Using the potential of energy losses in gas pressure reduction stations for producing power and fresh water

doi:10.1016/j.desal.2020.114763

Desalination

Volume 497, 1 January 2021, 114763

https://doi.org/10.1016/j.desal.2020.114763 Get rights and content

Highlights

•
The feasibility of producing power and water is investigated in the city gate station.
•
The heater exhaust heat and high pressure gas stream as energy sources was considered.
•
The optimal operating conditions are obtained based on using energy and eco-exergy analysis using Pareto method.
•
The TVC inlet temperature and pressure as well as the first effect outlet temperature are optimized.
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The produced water and total cost of the proposed system are calculated for different capacity of stations.

Abstract

Due to their different capacities, power and heat production possibility, distribution in high populated areas, city gas stations (CGS) are a good option to meet the energy for water desalination. This study is aimed at using the waste energy of the city gas stations for producing power and fresh water. Accordingly, the exhaust heat of CGS heater is employed in multi-effect desalination thermal vapor compression (MED-TVC) system and power is produced using the turboexpander. A comprehensive model is developed to evaluate the performance of three CGS with different capacities of 2.5, 5 and 11.5 based on energy-exergy-exergoeconomic analysis. In addition, the effective parameters like Thermal Vapor Compressor (TVC) inlet temperature and pressure and first effect outlet temperature are optimized by means of the multi-objective Pareto method. Since the operating conditions of the stations are different, eventually Results show that considering the drinking water production, cost, exergy efficiency and gain output ratio (GOR), MED-TVC system with two effects employed in 11.5 kg/s CGS is the optimal system. It is also found that the optimal TVC inlet temperature and pressure as well as the first effect outlet temperature are equal to 108 °C, 70 kPa and 81 °C, respectively.

Section snippets

Abbreviations

A (m²)

area

APC

absorption power cycle

brine water

c ($/kW)

cost per exergy unit

\dot{C}

($/s)

cost rate

combine cycle

CGS

city gate station

CHP

combine heat and power

CRF

capital recovery factor

disalination water

electric line

exergy rate

Exh

exhaust

exergoeconomic factor

GOR

gain output ration

intrest rate

LHV (kJ/kg)

lower heating value

MED

multi effect desalination

motive steam

natural gas

NPV

payback period

power

PEM

proton exchange membrane

relative cost differenc

rankin cycle

steam

T (°C)

temperature

TVC

System description

In CGSs, the pressure of gas is reduced to 1/4 of its initial pressure by means of pressure reducing valve. The common problem in CGSs is severe decrease in gas temperature during pressure reduction process which leads to freezing of gas and interruption of the gas flow. Water bath heaters are used to solve this problem. However, they waste most of the inlet energy through exhaust flow. Additionally, a significant amount of energy is also wasted during natural gas pressure reduction process

Design method

In this study, MED-TVC system is coupled with three CGSs with gas flow rates of 2.5, 5 and 11.5 kg/s as conventional CGS capacities in Iran. The proposed combined system is modelled based on mass conservation, energy conservation, exergy balance and exergoeconomic balance by means of EES. Then, the effective parameters in MED-TVC system are optimized using multi-objective optimization and optimal CGS capacity for employing desalination system is selected. The following assumptions are used in

Thermodynamic modeling

The proposed system in this study is composed of MED-TVC and CGS equipped with turboexpander. As described, the exhaust heat of the heater is used to produce steam to operate the MED-TVC. In this section, at first, the modeling of the turboexpander is presented and the heater's inlet and outlet temperatures are calculated. Then, based on the energy required for pre-heating of the natural gas, the heater exhaust heat is computed and MED-TVC is modelled.

Results and discussion

In this section, the modeling results for employing the proposed system in CGS with different capacities of 2.5, 5 and 11.5 kg/s is presented. Then, the optimization procedure is performed on effective parameters of the system such as TVC inlet temperature and pressure and first effect outlet temperature. Finally, the optimal CGS capacity for integrating the desalination system is selected through the optimization.

Conclusions

In this study, due to the high water shortage, the feasibility of employing the exhaust heat of CGS with different capacities in MED-TVC system as an integrated system is investigated. The proposed system is modelled based on energy-exergy-exergoeconomic analysis. Furthermore, the optimization process is performed on effective parameters such as TVC inlet temperature and pressure and first effect outlet temperature are optimized by means of multi-objective Pareto solution and TOPSIS method. The

CRediT authorship contribution statement

Mahdi Deymi-Dashtebayaz: Conceptualization, Methodology, Formal analysis, Supervision.

Daryoush Dadpour: Software, Data curation, Formal analysis, Writing- Original draft preparation.

Javad Khadem: Investigation. Writing- Reviewing and Editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (42)

A.N. Mabrouk et al.
Technoeconomic study of a novel integrated thermal MSF-MED desalination technology
Desalination
(Sep. 2015)
Sh. Yazdani et al.
Comprehensive comparison on the ecological performance and environmental sustainability of three energy storage systems employed for a wind farm by using an emergy analysis
Energy Convers. Manag.
(2019)
Kim Choon Ng et al.
Recent developments in thermally-driven seawater desalination: energy efficiency improvement by hybridization of the MED and AD cycles
Desalination
(Jan. 2015)
J. Nihill et al.
Investigating the prospects of water desalination using a thermal water pump coupled with reverse osmosis membrane
Desalination
(Nov. 2018)
Muhammad Wakil Shahzad et al.
Energy-water-environment nexus underpinning future desalination sustainability
Desalination
(Jul 2017)
Hyuk Soo Son et al.
Pilot studies on synergetic impacts of energy utilization in hybrid desalination system: multi-effect distillation and adsorption cycle (MED-AD)
Desalination
(March 2020)
A. Al-Karaghouli et al.
Energy consumption and water production cost of conventional and renewable-energy-powered desalination processes
Renew. Sust. Energ. Rev.
(Aug. 2013)
A. Tamburini et al.
CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: high efficiency assessment for different design options under the current legislative EU framework
Energy
(Nov. 2016)
A. Rezaei et al.
Economic evaluation of Qeshm island MED-desalination plant coupling with different energy sources including fossils and nuclear power plants
Desalination
(Nov. 2017)
M.A. Sharaf Eldean et al.
A novel study of using oil refinery plants waste gases for thermal desalination and electric power generation: energy, exergy & cost evaluations
Appl. Energy
(Jun. 2017)

S.R. Hosseini et al.

Cost optimization of a combined power and water desalination plant with exergetic, environment and reliability consideration

Desalination

(Jan. 2012)

B. Ortega-Delgado et al.

Operational analysis of the coupling between a multi-effect distillation unit with thermal vapor compression and a Rankine cycle power block using variable nozzle thermocompressors

Appl. Energy

(Oct. 2017)

M.T. Mazini et al.

Dynamic modeling of multi-effect desalination with thermal vapor compressor plant

Desalination

(Nov. 2014)

Muhammad Wakil Shahzad et al.

An experimental investigation on MEDAD hybrid desalination cycle

Appl. Energy

(Jun 2015)

Muhammad Wakil Shahzad et al.

A multi evaporator desalination system operated with thermocline energy for future sustainability

Desalination

(Jun. 2018)

K.M. Bataineh

Multi-effect desalination plant combined with thermal compressor driven by steam generated by solar energy

Desalination

(May 2016)

F.N. Alasfour et al.

Thermal analysis of ME-TVC + MEE desalination systems

Desalination

(Apr. 2005)

M. Deymi-dashtebayaz et al.

Multi objective optimization of using the surplus low pressure steam from natural gas refinery in the thermal desalination process

J. Clean. Prod.

(Nov. 2019)

I. Janghorban Esfahani et al.

Modeling and genetic algorithm-based multi-objective optimization of the MED-TVC desalination system

Desalination

(Apr. 2012)

M.A. Sharaf et al.

Exergy and thermo-economic analyses of a combined solar organic cycle with multi effect distillation (MED) desalination process

Desalination

(May 2011)

M.A. Jamil et al.

Effect of feed flow arrangement and number of evaporators on the performance of multi-effect mechanical vapor compression desalination systems

Desalination

(Mar. 2018)

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Using the potential of energy losses in gas pressure reduction stations for producing power and fresh water

Highlights

Abstract

Section snippets

Abbreviations

System description

Design method

Thermodynamic modeling

Results and discussion

Conclusions

CRediT authorship contribution statement

Declaration of competing interest

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Energy Convers. Manag.

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Renew. Sust. Energ. Rev.

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J. Clean. Prod.

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