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Objectives The aim is to solve the problems of low dehydration efficiency and high energy consumption in triethylene glycol dehydration process, and optimize the operating parameters. Methods The sensitivity analysis method and response surface method were used to optimize the operating parameters. (1) Sensitivity analysis method was used to select the rich liquid entering- tower temperature, reboiler temperature. lean TEG circulation volume flow. stripping gas volume flow as factor variables, and to select dry gas water dew point and operating cost as response values. and 25 groups of test data were simulated by HYSYS software. (2) The response surface method was used to analyze and optimize these operating parameters. Results The interaction between rich liquid entering-tower temperature and stripping gas volume flow rate had the most significant influence on the dew point of dry gas water. and the interaction between rich liquid entering-tower temperature and lean TEG circulation flow rate had the most significant influence on the operating cost. The optimal process parameters were as follows: The temperature of rich liquid entering tower was 144. 28 C, the temperature of reboiler was 205.4 C. the circulation flow rate of lean TEG was 4 m³/h, and the volume flow of stripping gas was 24. 96 m/h. Under the condition that the dew point of dry gas water met the requirements of external transmission and the natural gas treatment capacity was 3 000 X 10³ m³/d. the operating cost could be reduced by 693 300 yuan per year. Conclusions The response surface method can be used to provide the theoretical basis of field operation parameter optimization. [ABSTRACT FROM AUTHOR]

Petrochemical equipment is characterized by continuity, large scale, complexity of processes, and critical operation conditions. Based on auto-collected monitoring parameters, online prediction of critical process parameters can be used to maintain high reliability of petrochemical equipment, which is generally unpractical due to interference parameters and the difficulty in establishing prediction models. In this paper, a process parameter online prediction method for petrochemical equipment is proposed. Firstly, sensitive parameters are selected applying gradient boosting decision tree (GBDT). Then optimized Gaussian process (GP) is utilized to develop a mapping model in order to inference process parameter from auto-collected parameters. Natural gas water dew point online prediction method for triethylene glycol (TEG) dehydration unit is investigated. The effectiveness of the proposed method is verified on production data of a natural gas dehydration station. The method proposed provides a promising solution for process parameter prediction for petrochemical processes as well as other similar scenarios. [ABSTRACT FROM AUTHOR]

Objective Aiming at the problem of freezing and blocking of pipeline transportation in remote wells and scattered wells in the Tahe area, a pilot construction project of a small dehydration station which is unattended was carried out. Methods Considering the special problems of the skid, the skid-mounted molecular sieve dehydration plan was worked out. The export natural gas water dew point during the trial operation was detected and the complicated working conditions of sudden power outage was simulated to analyze the potential risk factors and take corresponding preventive measures. Results After testing, the highest water dew point of exported natural gas was-28 ℃, and the whole skid runs reliably. It can also ensure security even in sudden power outages in the absence of intervention. Conclusions The 200×10³ m³/d unattended molecular sieve dehydration skid has great advantages in cost, dehydration effect and safety operation, especially suitable for relocation-possible devices or remote areas. At the same time, it also has great adaptability for complex and changeable special working conditions. The skid can be actively promoted and applied. [ABSTRACT FROM AUTHOR]

In this study, a water- and heavy hydrocarbon-removal process of a natural gas refinery currently in operation using the temperature swing adsorption method is modeled and investigated. The aim of this process is to decrease the hydrocarbon dew point to −10 °C and diminish the water content of the gas to about 0.1 ppm. This unit consists of four beds with two layers in which two beds are in the adsorption state, while the others are kept in the regeneration state. The gas composition and the bed specification are obtained from the available data from the refinery. The Ergun equation is considered for the pressure drop calculation. The results show that the developed model can predict the outputs with good accuracy. Sensitivity analysis of operating condition parameters such as temperature, pressure, and regeneration gas flowrate are carried out. Analysis of the regeneration temperature proved that temperature reduction from 268 °C to 210 °C can improve recovery of the heavy components. In addition, the regeneration gas flow rate can be reduced to about 0.4 kmole·s−1 as an optimum value. Moreover, 303 to 310 °C is the optimum range for the feed temperature. Due to the presence of the air cooler in the upstream process, and according to the ambient air temperature, feed temperature can be decreased to obtain better results. [ABSTRACT FROM AUTHOR]

Objective In the gathering and transportation of natural gas mines with high hydrogen sulfide content, in order to effectively reduce the corrosion hazard of hydrogen sulfide to the system, dehydration is often used to control the water dew point. Methods Based on the research of dehydration technology of high sulfur natural gas at home and abroad, triethylene glycol solvent absorption method was selected as the dehydration treatment process of high sulfur natural gas in Shunbei No. 2 area. Considering the characteristics of high sulfur natural gas in Shunbei No. 2 area, the traditional triethylene glycol dehydration process was optimized and improved locally, and the separation process before the raw gas inlet adsorption tower and the flash-vapor recovery process were added at the same time. Based on the influence of the pre-heating location, regeneration purity and hydrogen sulfide, the paper adopted a two-stage low-liquid/high-liquid heat exchange pre-heating process and LNG gasification gas extraction process to form a dehydration process which is suitable for high-sulfur natural gas in Shunbei No. 2 area. Results After transformation, the dehydration process realized zero discharge of sulfur-containing tail gas from dehydration system by pressurized recovery, and the combination of efficient desulfurization and purification of triethylene glycol (TEG) realized by LNG gasification and gas stripping, the problem of corrosion and maintenance of regeneration device in acid environment was solved. Conclusions This dehydration process effectively promoted the realization of the overall development plan of Shunbei No. 2 area, and formed a high-pressure gathering and transportation dehydration process suitable for natural gas with high hydrogen sulfide content in Shunbei No. 2 area, which provides technical support for the further development of Shunbei natural gas blocks. [ABSTRACT FROM AUTHOR]

In view of the salt deposition problem in TEG dehydration system of the natural gas purification unit, which caused scaling on the solvent side of the reboiler and the water dew point rising of the product natural gas, the TEG solution component and the scale sample component were analyzed through the infrared spectrum analysis and liquid-mass spectrometry analysis etc. Combined with the actual process control situation on site, the reason of salt deposition was determined as salt compounds and organic solvents entering into the TEG system with natural gas, which caused the TEG to deteriorate and form scale. The experiment compared and selected ten kinds of solid materials. The results showed that macroporous adsorption resin DlOl has a better purification effect on TEG, which can provide references for similar devices to solve similar problems. [ABSTRACT FROM AUTHOR]

In order to optimize the TEG dehydration process in an offshore gas field, determine reasonable parameters and achieve the optimal treatment effect, the HYSYS model was established to make a simulation under certain working conditions that the natural gas treatment capacity was 2X 106 m3/d, the operation pressure (gauge pressure) of absorber was 10 600 kPa, and the lean TEG circulation was 1. 17 m3/h. The relationship between independent variables and dependent variables was obtained by simulating and optimizing the inlet temperature of natural gas and lean TEG, lean TEG mass fraction, reboiler temperature, and stripping gas flow. On this basis, the optimum operation parameters were obtained to guide the process. It was verified that under the conditions of optimum parameters that the inlet temperature of natural gas was 33 °C , the inlet temperature of lean TEG was 40 °C and the lean TEG mass fraction was 99. 30% , the natural gas dehydration system operated normally, and the dew point of the dry natural gas reached the standard of natural gas transportation in platform. It showed that the HYSYS software could simulate and optimize the field process parameters according to the actual working conditions, and the results were relatively accurate. It could he popularized and applied in other offshore gas field. [ABSTRACT FROM AUTHOR]

Dehydration is a critical operation in natural gas conditioning as it reduces the potential for corrosion, hydrate formation and freezing in process equipment and transportation pipelines. Water dew point adjustment is particularly challenging in the remote ultra-deepwater natural gas reserves of the Brazilian Pre-Salt fields due to their very high carbon dioxide contents – from 30% up to 90% in raw natural gas – which is a consequence from the carbonaceous rock of the reservoir structure and long term elevation of carbon dioxide content due to its injection for early enhanced oil recovery. Under this scenario, the study evaluates the impact of the carbon dioxide content of the natural gas on the performance of water dew point via water adsorption on 4 Å Zeolite molecular sieve beds. Process simulation with adsorption simulator Adsim (Aspen Technology, Inc), at varying operation pressures and carbon dioxide contents in raw natural gas, indicated that, although adsorption meets water removal specification in a condensation free operation, the high fugacity of carbon dioxide penalizes the dehydration performance due to probably two facts: (i) higher carbon dioxide fugacity in the humid natural gas imply higher saturation water content in the gas phase, which increases the service of dehydration units; and (ii) higher carbon dioxide fugacity in the humid natural gas establishes a discreet adsorption competition with water resulting in 6.5% increase of adsorbent bed volume for operating pressures of 35 bar or higher. [ABSTRACT FROM AUTHOR]

Natural gas dehydration is a crucial step in gas processing, and three-flow vortex tubes have numerous advantages over traditional dehydration methods. In this study, a three-flow vortex tube with a sintered metal porous material as the drain part was developed. Further, the gas–liquid behavior within the main tube and sintered metal porous material (SMPM) was experimentally analyzed. Owing to the different driving forces, the gas and liquid first separate in the main tube, followed by further separation in the SMPM. With the SMPM as the drain part, the adverse impact of the drain processes and the amount of discharged gas from the drain port can be minimized compared to the traditional drain part with an annular space. The cooling performance dominated the dehydration ability of the three-flow vortex tube, and the largest dew point drop was 18.3 °C. Further, the largest total moisture content reduction ratio of the two exits was 61.1% at an inlet pressure of 2.0 bar and cold mass fraction of 0.45. Thus, it was demonstrated that the three-flow vortex tube with SMPM as the drain part is a potential device for gas dehydration. • A three-flow vortex tube with a SMPM as the drain part was developed. • The gas–liquid behavior within the main tube and SMPM was analyzed. • The largest φ t o t a l of the two exits was 61.1% at P in = 2.0 bar and ε = 0.45. [ABSTRACT FROM AUTHOR]

Triethylene glycol (TEG) is one of the most effective sorbents for natural gas dehydration. There are many processes using this approach but none of them can combine high performance and economical energy consumption. In this study hydrocarbon-water phase behavior was investigated for different TEG concentrations in different natural gas dehydration processes. The equilibrium correlations were investigated for predicting water dew point as a function of TEG concentration. The effect of TEG concentration on the outlet gas dew point was also determined using phase envelope diagrams. The results showed that the (DRIZO) process achieved the most significantly reduces water dew point followed by conventional stripping gas dehydration process. Moreover, TEG was modified using potassium formate as additive. The results showed that the absorption capacity of the modified TEG was improved, that is almost duplicated. This modification augments the performance of the proposed mixture which can be potentially applied to a real scale process. [ABSTRACT FROM AUTHOR]