The volatile nature of the renewable energy sources requires energy storage to compensate for the imbalances and to provide reliable base load. Power-to-Methane technology facilitates long-term high capacity renewable energy storage in the form of Synthetic Natural Gas (SNG) in the gas network. Unlike hydrogen, SNG usage in the network has no restrictions and natural gas appliances can operate on SNG. The two inputs required to produce SNG in the methanator are hydrogen and CO2 and they can be obtained from several sources. This leads to multiple possible process flow configurations in SNG production, each of them with varying performance. An optimization model has been developed in GAMS to analyse the performance of these various configurations. The objective of this research is to determine the optimal configuration, key cost factors and their effects on the production cost to identify the areas that require further development for cost reduction. This work also aims to determine the production cost per unit of SNG and the factors with most significant influence on the production cost by implementing a factorial design and a multivariate analysis (analysis of variance) approach. Methanator, electrolyser, biogas upgrader and hydrogen storage are considered as the fundamental process units in this work. The lowest production cost identified in the first year of production is 0.432 €/kWhSNG. The discounted production cost obtained shows that the lowest cost in 20 years from now is 0.143 €/kWhSNG. The variable with the most influence on the production cost is the capex of the methanator followed by the capacity of the methanator.

Experiments were performed in a pilot-scale bubbling fluidized bed gasification reactor with air as a fluidizing agent. Birch wood chips and sand particles were used as biomass and bed materials. Average molar product gas composition was 0.214 of CO, 0.212 of CO₂, 0.103 of H₂, 0.074 of CH₄ and 0.397 of N₂. A kinetics-based model was developed for the gasification process and simulated using commercial software Barracuda®. The model is validated against the measured gas compositions. The validated model was used to study the product gas compositions for olive waste and straw pellets. The effects of equivalence ratio (ER) on the product gas composition for birch wood was also studied in one of the simulations. Birch wood gave the highest (20.5 mole %) CO production rate and lowest (9.0 mole %) H₂ production rate. The product gas flow rate was 1.96 Nm³ per kg of biomass and the lower heating value of the product gas was 6.65 MJ/Nm³. The CO concentration decreased from 25 to 13.2 mole %, whereas CO₂ concentration increased from 17 to 19.5 mole % when increasing ER from 0.2 to 0.3. The CO and H₂ concentrations for the olive waste were 8.1 and 56.1 mole %. The CO and H₂ concentrations for the straw pellets were 6 and 73.4 mole %.

Biomasses in the forms of agricultural and forestry residues are gaining attention as alternative sources of energy due to various limitations of conventional sources of energy. Their applications as energy sources should be renewable and eco-friendly. The selection of biomass needs pairing with a suitable thermochemical process for the generation of biofuels and their precursors. This article communicates the investigation of acacia nilotica branch, bagasse, berry branch, coconut coir, corn cob, cotton stalk, groundnut shell, rice husk, rice straw and wheat straw as biomasses, for their considerations to ther-mochemical transformations. The authors explored the residues for their bulk density, calorific values, proximate analysis, ultimate analysis, ash fusibility characteristics and thermogravimetric analysis. The bulk density and calorific values of materials considered were quite low compared to that of conventional solid fuels. Therefore, they required palletisation for their economical utilisation as feedstocks for thermochemical conversions to energy carriers. The proximate analysis indicated that the fixed carbon:volatile matter of acacia nilotica branch was highest at 0.35, suggesting it as the most preferred feedstock for pyrolysis. The ultimate analysis showed that H/C (molar element ratios) of all residues were near to a constant value indicating the emissions of volatiles/gases were close to same quality after their specific thermochemical transformation. Ash deformation and fusion temperatures of mate- rials lied in the range of 900–1500°C, fixing the operating temperature limits for their transformations through combustors and gasifiers. Thermogravimetric analysis in the N₂ atmosphere indicated that the rate of pyrolysis was highest for all residues, in the temperature range of 300–500°C, suggesting the sufficiency of one reactor to carry out pyrolysis for the individual biomass. Thus, the analysis of biomasses for their thermochemical transformations is the prerequisite for their effective utilisations.

This paper provides an overview of the leading role that energy efficiency plays in the development of modern socio-economic systems, which serve as the foundation for building green economies. The main purpose of the paper is to develop a methodological toolkit for assessing energy efficiency of large industrial complexes and test it on the world’s largest metallurgical complexes. The central object of the research is the Ural Mining and Metallurgical Company (UMMC), which mainly specializes in the production of copper and copper-based products. The study follows a comparative analysis of a set of preliminary selected energy efficiency indicators obtained from UMMC with those of the world’s leading copper manufacturers and copper-based products. At the same time, in accordance with the methodical approach, it is proposed to divide the energy efficiency indicators of an industrial complex into three levels: the level of an industrial complex as a whole (1); the level of certain types of products manufactured in the industrial complex (2); the level of the technological process (3). To obtain summarized (synthetic) energy efficiency estimates of the industrial complex, the hierarchy analysis method has been proposed. For the comparative analysis of energy efficiency indicators of UMMC, the authors chose the following companies: Norilsk Nickel and Russian Copper Company and leading world companies, such as Glencore Xstrata Plc (Switzerland), Codelco (Chile), KGHM Polska Miedz SA (Poland), and Vedanta Resources (India). The obtained results revealed that UMMC strongly lags behind in a number of key energy efficiency indicators. During 2010–2016, a negative trend was observed in the majority of UMMC enterprises. The results also showed the practical applicability of the given methodical approach and the possibility of its wide use in solving energy efficiency problems of Russian industrial complexes for their strategic development.

Nowadays energy efficiency is a global concern for the maritime organization and business. Rising operating costs, mainly fuel prices and stricter environmental regulations are forcing the ship- ping industry to find more effective ways of designing and operating the ships in an energy-efficient manner. An analysis of the energy system of ships and understanding the different energy flows can contribute to better energy management and efficiency in the ships. Keeping this objective in mind, the energy systems of typical medium-sized container ships are analysed in this paper based on the vessel’s operating data and equipment parameters collected by the crew over three months. The study focuses on the energy and exergy balances of the main components. It has been shown that more than 80% of total energy consumption is caused by the propulsion plant, while the electric power generation accounts for 14–17%. Up to 60% of the energy supply is lost to the environment through the cooling system, radiation, friction and exhaust from diesel engines. Exergy losses caused by the exhaust gas and heat transfer are other contributors. Roughly 6% of the fuel exergy input is lost due to heat transfer. The exergy lost through the exhaust gas flue mainly from the main engine is estimated at 12% of the total exergy input. There is considerable potential for waste heat recovery on container vessels. However, to improve the overall energy efficiency, a techno-economic study has to be carried out on waste heat recovery solutions for each category of vessels and trading mode.

Environmental and Social Impact Assessment (ESIA) is a tool for an integrated assessment of multifac- eted impacts of a proposed project. ESIA can identify areas of potential conflicts and prevent conflicts from occurring early through appropriate mitigation measures. This notwithstanding, conflicts and public opposition arising from implementation of proposed projects which have been subjected to ESIA have been observed in various sectors in different countries and jurisdictions. Kenya is one of the African countries endowed with substantial renewable energy resources including geothermal, wind and solar energy resources. The country is now scaling up the development and utilization of these resources to meet growing energy demand. However, implementation of environmental procedures mainstreamed in the development of renewable energy resources, if inappropriately applied, has the potential to slow down development and exploitation trajectory of these resources. While all proposed renewable energy projects are subjected to the ESIA process, in some instances challenges have emerged at implementation resulting in conflicts that could be avoided. There is a clear need to understand, empirically, which of the ESIA procedural steps is critical in underpinning conflict identification for appropriate application. To determine how each of the ESIA procedural steps is likely to influence conflict identification, a statistical analysis was carried out for ESIA procedures based on questionnaire survey responses from sampled ESIA practitioners in Kenya. This article presents findings on the effect of ESIA procedural steps in conflict identification using cumulative odds ordinal logistic regression with proportional odds. Results show that the overall effect (on the dependent variable conflict identification) of the variables, public participation and monitoring is statically significant, χ2(2) = 9.12, p = 0.01 and χ2(2) = 6.29, p = 0.04, respectively. Further, the exponential of the log odds of the slope coefficients indicate that the independent variables public participation, decision making, project implementation and monitoring are statistically significant [χ2(1) = 9.12, p = 0.00; χ2(1) = 4.04, p = 0.04; χ2(1) = 3.64, p = 0.05 and χ2(1) = 3.31, p = 0.00, respectively]. That is to say these independent variables have a statistically significant effect on the dependent variable conflict identification.

Service organizations in today’s globalized competitive business environment engaged in marketing strategies are geared toward responding to consumer needs and preferences and, at the same time, improve their competitive edge. Investigating the determinants of consumer preference is one of the important approaches to improving competitive edge of petrol station business. Despite significant studies on consumer behavior, especially factors that affect a new brand or products, there is limited empirical investigation on the premise of determinants of consumer preference particularly in petrol station business, thus creating a gap in this area. To this effect, this article intends to contribute in filling the knowledge gap by investigating the determinants of consumer preference and their impact on service station business in the Gambia. This article also identifies key marketing strategies that petrol station business can use to increase their market share. Using non-probability convenience sampling, data were collected from 200 customers of petrol stations using self-administered questionnaires. Descriptive statistics, correlation and regression analysis were applied to analyze data using IBM SPSS statistics Version 22. The results of regression analysis identify marketing program and additional ser- vices out of the eight variables (marketing program, additional services, petrol station image, location, price, product assortment, service quality and management of service station) as the major determinants of service station consumer preference in the Gambia. This implies that petrol station companies should engage key marketing program strategies such as sales promotion, innovative product advertising, event sponsorship or association besides the provision of additional services like windscreen cleaning, water and air pumping, convenience store, fuel and motor product accessories sales plus services in order to increase sales as well as retain a large number of buyers as loyal customers.