In order to gain a more mature share in the future energy supply, green gas supply chains face some interesting challenges. In this thesis green gas supply chains, based on codigestion of cow manure and maize, are considered. The produced biogas is upgraded to natural gas quality and injected into the existing distribution gas grid and thus replacing natural gas. Literature research showed that relatively much attention has been paid up to now to elements of such supply chains. Research into digestion technology, agricultural aspects of (energy) crops and logistics of biomass are examples of this. This knowledge is indispensable, but how this knowledge should be combined to help understand how future green gas systems may look like, remains a white spot in the current knowledge. This thesis is an effort to fill this gap. A practical but sound way of modeling green gassupply chains was developed, taking costs and sustainability criteria into account. The way such supply chains can deal with season dependent gas demand was also investigated. This research was further expanded into a geographical model to simulate several degrees of natural gas replacement by green gas. Finally, ways to optimize green gas supply chains in terms of energy efficiency and greenhouse gas reduction were explored.
Problems of energy security, diversification of energy sources, and improvement of technologies (including alternatives) for obtaining motor fuels have become a priority of science and practice today. Many scientists devote their scientific research to the problems of obtaining effective brands of alternative (reformulated) motor fuels. Our scientific school also deals with the problems of the rational use of traditional and alternative motor fuels.This article focused on advances in motor fuel synthesis using natural, associated, or biogas. Different raw materials are used for GTL technology: biomass, natural and associated petroleum gases. Modern approaches to feed gas purification, development of Gas-to-Liquid-technology based on Fischer–Tropsch synthesis, and liquid hydrocarbon mixture reforming are considered.Biological gas is produced in the process of decomposition of waste (manure, straw, grain, sawdust waste), sludge, and organic household waste by cellulosic anaerobic organisms with the participation of methane fermentation bacteria. When 1 tonne of organic matter decomposes, 250 to 500–600 cubic meters of biogas is produced. Experts of the Bioenergy Association of Ukraine estimate the volume of its production at 7.8 billion cubic meters per year. This is 25% of the total consumption of natural gas in Ukraine. This is a significant raw material potential for obtaining liquid hydrocarbons for components of motor fuels.We believe that the potential for gas-to-liquid synthetic motor fuels is associated with shale and coalfield gases (e.g. mine methane), methane hydrate, and biogas from biomass and household waste gases.
