Cascade refrigeration systems in integrated cryogenic natural gas process (natural gas liquids (NGL), liquefied natural gas (LNG) and nitrogen rejection unit (NRU))

Heavy components in the natural gas itself can feed downstream units and also due to the low temperature process may be formed solid. Therefore heavy components separation is a necessity and can produce useful products. Virtually all natural gases are containing nitrogen that would lower the heating value of natural gas. This study investigates design and optimization of integrated process recovery of natural gas liquids, natural gas liquefaction, and nitrogen remove unit. In this integrated process, design of low temperature processes is started from the core process and continued by heat exchangers network design and cooling system based on MFC. Design and integration processes of units at the same time reduces the number of required equipment and energy consumption. The results show that the new integrated process has specific power around 0.343–0.33 (kW-h/kg-LNG) and its thermal efficiency equal to 62.82%, compared to other integrated systems have the lowest and highest values. Exergy analysis shows that towers has the highest Exergy destruction among other equipment. Sensitivity analysis shows that the structure of the integrated process capable of removing nitrogen from natural gas at a concentration of between 5% and 15%. By analyzing the operating parameters shows reduction in the Total specific power from 19.5% to 24% and the Specific power from 2.57% to 11%, yet surging in the Ethane recovery from 2.5% to 17%. Sensitivity analysis is the method to identification of the Decision variables, finally Genetic Algorithm used to identify optimum of objective function (minimization of Specific Power) and reduction of it to 6%.

[1]  Majid Amidpour,et al.  Design of mixed refrigerant cycle for low temperature processes using thermodynamic approach , 2013 .

[2]  Jin-Kuk Kim,et al.  Application of exergy analysis for improving energy efficiency of natural gas liquids recovery processes , 2015 .

[3]  Sigurd Weidemann Løvseth,et al.  Optimization of a simple LNG process using sequential quadratic programming , 2013, Comput. Chem. Eng..

[4]  Yonglin Ju,et al.  Design and Optimization of a Novel Mixed Refrigerant Cycle Integrated with NGL Recovery Process for Small-Scale LNG Plant , 2014 .

[5]  Sanggyu Lee,et al.  Knowledge inspired investigation of selected parameters on energy consumption in nitrogen single and dual expander processes of natural gas liquefaction , 2015 .

[6]  Omer Kaynakli,et al.  Energy and exergy analysis of a double effect absorption refrigeration system based on different heat sources , 2015 .

[7]  M. Rosen,et al.  Optimum design and exergy analysis of a novel cryogenic air separation process with LNG (liquefied natural gas) cold energy utilization , 2015 .

[8]  Reza Shirmohammadi,et al.  Optimization of mixed refrigerant systems in low temperature applications by means of group method of data handling (GMDH) , 2015 .

[9]  Majid Amidpour,et al.  The Design of the Best Heat Integrated Separation Systems Using Harmony Search Algorithm , 2013 .

[10]  M. Mehrpooya,et al.  Novel LNG-Based Integrated Process Configuration Alternatives for Coproduction of LNG and NGL , 2014 .

[11]  Andrew Hoadley,et al.  An exergy analysis of small-scale liquefied natural gas (LNG) liquefaction processes , 2006 .

[12]  M. Mehrpooya,et al.  Energy and exergy analyses of five conventional liquefied natural gas processes , 2014 .

[13]  Majid Amidpour,et al.  Development and optimization of an integrated process configuration for natural gas liquefaction (LNG) and natural gas liquids (NGL) recovery with a nitrogen rejection unit (NRU) , 2016 .

[14]  Kyu-Yeul Lee,et al.  Determination of the optimal operating conditions of the dual mixed refrigerant cycle for the LNG FPSO topside liquefaction process , 2013, Comput. Chem. Eng..

[15]  Kyu Suk Hwang,et al.  Design process of LNG heavy hydrocarbons fractionation: Low LNG temperature recovery , 2014 .

[16]  Majid Amidpour,et al.  Mathematical Method and Thermodynamic Approaches to Design Multi-Component Refrigeration Used in Cryogenic Process Part I: Optimal Operating Conditions , 2013 .

[17]  Iftekhar A. Karimi,et al.  Evolution and optimization of the dual mixed refrigerant process of natural gas liquefaction , 2016 .

[18]  Majid Amidpour,et al.  Sensitivity analysis, economic optimization, and configuration design of mixed refrigerant cycles by NLP techniques , 2015 .

[19]  Hadi Ebrahimi,et al.  APCI- LNG single mixed refrigerant process for natural gas liquefaction cycle: Analysis and optimization , 2015 .

[20]  Majid Amidpour,et al.  A Pareto Front Approach to Bi-objective of Distillation Column Operation Using Genetic Algorithm , 2012 .

[21]  Mehdi Mehrpooya,et al.  A novel process configuration for co-production of NGL and LNG with low energy requirement , 2013 .

[22]  Reinhard Radermacher,et al.  Application of waste heat powered absorption refrigeration system to the LNG recovery process , 2009 .

[23]  Sigurd Skogestad,et al.  Optimal operation of a mixed fluid cascade LNG plant , 2006 .

[24]  Majid Amidpour,et al.  Exergy and exergoeconomic evaluation of gas separation process , 2012 .

[25]  Mehdi Mehrpooya,et al.  Introducing a new parameter for evaluating the degree of integration in cryogenic liquid recovery processes , 2011 .

[26]  Majid Amidpour,et al.  Simulation and optimization of refrigeration cycle in NGL recovery plants with exergy-pinch analysis , 2012 .

[27]  Majid Amidpour,et al.  THE DESIGN AND OPTIMIZATION OF DISTILLATION COLUMN WITH HEAT AND POWER INTEGRATED SYSTEMS , 2013 .

[28]  Majid Amidpour,et al.  Optimization of operation parameters of refrigeration cycle using particle swarm and NLP techniques , 2014 .

[29]  Mehdi Mehrpooya,et al.  A novel multi-hybrid model for estimating optimal viscosity correlations of Iranian crude oil , 2016 .

[30]  M.F.M. Fahmy,et al.  Enhancement of the efficiency of the Open Cycle Phillips Optimized Cascade LNG process , 2016 .

[31]  Marcelo Díaz Rincón,et al.  A novel absorption process for small-scale natural gas dew point control and dehydration , 2016 .

[32]  Majid Amidpour,et al.  Optimization of Distillation Column Operation by Simulated Annealing , 2013 .

[33]  Majid Amidpour,et al.  THE MATHEMATICAL METHOD AND THERMODYNAMIC APPROACHES TO DESIGN MULTI-COMPONENT REFRIGERATION USED IN CRYOGENIC PROCESS PART II: OPTIMAL ARRANGEMENT , 2014 .

[34]  Majid Amidpour,et al.  Superstructure optimization of the olefin separation system by harmony search and genetic algorithms , 2016 .

[35]  Majid Amidpour,et al.  Design and Optimization of Heat Integrated Distillation , 2012 .

[36]  Majid Amidpour,et al.  A hybrid artificial neural network and genetic algorithm for predicting viscosity of Iranian crude oils , 2014 .

[37]  Mehdi Mehrpooya,et al.  Thermoeconomic analysis of a large industrial propane refrigeration cycle used in NGL recovery plant , 2009 .