1 / 21

Electrochemical methods for monitoring and cleansing of H 2 S in the Black Sea using green energy

Electrochemical methods for monitoring and cleansing of H 2 S in the Black Sea using green energy. K. Petrov 1 , S. Z. Baykara 2 , D. Ebrasu 3 , M. Gulin 4 and A. Veziroglu 5. 1 Institute of Electrochemistry and Energy Systems of Bulgarian Academy of Sciences, Sofia, Bulgaria

gurit
Download Presentation

Electrochemical methods for monitoring and cleansing of H 2 S in the Black Sea using green energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electrochemical methods for monitoring and cleansing of H2S in the Black Sea using green energy K. Petrov1, S. Z. Baykara2, D. Ebrasu3, M. Gulin4 and A. Veziroglu5 1 Institute of Electrochemistry and Energy Systems of Bulgarian Academy of Sciences, Sofia, Bulgaria 2 Chemical Engineering Department, Yildiz Technical University, Davutpasa Campus, Topkapı, Istanbul, Turkey 3 National Institute for Cryogenics and Isotopic Technologies, Rm. Valcea, Romania 4 A.O. Kovalevsky Institute of Biology of the Southern Seas, Oceanology Centre, NationalAcademy of Science of Ukraine (OC-IBSS)- Sevastopol, Ukraine 5 International Association for Hydrogen Energy, Miami, USA

  2. Outlook • Introduction • Method for direct electrolysis of H2S from Black Sea Waters • Feasibility study • System for “in situ’ monitoring of Black Sea environment

  3. Introduction Black Sea is an elliptical basin with an area of 423.000 km2. More than 100 million people live around its coast. Black Sea is unique because 90% of the sea water is anaerobic. H2S is produced by sulphur reducing bacteria at an approximate rate of 10 000 tons per day. It keeps reducing the life in the Black Sea. Oxygen–hydrogen sulphide interface is established at about 70 -140 m below the surface.

  4. Map of the Black Sea

  5. Concentration of H2S and O2 in Black Sea water from different authors

  6. H2S content in Black Sea waters (HS-, 14% H2S (g)) Hydrogen sulphide Sigma-t 16.20 Depth, m Years Variation of oxygen – Hydrogen sulphide interface during the last century by Eremeev – Konovalov (OC-IBSS – Sevastopol)

  7. Main Idea • The main idea is to exploit the potential of Hydrogen sulphide (H2S) in the Black Sea waters for production of hydrogen, sulphides (sulphur) and sweet water using green energy sources like sun and wind. • The originality of the project is based on the thermodynamical possibility to produce hydrogen from H2S with much less energy than from water (H2O). The thermodynamical potential for splitting water to Hydrogen and Oxygen is E=1.23 V, compared with E=0.17 V for H2S. • Additionally to Hydrogen, electrolysis of H2S is producing polysulphides, which is valuable commercial product. • Proposed technological process and Feasibility study

  8. Flowchart of the process in consideration

  9. Feasibility study • Demonstrational pilot installation processing 200 m3/hr Sea water have been considered, Q = 200 m3/hr = 0.06 l/sec • Environmental evaluation of the proposed technology • Technical evaluation of different processes for H2S conversion: • Transportation of H2S containing water from the depth of the Black Sea • Extraction of H2S from sea waters by absorbents • Electrochemical production of hydrogen and polysulphides; • Economical feasibility

  10. Environmental evaluation of the proposed technology • Natural water conditions as well as the endemic biological communities are extraordinary and must be protected. • Unique spatial structure of the Black Sea basin can be sensitive to disturbances. Contamination of the uppermost, photosynthetic layer of the Black Sea by its deep waters can produce an effect of anthropogenic upwelling and strong intensification of already observable eutrophication. • Suggested technologies intend to move big volumes of deep Black Sea water.Outlet of technologically discharged deep-sea waters into the superficial layer of the Black Sea is definitely impossible. • Vertical fluctuations of the oxic/anoxic interface of the Black Sea can reach down to 165-meter depth. Hence, environmentally appropriated technology for back discharge of waters after absorption of H2S should be carried out to the depths which are not less than 200 m.

  11. Technical evaluation of processes included in technological scheme • Preliminary technical considerations: Demonstrational pilot installation processing 200 m3/hr Sea water have been considered: FR = Q = 200 m3/hr = 0.06 l/sec Concentration of H2S: C H2S = 8 mg/l. Length of the pipeline (LP) - closest to the shore depth of 1000 m: LP = 15 kM The depth of pumping (DP) of Sea water: DP = 1000 m Depth of Return: DR=200 m.

  12. 60 m 200 m m 1000 m Transportation of H2S containing water from the depth of the Black Sea Scheme of pumping water from the bottom of the Sea. ∆h=1000 m. “Grundfoss” pump, Q = 216 m3/hr; P = 60 kW; Polymer pipe with D 400 мм

  13. NaOH Sea water NaOH + HS- H2S Adsorption/Desorption Installation Adsorption of H2S from Sea water: Q=200m3/h; CH2S= 8mg/l; which makes 1,6 kg H2S Active carbon AD3 produced in “Buzau”, Romania: Adsorption capacity: aH2S = 0.0021 g H2S/g AD3 Relative weight of AD3 is RW= 400g/l Amount of AD3 = 760 kg ≈ 800 kg; 800 kg at RW=400g/l is equal to 2 m3. We chose 2,5m3 of carbon for reserve. Columns dimensions: diameter Ф=900mm and height H=1800; volume = 1,1m3 or 3,3m3 Desorption of H2S from carbon with NaOH Second group of three columns: about 200l NaOH, CNaOH =10g/l.

  14. Electrolysis Cell parameters of flow-type electrolyzer: long term test of 500 hrs at following conditions: NaOH=2M; NaSH=8M; T=80oC; cathode from Raney- nickel; anode is La0.79Sr0.20Mn403; Nafion membrane; Ecell=1.0 V at i=300 mA.cm-2; cathodic efficiency ≈ 100 %; polysulfide chain length - S6S- . There are not commercial H2S electrolyzers on the market. Similar to them are PEM water electrolyzers as a construction and price. The energy required for 1600g H2S/hr ≈ 2.5 kWhr. The produced Hydrogen ≈ 100 ghr, or 1000 l H2/hr and poly-sulfides ≈ 1500 g/hr.

  15. Economic Feasibility The economical feasibility is approximation of what is offered on the market. [polymer pipe differ between 30 Euro/m (FENIX) up to 80 Euro/m (REHAU)] All prices are in Euro Equipment: • 1.Transportation of Sea water: 1 300 000 Pump, Q = 200 m3/hr; P = 60 kW – 25 000; plus installment ≈ 50 000 Polymer pipe with Ф 400 мм – 80 Euro/m; For 15 000m – 1 200 000 Installment - 50 000. • 2. Electrolyzer: 2.5 kW ≈ 25 000 • 3. Adsorption – desorption unit: 21 000 Adsorption columns - Ф900 мм; Н1800 мм; V=1.1 м3, 6 by 3000 ≈ 20 000 Active carbon: 2 tons by 300 – 600. • 4. Evaporator – 10 000 • 5. Tanks for hydrogen and poly-sulfides – around 10 000 • Total: 1 400 000

  16. Economic Feasibility (2) Energy: 130 Euro • 1.Transportation of Sea water: 80 kWhr • 2. Electrolysis: 2.5 kWhr • 3. Evaporator: 100 kWhr Total: 182.5 ≈ 200 kWhr; . For 8 000 hr per year: ≈ 1.6 mWhr (price of 1 mWhr is 80 Euro) Total price of equipment and energy ≈ 1 400 000 Euro Conclusions The biggest share of the cost belongs to the pipeline. Probably we should contact the specialists from gas pipeline companies in order to find a cheaper (real) solution. If we assume that the installation will work 50 years the expenses per year will be approximately ≈ 28 000 Euro per year.

  17. Economic Feasibility (3) Products of the installation Hydrogen ≈ 100 ghr, or 1000 l H2/hr and poly-sulfides are about 1500 g/hr. For 8000 working hours per year the installation will produce: 8 000 m3 of Hydrogen and 12.0 tons of polysulfides Price of sulfur – 500 $/ton. (350 Euro/ton) for 12.0 tons – 4200 Euro Price of Hydrogen – 0.20 Euro/m3, market price; 3.0 Euro/m3, proposed EU price for renewable energy sources, or 8 000 m3 x 3.0 Euro = 24 000 Euro Total; 24 000 +4 200 ≈ 28 200 Euro

  18. System for “in situ’ monitoring of Black Sea environment Oceanographic stations in the SeaNet network in the North Sea

  19. Conclusions Conclusions The preliminary feasibility study of the proposed technology shows that the process of producing Hydrogen and poly-sulfides from Black Sea water is close to reach economic feasibility at supported by EU price of Hydrogen. The proposed technologies seems to be applicable for cleansing industrial H2S containing waters as well as some natural sources close to the ground. The biggest challenge is to coordinate the efforts of scientific, environmental, political, etc. organizations to really work on saving the Black Sea ecological system The preliminary feasibility study of the proposed technology shows that the process of producing Hydrogen and poly-sulfides from Black Sea water is close to reach economic feasibility at supported by EU price of Hydrogen. The proposed technologies seems to be applicable for cleansing industrial H2S containing waters as well as some natural sources close to the ground. The biggest challenge is to coordinate the efforts of scientific, environmental, political, etc. organizations to really work on saving the Black Sea ecological system

  20. Clean, Gas, Solution NaOH SO2 3 1 1 2 NaOH + H2S 5 4 S6S- + xNaOH 6 SO2 H2S , Gas, Solution S6S- x-yNaOH 7 Simultaneous redox reactions for cleansing H2S with SO2(alkaline solution) 2H2S + SO2 = 3S + 2H2O Spread micro-galvanic elements at corrosion potential

  21. Clean gas 1 2 SO2 Clean water Sulphur Waste water + H2S Simultaneous redox reactions for cleansing H2S with SO2(acidic solution)

More Related