Gas Processing Plant Research Articles

Effect of Alumosilicate Adsorbent Regeneration Conditions on the Dehydration of Methanol Extracted from Natural Gas

This paper focuses on the parameters of the technological regime for the regeneration of aluminosilicate adsorbents on natural gas processing plants adsorption type on the dehydration of methanol from natural gas. The object of this study were the non-hydrocarbon fraction of liquid products of the purification of natural gas from an adsorption unit on silica gel with countercurrent regeneration. Gas treatment plants was optimized using BASF KC-Trockenperlen silica gels and microporous silica gel adsorbents (АСМ). The direct-flow regeneration technology on natural gas processing plants with adsorption purification оn aluminosilicate adsorbents contributes to a more efficient reaction of the conversion of methanol to dimethyl ether and his process reduces the volume of non-hydrocarbon waste fraction. Decreasing methanol concentrations reduces atmospheric emissions and saves fuel gas consumed by a stationary thermal treatment unit.

К вопросу об оценке пожарной безопасности рабочих мест персонала компрессорных цехов газотранспортных предприятий

The method is considered related to fire safety evaluation of the workplaces located in the engine room of the compressor shop. The method is based on the methodology for evaluating safety of the systems at various levels (workplace, shop, enterprise). The method of constructing a scenario for the occurrence and development of a fire using cause and effect diagram (Ishikawa Diagram) based on the principle of «action — reaction» is shown. The mathematical model for assessment of the probability of implementing a fire scenario at a production facility, and the model for assessment of the probability of personnel evacuation in case of fire are considered. When developing a model for assessing the likelihood of personnel evacuation, the results of studies were used related to the time of the beginning of people evacuation conducted by the State Fire Service Academy of EMERCOM of Russia. The results of experiments on the evacuation of personnel from the technological structure of gas processing plant and from the compartments of gas-pumping unit are also shown.  The results of the practical implementation of the proposed approach on the examples of constructing fire scenario and assessment of the possibility of fire occurrence due to surge of the operating point of a centrifugal blower are presented.  The likelihood of the specified fire scenario occurrence is estimated. The estimation of the likelihood of personnel evacuation in case of fire in the engine room of the compressor shop is presented. The options for calculating the time of evacuation of the employees based on the specific conditions, parameters that characterize the specifics of people behavior in case of fire, as well as the reliability of the notification and evacuation management system are proposed. Comparison is made between the suggested models and the models used in the normative documents in the field of fire safety on the example of the evacuation of the compressor shop personnel located at the time of fire in the compartments of gas pumping unit. It is shown that the developed models allow for a more complete assessment of all the factors that affect the probability of employee evacuation. The option of using the proposed models for calculating an individual risk value, which is proposed to be considered as a criterion for the assessment of the workplaces fire safety, is discussed in the article.

Video surveillance and analytics technologies in the safety management system in construction projects realization

Pavel Kurochkin, manager of labor protection, industrial safety and ecology at NIPIGAS company, talks about the realization of the NIPIGAS project for the construction of the Amur gas processing plant for LLC Gazprom pererabotka Blagoveshchensk and about the design and implementation of preparatory works for the construction of the Amur gas-chemical plant for LLC SIBUR. New approaches to labor protection and safety, which are used at NIPIGAZ construction sites, make it possible to control the safety of work at heights and in inaccessible places and to monitor construction and installation works using video surveillance technologies and video analytics.

Conceptual design of adsorptive recovery of ethane from residue gas stream using Na-ETS-10

This work provides the conceptual design of a pressure/vacuum swing adsorption cycle for recovering ethane from the residue gas stream (a mostly methane stream) using Na-ETS-10 as the adsorbent. The conceptual design for treating a stream with 2.4% ethane (and the rest methane) evolved from a simple 4-step cycle to more complex configurations which were able to simultaneously improve the ethane purity and recovery. Feed temperature played a key role in the cycle performance in terms of purity and recovery. The minimization of the recompression work of the light product (methane) was achieved by proposing a cycle design which includes a heavy reflux step at high pressure and a further pressure equalization step. Purity values up to 88% ethane with recoveries of 95% and productivities higher than 0.4 mol ethane/m3(ads)s were quantified through the optimization of the operating conditions for the reduced energy-cost adsorption cycle suggesting an alternative for ethane recovery in gas processing plants.

Development of polyethylenimine (PEI)-impregnated mesoporous carbon spheres for low-concentration CO2 capture

A novel low-concentration CO2 capture material (PEI/MCS) was developed by loading polyethylenimine (PEI) over mesoporous carbon spheres (MCS) with high porosity. The effects of pore structure, PEI loading, capture temperature, and promoters on CO2 capture of PEI/MCS were studied. The MCS with perfect spherical morphology was successfully synthesized by a hard-template assisted reverse emulsion method. The pore structure of MCS was adjusted by tuning the ratio of silica to carbon (Si/C) in the precursors. With increasing the Si/C from 0.8 to 1.1, the pore volume of MCS increased from 1.25 to 2.68 cm3/g. The optimal PEI loadings depending on the pore volume of MCS were 45, 62.5, and 65 wt.% for MCS-0.8, MCS-1.1, and MCS-1.5, respectively. The highest CO2 capture capacity (3.22 mmol/g) was achieved on 62.5PEI/MCS-1.1 at CO2 partial pressure of 0.05 bar (5 vol.%, a typical concentration of the tail gas from natural gas power plant and natural gas processing plant) and temperature of 75 °C, outperforming most of the solid amine sorbents reported at similar condition. However, the cycling stability of PEI/MCS is poor at the capture-regeneration temperature of 75 °C. The promoters Span 80 and 1,2-epoxybutane did not show remarkable effect on the cycling stability of PEI/MCS at 75 °C. Decreasing the capture-regeneration temperature can significantly improve the stability of PEI/MCS and there is almost no CO2 capacity loss (regeneration >99.5 %) when the temperature decreased to 50 °C. As a result of high CO2 capacity and excellent regenerability and stability, PEI /MCS will be one of the ideal candidates for CO2 capture in the future.

Optimization and Selection of Maintenance Policies in an Electrical Gas Turbine Generator Based on the Hybrid Reliability-Centered Maintenance (RCM) Model

The electrical generation industry is looking for techniques to precisely determine the proper maintenance policy and schedule of their assets. Reliability-centered maintenance (RCM) is a methodology for choosing what maintenance activities have to be performed to keep the asset working within its designed function. Current developments in RCM models are struggling to solve the drawbacks of traditional RCM with regards to optimization and strategy selection; for instance, traditional RCM handles each failure mode individually with a simple yes or no safety question in which question has the possibility of major error and missing the effect of a combinational failure mode. Hence, in the present study, a hybrid RCM model was proposed to fill these gaps and find the optimal maintenance policies and scheduling by a combination of hybrid linguistic-failure mode and effect analysis (HL-FMEA), the co-evolutionary multi-objective particle swarm optimization (CMPSO) algorithm, an analytic network process (ANP), and developed maintenance decision tree (DMDT). To demonstrate the effectiveness and efficiencies of the proposed RCM model, a case study on the maintenance of an electrical generator was conducted at a Yemeni oil and gas processing plant. The results confirm that, compared with previous studies, the proposed model gave the optimal maintenance policies and scheduling for the electrical generator in a well-structured plan, economically and effectively.

Estimation of Solubility of BTEX, Light Hydrocarbons and Sour Gases in Triethylene Glycol Using the SAFT Equation of State

An accurate prediction of the absorption and desorption of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) is important for the estimation of BTEX emissions from glycol units in natural gas processing plants. This work presents an approach to accurately model the solubilities of BTEX in triethylene glycol (TEG). The absorption of gases studied in this work into TEG is physical in nature, and therefore is treated as physisorption in modeling. The Huang-Radosz version of Statistical Associating Fluid Theory (SAFT-HR) Equation of State (EoS) was utilized to estimate the solubilities of BTEX in TEG. A new set of SAFT parameters for TEG, as well as a new set of binary interaction parameters between TEG and other components were obtained by fitting experimental vapor pressure and liquid density of TEG and available experimental binary VLE data, respectively. Using these parameters, solubility of multicomponent gases in TEG are accurately predicted. To have an estimate of the relative accuracy of SAFT-HR EoS, the results from Perturbed–Chain SAFT (PC–SAFT) and Peng–Robinson (PR) EoS are also reported. The overall average of root–mean–square deviation (RMSD) for binary and ternary systems studied in this work, using SAFT-HR, PC–SAFT, and PR EoS obtained equal to 0.12, 0.20, and 1.56, respectively.

Characteristics study of foulants on air cooled heat exchangers of a gas processing plant in the Middle East

Fouling of heat exchangers in energy and power plant industry, oil and gas industry, pharmaceutical and food process industry, industrial waste heat recovery is a major problem which needs to be solved urgently. In the United Arab Emirates, a majority of oil & gas processing plants are located in the desert where water accessibility is limited, thus fin-fan type of heat exchangers are used for cooling and/or heating applications. Such harsh environments cause external fouling which becomes an unavoidable problem in these heat exchangers. With increased humidity and high process temperatures, the dust particulates start to stick on the outer surface of heat exchangers which drastically reduces the thermal performance and increases power consumption. In order to identify possible methods to control and/or eliminate such kinds of external fouling, it is important to identify the composition and morphology of such foulants. This study presents the characterization of selected fouling samples collected from several fin-fan type air cooled heat exchangers taken from a gas processing plant. Scanning electron microscope (SEM) tests were carried out to determine the physical characteristics of sample foulant. Variability in sizes and shapes was found between samples due, perhaps, to different working temperature ranges of the selected heat exchangers. X-ray diffraction (XRD) analyses revealed presence of quartz, calcite, and alumina with traces of halite and hematite. Laser flash analysis (LFA) was conducted to quantify the specific heat capacity, thermal diffusivity and thermal conductivity of the fouling samples. The diversity of these fouling samples reflects complexity with respect to their potential removal and effects on heat transfer characteristics. Though, this research work is a case study for a specific petrochemical plant, however, findings in this study can be adopted by other industries involved in similar chemical processing in the Middle East as well as other countries having similar weather and geological conditions.

Transformation Stages of the Cleaning Capacity of Agricultural Irrigation Fields by Wastewater from a Gas-Processing Plant

The dynamics of the cleaning capacity of agricultural fields irrigated with wastewater from a gas-processing plant is studied. It is shown that 5–7 irrigations at a rate of 480 m3/ha annually bring 2.98–4.17 t/ha of pollutants into the soil, and these pollutants are retained in the soils of the aeration zone and contribute to their salinization and alkalinization and, as a consequence, lead to a reduction in crop yields. In addition, calcium is carried from upper soil layers to deeper horizons, thereby forming a new geochemical barrier. Under conditions of a weak outflow of groundwater, we recorded a growth in its level, an accumulation of salts carried with wastewater, and an increase in the total mineralization of wastewater. It is established that the agricultural irrigation fields used for over 20 years undergo three transformation stages: adaptation stage (3–4 years); stable functioning of the geoecosystem utilizing industrial waste waters from the gas-processing plant (7–10 years), and the stage of the critical state of the geoecosystem due to the loss of the cleaning capacity by the soils and the necessity of soil-improving remediation activities.

A Look at the Aasta Hansteen Norwegian Deepwater Spar FPSO

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 29222, “Aasta Hansteen Spar FPSO—A Pioneer in Norwegian Deepwater,” by Torolf Christensen, Stig Arne Witsøe, and Helge Hagen, Equinor, et al., prepared for the 2019 Offshore Technology Conference, Houston, 6–9 May. The paper has not been peer reviewed. Copyright 2019 Offshore Technology Conference. Reproduced by permission. The complete paper describes the overall project execution of the Aasta Hansteen field development on the Norwegian Continental Shelf (NCS) north of the Arctic Circle. It is the deepest field yet developed on the NCS in 1300 m of water. In a harsh environment, with no other offshore installations in the area, the field is being developed with a spar floating, production, storage, and offloading (FPSO) structure using steel catenary risers and polyester mooring lines. Business Case The field is 300 km off the coast of northern Norway and 140 km from the nearest offshore installation. The field was discovered in 1997, with investment decision taken in December 2012 and production begun in December 2018. Total investment in facilities and infrastructure (including pipeline and modifications at Nyhamna) is approximately $7 billion. Equinor operates the field on behalf of its partners, Wintershall (24%), OMV (15%), and ConocoPhillips (10%). The field’s rich gas is exported through a 482-km-long, 36-in. pipeline to an on-shore processing plant at Nyhamna for further processing to sales gas. From there, the gas is exported to the European market. Stabilized condensate is stored in the spar FPSO and offloaded to shuttle tankers. The development of the field with the platform facilities and the Polarled pipeline was a strategic decision to open a new gas region in the Norwegian Sea and connect it to Europe by the NCS gas infrastructure. The development solution will serve as a gas hub enabling tie-in of future production from discoveries and prospects in the area. The objective of the Aasta Hansteen development is to maximize the recovery of the Aasta Hansteen reserves and to achieve maximum value creation in the value chain. Estimated recoverable reserves are 51 billion scm rich gas and 0.6 million scm condensate. The reserves consist of three separate discoveries—Luva, Haklang, and Snefrid Sør—all in the Nise formation and within the same production license. The development of Aasta Hansteen has been executed as a parallel development of the Polarled pipeline project to establish a new gas transport pipeline from Aasta Hansteen to Nyhamna. The pipeline has several tie-in points from Aasta Hansteen to the Nyhamna gas-processing plant. Snefrid Nord, the first subsea tieback development, is already being developed. The complete paper provides a brief description of the Polarled project.

Technical and economic evaluation of triethylene glycol regeneration process using flash gas as stripping gas in a domestic natural gas dehydration unit

AbstractNatural gas from an underground reservoir is typically saturated with water vapor. Removal of this water vapor is required in the gas processing to avoid serious problems. This study investigated the technical and economic aspects of a triethylene glycol (TEG) regeneration unit in a domestic natural gas processing plant. This study aims to improve the performance of this dehydration unit to meet sales gas specifications while minimizing the Total Annual Cost (TAC). The important variables in this work are TEG circulation mass flow and rerouting the gas from TEG Flash Drum to TEG Regenerator as stripping gas. The flash gas, instead of discharged directly to the Flare system, is routed to the TEG Regenerator and serves as stripping gas agent to improve the TEG purity. The results revealed that utilizing flash gas as stripping gas has allowed lower TEG circulation mass flow rate and reduced the reboiler duty from 1.464 to 0.934 GJ/h (a 36.2% reduction). The TAC was reduced from $ 296 058/year to $ 236 890 /year (20.0% reduction). Through this work, a more economical design was obtained compared to the base case design.

Evaluation of Hydrocarbon Gas Dispersion and Explosion in a Gas Processing Plant

Gas leakage is one of hazard sources in a gas processing plant, where the released gas may form vapor cloud, which is dispersed or accumulated. At certain concentration, the vapor cloud may induce fire and explosion, which could harm people, equipment and environment. The effects of the incidents can be estimated to determine the consequences and to improve the plant design. Due to several complexities including congestion of plant equipment, 3D CFD model was developed to represent real configuration. In this study, the as-built 3D plant geometry and FLACS software were utilized to run the CFD model simulation to evaluate the quantity and placement of the existing gas detectors. The recommendation given according to evaluation results was to install two additional gas detectors. Thereby, in the case of gas leak, the gas detection system may alarm personnel and preventive action may be taken into consideration. The effects of explosion result from the selected scenario were predicted to not be able to cause steel frame distortion or eardrum rupture. These demonstrated that the evaluation of release consequence using 3D CFD model gave more advantage than 2D method by representing accurately physical characteristic of gas dispersion and explosion, which could eventually improve the plant safety strategy.

A global gridded (0.1° × 0.1°) inventory of methane emissions from oil, gas, and coal exploitation based on national reports to the United Nations Framework Convention on Climate Change

Abstract. Individual countries report national emissions of methane, a potent greenhouse gas, in accordance with the United Nations Framework Convention on Climate Change (UNFCCC). We present a global inventory of methane emissions from oil, gas, and coal exploitation that spatially allocates the national emissions reported to the UNFCCC (Scarpelli et al., 2019). Our inventory is at 0.1∘×0.1∘ resolution and resolves the subsectors of oil and gas exploitation, from upstream to downstream, and the different emission processes (leakage, venting, flaring). Global emissions for 2016 are 41.5 Tg a−1 for oil, 24.4 Tg a−1 for gas, and 31.3 Tg a−1 for coal. An array of databases is used to spatially allocate national emissions to infrastructure, including wells, pipelines, oil refineries, gas processing plants, gas compressor stations, gas storage facilities, and coal mines. Gridded error estimates are provided in normal and lognormal forms based on emission factor uncertainties from the IPCC. Our inventory shows large differences with the EDGAR v4.3.2 global gridded inventory both at the national scale and in finer-scale spatial allocation. It shows good agreement with the gridded version of the United Kingdom's National Atmospheric Emissions Inventory (NAEI). There are significant errors on the 0.1∘×0.1∘ grid associated with the location and magnitude of large point sources, but these are smoothed out when averaging the inventory over a coarser grid. Use of our inventory as prior estimate in inverse analyses of atmospheric methane observations allows investigation of individual subsector contributions and can serve policy needs by evaluating the national emissions totals reported to the UNFCCC. Gridded data sets can be accessed at https://doi.org/10.7910/DVN/HH4EUM (Scarpelli et al., 2019).

SELECTION OF OPTIMUM REPLACEMENT OPTION FOR AMINE PUMP IN A GAS PROCESSING PLANT USING FUZZY ANALYTICAL HIERARCHY PROCESS

In order to excel in the competitive market, it is essential to make a flawless decision which is difficult without considering different factors that affect it. These factors can be qualitative or quantitative which are full of uncertainties. Fuzzy analytical hierarch process (FAHP) is a very useful tool to model such a decision making process. In this study FAHP is used to select the optimum replacement option of amine pump in a gas processing plant. The gas processing plant has 10 unit of amine circulation pumps. These pumps have been installed since 1996. After installation, various problems occurred which lead to low reliability and availability of the amine pump system and a lot of design modification has been done since then. In this study three different replacement options are investigated to solve the problem. These options are a) To continue with the existing pump system through repair, b) To modify the existing system by changing one or two of the old pumps which has low performance by `a new one and c) To add a new pump. These options were assessed with four criteria; Ease of operation, Flexibility, Maintainability and environment. Data was collected from 25 employees and a pairwise comparison was conducted. It is found that the weight of the first option which is continuing with the existing system is higher with 0.47 values which show this option is preferable for the selected case. A sensitivity analysis is conducted to explore how the ranking of the analysis varies when the input data were changed.

Sustainable Green Policy by Managing Flare Gas Recovery: A Case with Middle East Oil and Gas Industry

Push for sustainability is evident in areas such as energy generation where the focus has been on finding new deposits to outpace drawdown on existing reserves. Gas flaring is employed by oil and gas industries to burn-off associated gasses from refineries, hydrocarbon processing plants or oil and gas reserve wells. It is one of the most taxing energies and environmental problems challenging the world today. Generally, safety flaring was dubbed as the saviour of process plants and mostly covers for sudden or unplanned plant trips. It is an opportunity to cut greenhouse gases (GHGs) from oil and gas processing plants through flare gas recovery (FGR) process. Oil and gas plants can employ diverse FGR procedures to offset key concerns about the environmental bearing of GHGs emanation most of which necessitating novel apparatus and extraordinary outlay of design and construction. In this study, apart from economic aspects, a real-life case study is extensively analysed to highlight exploration and adoption of optimizing FGR that may be beneficial if flare gas can be recovered, instead of burning. The output of the study may have a significant impact for refineries towards both economic and sustainability towards greening. In a nutshell, this study highlights the efficacy of reducing ‘flare gas system’ towards environment-friendly ‘greening’ aspect as the core of designing.

Detailed Reaction Mechanism To Predict Ammonia Destruction in the Thermal Section of Sulfur Recovery Units

Ammonia and aromatics such as benzene, toluene, and xylene are typically found in acid gas and sour water stripper gas in oil and gas processing plants and gasification facilities. This gas is ofte...

CO2 Utilization Process Simulation for Enhancing Production of Dimethyl Ether (DME)

Increase in the world energy demand also increases the concentration of CO2 in the atmosphere, which contributes to global warming and ocean acidification. This study proposed the simulation process to utilize CO2 released from the acid gas removal unit in one of gas processing plants in Indonesia to enhance the production of dimethyl ether (DME) through unreacted gas recycle that can be beneficial in reducing CO2 emission to the atmosphere. Simulation was developed in Unisim R390.1 using Peng–Robinson–Stryjek–Vera (PRSV) as a fluid package. Simulation was validated by several studies conducted by many researchers and giving satisfactory results especially in terms of productivity, conversion, and selectivity as a function of reactor temperatures in the indirect and the direct DME synthesis processes. Simulation results show that the DME production was enhanced by around 49.6% and 65.1% for indirect and direct processes, respectively, at a recycling rate of 7 MMSCFD. Compressor is required to increase the unreacted gas pressure to the desired pressure in the methanol reactor or dual methanol-DME reactor in both processes. Specific power consumption (SPC) was used as a tested parameter for the effectiveness of recycling unreacted gas. Based on the simulation, the direct DME synthesis process is superior over the indirect process in terms of DME and methanol productions, SPCs, and system energy efficiencies.

Iot Enabled Pipeline Leakage Detection and Real Time Alert System in Oil and Gas Industry

Automation and control systems are necessary throughout oil & gas industries, to production and processing plants, and distribution and retailing of petroleum products. Pipelines are the efficient mode of transportations of fuels for processing plants over long distances. At present Automation is achieved by using PLC’s that are communicated through SCADA. But it is complex and remote operation is not possible. With the introduction of IoT, the pipeline leak detection system is improved through real-time monitoring of the pipelines. Our Proposed system is designed to detect even small leakage that occurs within the pipeline. The implementation of IoT in oil and gas industries prevents accidents and to make quick decisions based on real-time data.

Simulation of an Acid Gas Removal Unit Using a DGA and MDEA Blend Instead of a Single Amine

Abstract Most of the industrial acid gas removal (AGR) units employ chemical absorption process for the removal of acid gases from the natural gas. In this study, two gas processing plants operational in Saudi Arabia have been selected where two different amines n1amely, diglycolamine (DGA) and monoethanol amine (MDEA) are used to achieve the sweet gas purity with less than 4 ppm of H2S. This study performed a feasibility simulation of AGR unit by utilizing the amine blend (DGA+MDEA) for both plants instead of a single amine. The study used a commercial process simulator to analyze the impact of process variables such as amine circulation rate, amine strength, lean amine temperature, regenerator inlet temperature, and absorber and regenerator pressure on the process performance. The results reveal that when the MDEA (0–15 wt. %) is added to DGA, marginal energy savings can be achieved. However, significant operational energy savings can be made when the DGA (0–15 wt. %) is blended with MDEA being the main amine.

Natural Gas Industry Restructuring for Value Optimisation: A Case Study of Ghana

The global natural gas industry in emerging oil and gas producing countries faces the challenge of restructuring and regulations, making industry conduct revaluation inevitable. The main concern in restructuring the natural gas industry in these economies is how to break previously vertically integrated companies into separate business entities under an appropriate market structure along the gas value chain. There are two schools of thoughts on how to restructure the natural gas industry. The traditional school of thought favours a vertically integrated structure and the liberal school of thought advocates for competitive-based structures encompassing different regulatory reforms including ownership unbundling. The natural gas industry in Ghana, though nascent, is growing due mainly to rising demand for electricity, at about 5.8% annually. Currently GNPC owns the upstream gas, midstream infrastructures and champions final gas delivery to downstream consumers. Gas price harmonization, easing contractual agreements, maintaining the survival of GNGC, and energy security reasons are among the policy factors that seem to favour a state-owned vertically integrated structure. The aim of this paper is to examine and determine the industry structure that is optimal to sustain Ghana energy supply mix. The paper offers two natural gas industry structure models to describe the effect of unbundling infrastructure ownership of natural gas along its value chain on energy supply mix in Ghana. The paper suggests maintaining the aggregating role of GNPC is appropriate. However, the paper recommends unbundling infrastructure ownership from upstream natural gas owners. Thus, the Gas Processing Plants and Ghana National Gas Company (GNGC) transmission pipelines need an independent entity to operate the GNGC transmission pipeline as the National Gas Transmission Utility (NGTU) with open access allow IPPs equal access to natural gas at the market hubs.