Sensitivity analysis and optimization of the utility consumption of natural gas liquids (NGLs) process in the Siri Island Gas

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nilufar Kharaghani ◽  
Marzyeh Lotfi ◽  
Mani Safamirzaei ◽  
Niloufar Fatourehchi
Keyword(s):  
Sensitivity Analysis ◽  
Economic Evaluation ◽  
Heat Exchanger ◽  
Natural Gas ◽  
Gas Separation ◽  
Feed Stream ◽  
Aspen Hysys ◽  
Simulation Results ◽  
Feed Tray ◽  
Propane Butane

AbstractIn this study, the simulation of the natural gas liquids (NGLs) of Siri Island unit was carried out using Aspen Hysys software. Energy and economic evaluation of these towers were evaluated with Aspen Energy Analyses and Aspen Economic Evaluation, respectively. The effect of various parameters such as the use of heat exchanger instead of a cooler, feed tray changes and the mixing of two feed streams together were investigated to increase the efficiency of hydrocarbons - (Ethane, Propane, Butane, and Pentane) separation, utility consumption and costs. The simulation results showed that the input feed stream from the 10-tray using - mixing of two input 207 and 208 streams, which improves the efficiency of hydrocarbons gas separation and utility consumption compared to other parameters.

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 Numerical Study of Compact Plate-Fin Heat Exchanger for Rotary-Vane Gas Refrigeration Machine

2017 ◽  
Vol 53 (2) ◽  
Author(s):  
V. V. Trandafilov ◽  
M. G. Khmelniuk
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Model ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Numerical Study ◽  
Development Research ◽  
Aspen Hysys ◽  
Simulation Results ◽  
Refrigeration Machine

Plate-fin heat exchangers are widely used in refrigeration technique. They are popular because of their compactness and excellent heat transfer performance. Here we present a numerical model for the development, research and optimization of a plate-fin heat exchanger for a rotary-vane gas refrigeration machine. The method of analysis by graphic method of plate - fin heat exchanger is proposed. The model describes the effects of secondary parameters such as axial thermal conductivity through a metal matrix of the heat exchanger. The influence of geometric parameters and heat transfer coefficient is studied. Graphs of dependences of length, efficiency of a fin and pressure drop in a heat exchanger on the thickness of the fin and the number of fins per meter are obtained. To analyze the results of numerical simulation, the heat exchanger was designed in the Aspen HYSYS program. The simulation results show that the total deviation from the proposed numerical model is not more than 15%. 

scholarly journals Process Stability Identification Through Dynamic Study of Single-bed Ammonia Reactor with Feed-Effluent Heat Exchanger (FEHE)

2018 ◽  
Vol 156 ◽  
pp. 03003
Author(s):  
Tri Partono Adhi ◽  
Muhammad Iqbal Prasetyo
Keyword(s):  
Heat Exchanger ◽  
Exothermic Reaction ◽  
Reactor System ◽  
Hysteresis Phenomenon ◽  
Feed Stream ◽  
Process Stability ◽  
Aspen Hysys ◽  
System A ◽  
Feed Temperature ◽  
Hysteresis Phenomena

In ammonia reactor system, a feed-effluent heat exchanger (FEHE) is typically installed to utilize reaction-generated heat to heat the reactor’s feed. Utilizing energy from exothermic reaction to the incoming feed stream is often called “autothermic operation”. Despite the advantage of FEHE, there is a risk of utilizing FEHE in a reactor system such as instability of process temperature or known as hysteresis. Hysteresis phenomena in chemical process could cause operational problems, for example it could damage the integrity of the equipment’s material. This paper aims to evaluate the dynamic behavior of a single-bed ammonia reactor with FEHE, particularly to propose a way to prevent instability within the system. The dynamic simulation of the single-bed ammonia reactor with FEHE was performed with Aspen HYSYS v8.8. The result of the simulation result shows that hysteresis phenomenon in the ammonia reactor system occurs when the feed’s temperature is below a certain value. If the feed temperature reaches that value, the temperature of the reactor’s outlet oscillates. One of the solution to keep the feed temperature above that critical value is by installing a trim heater within the system. Based on the simulation, trim heater installation within the system is able to prevent hysteresis in the system evaluated.

DETONABILITY OF FUEL-AIR MIXTURES IN TERMS OF DEFLAGRATION-TO-DETONATION TRANSITION

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
V. I. ZVEGINTSEV ◽  
I. O. SHAMSHIN ◽  
M. V. KAZACHENKO ◽  
...  
Keyword(s):  
Natural Gas ◽  
Experimental Method ◽  
Pyrolysis Products ◽  
Ethylene Propylene ◽  
Pulse Detonation ◽  
Detonation Tube ◽  
Standard Pulse ◽  
Detonation Transition ◽  
Run Up ◽  
Propane Butane

A new experimental method for evaluating the detonability of fuel-air mixtures (FAMs) based on measuring the deflagration-to-detonation (DDT) run-up distance and/or time in a standard pulse detonation tube is used to rank gaseous premixed and nonpremixed FAMs by their detonability under substantially identical thermodynamic and gasdynamic conditions. In the experiments, FAMs based on hydrogen, acetylene, ethylene, propylene, propane-butane, n-pentane, and natural gas of various compositions, as well as FAMs based on the gaseous pyrolysis products of polyethylene (PE) and polypropylene (PP) are used: from extremely fuel-lean to extremely fuel-rich at normal temperatures and pressures.

scholarly journals Modelling an unconventional closed-loop deep borehole heat exchanger (DBHE): sensitivity analysis on the Newberry volcanic setting

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannah R. Doran ◽  
Theo Renaud ◽  
Gioia Falcone ◽  
Lehua Pan ◽  
Patrick G. Verdin
Keyword(s):  
Sensitivity Analysis ◽  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Energy Flow ◽  
Closed Loop ◽  
Working Fluid ◽  
Valuable Insight ◽  
Deep Borehole

AbstractAlternative (unconventional) deep geothermal designs are needed to provide a secure and efficient geothermal energy supply. An in-depth sensitivity analysis was investigated considering a deep borehole closed-loop heat exchanger (DBHE) to overcome the current limitations of deep EGS. A T2Well/EOS1 model previously calibrated on an experimental DBHE in Hawaii was adapted to the current NWG 55-29 well at the Newberry volcano site in Central Oregon. A sensitivity analysis was carried out, including parameters such as the working fluid mass flow rate, the casing and cement thermal properties, and the wellbore radii dimensions. The results conclude the highest energy flow rate to be 1.5 MW, after an annulus radii increase and an imposed mass flow rate of 5 kg/s. At 3 kg/s, the DBHE yielded an energy flow rate a factor of 3.5 lower than the NWG 55-29 conventional design. Despite this loss, the sensitivity analysis allows an assessment of the key thermodynamics within the wellbore and provides a valuable insight into how heat is lost/gained throughout the system. This analysis was performed under the assumption of subcritical conditions, and could aid the development of unconventional designs within future EGS work like the Newberry Deep Drilling Project (NDDP). Requirements for further software development are briefly discussed, which would facilitate the modelling of unconventional geothermal wells in supercritical systems to support EGS projects that could extend to deeper depths.

Qualitative comparative analysis of health economic evaluation guidelines for health technology assessment in European countries

2020 ◽  
pp. 1-8
Author(s):  
Konstantinos Zisis ◽  
Panagiota Naoum ◽  
Kostas Athanasakis
Keyword(s):  
Sensitivity Analysis ◽  
Content Analysis ◽  
Economic Evaluation ◽  
Health Technology Assessment ◽  
Technology Assessment ◽  
Evaluation Method ◽  
Outcome Measure ◽  
Health Technology ◽  
European Countries ◽  
Common Practices

Abstract Objective To classify, analyze, and compare published guidelines for economic evaluation within health technology assessment (HTA) in European countries and highlight differences and similarities. Methods We performed a literature review to identify published guidance for the conduct and assessment of economic evaluation studies that are undertaken within the context of HTA processes in European countries. Organizations and working groups were identified via the ISPOR, INAHTA, and EUnetHTA databases. Following the identification of official documents, we performed a qualitative content analysis to highlight discrepancies or common practices under the following categories: comparator, perspective on costs/benefits, time horizon, economic evaluation method, instrument used for utility measurement, outcome measure, source for efficacy, modeling, sensitivity analysis, discounting, and incremental cost-effectiveness ratio. Results A total of nineteen guidance documents were identified (in English) providing data for the analysis in nineteen countries. The comparative content analysis identified common practices in most countries regarding the approaches to the choice of comparator, source of data, the preferred economic evaluation method, the option for a lifetime analytical horizon, discounting, and the choice of key outcome measure—for which, most countries recommend the use of the EQ-5D instrument. Differences were mainly found in the choice of perspective, dealing with uncertainty and sensitivity analysis, the use of end points, and the required use of modeling. Conclusions The use of economic evaluation constitutes one of the key pillars of the HTA process in Europe. Although a methodological convergence has occurred during the last few years, notable differences still remain.

scholarly journals A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Simulation Software ◽  
Dual Fuel ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Cylinder Pressure ◽  
Marine Engine ◽  
Full Load ◽  
Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

Parametric analysis, response surface, sensitivity analysis, and optimization of a novel spiral-double ground heat exchanger

2021 ◽  
Vol 240 ◽  
pp. 114251
Author(s):  
Ahmed A. Serageldin ◽  
Ali Radwan ◽  
Takao Katsura ◽  
Yoshitaka Sakata ◽  
Shigeyuki Nagasaka ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Heat Exchanger ◽  
Response Surface ◽  
Parametric Analysis ◽  
Ground Heat Exchanger ◽  
Surface Sensitivity

scholarly journals A Molecular Simulation Study of Silica/Polysulfone Mixed Matrix Membrane for Mixed Gas Separation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2199
Author(s):  
Khadija Asif ◽  
Serene Sow Mun Lock ◽  
Syed Ali Ammar Taqvi ◽  
Norwahyu Jusoh ◽  
Chung Loong Yiin ◽  
...  
Keyword(s):  
Transport Properties ◽  
Molecular Simulation ◽  
Gas Separation ◽  
Membrane Separation ◽  
Gas Transport ◽  
Mixed Matrix ◽  
Mixed Gas ◽  
Gas Transport Properties ◽  
Simulation Results ◽  
Mixed Gases

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15–30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.

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