Features of monitoring storage of methane-hydrogen mixtures

The storage of methane-hydrogen mixtures (MHM) in existing underground gas storage facilities (UGS) is a prerequisite for the development of a "carbonneutral" strategy of the Russian Federation. The use of technologies for storage and delivery of MHM in industrial volumes should be ensured by experimental research, the creation of a regulatory framework and the introduction of modern methods for maintaining the operational reliability of the existing Unified Gas Transportation System (UGSS). The need for scientific and project work is determined by the peculiarities of the storage of MHM and the assessment of the likelihood of negative technogenic and mechanical consequences during the operation of the equipment. The materials provide the main risk models of the processes that arise in the case of hybrid storage of MHM. The use of cluster technology for storage and transportation of MHM is proposed, and the need to ensure constant monitoring of the component composition of gas as part of the implementation of an integrated automated flow technology is shown. Keywords: methane-hydrogen mixtures; hydrogen energy; underground gas storage; hardware control; risks.

Research of the possibilities of the existing transport system in Russia for the transportation of goods and methane-hydrogen mixtures for export

The theory of using hydrogen and hydrogen-methane mixtures (HMC) assumes the operation of an industrial cluster created in the presence of significant reserves of methane, excess electricity, trunk pipeline facilities for transportation and storage, as well as contracts for the supply of mixtures to the domestic market and export. For a balanced decision on the use of existing facilities of the gas transmission network and underground storage facilities for methane-hydrogen mixtures, determination of transit volumes, additional research is required in order to take into account the peculiarities of the behaviour of hydrogen and its mixtures. The authors carried out work to systematize the features of production and storage, assess the consequences of accompanying negative effects to maintain the operational reliability of the production complex. Taking into account the preliminary results, additional research and the adoption of national and industry standards are required before starting significant investments in the creation of a hydrogen energy industry.

RESEARCH OF THE PHYSICAL PROPERTIES OF DIESEL FUEL-HYDROGEN MIXTURES

The change in the viscosity of diesel fuel with dissolved hydrogen, the rate of dissolution of hydrogen in the diesel fuel, and the hydrogen diffusion coefficient in diesel fuel were experimentally determined. Dissolving hydrogen in liquid fuel changes its physical-chemical properties. It has been found that the viscosity and density of diesel fuel change little when it is saturated with hydrogen. The flashpoint in a closed crucible is reduced by 3–4 °C. The rate of dissolution of hydrogen in diesel fuel has been investigated. It has been found that the diffusion coefficient of hydrogen in diesel fuel depends significantly on the initial concentration of H2 in the fuel. The liquid fuel is advisable to supply with saturated hydrogen for the safety of the heat engine operation. The design of the hydrogen fuel saturation system with a special hydrogen sensor based on the MQ-8 sensor was proposed. The system of protection of the research stand from unauthorized emissions of hydrogen into the environment has been worked out. The protection ensures the shutdown of the stand equipment when the hydrogen concentration in the zone of its generation and supply to the fuel is at the level of 1%.

Experimental Study of Biogas–Hydrogen Mixtures Combustion in Conventional Natural Gas Systems

Biogas is a renewable gas with low heat energy, which makes it extremely difficult to use as fuel in conventional natural gas equipment. Nonetheless, the use of hydrogen as a biogas additive has proven to have a beneficial effect on flame stability and combustion behavior. This study evaluates the biogas–hydrogen combustion in a conventional natural gas burner able to work up to 100 kW. Tests were performed for three different compositions of biogas: BG70 (30% CO2), BG60 (40% CO2), and BG50 (50% CO2). To achieve better flame stability, each biogas was enriched with hydrogen from 5% to 25%. The difficulty of burning biogas in conventional systems was proven, as the burner does not ignite when the biogas composition contains more than 40% of CO2. The best improvements were obtained at 5% hydrogen composition since the exhaust gas temperature and, thus, the enthalpy, rises by 80% for BG70 and 65% for BG60. The stability map reveals that pure biogas combustion is unstable in BG70 and BG60; when the CO2 content is 50%, ignition is inhibited. The properties change slightly when the hydrogen concentrations are more than 20% in the fuel gas and do not necessarily improve.