The problem to be solved by the research work

Development of scientific and technological foundations for the creation of floating production facilities that will ensure efficient extraction of hydrogen sulphide from the Black Sea, production of hydrogen from it, and safe accumulation and transportation of hydrogen.

Object and subject of the research work

The object is the processes of hydrogen sulfide separation from seawater, hydrogen sulfide destruction, hydrogen separation, accumulation and transportation, as well as the design features of creating a floating production facility for their implementation. The subject is the laws and parameters of the processes of hydrogen sulfide separation and destruction, hydrogen separation and sorption.

Purpose of the research work

The goal is to develop a technology for floating production of hydrogen sulphide from the depths of the Black Sea with subsequent hydrogen production, its safe accumulation and transportation, as well as to establish rational parameters for the operation of such production, which will enable the efficient use of a new renewable energy resource in the economic complex of Ukraine and can be a competitive high-tech product in foreign markets.

Key performance indicators

List of articles in journals included in scientometric databases (Social Science Citation Index, Web of Science, Scopus, etc.) - 4Articles in journals included in the list of professional journals of Ukraine - 8Monographs and (or) chapters of monographs published in Ukrainian editions on the project topic in Ukrainian - 1 Monographs and/or chapters of monographs published in foreign publications in English or official languages of the European Union - 2Dissertations defended - 2Number of implementation agreements concluded - 2

Scientific results obtained

1. The fundamental composition of the floating production facility for hydrogen sulfide production, hydrogen production, safe hydrogen accumulation and transportation, consisting of a number of systems and subsystems, is determined: transportation of a mixture of hydrogen sulfide and seawater from the deep layers of the Black Sea, separation of hydrogen sulfide from seawater, production of gas containing hydrogen by hydrogen sulfide destruction, separation of hydrogen from the produced gas, hydrogen accumulation, and hydrogen transportation. 2. An analysis of modern methods of safe hydrogen accumulation and storage has shown that one of the safest storage systems is metal hydride batteries, in which hydrogen is stored at low pressure and can be supplied to consumers at high pressure. The absence of mechanically moving parts ensures high reliability of operation. 3. A mathematical model of floating hydrogen production based on a system of balance equations has been developed, which includes models of subsystems (hydrogen sulfide extraction from the Black Sea; separation of hydrogen sulfide and seawater; destruction of hydrogen sulfide to produce hydrogen sulfide gas; separation of hydrogen from hydrogen sulfide gas; safe hydrogen storage; safe hydrogen transportation), units (elements) and properties of energy carriers. 4. The influence of the submergence depth of the lifting pipeline on the supply pressure of the gas-liquid mixture at a relative hydrogen sulfide content in seawater of 2.5...10 m3/m3 is determined. 5. The thermal power required to be supplied to the thermochemical reactor for the destruction of hydrogen sulphide, depending on the degree of conversion at the production of 100...1000 m3/day of seawater, is determined. In this case, the use of a regeneration circuit will provide 96%...24% of the required thermal power for the relative content of hydrogen sulfide in seawater of 2.5 m3/m3, 56%...14% for 5 m3/m3, 45%...11% for 7.5 m3/m3, and 40%...10% for 10 m3/m3. 6. The dependence of the capsule length on its diameter, the thickness of the walls of the upper and lower bottoms and the shell of one capsule, as well as the specific mass of the structure in relation to the mass of the metal hydride battery was determined. For example, when using metal hydride materials of the lanthanum group, the mass of the structure is 30...40% of the mass of the metal hydride material. 7. Experimental studies have confirmed the feasibility and effectiveness of metal hydride technologies, and also allowed to obtain with sufficient accuracy the nature of changes in the main parameters of the process of hydrogen extraction from the gas mixture. The kinetic characteristics of the experimental unit were studied and the performance of the process of hydrogen extraction from the gas mixture was determined. The lowest hydrogen absorption rate is 0.9 g/min at a gas mixture pressure of 0.2 MPa and a temperature of 313 K. The maximum hydrogen absorption rate from the gas mixture reaches 2.3 g/min at a suspension temperature in the desorber of 298 K and a pressure of 0.3 MPa.

Scientific results obtained

8. The dynamics of the relative mass of hydrogen released from the high pressure of the accumulator/compressor depending on the heating temperature was determined. An increase in the heating temperature from 75 oC to 90 oC allows 95% of hydrogen to be released at high pressure. The suspension of the hydrogen-forming material absorbs hydrogen very quickly if the cooling water temperature is minimal. 9. Increasing the content of hydrogen-forming material in the suspension increases the thermal efficiency of the experimental unit for hydrogen extraction from the gas mixture and reduces the energy consumption for the operation of this unit. With an increase in the content of the hydride-forming compound, the energy consumption for heating the ballast silicone fluid, as well as the cost of its transportation, decreases. 10. The rational operating modes and limit values of the efficiency of using the technology for the production and safe accumulation of hydrogen from Black Sea hydrogen sulphide for daily hydrogen production of 200 kg/day were determined, depending on the degree of hydrogen sulphide conversion in the destruction reactor, the hydrogen sulphide gas content in seawater and the submergence depth of the lifting pipeline. 11. The minimum permissible conversion rate at which the efficiency of using the technology of hydrogen production and safe accumulation from Black Sea hydrogen sulphide is achieved for hydrogen sulphide content DH2S = 2.5...10 m3/m3 at the submergence depth of the lift pipeline H = 250...1000 m is xmin = 0.427...0.343. 12. The technical documentation for the creation of a 40 kg hydrogen battery was developed, namely, working drawings of a metal hydride battery, its module and technical requirements for manufacturing. 13. Technical documentation was developed for the creation of technological systems for a 40 kg hydrogen battery, namely: drawings of a hydrogen technological system, a vacuum technological system, a technological cooling and heating system, a technological system for personnel protection. 14. Technical documentation for the creation of an automatic control system for the hydrogen accumulator was developed, namely: drawings of the system scheme, wiring diagrams and its specification, specification of the designation of two-wire connectors of the system. Algorithms for the operation of the hydrogen accumulator in the main modes of its functioning were developed: primary vacuum leakage test, overpressure leakage test, activation of the powder in the hydrogen layer, desorption, absorption.