR-spectroscopy (Alpha Bruker, Germany) at Sohag University with 400–4000 cm⁻¹ spectral range via Attenuated total reflection, ATR.

Montmorillonite is activated by hydrochloric acid, HCl for different concentrations (0.5 to 2 mole of HCl) for 12 h. IR spectrum, IR, for montmorillonite and

Adsorption isotherms

In this section test procedure and adsorption models are presented. The AAM is dried and regenerated at 120 °C for 8 h under vacuum pressure of 50 Pa. Water vapor is charged to the dosing chamber from evaporator at a certain pressure. After stable initial temperature and pressure readings the valve (V2) is opened to start adsorption process. The dosing chamber pressure is reduced steadily. During adsorption process, temperature of adsorber increases and decreases again to its initial value.

Adsorption kinetics

In this section test procedure and the Linear Driving Force model, LDF, for montmorillonite (with average grain size 1 × 10⁻³ mm) are presented. The steps of Ad_kin is the same steps of Ad_isosection (3) but each run steps take 30 s to explore the time influence on the adsorption rate. The vapor relative pressure is taken from 0.65 to 0.7 at each step.

The behavior uptake of semi-infinite medium can be expressed as [38]: $\frac{C}{C_{o}} = \frac{2 A}{V} \sqrt{\frac{D_{s} t}{π}}$ where $D_{S}$ is given by [39]; $D_{S} = D_{s o} e x p (\frac{- E_{a}}{R T})$ The values $(E_{a})$ and (D_so)

Results for adsorption characteristics (Ad_iso and ad_kin)

Fig. 3 illustrates Ad_isoof montmorillonite/water vapor pair for different concentrations at 25 °C. Also, the figure specifies that the activated montmorillonite with 2 mole HCl has a maximum adsorption capacity (C_o) of about 0.52 kg_{water vapor}/kg_AAM at 25 °C while, the raw montmorillonite has only 0.30 kg_{water vapor}/kg. The acid activation rise the adsorption capacity for montmorillonite by about 73%. This is because the acid attacked the layers to replace the exchangeable montmorillonite

Mathematical model

Fig. 7a and 7b shows modes of single-bed ADCS filled with AAM (2 mole HCl) as an adsorption material. Operation procedure, ADCS basics and model assumptions can be found in the literature [43], [44], [45].

The mass balance of ADCS is given by; $\frac{d M_{s w, e v a p}}{d t} = θ m_{s w, i n}^{.} - γ m_{b}^{.} - n (\frac{d C_{a d s}}{d t}) M_{M o n t}$ $M_{s w, e v a p} \frac{d X_{s w, e v a p}}{d t} = θ X_{s w, i n} m_{s w, i n}^{.} - γ X_{s w, i n} m_{b}^{.} - n . X_{D} (\frac{d C_{a d s}}{d t}) M_{M o n t}$

Where, θ, γ and n values are stated in [41].

The components energy balances are given by Eqs. (14–16) [46,47]; ${[{(M c_{p})}_{c u} + {(M c_{p})}_{M o n t} + M_{M o n t} {c_{p}}_{v} C]}^{b e d} \frac{d T_{b e d}}{d t} = M_{M o n}$

Experiments of adsorption desalination system

This section expresses the experimental test rig of ADCS. The test rig is based on a single-bed cycle, which has the simplest adsorption system structure. Fig. 8 shows the preset experimental test rig for ADCS. The test rig comprises three main components; adsorption bed, evaporator and condenser. The adsorption bed consists of a steel shell (600 mm length and 150 mm diameter) which contains three axial finned tubes heat exchangers (Hex) packed with adsorbent material. The adsorption bed

Temperature profiles

The performance of ADCS can be assessed by observing the inlet and outlet heat transfer fluids temperatures variance. Fig. 11 displays a comparison between the simulated and experimental heat transfer fluids temperatures variance for the each system components as well as the adsorption beds temperatures at the previous mentioned operating conditions. The comparison is performed on the ADCS operating over three cycles.

As it can be observed, the simulated model calculates well the different

Conclusions

Adsorption characteristics (Ad_isoand Ad_kin) of AAM/water vapor pair have been expressed. The maximum adsorption capacity is about 0.52 kg/kg of AAM. A new proposed single-bed ADCS driven by low grade heat source is designed, built, and tested as an innovative axial finned tube $Hex$ packed with 2.65 kg acid activated montmorillonite as adsorbent material. The experimental results exhibited that, at 85 °C T_hwi that can be achieved from low grade heat source such as solar energy or waste heat, the

CRediT authorship contribution statement

Ehab S. Ali: Experimental work, Software, Formal analysis, Data curation, Writing - original draft, Visualization. Ahmed A. Askalany: Conceptualization, Methodology, Data curation, Formal analysis, Writing - review & editing, Supervision. K. Harby: Supervision, Writing - original draft, Writing - review & editing. Mohamed Refaat Diab: Formal analysis, Data curation, Writing - original draft, Writing - review & editing. Bahgat.R.M. Hussein: Formal analysis, Data curation. Ahmed S. Alsaman:

Declaration of Competing Interest

The authors whose names are listed immediately below certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in

References (56)

A.A. Askalany et al.
A new approach integration of ejector within adsorption desalination cycle reaching COP higher than one
Sustain. Energy Technol. Assessm.
(2020)
M.M. Aboelmaaref et al.
Hybrid solar desalination systems driven by parabolic trough and parabolic dish CSP technologies: technology categorization, thermodynamic performance and economical assessment
Energy Convers. Manag.
(2020)
K. Harby et al.
A novel combined reverse osmosis and hybrid absorption desalination-cooling system to increase overall water recovery and energy efficiency
J. Clean. Prod.
(2021)
Y.-.D. Kim et al.
Adsorption characteristics of water vapor on ferroaluminophosphate for desalination cycle
Desalination
(2014)
E.S. Ali et al.
A daily freshwater production of 50 m3/ton of silica gel using an adsorption-ejector combination powered by low-grade heat
J. Clean. Prod.
(2021)
E.S. Ali et al.
Recycling brine water of reverse osmosis desalination system employing adsorption desalination system: a theoretical study
Desalination
(2017)
E.S. Ali et al.
Solar-powered ejector-based adsorption desalination system integrated with a humidification-dehumidification system
Energy Convers. Manag.
(2021)
A.A. Askalany et al.
A novel cycle for adsorption desalination system with two stages-ejector for higher water production and efficiency
Desalination
(2020)
A. Askalany et al.
Experimental optimization of the cycle time and switching time of a metal organic framework adsorption desalination cycle
Energy Convers. Manag.
(2021)
R.H. Mohammed et al.
Metal-organic frameworks in cooling and water desalination: synthesis and application
Renew. Sustain. Energy Rev.
(2021)

P.G. Youssef et al.

Experimental investigation of adsorption water desalination/cooling system using CPO-27Ni MOF

Desalination

(2017)

A.S. Alsaman et al.

Performance evaluation of a solar-driven adsorption desalination-cooling system

Energy

(2017)

M.J. Goldsworthy

Measurements of water vapour sorption isotherms for RD silica gel, AQSOA-Z01, AQSOA-Z02, AQSOA-Z05 and CECA zeolite 3A

Microporous Mesoporous Mater.

(2014)

K.C. Ng et al.

Experimental investigation of silica gel-water adsorption isotherm characteristics

Appl. Therm. Eng.

(2001)

B. Sun et al.

Thermodynamic frameworks of adsorption kinetics modeling: dynamic water uptakes on silica gel for adsorption cooling applications

Energy

(2015)

A. Allouhi et al.

Optimal working pairs for solar adsorption cooling applications

Energy

(2015)

Y.Z. Lu et al.

Adsorption cold storage system with zeoliteewater working pair used for locomotive air conditioning

Energy Convers. Manag.

(2003)

P.G. Youssef et al.

Performance analysis of four bed adsorption water desalination/refrigeration system, comparison of AQSOA-Z02 to silica-gel

Desalination

(2015)

A. Abdel-Motelib et al.

Suitability of a miocene bentonite from North Western desert of Egypt for pharmaceutical use

Appl. Clay Sci.

(2011)

K. Thu et al.

Thermo-physical properties of silica gel for adsorption desalination cycle

Appl. Therm. Eng.

(2013)

F. Kooli et al.

Chemical and thermal properties of organoclays derived fromhighly stable bentonite in sulfuric acid

Appl. Clay Sci.

(2013)

C.G. Fonseca et al.

Investigation of the initial stages of the montmorillonite acid-activation process using DFT calculations

Appl. Clay Sci.

(2018)

E.S. Ali et al.

Adsorption desalination-cooling system employing copper sulfate driven by low grade heat sources

Appl. Therm. Eng.

(2018)

E.S. Ali et al.

Weather effect on a solar powered hybrid adsorption desalination-cooling system: a Case Study of Egypt's Climate

Appl. Therm. Eng.

(2017)

E.S. Ali et al.

Solar-powered ejector-based adsorption desalination system integrated with a humidification-dehumidification system

Energy Convers. Manag.

(2021)

K.C. Ng et al.

Adsorption desalination: an emerging low-cost thermal desalination method

Desalination

(2013)

M.H. Elbassoussi et al.

Thermoeconomic assessment of an adsorption cooling/desalination cycle coupled with a water-heated humidification-dehumidification desalination unit

Energy Convers. Manag.

(2020)

X. Li et al.

A review on development of adsorption cooling-Novel beds and advanced cycles: review Article

Energy Convers. Manag.

(2015)

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Experimental adsorption water desalination system utilizing activated clay for low grade heat source applications

Highlights

Abstract

Introduction

Section snippets

Material

Adsorption isotherms

Adsorption kinetics

Results for adsorption characteristics (Adiso and adkin)

Mathematical model

Experiments of adsorption desalination system

Temperature profiles

Conclusions

CRediT authorship contribution statement

Declaration of Competing Interest

Sustain. Energy Technol. Assessm.

Energy Convers. Manag.

J. Clean. Prod.

Desalination

J. Clean. Prod.

Desalination

Energy Convers. Manag.

Desalination

Energy Convers. Manag.

Renew. Sustain. Energy Rev.

Desalination

Energy

Microporous Mesoporous Mater.

Appl. Therm. Eng.

Energy

Energy

Energy Convers. Manag.

Desalination

Appl. Clay Sci.

Appl. Therm. Eng.

Appl. Clay Sci.

Appl. Clay Sci.

Appl. Therm. Eng.

Appl. Therm. Eng.

Energy Convers. Manag.

Desalination

Energy Convers. Manag.

Energy Convers. Manag.

Results for adsorption characteristics (Ad_iso and ad_kin)