CO2 emission from anthropogenic activities is one of the major causes of global warming. India being an agriculture dependent country, global warming would mean monsoon instability and consequent ...food scarcity, natural disasters and economic concerns. However with proper policy interventions, CO2 emissions can be controlled. Input–output analysis has been used to estimate direct and indirect CO2 emissions by households for 1993–94, 1998–99, 2003–04 and 2006–07. Complete decomposition analysis of the changes in CO2 emissions between 1993–94 and 2006–07 has been done to identify the causes into pollution, energy intensity, structure, activity and population effects according to broad household consumption categories. Results indicate that activity, structure and population effects are the main causes of increase in CO2 emission from household fuel consumption. To identify the causes at the sectoral level a second decomposition has been done for changes between 2003–04 and 2006–07 to identify the causes in the next stage. Finally alternative energy policy options have been examined for each consumption category to reduce emissions. Combined strategies of technology upgradation, fuel switching and market management in order to reduce CO2 emissions for sectors like Batteries, Other non-electrical machinery, Construction and Electronic equipments (including Television), for which all the effects are positive, need to be adopted.
•Household CO2 emissions (direct & indirect) from 1993–94 to 2006–07 using IOTT.•Decomposition of changes between 1993–94 & 2006–07 for consumption categories.•Decomposition of changes in CO2 emission from 2003–04 to 2006–07 at the sectoral level.•Monetary and physical resource saving under different energy policy options.•Energy policy guideline pertaining to the consumption categories at the sectoral level.
Magnetite nanoparticles (MNP)-caused enhancements for H2 yield (HY) are usually justified based on oxidation-reduction potential (ORP), iron ions (Fe+2/+3) concentration, and enzymatic activity, that ...is pH-dependent. However, the questions “If pH, ORP, and Fe+2/+3 impacts are excluded, will MNP-caused HY enhancement be still present? and how electrical energy input (EEI) affects HY?” are still unanswered. Herein, control, MNP-supplemented, EEI-applied, FeCl3-, and Na2S-supplemented batches, referred as G1, G2, G3, G5, and G6, respectively were conducted, under fixed pH (6.0 ± 0.1). G5 and G6 targeted quantifying sole impact of Fe+2/+3, and ORP, respectively on HY. G1, G2, G3, G5, and G6 achieved HY values of 1.10 ± 0.05, 1.66 ± 0.07, 1.38 ± 0.06, 1.18 ± 0.04, and 1.16 ± 0.05 mol H2/molhexose, respectively. Neither Fe+2/+3 release nor ORP reduction significantly affected HY. Further, Clostridium amylolyticum dominance was almost similar among G2, and G3. Metabolites flux analysis and functional genes’ prediction highlighted that G2 achieved highest hydrogenase expression and lowest homoacetogenic H2 consumption.
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•Oxidation-reduction potential, iron, and pH effects on H2 production were excluded.•Magnetite nanoparticle (MNP) and electrical energy input (EEI) impacts were tested.•MNP and EEI achieved 50% and 25%, respectively higher H2 yield than control.•The reasons were revealed by flux balance and functional gene analysis.•The unique role of MNP and EEI were increased expression of hydrogenase.
A fluid-structure interaction (FSI) solver is developed to simulate the vortex-induced vibrations (VIVs) of flexible cylinders by coupling the large-eddy-simulation (LES) with the mode superposition ...method. The simulations included cylinders with different inclination angles (θ) in a uniform current and a vertical cylinder subjected to different sheared currents. The effects of the wake patterns on the surface pressures, spanwise correlation, and the powers of hydrodynamic forces are analyzed. It is observed that the vortex shedding along the inclined cylinders exhibited two distinct modes: straight vortex tubes and clip-shaped vortex tubes. With increasing θ, the fragmentation of the continuous straight vortices into smaller-scale clip-shaped vortices results in a reduction in surface pressure, thereby diminishing the promoting effect of the hydrodynamic forces on VIVs. For the sheared current cases, an increase in sectional current velocity leads to larger vortical structures. The hydrodynamic force within regions with higher vorticity magnitude promotes the VIVs; however, the cylinder encounters resistance from the ambient fluid and dissipated energy within regions that exhibits lower vorticity magnitudes.
•The VIVs of flexible cylinders are simulated by integrating LES and mode superposition method.•The influences of the inclination angle and sheared currents on VIVs VIVare investigated.•The effects of vortex structures on the surface pressure and mean power of hydrodynamic force are analyzed.•The straight vortex has greater promoting effects on VIV than that of the clip-shape vortex for inclined cylinder.•The cylinder in the sheared current hinders structural vibrations by dissipating energy in regions with low vorticity magnitudes.
The effect of particle shape on particle breakage is investigated through triaxial tests on sand assemblies mixed with non-spherical agglomerates using the discrete element method. Mixed assembly is ...generated in terms of cumulative distribution of sphericity of real sands. Comparable macro-mechanical results are found between DEM and experimental observations, including non-linear stress-strain relationship, peak deviatoric stress, and peak friction angle. More broken bonds and agglomerates numbers are generated in mixed assembly than that in spherical assembly. The hyperbolic relationship between particle breakage and energy input is found to have relevance to particle shape, and the fitting result of mixed assembly is in better accordance with real sands.
Steam methane reforming reaction was carried out in a dielectric barrier plasma reactor. A systematic study is conducted to understand the influence of input power, flow rate, and water for the ...conversion, yield, and selectivity of the reaction over strategically designed catalysts. In particular, the production rate and selectivity of the products (H2, CO and C2 hydrocarbons) are monitored. CeO2 was used as packing material, mixed with oxides of manganese or copper and their combination. The optimum Cu/CeO2 catalyst illustrated the production rate of 248.7 μmolg−1h−1 and 11.25 μmolg−1h−1 for H2, and CO, respectively at specific energy input of 19.8 JL-1. DFT calculations exhibit apparent change in electronic structure of the CeO2 after inclusion of oxides of manganese and copper that enhance interaction with methane. Based on these findings, a plausible mechanism is elucidated which can help to design catalyst for other applications in non-thermal plasma atmosphere.
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•Steam methane reforming reaction is investigated in a non-thermal plasma reactor.•H2, CO, C2 hydrocarbons are obtained as products.•Oxides of Co and Mn are supported on ceria and tested as catalysts.•Among tested catalysts, Cu/Ce exhibited maximum production rate of H2 and CO.•DFT suggests increase in electronic interaction with methane for Mn/Ce, and Cu/Ce.
Biohydrogen production from agro waste biomass through combinative pretreatments is an emerging cost effective, alternative energy technology. The present study aimed to ascertain the extent to which ...the combinative dispersion thermochemical disintegration (DTCD) enhances the cost effective and energy efficient biohydrogen production from rice straw. The efficiency of the combinative pretreatment was evaluated in terms of degree of disintegration and biohydrogen generation. The optimal conditions for combinative pretreatments are pH 10, temperature 80 °C, rpm 12000 and disintegration time 30 mins. A higher degree of disintegration of about 20.9% was achieved through DTCD pretreatment when compared to dispersion thermal disintegration (DTD) (13.2%) and disperser disintegration (DD) (9.5%). The specific energy spent to achieve maximal degree of disintegration for the three pretreatments were in the following order: DD (1469 kJ/kg Rice Straw) > DTD (1044 kJ/kg Rice Straw) > DTCD (742 kJ/kg Rice Straw). Hence, a considerable amount of energy could be saved through this combinative pretreatment. First order kinetic model (exponential rise to maximum) of biohydrogen production is helpful in deriving the two parameters of uncertainty: substrate biodegradability and hydrolysis rate constant. These two parameters evaluate the maximal biohydrogen yield potential of rice straw through combinative pretreatments. As expected, a higher biohydrogen yield of about (129 mL/g COD) was observed in DTCD when compared to DTD (81 mL/g COD) DD (58 mL/g COD) and Control (8 mL/g COD). To gain insights into the feasibility of implementing the pretreatment at large scale, scalable studies are essential in terms of energy balance and cost. A higher positive net energy of about 0.39621 kWh/kg rice straw was achieved for DTCD when compared to others.
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•A higher degree of disintegration of 20.9% was achieved through DTCD.•A considerable amount of energy could be saved by DTCD when compared to others.•A higher biohydrogen yield of about 129 mL/g COD was observed in DTCD.•A positive net energy of about 0.39621 kWh/kg rice straw was achieved for DTCD.
The EU is committed to become climate-neutral by 2050 while keeping its prosperity intact. To align the bloc towards this goal, it is fundamental to understand the spatial differences in energy ...performance among its members. The present study aims to identify the main drivers of primary energy intensity differences among fourteen European countries (i.e., the EU15 without Luxemburg) during the period 2000–2010. To do so, we apply for the first time the multi-factor energy input-output model to spatial structural decomposition analysis. The results show that differences in the industrial direct energy intensity and in the mix of final energy demand were the driving factors of primary energy intensity differences among countries, while, remarkably, structural differences in both the energy sector and in the rest of the economy were not as relevant. This implies that deepening industrial and residential efficiency policies should be a key objective in addition to the current policy efforts to deploy renewables in the energy sector. In addition, we show that the proposed approach helps overcome the main shortcomings of conventional spatial decomposition approaches, e.g., the inconsistent accounting of energy conversion processes in the economy; and its detailed results can be translated into more effective policy making.
•Spatial, Structural Decomposition Analysis (SSDA) of EU15 primary energy intensity.•First application of the more suitable multi-factor energy IO model to SSDA.•The industrial energy intensity was determinant in primary intensity differences.•The final energy demand mix was also determinant in primary intensity differences.•Remarkably, energy and economic structural differences were not as relevant.
Biomass transport represents a significant share of the final price of biomass for energy, and transport itself requires fuel, whose combustion adds to greenhouse gas emissions. We conducted a ...techno-economic analysis of biomass transport for the main forest wood products in Switzerland (firewood and woodchips), as well as for solid and liquid manure. First, we identified the most common transport chains from the supplier to the final consumer in Switzerland, by conducting expert interviews that followed a mental models approach. Then, we quantified the cost, energy and environmental performance of 12 identified transport chains for these types of biomass, using performance ratios. The results show that transport of forest wood is more performant than transport of manure, except when underground pipes are used for liquid manure. In the case of Switzerland, the main barrier to biomass transport is cost rather than energy or emissions performance. Energy required to deliver biomass to final consumers represents between 0.4% and 1.8% of the primary energy contained in the forest wood, and less than 5% in the case of manure. Some forest wood chains attain the maximum break-even transport distances after 36 km only, whereas others could reach over 400 km. Using agricultural transport for slurry should not exceed 3 km from the viewpoint of cost, but could be extended to over 145 km in the case of energy or CO2 emissions.
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•Mental models interviews are used to identify forest wood and manure transport chains.•Costs, energy requirements and CO2 emissions are calculated for each transport chain.•Economic, energy and environmental performance differences can occur regionally.•The main barrier to biomass transport is its costs, not energy or CO2 performances.
•The dispersion of diaspore and kaolinite was controlled by energy input.•The surface properties of mineral particles changed with the energy input.•Fluid strengthening improved the flotation ...recovery of diaspore from kaolinite.
Fluid strengthening and interfacial regulation are two important means to improve the flotation recovery of fine minerals. The fluid strengthening process often affects the surface properties of minerals and thus the dispersion of minerals. The effects of energy input on the dispersion and surface properties of kaolinite and diaspore were investigated in this work. The dispersion of minerals was examined through optical observation, turbidity measurement, and particle size analysis. The surface properties of minerals were characterized by measuring the zeta potential and the contact angle. Micro-flotation was used to test the effect of energy input on flotation performance. The findings revealed that increasing energy input resulted in improved particle dispersion, reduced hetero-coagulation, modified surface properties of minerals, and facilitated the separation of kaolinite and diaspore. This research would provide theoretical and technical support for the flotation of diasporic bauxites.
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