scholarly journals Membrane Distillation Crystallization Hybrid Process for Zero Liquid Discharge in QAFCO Plant

2021 ◽  
Author(s):  
Mona Gulied ◽  
Sifani Zavahir ◽  
Tasneem Elmakki ◽  
Hazim Qiblawey ◽  
Bassim Hameed ◽  
...  
Keyword(s):  
Research Work ◽  
Membrane Distillation ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Hybrid Process ◽  
Optimum Operating ◽  
Low Grade ◽  
Water Recovery ◽  
Ongoing Research ◽  
Liquid Discharge

Qatar fertilizer company (QAFCO) is one of the world’s largest single site producer of ammonia and urea with production capacity of 12,900 metric tons per day. Currently, QAFCO faces major challenges in terms of water streams management that is generated from many processes such as wastewater from Harbor-Bosch process and brine solution from multi-stage flash (MSF) desalination process. To protect the environment; QAFCO has been making an effort to minimize the disposal of all types of water disposed into the sea. Here, this project proposes to develop a viable and economically effective process that can reach zero-liquid discharge (ZLD) of all processed water or wastewater from QAFCO facilities. The best method for ZLD is membrane distillation crystallization (MDC) hybrid process that concentrates and minimizes the volume of wastewater/brine streams to form solid through crystallizer. Membrane distillation (MD) is a thermally driven membrane process. It applies low-grade energy to create a thermal gradient across a microporous hydrophobic to vaporize water in the feed stream and condense the permeated vapor in the cold side. This research work aims to evaluate the performance of MDC for ZLD using commercial/fabricated electrospun nanofiber membrane (ENM) PVDF –base membranes at different type water streams. A general observation, higher water vapor flux and water recovery were exhibited at higher feed conductivity at 70°C. Moreover, the fabricated hydrophobic PVDF ENMs results confirmed the formation of nanofiber at the membrane surface using scanning electron microscopy (SEM). In addition, the water contact angle values of PVDF ENMs were greater than 100° and have stable mechanical and chemical properties. The ongoing research work will conduct a comparison between the optimum PVDF ENMs and the commercial MD membranes in terms of water recovery, salt rejection%, fouling/scaling, amount of collected solid and energy consumption at optimum operating conditions in MDC. In addition, it will perform a techno- economic feasibility assessment of the MDC hybrid process.

scholarly journals Feasibility and Cost Optimization study of Osmotic Assisted Reverse Osmosis Process for Brine Management

2020 ◽  
Author(s):  
Mona Hersi Gulied ◽  
Ahmed Al Nouss ◽  
Tasneem ElMakki ◽  
Fathima Sifani Zavahir ◽  
Dong Suk han
Keyword(s):  
Reverse Osmosis ◽  
Negative Impact ◽  
Minimum Energy ◽  
Research Work ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Solute Flux ◽  
Hydraulic Pressure ◽  
Feed Concentration ◽  
Ongoing Research

Due to the excessive demand to desalinate seawater to satisfy the domestic need in Qatar, it was needed to develop safe and cost effective desalination processes with the consideration of stringent regulation for water quality production and wastewater/brine discharge quality. The direct disposal of brines to the environment raised potential negative impact to the aquatic system and therefore the best practice is to minimize the volume of brine production and reuse it for beneficiary application. Several brine-dewatering techniques include both evaporative and non-evaporative approaches, which are capable to dewater high salinity brines with 50-350 g/L of total dissolved solids (TDS). The commonly adopted technology for dewatering brine is mechanical vapor compression that is known for its significant energy consumption up to 25 kWh/m3 of produced water for 50% of water recovery1. Non-evaporative membrane base technologies are a promising approach to dewater brines with minimum energy usage. Osmotically assisted reverse osmosis (OARO) is an advance membrane based technology for energy efficient and high recovery desalination of saline brine. OARO differ from reverse osmosis (RO) by adding saline sweep on permeate side to reduce osmotic pressure difference across the membrane to generate more water flux. The ongoing research work are based on mathematical/numerical approach that focuses on finding the optimum OARO configuration, inlet hydraulic pressure to avoid membrane burst and cost analysis. However, most of these studies are conducted by considering ideal conditions. In this study, an algorithm for simulating OARO process based on MATLAB and Aspen Plus to model membrane calculation and to design process configuration is considered to the effect of concentration polarization (CP) and reverse solute flux (RSF). The objective is to study the effect of inlet feed concentration and flowrate, sweep concentration and flowrate, inlet hydraulic pressure, number of stages, membrane size and characteristics and module configuration flow. In addition, technical economic analysis to evaluate the economic feasibility of OARO process. The stopping criteria of this model is the quality of water permeating at the feasible operating conditions and the cost. This model demonstrated high potential simulating OARO process to be used as a palate form for the user to predict the behavior of the process by varying operating conditions to desired outcomes.

Investigation of a Duct Burner Design Using CFD in Comparison With Full-Scale Experiments

2003 ◽  
Author(s):  
Michael A. Lorra ◽  
Carol A. Schnepper ◽  
Stephen Somers
Keyword(s):  
Experimental Testing ◽  
Full Range ◽  
Research Work ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Exhaust Gas ◽  
Ongoing Research ◽  
Water Steam ◽  
Duct Burner ◽  
Turbine Exhaust

Most new duct burners are supplied to heat recovery steam generator (HRSG) manufacturers for use in cogeneration systems. Key components of a simple cycle cogeneration plant include a turbine, generator, turbine exhaust gas duct, duct burner (optional), HRSG and downstream flue gas cleaning equipment. New developments in gas turbine technology are changing the boundary conditions for supplemental firing. In response, John Zink has an ongoing research project for the development of new duct burners achieving ultra low NOx emissions maintaining a good flame quality. The scope of this research work includes computational fluid dynamic modeling (CFD) and experimental testing of current design duct burner to obtain baseline data comparable with CFD results, and various experimental configurations through a full range of expected operating conditions. Experimental testing is performed in a test furnace at John Zink Company, Tulsa. Turbine exhaust gas (TEG) is simulated using John Zink Duct burners, which are supplied with air from a combustion air fan. Different O2 levels can be achieved by a combined water/steam injection. The temperature level of the TEG to the test burner can be adjusted with an air-cooled heat exchanger. Temperature and concentration measurements can be made at the test burner location and in the stack. Flame length, as well as NOx and CO emissions were measured for each data point. CFD modeling focused on the performance effects of turbine exhaust gas flow mal-distribution and the investigation on how reliable CFD models are, regarding flame stability calculations and NOx production. The results of this comprehensive testing and results from the CFD calculations will be compared and presented.

Evaluation of Natural Flocculants for Conventional Water Treatment

2012 ◽  
Vol 248 ◽  
pp. 298-303
Author(s):  
Ayo Samuel Afolabi ◽  
Rudzani Sigwadi ◽  
Ambali Saka Abdulkareem ◽  
Corina Mary Mateescu
Keyword(s):  
Developing Countries ◽  
Water Treatment ◽  
Water Purification ◽  
Guar Gum ◽  
Research Work ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Raw Water ◽  
Aluminium Sulphate ◽  
The World

Drinking water is contaminated from the chemicals and biological impurities around the world mostly in rural area. These contaminations may come from natural sources and leaching of waste deposits which cause a major human health hazard in many parts of the world. There has been very little scientific research work into the use of natural flocculants to purify raw water. Most of the research studies that have been done on conventional water purification in developing countries have focussed on conventional water purification systems using inorganic and poly-electrolyte flocculants. Such systems are very expensive for rural communities in these developing countries as our objective is to provide water that is safe for human consumption by using facilities which can be constructed and operated at a reasonable cost. There is a need to evaluate natural flocculants for conventional water treatment in order to develop inexpensive ways for developing countries to purify their water. In this study, the natural flocculants such as Moringa seeds powder, Guar Gum seeds powder, aluminium sulphate and polyelectrolyte were tested in a jar test apparatus to determine the optimum operating conditions for water or wastewater treatment plants. The results showed that the addition of Moringa Oleifera seeds powder, Guar Gum seeds powder, aluminium sulphate and polyelectrolyte flocculants improved the quality of raw water. The raw water samples from all treatment plants showed a reduction in turbidity that was more than 70% when all the four flocculants applied synergistically.

scholarly journals Study of Nickel Leaching Using Sulfuric Acid and Phosphoric Acid on The Selectivity Nickel Ore

2021 ◽  
Vol 16 (3) ◽  
pp. 393
Author(s):  
Syamsul Hidayat ◽  
Sri Yulianti ◽  
Dian Anggreini ◽  
Syamsul Bahtiar
Keyword(s):  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Nickel Content ◽  
Operating Time ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Low Grade ◽  
Atmospheric Conditions ◽  
Nickel Leaching

Study of nickel leaching using sulfuric acid and phosphoric acid on the selectivity of low-grade laterite nickel ore under atmospheric conditions has been successfully carried out. In this study, the laterite nickel leaching process was carried out by varying the solution concentration and operating time. The concentrations of sulfuric acid and phosphoric acid solutions were varied at 5 M and 6 M concentrations, while the operating time was varied at 4 hours and 6 hours. For other operating conditions, it is kept constant with an operating temperature of 90 ℃, pulp density 15% w / v, particle size ≤ 200 mesh. After that, the analysis stage was carried out using an atomic absorption spectroscopy (AAS) tool to determine the nickel content in the sample. The results showed that the highest nickel recovery was obtained at the concentration of 5 M sulfuric acid solution of 2.60% and 5 M phosphoric acid of 2.59% with the optimum operating time at 4 hours of operating time.

scholarly journals Electrocoagulation (EC) for Reduction of Chemical Oxygen Demand (COD) of Surface Water

2012 ◽  
Vol 47 (1) ◽  
pp. 77-82 ◽  
Author(s):  
SH Rahman ◽  
SMN Islam ◽  
N Kaiser ◽  
Md M Rahman
Keyword(s):  
Surface Water ◽  
Research Work ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Canal Surface ◽  
Canal Water ◽  
Time Period ◽  
Wide Range ◽  
Water Ph

Karnopara Canal water containing high COD values (1050 mg O2/L) was treated by electrocoagulation (EC) method covering a wide range of operating conditions such as, water pH, internal electrode distances, final pH, supplying 30V electricity for constant time period (30 minutes) through same electrode material (Al electrode). The effects of different operating parameters on the efficiency of the process were examined. Targeting to reduce the COD value within the recommended limit (200 mg O2/L), this research work was emphasized on EC treatment at the simplest and cheapest way. The batch experiment results showed that the high COD contained canal water can be effectively treated using electrocoagulation. The overall COD removal efficiencies have been obtained at 87.3%, under optimum operating conditions. Taking all the factors into account, it was found that polluted Karnopara canal water can be treated using EC consisting of Al electrodes without pre-adjustment of pH at laboratory. Therefore, EC technique to reduce high COD from canal surface water is found effective, cheaper and environmental friendly. DOI: http://dx.doi.org/10.3329/bjsir.v47i1.10728 Bangladesh J. Sci. Ind. Res. 47(1), 77-82, 2012

scholarly journals Electrodeposition of Zn-Co Alloy from an Acid Sulphate Bath Containing Triethanolamine and Thiaminehydrochloride

2021 ◽  
Vol 7 (1) ◽  
pp. 698-701
Author(s):  
V. Narasimhamurthy ◽  
L.H. Shivashankarappa
Keyword(s):  
Metal Ion ◽  
Alloy Composition ◽  
Research Work ◽  
Operating Conditions ◽  
Optimum Operating ◽  
X Ray Diffraction ◽  
Cathodic Current ◽  
X Ray ◽  
Acid Sulphate ◽  
Sulphate Bath

Electrodeposition of Zn-Co alloy from an acid sulphate bath has been carried out in this research work. The effects of metal ion ratio in the bath, pH current density, temperature, stirring, thickness and concentrations of triethanolamine and thiaminehydrochloride on the alloy composition and on cathodic current efficiency have been investigated. The deposition potentials of Zn-Co alloy are less noble of zinc and cobalt. The structure of Zn-Co alloy was investigated by X-ray diffraction indicates zinc structure. The surface morphology of alloy deposits is found to depend on the percentage of cobalt in the alloy. Under the optimum operating conditions, Zn-Co alloy deposition follows anomalous co-deposition.

scholarly journals Power generation from low grade waste heat using thermoelectric generator

2018 ◽  
Vol 64 ◽  
pp. 06005
Author(s):  
Rana Sohel ◽  
Iqbal Arbab ◽  
Date Abhijit ◽  
Akbarzadeh Aliakbar
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Heat Exchanger ◽  
Waste Heat ◽  
Electrical Power ◽  
Channel Length ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Low Grade ◽  
Optimum Flow Rate

Thermoelectric technology is thought to be a great solution in near future for producing electrical power and recovering low grade waste heat to cut the cost of power generation because of its consistency and eco-friendly affability. Though commercial accessibility of TEG is available currently but heat to electricity conversion efficiency is still low and cost of the module is reasonably high. It’s essential to use the modules competently which is strongly depends on suitable heat exchanger design and selection of proper operating conditions. In this work, TEG module has been selected from the commercially available modules with efficiency of 1.91% for the targeted low-grade waste heat temperature of Th=90°C and Tc=15°C which validated by experiment. Mathematical model has been proposed to simulate TEG based power generation system; the model can predict maximum net power, choose optimum operating conditions and dimensions of heat exchanger. Lab scale design with channel length 1 m, width 0.08 m and gap size 9 mm which is suitable for 50 TEG module (4 mm x 4 mm) have been simulated using proposed mathematical model. For above temperature range, predicted optimum net power was 76.45 W with optimum flow rate 0.94 L/s (56.4 L/min). This lab scale setup will be used for experimental validation of the proposed mathematical model. The obtained results from experiments and simulation are closely matched.

scholarly journals Experimental Evaluation of the Thermal Polarization in Direct Contact Membrane Distillation Using Electrospun Nanofiber Membranes Doped With Molecular Probes

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 638 ◽  
Author(s):  
Sergio Santoro ◽  
Ivan Vidorreta ◽  
Isabel Coelhoso ◽  
Joao Lima ◽  
Giovanni Desiderio ◽  
...  
Keyword(s):  
Experimental Evaluation ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Low Grade ◽  
Electrospun Nanofiber ◽  
Direct Contact Membrane Distillation ◽  
Thermal Polarization ◽  
Nanofiber Membranes ◽  
The Impact

Membrane distillation (MD) has recently gained considerable attention as a valid process for the production of fresh-water due to its ability to exploit low grade waste heat for operation and to ensure a nearly feed concentration-independent production of high-purity distillate. Limitations have been related to polarization phenomena negatively affecting the thermal efficiency of the process and, as a consequence, its productivity. Several theoretical models have been developed to predict the impact of the operating conditions of the process on the thermal polarization, but there is a lack of experimental validation. In this study, electrospun nanofiber membranes (ENMs) made of Poly(vinylidene fluoride) (PVDF) and doped with (1, 10-phenanthroline) ruthenium (II) Ru(phen)3 were tested at different operating conditions (i.e., temperature and velocity of the feed) in direct contact membrane distillation (DCMD). The temperature sensitive luminophore, Ru(phen)3, allowed the on-line and non-invasive mapping of the temperature at the membrane surface during the process and the experimental evaluation of the effect of the temperature and velocity of the feed on the thermal polarization.

Thermodynamic modelling of a membrane distillation crystallisation process for the treatment of mining wastewater

2015 ◽  
Vol 73 (3) ◽  
pp. 557-563 ◽  
Author(s):  
Jeeten Nathoo ◽  
Dyllon Garth Randall
Keyword(s):  
Membrane Fouling ◽  
Mining Industry ◽  
Calcium Sulphate ◽  
Membrane Distillation ◽  
Thermodynamic Modelling ◽  
Water Recovery ◽  
Liquid Discharge ◽  
Different Temperatures ◽  
Mining Wastewater ◽  
Crystallisation Process

Membrane distillation (MD) could be applicable in zero liquid discharge applications. This is due to the fact that MD is applicable at high salinity ranges which are generally outside the scope of reverse osmosis (RO) applications, although this requires proper management of precipitating salts to avoid membrane fouling. One way of managing these salts is with MD crystallisation (MDC). This paper focuses on the applicability of MDC for the treatment of mining wastewater by thermodynamically modelling the aqueous chemistry of the process at different temperatures. The paper is based on the typical brine generated from an RO process in the South African coal mining industry and investigates the effect water recovery and operating temperature have on the salts that are predicted to crystallise out, the sequence in which they will crystallise out and purities as a function of the water recovery. The study confirmed the efficacy of using thermodynamic modelling as a tool for investigating and predicting the crystallisation aspects of the MDC process. The key finding from this work was that, for an MDC process, a purer product can be obtained at higher operating temperatures and recoveries because of the inverse solubility of calcium sulphate.

scholarly journals Experimental Study and Analysis on Degradation of Oily Sludge from Process Equipment by Continuous Hybrid Treatment

2018 ◽  
Vol 24 (7) ◽  
pp. 35
Author(s):  
Mohammad Fadhil Abid ◽  
Luma Hussein Mahmod ◽  
Samer Talib Breesam ◽  
Wasen Samie
Keyword(s):  
Oil Recovery ◽  
Operating Conditions ◽  
Solid Particles ◽  
Oil Refinery ◽  
Hybrid Process ◽  
Optimum Operating ◽  
Process Equipment ◽  
Oily Sludge ◽  
Efficient Treatment ◽  
Hybrid Treatment

It is well known that petroleum refineries are considered the largest generator of oily sludge which may cause serious threats to the environment if disposed of without treatment. Throughout the present research, it can be said that a hybrid process including ultrasonic treatment coupled with froth floatation has been shown as a green efficient treatment of oily sludge waste from the bottom of crude oil tanks in Al-Daura refinery and able to get high yield of base oil recovery which is 65% at the optimum operating conditions (treatment time = 30 min, ultrasonic wave amplitude = 60 micron, and (solvent: oily sludge) ratio = 4). Experimental results showed that 83% of the solvent used was recovered meanwhile the main water which was separated from solid particles was reused. Three types of sonic probes were used to compare effects of their amplitude created. Results revealed that beyond optimum ultrasound intensity, the treating time has an adverse effect on process efficiency. Results proved that usage 0.05% NaOH during the proposed hybrid process increased the oil recovery from 50 to 65%. The proposed hybrid treatment method could represent an environmentally friendly treatment of waste sludge produced from an oil refinery.  

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