| 1. |
- Asuquo, Asuquo Jackson, et al.
(författare)
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Green heterogeneous catalysts derived from fermented kola nut pod husk for sustainable biodiesel production
- 2024
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Ingår i: International Journal of Green Energy. - : Taylor & Francis Group. - 1543-5075 .- 1543-5083.
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Tidskriftsartikel (refereegranskat)abstract
- The use of green heterogeneous catalysts that are obtained from waste agricultural biomass can make the production of biodiesel more economical. In this research, three solid base heterogeneous catalysts (Catalyst A, B, and C) were synthesized from kola nut pod husks, and the synergistic effects of the elemental composition on catalytic activities for biodiesel production were studied. The results revealed a high surface area of Catalysts A, B, and C at 419.90 m2/g, 430.54 m2/g, and 432.57 m2/g, respectively. Their corresponding pore diameters are 3.53 nm, 3.48 nm, and 3.32 nm, showing that the catalysts are mesoporous in nature. The X-ray Fluorescence (XRF) results revealed the presence of a variety of alkaline earth metals and their corresponding metal oxides in substantial amounts. Catalyst A was produced with the highest concentration of calcium at 40.84 wt.% and calcium oxide at 68.02 mole%. The substantial concentration of other elements, such as potassium, magnesium, and aluminum, and their corresponding metal oxides are the proof of high catalytic activity of the produced green catalysts. The high CaO contents of all three produced catalysts and their high surface areas indicate their strong potential for good catalytic activities applied to the synthesis of biodiesel.
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| 2. |
- Bartusch, Cajsa, 1965-, et al.
(författare)
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Potential of hourly settlements in the residential sector of the Swedish electricity market : Estimations of risk reduction and economic result
- 2010
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Ingår i: International Journal of Green Energy. - : Taylor & Francis. - 1543-5075 .- 1543-5083. ; 7:3, s. 224-240
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Tidskriftsartikel (refereegranskat)abstract
- Increased demand response is essential in order to boost the effectiveness of the Swedish power market. The all-embracing installation of automatic meter reading systems enables power suppliers to introduce hourly settlements in the residential sector. The aim of the study has been to assess the impact of electricity retailers’ physical and financial risk in customer segments with different heating systems as well as to estimate the potential of the electricity contract ”Fixed price with the right to return” in terms of economic consequences and risk management. The results show that households whose main heating system consists of a geothermal heat pump constitute the largest physical price and volume risk of suppliers. The gain of introducing hourly settlements in the residential electricity market has furthermore proven to be manifold from both an economic and risk reducing point of view.
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| 3. |
- Campana, Pietro Elia, et al.
(författare)
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An economic analysis of photovoltaic water pumping irrigation systems
- 2016
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 13:8, s. 831-839
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Tidskriftsartikel (refereegranskat)abstract
- Irrigation using the photovoltaic water pumping (PVWP) systems represents a sustainable and attractive solution, which can combat Chinese grassland desertification and promote a sustainable development of the agricultural sector. This paper investigates the economics of PVWP systems taking into consideration the effects of the key components on the initial capital cost (ICC), life cycle cost (LCC), and revenues. Sensitivity analyses are conducted regarding the crop yield and price, cost of photovoltaic modules, and system components included in the ICC. Results show that the cost of the PVWP system is the most sensitive parameter affecting the ICC under the assumptions made, especially the cost of the PV modules; whereas, the crop production and price affect the net present value (NPV) and payback period (PBP) clearly. The PVWP has surplus power output when the crop water demand is low or it is non-irrigation season. The potential benefit from selling the surplus electricity is also discussed. In addition, the indirect benefits of carbon sequestration and CO2 emission reduction by applying PVWP systems are addressed in this paper.
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| 4. |
- Christia, Abdi, 1991, et al.
(författare)
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Ethanol production from alkali-pretreated oil palm empty fruit bunch by simultaneous saccharification and fermentation with mucor indicus
- 2016
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 13:6, s. 566-572
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Tidskriftsartikel (refereegranskat)abstract
- Oil palm empty fruit bunch (OPEFB) is a potential raw material for production of lignocellulosic bioethanol. The OPEFB was pretreated with 8% sodium hydroxide (NaOH) solution at 100°C for 10 to 90 min. Enzymatic digestion was carried out using cellulase and β-glucosidase at 45°C for 24 h. It was then inoculated with Mucor indicus spores suspension and fermented under anaerobic conditions at 37°C for 96 h. Sodium hydroxide pretreatment effectively removed 51–57% of lignin in the OPEFB and also its hemicellulose (40–84%). The highest glucan digestibility (0.75 g/g theoretical glucose) was achieved in 40-min NaOH pretreatment. Fermentation by M. indicus resulted in 68.4% of the theoretical ethanol yield, while glycerol (16.2–83.2 mg/g), succinic acid (0–0.4 mg/g), and acetic acid (0–0.9 mg/g) were its by-products. According to these results, 11.75 million tons of dry OPEFB in Indonesia can be converted into 1.5 billion liters of ethanol per year.
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| 5. |
- Dahlquist, Erik, et al.
(författare)
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OPTIMIZATION OF THE ENERGY SYSTEM TO ACHIEVE A NATIONAL BALANCE WITHOUT FOSSIL FUELS
- 2011
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 8:6, s. 684-704
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Tidskriftsartikel (refereegranskat)abstract
- In this article, the overall energy balance for Sweden and to some extent EU27 is discussed. It deals with the reduction of the total consumption in industrial, transport, and domestic sectors through more efficient vehicles, industrial processes, and buildings and individual behavior. The conclusion is that it should be relatively easy for Sweden to reach a sustainable society if the political will, in the form of policies and incentives, is present. It would also be possible for the EU27 to reach a sustainable society, although it would be more demanding (challenging?).
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| 6. |
- Feng, Dawei, et al.
(författare)
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Pathways for carbon emission prediction and mitigation of sustainable industrial parks : a LEAP model application
- 2024
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Ingår i: International Journal of Green Energy. - : Taylor & Francis. - 1543-5075 .- 1543-5083.
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Tidskriftsartikel (refereegranskat)abstract
- Industrial parks play a crucial role as a carrier of industrial clusters and energy consumption. Accurately predicting the energy demand and carbon emissions trend is key to scientifically determining the pathways for low-carbon industrial parks. However, exploration in carbon emission prediction on industrial park scale is still in its infancy stage. This paper investigates fuel demand and carbon emissions from 2021 to 2035 in an industrial park in Jiangsu Province, utilizing the Long-range Energy Alternative Planning (LEAP) model to explore the pathways for low carbon development. Energy-saving and emission-reduction effects of different macro-economic policies and micro-energy planning are analyzed based on the energy balance and emission factor methods. Four scenarios are compared: the baseline scenario (BAS), green development scenario (GDS), low carbon scenario (LCS), and strength low carbon scenario (SLS). Results indicated that energy demand under BAS reached at 31.37 Mtce in 2035, and energy-saving rates of GDS, LCS, and SLS in 2035 were 12.94%, 14.00% and 19.08%, respectively. Carbon emissions reached 53.96 MtCO2e in BAS of 2035. However, in the same year, emissions decreased by 24.88%, 43.09%, and 52.52% in GDS, LCS, and SLS, respectively, with SLS being the most suitable for the park.
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| 7. |
- Fiedler, Frank, et al.
(författare)
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Optimisation method for solar heating systems in combination with pellet boilers/stoves
- 2007
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 4:3, s. 325-337
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Tidskriftsartikel (refereegranskat)abstract
- In this study an optimisation method for the design of combined solar and pellet heating systems is presented and evaluated. The paper describes the steps of the method by applying it for an example system. The objective of the optimisation was to find the design parameters that give the lowest auxiliary energy (pellet fuel + auxiliary electricity) and carbon monoxide (CO) emissions for a system with a typical load, a single family house in Sweden. Weighting factors have been used for the auxiliary energy use and CO emissions to give a combined objective function. Different weighting factors were tested. The results show that extreme weighting factors lead to their own minima. However, it was possible to find factors that ensure low values for both auxiliary energy and CO emissions, and suitable weighting factors are suggested.
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| 8. |
- Gunaratne, Tharaka, 1982-, et al.
(författare)
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Framework to benchmark sustainability of biomethane supply chains : Facilitating sustainability decision making in adopting biomethane as a public transportation fuel in Western Europe
- 2016
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Ingår i: International Journal of Green Energy. - : Taylor & Francis. - 1543-5075 .- 1543-5083. ; 13:8, s. 759-766
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a framework from a systems' perspective to benchmark biomethane supply chains consisting of biogas upgrading, biomethane distribution, and refilling in the context of Western Europe.Compressed biomethane is already widely adopted as a vehicle fuel, whereas liquefied biomethane is also a vialble alternative. Distribution in gas grids is a feasible option only in short distances and large scale, whereas trucks with composite swap bodies is the preferable alternative otherwise. As a whole, liquefied biomethane supply chains manifests better attributes from both climate and cost perspectives, whereas compressed biomethane supply chains imply better energy intensity.
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| 9. |
- Hermansson, Roger, et al.
(författare)
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Solar assisted small-scale biomass district heating system in the northern part of Sweden
- 2004
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Ingår i: International Journal of Green Energy. - 1543-5075 .- 1543-5083. ; 1:4, s. 467-482
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a case study of a projected solar assisted biomass district heating system in the north of Sweden. It is generally known that a biomass district heating system combined with solar heat brings many important benefits. The most common system solution is to install a heat store and a large solar collector field near the heating central. No plant of this type is however in operation in the northern part of Sweden. The main reason for this is that the solar irradiation at these latitudes is very low when the demand for heat is high. Solar heat could however be useful during summer in order to generate hot tap water. One problem is that the heat losses, calculated as percentage of the delivered heat, become very large during these months. This article presents the idea of allowing the connected households to generate their own hot tap water using solar collectors and heat stores installed in each house. The district heating network can therefore be closed in summer, which eliminates the heat losses outside the heating period. A case study of a projected plant has been carried out and it is shown that it is possible to reduce the heat losses by 20% compared to a conventional system. This idea also provides many other important technical and economic benefits.
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| 10. |
- Hu, Yukun, et al.
(författare)
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Integration of Evaporative Gas Turbine with Oxy-Fuel Combustion for Carbon Dioxide Capture
- 2010
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 7:6, s. 615-631
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Tidskriftsartikel (refereegranskat)abstract
- This paper studied the integration of Evaporative Gas Turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture. The impact of key parameters on system electrical efficiency, such as the oxygen purity, Water/Gas ratio (W/G) has been investigated concerning thermal efficiency. The performance of dry recycle and wet recycle also has be analyzed and compared. Simulation results shows that: (1) 97% can be considered as the optimum oxygen purity taking into account the trade-off between the air separation unit (ASU) consumption penalty of producing higher-purity oxygen and electrical efficiency; (2) there" exists an optimum point of W/G for both EvGT and EvGT combined with oxy-fuel combustion CO2 capture technology; (3) dry recycle has a" considerably higher electrical efficiency comparing with wet recycle, but more cooled water can be saved in the wet recycle. The performance of EvGT cycle was also compared to the combined cycle (CC) when CO2 capture was considered. The comparison shows that CC has a higher net power output and electrical efficiency than the EvGT cycle no matter if combined with oxy-fuel combustion CO2 capture technology or not.
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