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Abstract This study develops a novel sustainability assessment methodology for energy systems using life-cycle emission factors and sustainability indicators. Here, the global warming and environmental impact dimensions of the sustainability assessment methodology are examined in detail. A comparative analysis shows that a wind-battery system produces fewer potential global warming, stratospheric ozone depletion, air pollution, and water pollution impacts compared to a gas-fired system. The wind-battery system generates 13% of the life-cycle GHG emissions and 22% of the life-cycle ozone-depleting substance emissions of a gas-fired power plant. Nitrous oxide contributes more than 90% of the stratospheric ozone depletion potential of gas-fired and wind-battery systems.

Abstract In the present study, Loblolly pine biomass residue was converted to bio-oil in a two-step process, consisting of 1) fast pyrolysis in the presence of zeolite ZSM-5 as a catalyst to produce pyrolysis oil, 2) hydrogenation of pyrolysis oil using formic acid as the hydrogen source in presence of Ru/activated carbon catalyst. Pyrolysis oils were analyzed by 13C, 31P and HSQC-NMR and the results revealed that the zeolite-induced catalytic fast pyrolysis process led to effective demethoxylation, producing more catechol and p-hydroxy-phenyl hydroxyl groups in the bio-oils, resulting in a decrease in the methoxyl group content by about 85 % and rich aromatic structures in the pyrolysis oils. The properties of pyrolysis oil with and without zeolite were in the bio-oil range. Hydrogenated pyrolysis oil showed that 79 % of the aromatic protons are eliminated and 87 % of protons are aliphatic in nature, with no oxygen attached to the α-carbon.

In the backdrop of COVID19 recovery, Pakistan is still struggling to cope with the economic challenges and disruptions caused in the energy supply chain. On one hand where COVID has brought serious socio-economic costs and prolonged delays, it has also provided opportunity for developing countries such as Pakistan to “build-forward-better” their economies in a more sustainable and climate friendly manner. This study particularly highlights the impact of COVID on energy supply and demand sectors of Pakistan, its near- and long-term impacts, and what policy interventions can be adopted to put Pakistan on-track to achieve its Nationally Determined Contributions (NDCs). The economic focus in on “Green Recovery” and what key interventions will foster a rapid transition towards decarbonization in Pakistan. Low Emission Analysis Platform (LEAP) model is used to provide energy sector outlook (2020-2040) of Pakistan under different scenario i.e., Pre COVID growth, Business-as-Usual, Slow Recovery, and Green Recovery from COVID. The results obtained from the model depicts that following a green recovery scenario, Pakistan can reduce around 10 Mtoe (9%) of its total energy use, 53 TWh of electricity, 19 Mt of emissions from demand sectors, and 11 Mt of emissions from the power sector by 2030. For total levelized cost of the power sector, the green recovery scenario represents a generation cost of $13 billion by 2030 which further highlights that energy efficiency could lead to cost savings of approximately $3 billion each year by 2030. Green recovery is however still a daunting task as it would require economic stimulus of $8 billion only to recover to its pre COVID scenario and total investments of $120 billion by 2030.

Abstract Space–time kinetics calculations for CANDU ® 1 reactors are routinely performed using the Improved Quasistatic (IQS) method. The IQS method calculates kinetics parameters such as the effective delayed-neutron fraction and generation time using adjoint weighting. In the current implementation of IQS, the direct flux, as well as the adjoint, is calculated using a two-group cell-homogenized reactor model which is inadequate for capturing the effect of the softer energy spectrum of the delayed neutrons. Additionally, there may also be fine spatial effects that are lost because the intra-cell adjoint shape is ignored. The purpose of this work is to compare the kinetics parameters calculated using the two-group cell-homogenized model with those calculated using lattice-level fine-group heterogeneous adjoint weighting and to assess whether the differences are large enough to justify further work on incorporating lattice-level adjoint weighting into the IQS method. A second goal is to evaluate whether the use of a fine-group cell-homogenized lattice-level adjoint, such as is the current practice for Light Water Reactors (LWRs), is sufficient to capture the lattice effects in question. It is found that, for CANDU lattices, the generation time is almost unaffected by the type of adjoint used to calculate it, but that the effective delayed-neutron fraction is affected by the type of adjoint used. The effective delayed-neutron fraction calculated using the two-group cell-homogenized adjoint is 5.2% higher than the “best” effective delayed-neutron fraction value obtained using the detailed lattice-level fine-group heterogeneous adjoint. The effective delayed-neutron fraction calculated using the fine-group cell-homogenized adjoint is only 1.7% higher than the “best” effective delayed-neutron fraction value but is still not equal to it. This situation is different from that encountered in LWRs where weighting by a fine-group cell-homogenized adjoint is sufficient to calculate the correct effective delayed-neutron fraction. It is concluded that lattice-level weighting with a detailed fine-group heterogeneous adjoint is desirable for the correct calculation of the effective delayed-neutron fraction in CANDU lattices.

Several methods were known to observe the cloud height. Since the meteorological administration mainly has been using human eye method, an automatic cloud height observer is proposed to reduce human errors.The proposed cloud observer system is for the cloud automatic observation system which has been operating at weathers stations in Korea since 1993. The high hand camera is adapted to get high resolution images without a capture board that has the low resolution. And the man-made passive filter for extracting sky reign is replaced by the active filter using image processing. The famous BRISK matching is selected instead of the block mating to get more precise disparity form a pair of stereo image.The Cloud cover announced by the Korean Meteorological Agency is the eye observation result nowadays, even though an intelligent cloud observation system was supplied. The reason is the impermissible error in the observed data of the automatic observation system. The current system is applied a man-made passive filter has to be changed periodically due to the boundary transition, but the proposed system is maintenance-free, since the active filter using edge detection algorithm automatically adjusts itself. The measuring of disparity which is important to analyze spatial information, has improved up to the resolution of observing height is 100m by getting image data directly form the high resolution camera, the old resolution from the capture board. Also, the disparity analyzing method is changed to the BRISK matching algorithm instead of the block mating algorism to get more deliberate disparity analysis since the dimension of the block is too big relatively compare to the cloud in the stereo all sky image. The test results are acceptable range which is human observation value ± 10% since the resolution of observing height is 100m at lower cloud in the sky. The proposed system is conducting the comparison research to compare with the result of reading satellite images and ceilometer. 

The combustion possibility of Indonesia KBB coal as a pulverized fuel for a thermal power plant was studied with a thermogravimetric analysis (TGA), drop tube furnace (DTF) and ignition temperature (IT) tester. TGA results showed that combustion patterns of coal samples were divided into devolatilization and oxidation reactions, and the fixed carbon contained with minor content in high moisture KBB coal (HM KBB) was quickly burned at a lower temperature than that of bituminous C&A coal (Design C&A). The linear regression for the Arrhenius plot to the experimental data is very good, and activation energies for overall combustion of Design C&A and HM KBB are 63.19 and 81.89 kJ/mol, respectively. It was derived that activation energies of dry KBB coal (Dry KBB) produced through drying of HM KBB and its mixture (Dry KBB Mixture) are 79.82 and 61.66 kJ/mol in reciprocal proportion to specific surface area. Test results show that the volatile content contained in coal samples except for HM KBB with the lowest surface area significantly improved the combustion reactivity. The conversion behavior of the coals observed in DTF was similar to that reflected in TGA. DTF studies showed that the combustion of Dry KBB Mixture was also completed at a residence time of around 1 s and set temperature range of 1,200°C similar to commercial coal fired plant. Although Dry KBB has the highest conversion of the four coals, it was not appropriate as a single pulverized fuel of coal fired plant because its initial deformation (IDT) and ignition temperatures of about 1,088 and 198°C, respectively, were too low to cause slagging in boiler, and firing at the pulverizer. The high IDT of Dry KBB Mixture ash with minimum of 1,250°C is not expected to be associated with slagging and fouling in pulverized coal fired systems. The liability of spontaneous combustion of coal samples was increased with increasing the moisture and volatile contents whereas that of Dry KBB was the highest due to the high surface area. It was, therefore, proposed that the combustion of mixtures of Dry KBB with Design C&A was the most appropriate for the prevention of slagging and spontaneous combustion in pulverized coal fired boilers and has excellent combustion efficiency.

Torrefaction is a thermal treatment process to pre-treat biomass at temperature of under an inert atmosphere. It was known that torrefaction process strongly depended on the decomposition temperature of the lignocellulosic constituents in biomass. In this work, the torrefaction characteristics of baggase has been studied. This study focuses on the relation between the energy yields, heating values, gas emission, volatile and ash constituents with torrefaction temperatures and times. The activation energies of baggase torrefaction has been studied by using TGA (Thermogravimetric Analyzer). From this work, it was seen that ash constituents and heating values were increased with torrefaction temperature, while volatile constituents and energy yields decreased. It was also found that carbon monoxide containing oxygen were decomposed at a lower temperature than those of hydrocarbon compounds, .

This paper presents a CFD analysis of three types of axial-flow magnesium-based automotive cooling fans. The numerical modeling was conducted for geometrically modified fan designs: one with no-beads, the second one with beads at the suction-side of the fan namely reverse-beads fan, and the third one with beads installed at the pressure-side of the fan namely forward-beads fan. The effect of geometric modifications of the fan blades on the volumetric flow rate, fan efficiency, and energy efficiency was investigated using Reynolds-averaged Navier-Stokes (RANS) equations following the multiple reference frame methodology. The fan with no-beads was fabricated using 3D printing technology and tested to measure the flow velocity. Subsequently, the fans with beads along with the no-beads fan designs were numerically analyzed. The volumetric flow rate, fan efficiency, and energy efficiency were quantified as a function of fan rotating speed. The results show that the reverse-beads fan produced a relatively more volumetric flow rate and energy-efficient compared to the forward-beads fan. Moreover, to further improve the performance of the reverse-beads fan, the location and size of the bead structure were varied along the radial direction of the fan blade. The optimized reverse-beads fan significantly improves the fan performance.

The paper presents a method for decentralized coordination of inter-regional static stability management. This approach allows for an optimal "central" result using a decentralized coordinated solution procedure. The proposed optimization-based approach achieves system-wide efficiency of inter-regional electricity systems or markets while minimizing the amount of information that needs be exchanged. The solution is obtained by adapting decentralized solution techniques of interior point methods to the static stability problem.