The pot experiment was conducted to access the soil microorganisms biomass (physiological method – Substrate Induced Respiration) and emissions of N2O, CO2 and CH4 (photoacoustic infrared detection method), and grasses biomass (weight method). The obtained results of analysed gases were converted to CO2 equivalent. There was no effect of the microorganisms biomass on the N2O emissions. The increase in CO2 emissions was accompanied by an increase in the microorganisms biomass (r = 0.48) under the conditions of the I swath and acid soil reaction, as well as the II swath and neutral reaction ( r = 0.94). On the other hand, in the case of CH4 emission, such a relationship was noted both swaths under the conditions of neutral reaction ( r = 0.51), but a negative correlation ( r = –0.71) was noted for the acid reaction only at the II swath. The increase in the grasses biomass with the increase in the microorganisms biomass was recorded only at the II swath in neutral reaction ( r = 0.91). In a short period of time, with the neutral soil reaction with the increase in the soil microorganisms biomass, an increase in CO2 sequestration and biomass of cultivated grasses was noted. Information on the determination of the microorganisms groups responsible mainly for the transformation of carbon compounds and CO2 and CH4 emissions from the soils of grasslands would be valuable scientifically.

Mordenite-zeolite supported Ca-Cu and Ba-Cu catalysts (Ca-Cu/MOR and Ba-Cu MOR) were successfully fabricated for direct decomposition of both NF3 and N2O gases contained in waste gas stream of (semiconductor) electronics industry. N2O conversion rates of Ca-Cu and Ba-Cu catalysts were 79 and 86%, respectively, at 700°C and 1 atm under space velocity of 5000 h–1. The Ca-Cu catalyst was especially noteworthy in that its capability of converting N2O could be maintained even after its exposure to co-feeding NF3 gas constituent in the waste gas stream. Compositional and surface morphological analyses of the Ca-Cu and Ba-Cu catalysts were made before and after exposure to the waste gas stream to examine any noticeable degradation or change of the catalysts. Unlike Ba-Cu catalyst, SiO2 constituent of the Ca-Cu catalyst was found to remain immune to the NF3-cofeeding waste gas stream, casting a positive prospect for superior and steady N2O decomposition performance via maintenance of its structural integrity.

Nitrous oxide is often used in the space industry, as an oxidiser or monopropellant, mostly in self-pressurised configurations. It has potential for growth in use due to the recent rising interest in green propellants. At the same time, modelling the behaviour of a self-pressurising nitrous oxide tank is a challenging task, and few accurate numerical models are currently available. Two-phase flow, heat transfer and rapid changes of mass and temperature in the investigated system all increase the difficulty of accurately predicting this process. To get a get better understanding of the emptying of a self-pressurised nitrous oxide tank, two models were developed: a phase equilibrium model (single node equilibrium), treating the control volume as a single node in equilibrium state, and a phase interface model, featuring a moving interface between parts of the investigated medium. The single node equilibrium model is a variation of equilibrium model previously described in the literature, while the phase interface model involves a novel approach. The results show that the models are able to capture general trends in the main parameters, such as pressure or temperature. The phase interface model predicts nitrous oxide as a liquid, a two-phase mixture, and vapour in the lower part of the tank, which is reflected in the dynamics of changes in pressure and mass flow rate. The models developed for self-pressurisation, while created for predicting nitrous oxide behaviour, could be adapted for other media in conditions near vapour– liquid equilibrium by adding appropriate state equations.