Complex In Iran Research Articles

Efficient recovery of organic phase from crud in solvent extraction unit of Sarcheshmeh copper complex in Iran by powerful water-absorbent reagents

The formation of stable multi-phase emulsions (crud) is a serious problem in almost all commercial solvent extraction (SX) plants. Crud is a mixture of organic and aqueous phases, air, and organic or inorganic solid particles, often found to distribute itself randomly throughout the separating phases of SX plants. Crud formation is encountered in almost all SX units in metal extraction plants. It causes the loss of solvent and thus increases the process costs. Therefore, the removal of crud and recovery of the expensive organic phase including diluent and extracting reagents from it is of great importance. In this research, the applicability of a range of powerful water absorbent reagents was studied for the recovery of organic phase from the crud formed in copper extraction/electrowining unit of Sarchashmeh copper complex (IRAN). The reagents included gypsum, carbomer, sodium polyacrylate, sodium sulfate, magnesium sulfate and calcium chloride. The results showed that gypsum, carbomer and sodium polyacrylate are effective additives which let the organic phase to be recovered with up to 95 % yield. To ensure that gypsum does not cause a negative effect on the copper loading and stripping of the recovered solvent, the extraction/stripping properties of the organic phase separated with gypsum was compared with the organic phase separated by centrifugation without additives. Surface tension analysis of the gypsum-recovered organic phase also confirmed its suitability for recovery of organic phase from crud. Finally, the calcium content of gypsum-recovered organic phase was measured and compared with that of the organic phase separated by centrifugation without any additive.

Potentials of greenhouse gas emission reduction through energy efficiency improvement in Iran's petrochemical sector

Reducing energy consumption and increasing energy efficiency is a key strategy to mitigate greenhouse gases (GHGs) in the petrochemical sector, both because of the high share of energy-related emissions and because of the economic attractiveness in terms of return on investment. This paper aims to calculate the GHG mitigation potentials of the energy reduction projects in Iran's petrochemical sector. firstly, we estimated the trend of GHG emissions until 2035 using data collected from the petrochemical complexes in Iran. Then, by assessing the energy audits and other studies, we calculated the energy consumption reduction potentials as well as their costs and benefits for petrochemical complexes. Finally, we modelled the energy supply and demand of the petrochemical sector in LEAP software to evaluate the mitigation potentials of the energy reduction projects. The results show that a 6.7 % emission reduction in the existing petrochemical complexes can be achieved with a capital of about 160 million dollars. The net present value of the projects will be about 2 billion dollars, and the cost of carbon reduction will be −60.7 dollars per ton. The results of this research can be used for policymakers to plan the mitigation pathway of the sector since the revenues obtained from the energy conservation measures can be used to fund capital-intensive GHG mitigation projects.

Taxonomic diversity of racerunners with descriptions of two new Eremias species (Sauria: Lacertidae) from Central Iran.

We provide a diversity assessment of Iranian species of the genus Eremias based on the cytochrome oxidase I mtDNA gene fragment. We analyzed 93 genetic samples from the entire distribution of the Eremias fasciata species complex in Iran and surrounding regions, along with morphological data to support the description of two new species from Central Iran. We hypothesize that the diversification of the Eremias fasciata species complex was largely influenced by the fragmentation of sand massifs in the region. This same hypothesis has been used to explain the high level of endemism among the sand-dwelling species of reptiles along the Iranian Plateau in the same area. The two new species described herein can be distinguished from other congeneric species by their phylogenetic position and a combination of morphological characters. We use these data to discuss the taxonomy of Eremias based on morphology, habitat choice, and genetic data.

An efficient method for recovery of organic phase from crud in solvent extraction unit of Sarcheshme copper complex in Iran by guar gum

One of the problems of all industries that use metal extraction with organic solvents is stable emulsions and finally the formation of crud. The formation of crud is usually accompanied by the loss of a significant amount of the causal solvent and thus increases the process costs. Therefore, the removal of crud and recovery of its organic phase is of particular importance. In this research, the applicability of polysaccharides such as guar gum, xanthane gum, Arabic gum and starch for recovery of organic phase from the crud formed in copper extraction/electrowining unit of Sarchashmeh copper complex (IRAN) was studied. The results showed that guar gum is an effective additive which let the organic phase to be recovered with up to 95% yield. To ensure that gum do not have a negative effect on the system and that the absorption and desorption of copper is done correctly, the extraction/stripping properties of the organic phase separated with guar gum is compared with the organic phase separated without additives. Surface tension analysis of the guar gum-recovered organic phase also confirmed the suitability of guar gum for recovery of organic phase from crud.

Proposal and investigation of CO2 capture from fired heater flue gases to increase methanol production: A case study

In a petrochemical complex in Iran, for production of 209575 kg of MeOH/h, 154,712 kg/h of flue gas with a CO2 concentration of 10.74 mol% enter the atmosphere through a fired heater. The target of this study is to investigate the effect of using post-combustion CO2 capture technology to reduce carbon dioxide emissions and use it to increase methanol production. In order to, the proposed process was simulated and effect of three different solvents, including piperazine (PZ) 30 wt%, monoethanolamine (MEA) 30 wt%, and a blend of MEA 20 wt %+ PZ 10 wt % were investigated. This study investigated solvent regeneration energy, CO2 absorption rate, energy efficiency, and exergy efficiency of stripper column. Simulation results showed PZ with 93% energy efficiency, 55.45% exergy efficiency of stripper column, CO2 emission intensity equal to 0.01 tCO2/tMeOH and lowest solvent regeneration energy equal to 2.6 GJreb/tCO2 has better performance than the other two solvents. Also, the simulation results showed that blending CO2 output from PZ solvent with syngas increases methanol production by 7.8%. The techno-economic analysis also indicated proposed process is more profitable than original process.

Development and validation of a task load index for process control room operators (PCRO-TLX)

Process control room operators (PCRO) perform a range of complex cognitive safety-critical tasks. The aim of this exploratory sequential mixed methods study was to develop an occupation specific tool to measure the task load of PCRO using NASA Task Load Index (TLX) methodology. Participants were 30 human factors experts and 146 PCRO at two refinery complexes in Iran. Dimensions were developed via a cognitive task analysis, a research review, and three expert panels. Six dimensions were identified: perceptual demand, performance, mental demand, time pressure, effort, and stress. Data from 120 PCRO confirmed that the developed PCRO-TLX has acceptable psychometric properties, and a comparison with the NASA-TLX confirmed that perceptual, not physical, demand was relevant for measuring workload in PCRO. There was a positive convergence of scores of the Subjective Workload Assessment Technique and the PCRO-TLX. This reliable tool (α = 0.83) is recommended for risk assessing the task load of PCRO. Practitioner summary: There are benefits of having a specific tool to measure task load in safety critical roles. Thus, we developed and validated an easy-to-use targeted tool, the PCRO-TLX, for process control room operatives. Timely use and response will assure optimal production alongside health and safety in an organisation. Abbreviations: PCRO: process control room operator; TLX: task load index; PCRO-TLX: process control room operator task load index; NASA-TLX: National Aeronautics and Space Administration task load index; SWAT: subjective workload assessment technique; DALI: driving activity load index; SURG-TLX: surgery task load index; SIM-TLX: virtual reality simulation task load index; VACP: visual, auditory, cognitive and psychomotor; CVI: content validity index; CVR: content validity ratio; RMSEA: root mean square of error approximation; GFI: goodness of fit index; AGFI: adjusted goodness of fit index; CFI: comparative fit index; ANOVA: analysis of variance; CI: confidence interval

A New Look at Excavation Techniques and Design of Rock-Cut Architectures

Rock-cut architecture is an essential yet little-known type of vernacular architecture whose nature is different from what we understand by the term “architecture”. This research seeks to answer the question of which technics, designs and digging procedures have been applied in this type of vernacular architecture. Out of the 300 rock-cut buildings and complexes found in Iran, nearly 70 were functionally assessed. Ten complexes were found to serve residential functions in different climates. Technique, type and the settlement context material were also briefly compared and contrasted, and thus, three general excavation techniques were recognized. The largest rock-cut residential complex in Iran, Meymand, was selected as the main case study. Fifty residential units in the oldest part of the village in two regions on both sides of the main valley were studied in terms of technique and design style. They were also compared and contrasted. The quantitative data obtained in this section were compared and contrasted using the descriptive statistical method. Although the rock-cut buildings are dispersed throughout Iran, three main techniques were employed to excavate them. Most of them were excavated using two or three of the said techniques. Application of the fine technique and the size of the particles constituting the settlement context are the two factors determining the quality of excavation. The findings in the area of special climatic design standards and technologies not only give us a better insight into rock-cut architecture but also contribute to setting some standards for design and construction of rock-cut buildings in the present era.

A systems dynamics simulation model of a steel supply chain-case study

Considering the complexity, interactions, and dynamics that permeate the Supply Chain (SC), computational modeling and simulation promote determining the system's behavior and decision-making. Among simulation techniques, system dynamics (SD) investigate on recognition of variables and their dynamic behavior trend throughout time in the SC. This paper presents a comprehensive SD model related to upstream steel SC management up to four echelons: concentrate, pellet, sponge iron, and steel. The model noticed Causal-Loops Diagrams (CLD) and Stock-Flow Diagrams (SFD) and provided a simulation framework. The robustness of the proposed model was evaluated by implementing the defined model in a multi-echelon steel complex in Iran. Various scenarios were analyzed applying stochastic simulation to include selected random variables. Iron ore grade and tonnage play the most critical role in the network’s performance. With an approximately 4% increase in the iron ore grade, steel production costs decreased 2.4%. The influence of the simultaneous uncertainty in iron ore grade and iron ore supply in the range of extreme levels of actual historical data resulted in an increase and decrease of +14% and −32% on the total steel production costs, respectively. Furthermore, removing energy subsidies and increasing five times in price results in a rise in total expenses up to 60% and a fall in the marginal profit up to 48%.

Improving Outdoor Thermal Comfort for Elderly in Residential Complexes

One of the crucial factors for the presence of more people outdoors is to create comfortable conditions. This issue is significant for the elderly due to the different physical conditions. The purpose of this study is to improve the micro-climatic condition around residential complexes considering the elderly in a linear type. For this purpose, two physical indicators, the ratio of the height of buildings to their distance from each other (H/D) and the orientation of them towards the street, were investigated. Regarding H/D, ratios of 0.5, 1, 1.5, and 2, and about the orientation factor, angles of 135° to 200° were examined. This study was conducted outdoors around residential complexes in Iran, Tabriz, with a cold semi-arid climate. Envi-met software model 4.4.5 was used for the simulation. The days June 22 and December 22, 2020 were selected as one of the hottest and coldest day of the year. Two indexes of the Predicted Mean Vote (PMV) and the Universal Thermal Climate Index (UTCI) were examined as essential thermal comfort indexes. Also, for validation, local and field data in six days (21, 22, 23 June in summer and 21, 22, 23 December in winter) were extracted and compared with the data of the software. The results display, the ratio of H/D=1.5 and the angles of 135° and 145° were the most suitable comfort conditions.

Optimized design of water-saving system in-slab cooling plant of Mobarakeh steel complex

The aim of this paper is to provide a solution to decrease water consumption in the slab-cooling unit of Mobarakeh Steel Complex in Iran. The plan should give an hourly decline in water consumption during a one-year operation period to calculate the annual reduction in water consumption of the proposed process. Recommended solutions for the conversion scheme of an existing wet cooling tower to a dry or hybrid cooling system require modeling of the slab cooling process. The curves of temperature drop in slabs are extracted in this paper by modeling the transient heat transfer of the slabs in the cooling process. This will reduce the computational volume. Then, the design and optimization of the hybrid cooling system done by the Genetic Algorithm (GA) is investigated. Accordingly, the objective function (reducing the costs of construction, operation, waste of water during the year) is chosen by single-objective method, and the modeling of the series hybrid system is done for the off-design mode during one year. The present design is for different scenarios and various savings of water consumption. The results demonstrate that if the control system is fitted with the sensitivities of the ambient temperature and also is based on the water consumption reduction and equipment design according to reliable standards, then the annual water consumption will be reduced by 88.3% (1.89 million m3). The payback period will be 3.63 years for the proposed system.

Applying machine learning techniques to implement the technical requirements of energy management systems in accordance with ISO 50001:2018, an industrial case study

ABSTRACT This article developed an innovative data-driven framework utilizing machine learning models to implement effective energy management systems in the energy-intensive industries to comply with ISO 50001:2018. By implementing this three-level framework, the following standard’s requirements are fulfilled: (a) indicating the variables that significantly affect energy performance, (b) energy performance indicator and energy baseline development, (c) analysis of the current energy performance, (d) energy conservation opportunity quantification, (e) determining the energy target, and (f) defining the energy action plan. The proposed data-driven energy management approach was implemented in an industrial-scale ethane decarbonization unit in South Pars Gas Complex in Iran. The dataset consists of 52,560 records of unit states sampled throughout 2020 as a baseline period. A high-accuracy model with 99% R-squared is developed by applying the Gradient Boosting Machines algorithm to predict the unit’s energy consumption as an energy baseline. As a critical finding, the offline analysis reveals a great potential to save energy by 10.31% or 63,119 metric tons of yearly steam consumption decreasing and a reduction of 7,027 tons of carbon dioxide emissions per year. By adjusting the unit working modes to the best practices, as an action plan, the intended outcome would be achievable.

The Relationship Between Cultural Intelligence (CQ), Spiritual Intelligence (SQ), and Interpersonal Communication Skills: The Case of Cultural Tour Guides

The present study aims to examine the relationship between spiritual intelligence (SQ) and cultural intelligence (CQ) and measure their impacts on interpersonal communication skills on cultural tour guides in a religious complex in Iran via structural equation modeling (SEM). The results of the survey show that there is a positive and significant relationship between SQ and CQ. Also, we found that CQ has a significant effect on interpersonal communication skills. The effect of SQ on communication skills was not supported in this study.

Exergoeconomic Analysis of the Cycle of Cogeneration of Power, Cooling and Freshwater for a Residential Complex in Iran

This research presents a system to use natural gas to meet electricity, freshwater and cooling needs for a residential building in Bandar Abbas. The system includes a gas turbine, absorption chiller and multi-effect desalination (MED) plant. The energy produced in the gas turbine is used to generate electricity, and the excess energy is used to produce cooling and freshwater. Finally, an exergoeconomic evaluation of the system is performed. The effects of ambient temperature on the output power as well as the exergy current have been investigated. The COP of the absorption cycle has been investigated, and the results show that at an operating temperature of 150∘C compared to 90∘C, the efficiency rate increases to 20%. The highest exergoeconomic cost rate is related to absorption chiller, and the lowest is related to heat recovery steam generation. The results show that if the ambient temperature increases, the production capacity decreases. Increasing the fuel flow rate increases the power. Evaluation of two different solutions to reduce the ambient temperature and increase the fuel flow shows that increasing the fuel flow is a better solution, considering the exergy cost of the absorption chiller, which is 10 times higher than that of the gas turbine.

The tracheal virome of broiler chickens with respiratory disease complex in Iran: the metagenomics study.

Background and Objectives:Avian respiratory disease complex (RDC) is one of the most detrimental economic diseases that affected different parts of the world. Various pathogens cause the disease, but the most significant viral pathogens include avian influenza virus (AIV), infectious bronchitis virus (IBV), and Newcastle disease virus (NDV) are the most prevalent. To detect these pathogens, various methods have been discovered in the last decades. Detection and characterization of viruses by metagenomics methods have improved our knowledge about the role of virome in the avian complex respiratory disease.Materials and Methods:This research investigates the viral pathogen populations that mostly participate in emerging these diseases using the NGS method RNA-sequencing. In surveillance of ten broiler farms from different cities with respiratory symptoms, trachea samples were collected to determine the pathogenic virome causing the disease.Results:In this metagenomics analysis, nine viral families were identified, comprising 72.82% of RNA viruses, 24.32% of RT viruses, and 2.86% of DNA viruses. RNA viruses had the highest contribution to the respiratory disease complex instead of disease, including paramyxoviridae, orthomyxoviridae, coronaviridae, and picornaviridae viruses. Other viruses from the RNA viruses and DNA virus families were also identified in addition to these results.Conclusion:This research suggests that studies of pathogenic viromes in different diseases can help monitor different diseases and predict their future occurrence.

Taxonomic investigation of the Xanthium strumarium L. complex (Asteraceae) distributed in Iran inferred from morphological, palynological and molecular data

Abstract. Noedoost F, Vaezi J, Nikzat Siahkolaee S. 2021. Taxonomic investigation of the Xanthium strumarium L. complex (Asteraceae) distributed in Iran inferred from morphological, palynological and molecular data. Biodiversitas 22: 1961-1974. Unclear species boundaries due to high morphological similarities lead to different opinions on Xanthium classification. To solve this problem, we conducted investigation on morphological, palynological and molecular (ITS sequencing) of three species of Xanthium (i.e., X. strumarium, X. sibiricum, and X. brasilicum) forming Xanthium strumarium complex in Iran. We randomly collected 110 plant individuals of the Xanthium strumarium complex as well as X. spinosum from 30 geographical populations in eight provinces of Iran. Pollen grains of 19 populations were studied by scanning electron microscope (SEM). Results obtained from the analysis of morphological characters showed that the three species, X. strumarium, X. brasilicum and X. sibiricum were placed nearly together specially X. strumarium and X. brasilicum are obviously overlapped. Palynological results indicated the pollen grains of section Acanthoxanthium (i.e., X. spinosum) and Xanthium (i.e., X. strumarium, X. sibiricum, and X. brasilicum) are clearly differing by their LM and SEM characters. However, no significant difference found between the pollen of X. strumarium and X. brasilicum. The Bayesian phylogenetic tree of the ITS region of rDNA sequences revealed that X. strumarium, X. sibiricum and X. brasilicum could not be discriminated as independent species. Overall, the morphological, palynological and molecular data provided evidence to synonymize X. brasilicum and X. strumarium with X. orientale and X. sibiricum with X. strumarium.

Risk and incident analysis on key safety performance indicators and anomalies feedback in south pars gas complex

Our research focused on the Health, Safety, and Environment (HSE) management systems. These issues impact business processes and organizations to achieve risk, incident, and anomaly feedback analysis. Our research goal was to investigate an HSE integrated management system’s impact on key safety performance indicators, a retrospective empirical nature. This system was done in phase one of the South Pars gas complex in Iran by using three safety indices; total recordable incident rate (TRIR), lost time injury frequency (LTIF), and total recordable cases frequency (TRCF). In this study, we investigate these indicators for contractors and operators in industrial and non-industrial areas. The data collected included accident reporting, incident analysis, and incident review for two years from April 2017 to March 2018. The results showed an essential difference in the number of hot spots between different safety indices in this period. In this study, the primary sources of accidents have been considered. The research results in total TRIR have not significant changes from Apr to Jun 2017, and its changes only amount to 0.03. The maximum value for TRIR decreased continuously, and the LTIF indicator value for both company and contractor is zero, while its target in 2017 and 2018 can get to 0.33 and 0.25, respectively. An essential part of the conclusions shows that defining indicators can help the immune system’s effectiveness, detecting malformed feedback, risk reduction, and continually improving the system.

Thermo-economic analysis and optimization of the steam absorption chiller network plant

Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modelling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modelling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the pay-back period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.

Removal of gas condensate from industrial wastewater using low‐cost adsorbents: Optimization by Box–Behnken design method

AbstractIn this study, three effective adsorbents such as Padina sanctae cruces algae (PSC), activated carbon (AC), and bentonite clay were used to remove gas condensates from industrial wastewater generated in the fourth refinery of South Pars Gas Complex in Iran. Physical and surface properties of the adsorbents were characterized using Brunauer–Emmett–Teller (BET), field‐emission scanning electron microscope, Fourier transform‐infrared spectroscopy, and energy dispersive X‐ray spectroscopy (EDAX) analyses. Also, droplet size distribution analysis was used to determine the size distribution of gas condensate droplets in the emulsion and to evaluate the emulsion stability. According to the BET analysis, the specific surface area of AC, PSC, and bentonite were obtained as 900.93, 0.0463, and 40.70 m2/g, respectively. To check the effect of different parameters on the removal efficiency of gas condensates, the Box–Behnken design method was used. Moreover, the optimal conditions for the removal of gas condensates included pH 9, temperature of 65°C, contact time of 120 min, and an adsorbent dosage of 5 g/L. Under such optimal conditions, the adsorption efficiencies using AC, PSC, and bentonite were obtained as 98.90%, 96.35%, and 97.24%, respectively. Furthermore, the maximum adsorption capacities of 1250, 54.95, and 99.01 mg/g were achieved using AC, PSC, and bentonite, respectively, in which AC showed the highest adsorption capacity ever achieved for the removal of gas condensate from wastewater. Besides, the thermodynamic study indicated that the sorption process was exothermic and spontaneous.

Analyzing the sensitivity and energy efficiency of a residential complex in warm and dry climate of Iran: the case study Yazd Province

In recent years, the limited energy sources and their huge costs in many countries to save money have attracted the attention of many scholars. The purpose of the energy consumption assessment of a building is to reduce the waste of the energy, and this reduction in the energy has a direct relationship to the lower costs. In this paper, the researcher tends to investigate the sensitivity and the energy analysis of a warm and dry residential complex in Iran (Yazd). Initially, the simulation of the energy consumption of a building was calculated by using the eQUEST software, to determine the thermal load of the building for a range of important parameters (such as wall insulation, roof and floor insulation, air penetration, glass type and window size). Then by using the SPSS software, the relationships have been extracted to connect the energy of the building with these factors. Then, by using the SPSS software, it attempted to connect a meaningful relationship between the energy consumption of the building and the mentioned factors. Also, the energy efficiency of the building was optimized by converting the data to the neural network, by using the genetic algorithm. Finally, this study was also carried out in warm and dry areas, to describe the accuracy of the results, and in each step, appropriate validations have been done.

Radiometric properties of virgin and cultivated soil around the Shazand Refinery Complex in Iran

Radiometric properties of virgin and cultivated soil around the Shazand Refinery Complex in Iran