• Energy Research
• Closed Access close
• FI close

AbstractThe presented synthesis of the title compounds (II), (IV), (VI) and (VIII) is extremely simple and highly efficient without the use of any chromatographic purification.

Abstract Agricultural practice is facing multiple challenges under volatile commodity markets, inevitable climate change, mounting pest pressure and various other environment-related constraints. The objective of this research is to present a dynamic optimization model of crop rotations and farm management and show its suitability for economic analysis over a 30 year time period. In this model, we include management practices such as fertilization, fungicide treatment and liming, and apply it in a region in Southwestern Finland. Results show that (i) growing pest pressure favours the cultivation of wheat-oats and wheat-oilseeds combinations, while (ii) market prices largely determine the crops in the rotation plan and the specific management practices adopted. The flexibility of our model can also be utilized in evaluating the value of other management options such as new cultivars under different projections of future climate and market conditions.

The stomach of urethane-anaesthetised rats was perfused with 10% (v/v) ethanol. At 40 min, the secretion of acid was strongly inhibited and the contents of cyclic AMP and ATP were lowered in the superficial mucosa, but not in whole gastric mucosa. After discontinuation of the ethanol perfusion, the rate of gastric acid output as well as the cyclic AMP and ATP levels recovered. Most of the acid-secreting parietal cells were found in the superficial mucosa where the changes of cyclic AMP and ATP took place. The results suggest that lowering of the mucosal contents of cyclic AMP and ATP may be involved in the ethanol-induced inhibition of the gastric acid output.

Sugarcane biorefineries, despite their contribution to sustainable transportation fuels and mitigation of carbon emissions in the mobility sector, produce a large amount of carbon dioxide in their conversion processes. According to the Paris climate agreement, a carbon neutral energy system has to be launched in the years to come, and in this scenario, greenhouse gases emission free industrial processes and alternative carbon sources will be needed. Therefore, this paper presents the evaluation of carbon mass balance of a typical Brazilian ethanol mill to better understand its potential for energy and carbon yield improvement. Due to the fact that Brazilian sugarcane mills are evolving from first generation to integrated first and second generation plant, four different scenarios were analysed. For a first generation plant without (S-I) and with conversion of straw to electricity (S-II) and for the integrated plant (S-III), results of carbon mass balance showed that the harvested sugarcane carbon was mainly converted into CO2 and in a smaller proportion into ethanol. In the modelled cases S-I to S-III the conversion of sugarcane carbon into CO2 and ethanol ranged from 41% to 53% and 17%-22%, respectively. Because this carbon amount in the CO2 flows provides an interesting platform to both increase the bioenergy produced and the harvested carbon-to-fuels ratio, a fourth scenario (S-IV) that studies the integration of power-to-gas (PtG) technologies into the mill was also considered. PtG can increase the sugarcane fuels energy content from 9.3 kW/ha to 33.6 kW/ha using 1361.3 MWe of electricity, increasing the amount of sugarcane carbon transformed into sugarcane based fuels to 54% and converting CO2 into a high value added product.

PurposeThe purpose of this paper is to outline a comprehensive picture of the coverage of various certification schemes and sustainability principles relating to the entire value‐added chain of biomass and bioenergy and comparing them accordingly.Design/methodology/approachA tri‐dimensional approach (sustainability issues; technical biomass conversion routes; physical trade flows) was developed for testing the coverage of various sustainability dimensions in different phases of the value‐added chain with the chosen certification schemes and sustainability principles.FindingsUsing the tri‐dimensional approach, a comparison of the chosen schemes and principles demonstrated that the application of existing schemes and the development of new ones have placed a major emphasis on the primary production of biomass. Economic and social dimensions related to biofuels and bioenergy processing and trade were either emphasised less or they were covered inadequately. In view of this, the schemes sometimes seem to ignore that the utilisation of renewable energy as such guarantee no positive or neutral climate impact and may not be economically sustainable, especially when bioenergy can often be more expensive than energy generated from fossil energy sources.Originality/valueThe analysis showed that the tri‐dimensional model is an applicable framework that could facilitate policy makers to formulate policies that comprehensively take into consideration the various sustainability dimensions throughout the entire value‐added chain, now and in the future. It can be applied to the future outlining and completion of certification schemes and sustainability principles for biomass and bioenergy, as well as in the testing of their applicability in the implementation.

With increasing concern over global climate change and rapid rise in energy consumption on the data-driven market, data centres are an important renewable energy target. As cooling contributes a substantial portion of the energy use of data centres, minimising the cooling energy demand in data centres is one of the main objectives for improving renewable energy. This paper investigates overall energy consumption and the energy efficiency of the cooling system for a data centre in Finland as a case study. The temporal energy consumption characteristics, cooling infrastructure and operation of the data centre are analysed. The main problems associated with cooling energy efficiency and the factors that may contribute toward higher efficiency are identified and further suggestions are put forward. Results are presented of an extensive evaluation of the energy performance of the study data centre with a view to energy recovery. The conclusion we can draw is that even though the analysed data centre demonstrat...

Stability of power systems can be analyzed by monitoring the electromechanical oscillatory modes. This paper investigates the use of multichannel Yule-Walker (YW) estimation of a multivariate autoregressive model (MAR) for the measurement based modal analysis of power systems. The proposed YW-MAR method utilizes data that are simultaneously measured through a wide area monitoring system (WAMS). The performance of the method is analyzed by applying it to data generated with the New England test system. The results indicate that the frequencies and the damping ratios of electromechanical oscillatory modes can be accurately analyzed by using the YW-MAR method and the method is not significantly affected by measurement noise or losing a measurement signal.

Abstract The proper understanding and description of the spatial distributions of volatile species is important to the circulating fluidized bed (CFB) reactor design and modeling. Aiming at this issue, a mathematical model has been developed in the present work, which constitutes of two main modules that are validated by experiments, one-dimensional fluid dynamic model and single fuel particle devolatilization model. The simulation of a 135 MWe CFB boiler was conducted. Results show that all volatile species exhibit in general a vertical release profile of bimodal shape (coal inlet area and bottom dense bed) while with quantitative differences, which is mainly attributed to the wide size range of feeding fuel. Compared to the influence of bed temperature, the effect of feeding coal size on the volatile nitrogen release is more obvious. This model can be applied as the devolatilization sub-model for the integral combustion simulation of a CFB boiler.