scholarly journals Single-Solution-Based Vortex Search Strategy for Optimal Design of Offshore and Onshore Natural Gas Liquefaction Processes

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1732 ◽  
Author(s):  
Muhammad Abdul Qyyum ◽  
Muhammad Yasin ◽  
Alam Nawaz ◽  
Tianbiao He ◽  
Wahid Ali ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Optimal Design ◽  
Natural Gas ◽  
Point Of View ◽  
Base Case ◽  
Aspen Hysys ◽  
Design Variables ◽  
Single Solution ◽  
Natural Gas Liquefaction

Propane-Precooled Mixed Refrigerant (C3MR) and Single Mixed Refrigerant (SMR) processes are considered as optimal choices for onshore and offshore natural gas liquefaction, respectively. However, from thermodynamics point of view, these processes are still far away from their maximum achievable energy efficiency due to nonoptimal execution of the design variables. Therefore, Liquefied Natural Gas (LNG) production is considered as one of the energy-intensive cryogenic industries. In this context, this study examines a single-solution-based Vortex Search (VS) approach to find the optimal design variables corresponding to minimal energy consumption for LNG processes, i.e., C3MR and SMR. The LNG processes are simulated using Aspen Hysys and then linked with VS algorithm, which is coded in MATLAB. The results indicated that the SMR process is a potential process for offshore sites that can liquefy natural gas with 16.1% less energy consumption compared with the published base case. Whereas, for onshore LNG production, the energy consumption for the C3MR process is reduced up to 27.8% when compared with the previously published base case. The optimal designs of the SMR and C3MR processes are also found via distinctive well-established optimization approaches (i.e., genetic algorithm and particle swarm optimization) and their performance is compared with that of the VS methodology. The authors believe this work will greatly help the process engineers overcome the challenges relating to the energy efficiency of LNG industry, as well as other mixed refrigerant-based cryogenic processes.

scholarly journals Performance Enhancement of Nitrogen Dual Expander and Single Mixed Refrigerant LNG Processes Using Jaya Optimization Approach

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3278
Author(s):  
Ali Rehman ◽  
Muhammad Abdul Qyyum ◽  
Ashfaq Ahmad ◽  
Saad Nawaz ◽  
Moonyong Lee ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Natural Gas ◽  
Design Optimization ◽  
Lower Energy ◽  
Operating Costs ◽  
Small Scale ◽  
Exergy Destruction ◽  
Capital Costs ◽  
Design Variables

The nitrogen (N2) expander and single mixed refrigerant (SMR) liquefaction processes are recognized as the most favorable options to produce liquefied natural gas (LNG) at small-scale and offshore sites. These processes have a simple and compact design that make them efficient with respect to their capital costs. Nevertheless, huge operating costs, mainly due to their lower energy efficiency, remains an ongoing issue. Utilization of design variables having non-optimal values is the primary cause for the lower energy efficiency; which, in turn, leads to exergy destruction (i.e., entropy generation), and ultimately the overall energy consumption is increased. The optimal execution of the design variables of LNG processes can be obtained through effective design optimization. However, the complex and highly non-linear interactions between design variables (refrigerant flowrates and operating pressures) and objective function (overall energy consumption) make the design optimization a difficult and challenging task. In this context, this study examines a new optimization algorithm, named “Jaya”, to reduce the operating costs of nitrogen dual expander and SMR LNG processes. The Jaya approach is an algorithm-specific parameter-less optimization methodology. It was found that by using the Jaya algorithm, the energy efficiency of the SMR process and nitrogen dual expander natural gas (NG) liquefaction process can be enhanced up to 14.3% and 11.6%, respectively, as compared to their respective base cases. Using the Jaya approach, significant improved results were observed even compared to other previously used optimization approaches for design optimization. Results of conventional exergy analysis revealed that the exergy destruction of SMR and N2 dual expander process can be reduced by 17.4% and 14%, respectively. Moreover, economic analysis identified the 13.3% and 11.6% relative operating costs savings for SMR and N2 dual expander LNG processes, respectively.

scholarly journals Energy Efficiency Improvement of Debutanizer Column, for NGL Separation

2021 ◽  
Vol 12 (9) ◽  
pp. 255-260
Author(s):  
Ahmed Ould Brahim ◽  
◽  
Souad Abderafi
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Natural Gas ◽  
Co2 Emission ◽  
Reflux Ratio ◽  
Gas Combustion ◽  
Economic Point ◽  
Head Pressure ◽  
Optimal Values ◽  
Natural Gas Combustion

Compared to other petroleum, the natural gas combustion remains the cleanest and the one showing less CO2 emission. These reasons make the natural gas combustion one of the important issues to study. The separation of NGL is energy intensive. This operation is performed through a series of column including the debutanizer column. The present work is devoted to optimize the energy consumption at the level of the debutanizer column. The response surface technique and deploying a central composite numerical design is followed makes use of available data from a refinery. Using a multiple linear regressions, the optimization method leads us to three reliable models. Each of the three models takes as input the reflux ratio and the head pressure in order to predict the condenser heat duty, the reboiler heat duty and the purity of the produced butane. Suggested mathematical models were validated and their reliability was assessed via a set of statistical analyses. The optimization aims to simultaneously minimize the energy consumption of the condenser and reboiler, and maximize the purity of the ejected Butane. This optimization step allowed us to define the optimal values of reflux ratio and head pressure, with desirability function equal to 99 %. Under the determined optimal values, operating energy and cost of the industrial process were reduced by 38 % and 37 %, respectively, and besides, a high purity of butane was noticed reaching 99 %. From an economic point of view, separation NGL with optimal values of pressure and reflux ratio, may contribute to a decrease of CO2 emission and increases the energy efficiency.

scholarly journals Towards zero carbon dioxide concentration in sweet natural gas product from amine sweetening plant

2021 ◽  
Vol 1195 (1) ◽  
pp. 012038
Author(s):  
Abdulqader Bin Sahl ◽  
Tharindu Siyambalapitiya ◽  
Ahmed Mahmoud ◽  
Jaka Sunarso
Keyword(s):  
Natural Gas ◽  
Carbon Dioxide Concentration ◽  
Circulation Rate ◽  
Base Case ◽  
Step Method ◽  
Aspen Hysys ◽  
Process Modification ◽  
Zero Carbon ◽  
Plant Data ◽  
Simulation Results

Abstract This work presents a two-step method to reduce CO2 concentration of sweet natural gas product from amine sweetening plant via amine blending (Step 1) followed by minor process modification (Step 2). In Step 1, an industrial natural gas sweetening plant was simulated using Aspen HYSYS and the simulation results were validated against the plant data. Afterwards, different blends of methyl diethanolamine and monoethanolamine (MDEA-MEA) and methyl diethanolamine and diethanolamine (MDEA-DEA) were investigated. Then the optimum amine blend of 28 wt.% MDEA and 10 wt.% MEA was reported. The optimum amine blend achieved a significant reduction in CO2 concentration of sweet natural gas of 99.9% compared to the base case (plant data). In Step 2, two types of amine stream splits, i.e., lean amine stream split and semi-lean amine stream split were studied. The study covered split stream amount, absorber recycle stage, and regenerator stage withdrawal. Both types of stream splits attained a significant reduction in CO2 concentration of sweet natural gas product and amine circulation rate compared to Step 1. However, the semi-lean amine stream split was superior to lean amine split with 69.1% and 63.6% reduction in CO2 concentration of sweet natural gas and lean amine circulation rate, respectively.

scholarly journals NGL Recovery Enhancement for GUPCO Trans Gulf Gas Plant by using New Applicable Technique

2019 ◽  
Vol 8 (3) ◽  
pp. 3723-3731
Keyword(s):  
Natural Gas ◽  
Point Of View ◽  
Operating Conditions ◽  
Great Decrease ◽  
Process Safety ◽  
Economic Point ◽  
Simple Modification ◽  
Plant Behavior ◽  
Aspen Hysys ◽  
Plant Equipment

It is known that the price of natural gas liquids (NGL) is higher than that of natural gas from which it is derived, so more modifications needed for existing plants to derive more NGL is economically accepted point of view. The main objective of the present work is to present the method applied on Trans gulf (T/G) gas plant to overcome its performance decrease happened after the plant feed gases becoming leaner than its design margin and hence it led to a great decrease in the plant NGL recovery. This achieved by introducing a new simple modification to the existing process scheme obtained by using a condensate stream to enrich the reflux of the de-ethanizer tower so more recovery is obtained. In order to accomplish that goal, some changes in the existing process operating conditions were needed. A simulation is used in this study to examine the existing and the introduced modification utilizing ASPEN-HYSYS software version 8.4 using Peng-Robinson equation of state (EOS). The simulation of the existing plant results in a better understanding of the plant behavior in the different iterations to reach the maximum benefits. The plant after suffering from low butane recovery from its feed gas and which considered as a figure to the plant efficiency, it increased by this method from 38 % to reach 86-90 % butane recovery and its LPG production increased by 170% to be ≈ 122 tonne/day instead of ≈ 44 tonne/day while only losing ≈ 16 tonne/day of condensate production. An optimization to the new method is done in this paper so that it doesn't intercept with the existing plant equipment performance for the process safety triggers. Also, the last section of the study describes the economic point of view and the return on investment (ROI) how it was paid back only in 7 days. This modification can be taken as a guideline for both new and existing LPG plants which use only propane refrigeration systems for LPG recovery to increase their profits with the lowest cost possible.

scholarly journals Appraisal of CO2 Emission in Tunisia's Industrial Sector: A Dynamic Vector Autoregression Method

2021 ◽  
Author(s):  
Besma Talbi ◽  
Muhammad Ramzan ◽  
Hafiz Arslan Iqbal ◽  
Buhari Doğan
Keyword(s):  
Economic Growth ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Natural Gas ◽  
Environmental Degradation ◽  
Large Scale ◽  
Dominant Role ◽  
Industrial Sector ◽  
Kuznets Curve ◽  
Additional Energy

Abstract The World is confronted with a slew of environmental issues, one of which is how to attenuate the detrimental impacts of CO2 emissions-induced climate change. The ever-increasing use of energy is eroding natural resources to the point that our economic future may be jeopardized. The Tunisian economic growth indicates the excellent performance in the industrial sector as the minimum required input for these developments necessitates additional energy consumption, resulting in increased CO2 emissions and environmental degradation. This study explores the role of energy efficiency, urbanization, economic growth, and natural gas energy usage in the industrial sector on carbon dioxide (CO2) emissions of Tunisia. The research mainly employs the Vector Autoregressive Model (VAR) to examine the factors driving the evolution of CO2 emissions through the industrial sector from 2000 to 2018. The findings assess that natural gas as an energy source and efficiency are crucial for reducing CO2 emissions. The study has shown the existence of the Environmental Kuznets Curve (EKC), which demonstrates that economic development in Tunisia has an inverted U-shape connection with CO2 emissions. The results indicate that energy consumption and GDP significantly affect CO2 emissions due to large-scale population movements and industrial structure transformation. In contrast, energy efficiency plays a dominant role in decreasing CO2 emissions. The article will assist economic decision-makers and related authorities in formulating an appropriate energy policy for the industrial sector based on the study's outcomes to protect environmental degradation in the long run by reducing carbon emissions.

Offshore Adaptability of the CO2 Pre-Cooling Dual Nitrogen Expander Natural Gas Liquefaction Process

2012 ◽  
Vol 608-609 ◽  
pp. 1369-1374 ◽  
Author(s):  
Jian Lu Zhu ◽  
Yu Xing Li ◽  
Wu Chang Wang ◽  
Huan Huan Sheng ◽  
Yong Hao Liu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Large Scale ◽  
Point Of View ◽  
Gas Temperature ◽  
Natural Gas Liquefaction ◽  
Liquefaction Process

CO2 pre-cooling dual nitrogen expander liquefaction process was proposed for the LNG-FPSO unit and compared with propane pre-cooling dual nitrogen expander process and mixed refrigerant pre-cooling nitrogen expander process by simulation. Gas property sensitivity of the process was analyzed from the thermodynamic point of view. And offshore adaptability of the process was evaluated. The results show that the process will be suitable for mid to large-scale LNG production in severe sea condition. And it will be not sensitive to the changes of gas temperature, pressure and composition.

scholarly journals Energy saving optimal design and control of electromagnetic brake on passenger car

2019 ◽  
Vol 10 (1) ◽  
pp. 57-70
Author(s):  
Donghai Hu ◽  
Yanzhi Yan ◽  
Xiaoming Xu
Keyword(s):  
Energy Consumption ◽  
Optimal Design ◽  
Energy Saving ◽  
Prediction Models ◽  
Control Method ◽  
Optimal Solution ◽  
Electromagnetic Brake ◽  
Design Variables ◽  
And Control ◽  
Optimal Design And Control

Abstract. In this paper, the optimal design and control method of electromagnetic brake for a typical city driving cycle are studied to improve its energy consumption characteristics. The prediction models of the braking performance and power consumption for electromagnetic brake were established, and their accuracies were verified on the hardware of the loop simulation platform. Moreover, the energy consumption based on the ECE-EUDC driving condition was taken as the objective function, and a mathematical model for the optimal design of the electromagnetic brake was established. Genetic Algorithm was used to seek global optimal solution of these design variables on the premise of the given electrical and space constraints. Finally, the effect of thermodynamic properties of electromagnetic brake on the energy consumption characteristics was analyzed, and the energy saving control method of electromagnetic brake was also proposed. Experimental results show that the energy saving optimal design and control that this paper investigates can significantly improve the energy efficiency of electromagnetic brake.

scholarly journals Optimal Design of Natural Gas Liquefaction Processes

2013 ◽  
Vol 51 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Hyun Jun Cho ◽  
Yeong-Koo Yeo ◽  
Jin-Kuk Kim
Keyword(s):  
Optimal Design ◽  
Natural Gas ◽  
Natural Gas Liquefaction

Energy consumption and improvement of energy efficiency for the European agricultural-food system

2020 ◽  
pp. 91-103
Author(s):  
Carlo Greco ◽  
Alessandro Campiotti ◽  
Patrizia De Rossi ◽  
Pierluigi Febo ◽  
Germina Giagnacovo
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Food Systems ◽  
Energy Use ◽  
Food System ◽  
Point Of View ◽  
Fossil Energy ◽  
Improve Energy Efficiency ◽  
Mediterranean Countries ◽  
Agricultural Food

This work addresses the subjects of reducing fossil energy consumption and the interventions to improve energy efficiency in the European agricultural-food sys-tem. Following an overview on both such subjects, the results of European projects TESLA and SCOoPE are also analysed with attention to best practices and technologies available to improve energy efficiency in order to reduce the fossil energy use in agri-food systems of Mediterranean countries. A list of Key Performance Indicators for the fruit and vegetable sector, useful for comparative analyses aimed at selecting best methods of energy management and technologies for improving energy efficiency, is reported. Finally, a brief focus on European policies concerning the solutions adopted by the new European Commission to make the agri-food system more sustainable from an energy and environmental point of view is also discussed.

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