New Compounds For Hydrogen Sulfide Scavenging And Iron Sulfide Control

2011 ◽  
Author(s):  
Carl W. Aften ◽  
Gayla Roberts
Keyword(s):  
Hydrogen Sulfide ◽  
Iron Sulfide ◽  
New Compounds ◽  
Sulfide Control

scholarly journals Electrochemical removal of pyrite scale using green formulations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Musa Ahmed ◽  
Ibnelwaleed A. Hussein ◽  
Abdulmujeeb T. Onawole ◽  
Mohammed A. Saad ◽  
Mazen Khaled
Keyword(s):  
Hydrogen Sulfide ◽  
Current Density ◽  
Iron Sulfide ◽  
Chelating Agent ◽  
Electrical Current ◽  
Electrochemical Process ◽  
Chemical Dissolution ◽  
Hydrocarbon Production ◽  
Rotational Rate ◽  
Diethylenetriamine Pentaacetic Acid

AbstractPyrite scale formation is a critical problem in the hydrocarbon production industry; it affects the flow of hydrocarbon within the reservoir and the surface facilities. Treatments with inorganic acids, such as HCl, results in generation toxic hydrogen sulfide, high corrosion rates, and low dissolving power. In this work, the dissolution of pyrite scale is enhanced by the introduction of electrical current to aid the chemical dissolution. The electrolytes used in this study are chemical formulations mainly composed of diethylenetriamine-pentaacetic acid–potassium (DTPAK5) with potassium carbonate; diethylenetriamine pentaacetic acid sodium-based (DTPANa5), and l-glutamic acid-N, N-diacetic acid (GLDA). DTPA and GLDA have shown some ability to dissolve iron sulfide without generating hydrogen sulfide. The effect of these chemical formulations, disc rotational rate and current density on the electro-assisted dissolution of pyrite are investigated using Galvanostatic experiments at room temperature. The total iron dissolved of pyrite using the electrochemical process is more than 400 times higher than the chemical dissolution using the same chelating agent-based formulation and under the same conditions. The dissolution rate increased by 12-folds with the increase of current density from 5 to 50 mA/cm2. Acid and neutral formulations had better dissolution capacities than basic ones. In addition, doubling the rotational rate did not yield a significant increase in electro-assisted pyrite scale dissolution. XPS analysis confirmed the electrochemical dissolution is mainly due to oxidation of Fe2+ on pyrite surface lattice to Fe3+. The results obtained in this study suggest that electro-assisted dissolution is a promising technique for scale removal.

New Technology of Base Metals Precipitation by Hydrogen Sulfide Obtained Using Desulfurella acetivorans and Desulfurella kamchatkenis

2015 ◽  
Vol 1130 ◽  
pp. 477-481 ◽  
Author(s):  
Aleksandra N. Mikhailova ◽  
A.A. Faiberg ◽  
S.S. Gudkov ◽  
V.Ye. Dementev
Keyword(s):  
Hydrogen Sulfide ◽  
Electron Donor ◽  
Iron Sulfide ◽  
New Technology ◽  
Base Metals ◽  
Total Consumption ◽  
Thermophilic Microorganisms ◽  
Selective Precipitation ◽  
Sulfide Production ◽  
Hydrogen Sulfide Production

Nowadays, efficient recovery of base metals from the solutions when processing gold ores is a topical issue. In this connection, the focus is on the use of hydrogen sulfide produced in bioreactors using sulfate-reducing (SRB) and sulfur-reducing bacteria. A new technology of biogenic hydrogen sulfide production followed by the precipitation of base metals from the solutions as sulfides was developed. The strains of anaerobic sulfidogenic thermophilic microorganisms: Desulfurellaacetrivans and DesulfurellaKamchatkensis which were obtained at S.N.Vinogradsky Institute of Microbiology RAS, Moscow were used for these tests. They have anaerobic respiration using sodium acetate as an electron donor and elemental sulfur as an electron acceptor. In order to cut costs for biogenic hydrogen sulfide production, the possibility of using acetic acid as an electron donor was studied. Scaled-up test work was conducted in a 1.5L bioreactor at the temperature of 55°C, pH of 5.0, redox of-250mV and using POX solution with the content of C2+=5700.0 mg/L, Fe2+=4890.0 mg/L and Zn2+=1200.0 mg/ L. Selective precipitation of copper (at pH of ≤0.5), zinc (pH=1.0-2.0) and iron (II) (pH≥5.5) was carried out. Recycled gas contacted with the metals solutions (in a series of reactors for the precipitation of metals) coupled with the removal of hydrosulfuric acid from the recycled gas and the recovery of metals from the solution as sulfides. The precipitate was separated from the solutions by filtering. Then the filtrate was directed to the next stage. Carbon dioxide was removed from the recycled gas by filtrating through alkaline solution. After that, about 10% of ultra high purity nitrogen was added from the balloon and the recycled gas was again directed to the bioreactor. The average hydrogen sulfide reactor throughput was 1 g/L per day of culture medium. The total consumption of hydrogen sulfide was 1.28 g/L of the process solution. Results showed that this process can selectively recover metals from POX solutions with generation of high grade copper (50%), zinc (45%) and iron sulfide (45%) concentrates.

RESEARCH OF THE PROCESS OF CLEANING BIOGAS FROM SULFUR COMPOUNDS USING THE VORTEX LAYER APPARATUS

2020 ◽  
Vol 4 (41) ◽  
pp. 63-67
Author(s):  
DMITRIY KOVALEV ◽  
◽  
ANDREY KOVALEV
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Iron Sulfide ◽  
Magnetic Layer ◽  
Sulfur Compounds ◽  
Research Purpose ◽  
Working Chamber ◽  
Vortex Layer ◽  
Information Research ◽  
Ferromagnetic Particles

The use of biogas for the operation of recycling equipment in its pure form is unacceptable due to the high content of sulfur compounds (hydrogen sulfide), which leads to corrosion of metal parts of the equipment contacting with biogas and reduces its service life. The article considers various ways of cleaning biogas from sulfur compounds. (Research purpose) The research purpose is in studying the process of biogas purification from sulfur compounds by sulfonating in the vortex layer apparatus. (Materials and methods) The laboratory of bioenergetic and supercritical technologies of VIM created an experimental device of a vortex magnetic layer. Authors used information research methods, including standard analytical methods of modern system approach, processing and analysis. (Results and discussion) The amount of hydrogen sulfide in the biogas was sharply reduced and when the gas stayed in the working chamber for 5 minutes, it did not exceed 20 parts per million. The concentration of carbon dioxide decreased slightly. The water in the working chamber of the installation serves as a solvent for incoming gases, and the ferromagnetic particles, when worn out, form a fine (20-50 micrometers) iron powder, which reacts chemically with dissolved hydrogen sulfide to form iron sulfide. Fast-rotating ferromagnetic particles create a large contact surface of liquid and gas, which improves the absorption of hydrogen sulfide and carbon dioxide. (Conclusions) It is possible to purify biogas from sulfur compounds by sulfonating in the vortex layer apparatus. The article proposes a method for improving the cleaning process by increasing the pressure and reducing the temperature of water in the working chamber of the vortex layer apparatus.

Management of Discolored Tooth with separated Instrument

2017 ◽  
Vol 2 (1) ◽  
pp. 36-39
Author(s):  
Aadit Anilkumar ◽  
Faisal Nazar ◽  
Ratheesh Rajendran
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrogen Sulfide ◽  
Root Canal ◽  
Iron Sulfide ◽  
Tooth Bleaching ◽  
Sodium Perborate ◽  
Root Canal Preparation ◽  
Tooth Structure ◽  
Tooth Discoloration ◽  
The Common

ABSTRACT Tooth discoloration commonly occurs after trauma to tooth, which leads to pulpal injury. Trauma to the pulpal blood vessel leads to hemorrhage and releases iron from hemoglobin. The iron which is released from hemoglobin combines with hydrogen sulfide to form iron sulfide, which gives the tooth its characteristic dark appearance. Tooth discoloration can be treated by nonvital tooth bleaching, if the tooth structure is intact. A combination of hydrogen peroxide and sodium perborate reduces the discoloration of the tooth by a process of oxidation. During root canal preparation procedures, the common mishap that occurs is instrument separation inside the root canal. The fractured fragment in the root canal can hinder proper preparation of root canal space. Continuous pain or discomfort may result if it is not removed or bypassed. It is more conservative to bypass the fractured instrument, particularly in cases where access to the fragment is restricted (apical one-third of canal or beyond the canal curvature) and its removal may lead to excessive removal of dentin with associated sequelae. How to cite this article Rajendran R, Nair KR, Kuriakose MC, Anilkumar A, Nazar F. Management of Discolored Tooth with separated Instrument. Cons Dent Endod J 2017;2(1):36-39.

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