• Energy Research
• Open Access close
• Restricted close
• CN close
• IN close
• HK close

Microalgae are recognized as a third generation feedstock for biofuel production due to their rapid growth rates and lignin-free characteristics. In this study, a lipid extracted microalgal biomass residues was used as the raw material to produce isoprene, α-pinene and β-pinene with an engineered E. coli strain. We adopted an optimal sulfuric acid hydrolysis method (1:7 ratio of solid to acid solution, 32% (w/v) concentration of sulfuric acid solution at 90 °C for 90 min) to efficiently convert holocellulose into glucose efficiently (6.37 g/L). Futhermore, we explored a novel detoxification strategy (phosphoric acid/calcium hydroxide) to remove inhibitors and notably acetic acid, furfural and 5-hydroxymethylfurfural (5-HMF) were reduced by 5.32%, different number given later 99.19% and 98.22%, respectively. Finally, the fermentation concentrations of isoprene (223.23 mg/L), α-pinene (382.21 μg/L) and β-pinene (17.4 mg/L) were achieved using the detoxified hydrolysate as the carbon source, equivalent to approximately 86.02%, 90.16% and 88.32% of those produced by the engineered E. coli strain fermented on pure glucose, respectively.

AbstractElevated carbon-dioxide concentration [eCO2] is a key climate change factor affecting plant growth and yield. Conventionally, crop modeling work has evaluated the effect of climatic parameters on crop growth, without considering CO2. It is conjectured that a novel multimodal ensemble approach may improve the accuracy of modelled responses to eCO2. To demonstrate the applicability of a multimodel ensemble of crop models to simulation of eCO2, APSIM, CropSyst, DSSAT, EPIC and STICS were calibrated to observed data for crop phenology, biomass and yield. Significant variability in simulated biomass production was shown among the models particularly at dryland sites (44%) compared to the irrigated site (22%). Increased yield was observed for all models with the highest average yield at dryland site by EPIC (49%) and lowest under irrigated conditions (17%) by APSIM and CropSyst. For the ensemble, maximum yield was 45% for the dryland site and a minimum 22% at the irrigated site. We concluded from our study that process-based crop models have variability in the simulation of crop response to [eCO2] with greater difference under water-stressed conditions. We recommend the use of ensembles to improve accuracy in modeled responses to [eCO2].

Plug-in hybrid electric vehicles (PHEVs) have a larger battery and can replace a certain amount of conventional fossil fuels with grid electricity, which differs from the traditional hybrid electric vehicles (HEVs). The application of the onboard electrical energy significantly influences the energy utilization efficiency and thus impacts the fuel economy. In this paper, the basic PHEV operation modes are defined as pure electric driving (PED), hybrid driving charge depleting (HDCD) and hybrid driving charge sustaining (HDCS) based on the battery state of charge (SoC) profile. For a plug-in hybrid electric bus (PHEB), three different energy management strategies, which are combined with two or three of the basic operation modes, are put forward and comparatively examined based on simulation models. If some trip information can be approximately known in advance such as the trip distance and the mean power demand, the PED + HDCD + HDCS strategy comprised optimally of the PED mode, the HDCD mode and the HDCS mode would be the best energy management strategy.

Abstract Background The aim of this paper is to reconsider the necessity for the green transition and the key preconditions for the implementation of a circular economy in Western Balkan countries. With the objective of the research in mind, the method of analysis and synthesis was applied to determine (1) regulatory and institutional prerequisites for the green transition; (2) the need for the Western Balkan countries to redefine the model of sustainable economic growth towards the green transition; (3) the development opportunities for recovery defined in the Green Agenda for the Western Balkans; and (4) the possibility of implementing the circular economy in the Western Balkans. Main text The main findings of the research indicate that: (1) the countries of the Western Balkan region, following the example of the EU, should define a national strategic approach to the green transition with an accompanying action plan and regulatory framework; (2) the biggest challenge of the green transition is the reform of the energy sector and the restructuring of the energy-intensive economy; (3) the countries have untapped potential in renewable energy sources and report the improvement of energy efficiency; (4) the circular economy can boost the green transition, because the countries of the region have a five-time lower value of resource productivity than the average of the EU, while the generation of waste (excluding major mineral wastes) per GDP unit is lower compared to the EU; (5) cross-sectoral governance should be more coordinated. Conclusions The green transition might be a development opportunity for the Western Balkans, which should enable sustainable economic growth as well as energy security and environmental protection. However, the implementation of the Green Agenda is not easy, because the region faces the problem of underdeveloped regulatory and institutional capacities that might provide not only the base for long-term planning but also financial resources for the efficient implementation of projects. In addition, it is essential to understand the principles of the Green Agenda and the interaction of all activities that should enable the achievement of defined goals.

A field experiment was conducted during 1993–1995 to study the effect of industrial effluent on the initial growth of Azadirachta indica A. Juss. (Neem) in arid region. The effluent released from textile industry had high pH, EC, SAR and RSC. Various treatments were: irrigation with effluent only (W1), effluent mixed with canal water at 1:1 ratio (W2), gypsum‐treated effluent (W3), gypsum‐treated soil (W4) and wood ash‐treated soil (W5). W5 was the best treatment where neem attained 218 cm height, 118 cm crown diameter and 11.2 cm collar circumference at 28 months of age; followed by W1 treatment, where trees were on an average 186 cm tall and had 104 cm crown diameter and 9.4 cm collar circumference. Growth of the seedlings was the poorest in W2treatment. Increase in biomass accumulation over W2 treatment (1.89 kg tree−1) was 3.6 fold in W5, 2.1 fold in W1, 2.0 fold in W4 and 1.4 fold in W3 treatments. Though effluent application increased soil organic matter, electrical conductivity and in some cases pH also, but gypsum‐ and wood ash‐ treated soil ameliorated the pH by 0.25 units in comparison to the initial data. These results suggest that industrial wastewater can be effectively used to boost up establishment and growth of Neem (Azadirachta indica) in arid zone. Addition of wood ash improves the rate of growth. Irrigation with industrial effluent caused slight increase in electrical conductivity and decline in the soil pH. Santrauka Eksperimentas vyko 1993–1995 m. siekiant ištirti pramoninių nuotekų poveikį Azadirachta indica A. Juss. (Neem) sodinukų augimo pradžiai sausringuose regionuose. Tekstilės pramonės išleidžiamų nuotekų didelės pH rodiklio reikšmės, elektrinis laidumas, natrio adsorbcijos santykis ir natrio karbonato liekana. Tiriant taikyti įvairūs dirvožemio apdorojimo būdai: drėkinta tik nuotekomis (W1 ), nuotekos maišytos su kanalo vandeniu santykiu 1:1 (W2 ), nuotekos veiktos gipsu (W3 ), į dirvožemį dėta gipso (W4 ) ir dirvožemis tręštas medienos pelenais (W5 ). Efektyviausias buvo W5 apdorojimo būdas. 28 mėnesių augalai siekė 218 cm aukštį, jų vainiko skersmuo buvo 118 cm, žiedo perimetras – 11,2 cm. Stebint W1 apdorojimo tipą, medžiai buvo vidutiniškai 186 cm aukščio, vainikas – 104 cm skersmens, žiedai 9,4 cm perimetro. Blogiausiai sodinukai augo apdorojant W2 būdu. Nors naudojant nuotekas dirvožemio organinių medžiagų kiekis, elektrinis savitasis laidumas ir kai kuriais atvejais pH reikšmė padidėjo, tačiau gipsu ir medienos pelenais apdorotame dirvožemyje pH padidėjo per 0,25 vienetus, palyginti su pirminiais duomenimis. Šie rezultatai rodo, kad pramoninės nuotekos gali būti efektyviai naudojamos Neem (Azadirachta indica) želdinti ir auginti sausose teritorijose. Medienos pelenai pagerino augimo spartą. Drėkinimas pramoninėmis nuotekomis lėmė nežymų elektrinio savitojo laidumo augimą ir dirvožemio pH sumažėjimą. Резюме Экспериментальное поле возделывалось в 1993–1995 гг. с целью изучить воздействие промышленных стоков на начало роста Azadirachta indica A. Juss. (Neem) в засушливых районах. В стоках от производства текстиля высоко значение pH, электропроводимость, соотношение адсорбции натрия и остаток карбоната натрия. Применялись разные способы обработки почвы: орошение только стоками (W1 ); смесью стоков с водой из канала в соотношении 1:1 (W2 ); стоками, обработанными гипсом (W3 ); обработка почвы гипсом (W4 ) и удобрение древесной золой (W5 ). Наиболее эффективным способом оказалась обработка древесной золой. Высота растений в возрасте 28 месяцев составляла 218 см, венчик в поперечнике – 118 см, цветок – 11,2 см. После обработки почвы по типу W1 растения достигали 186 см в высоту, венчик в поперечнике – 104 см, цветок – 9,4 см. Наименее эффективным для растений способом оказалась обработка почвы по типу W2 . Несмотря на то, что при применении стоков количество органических веществ в почве, электропроводимость и в некоторых случаях значение pH увеличилось, однако при обработке почвы гипсом и древесной золой pH увеличилось более чем на 0,25 единиц по сравнению с начальными данными. Эти результаты показали, что промышленные стоки могут эффективно применяться для озеленения и выращивания Neem (Azadirachta indica) на засушливых территориях. Древесная зола ускоряла рост растений. Орошение промышленными стоками способствовало незначительному увеличению электропроводимости и уменьшению в почве pH.

Abstract The improvement of thermodynamic efficiency of power plants is of great interest for the whole energy industry. The use of Kalina cycle has a great potential to improve the thermal efficiency of a nuclear power plant. This cycle uses a mixture of ammonia and water as working fluid. In this paper, we discuss the development of an Ammonia-Water mixture Property Code (AWProC). The estimation of the mixture properties are based on the Gibbs free energy functions. The code is verified and validated against experimental data available in the literature and REFPROP code. It is shown that AWProC can accurately estimate the thermodynamic properties of ammonia-water mixtures over a wide range of conditions, including high temperature and pressure regions. The code is then used to investigate the feasibility of applying the Kalina cycle to a typical Pressurizer Water Reactor (PWR) plant as an effective way to improve the plant efficiency. The fundamental of Basic-Kalina (B-K) cycle is described in detail firstly. Then, two modified configurations, Recuperation-Kalina (R-K) and Flash-Kalina (F-K) cycles respectively, are proposed for a typical 1000 MWe PWR. The simulation results indicate that the R-K type cycle can reach about 31.2% efficiency with simple equipment requirements, while the F-K type cycle can reach efficiencies up to about 34.8%, but at the expenses of a slightly more complex design. The present work demonstrates the applicability of the Kalina cycle as a way to improve the thermal efficiency of a nuclear power plant. This concept is meaningful for improving nuclear power plants economic and competitiveness.