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Abstract Bamboo has been considered a potential feedstock of energy for the future. It can be subjected to the pyrolysis for biofuels production. The thermogravimetric analysis (TGA) combined with differential thermogravimetric analysis (DTG) for bamboo was carried out prior to pyrolysis. The thermal degradation of bamboo was mainly between 230 and 420 °C. The conventional pyrolysis of bamboo was investigated in a bubbling fluidized-bed reactor using silica sand. The product distribution and composition of pyrolysis bio-oil were dependent on biomass component and operating conditions such as pyrolysis temperature, fluidization velocity, and particle size of biomass. The fractional catalytic pyrolysis of bamboo was also studied to upgrade the pyrolysis vapor, using HZSM-5 and red mud. The highest yield of bio-oil was 54.03 wt% compared to 49.14 wt% and 50.34 wt% of HZSM-5 and red mud catalyst, respectively. In the red mud catalytic pyrolysis, the oxygen content was rejected from pyrolysis vapor mostly via decarboxylation to produce more CO2 than CO; in contrast, for the HZSM-5 catalytic pyrolysis, the production of CO through decarbonylation was more favored than CO2. The main composition of catalytic pyrolysis bio-oil was 4-vinylphenol, which was employed as a raw material source to synthesize valuable material for energy storage.

Abstract In some shelf sea regions of the world, the tidal range is sufficient to convert the potential energy of the tides into electricity via tidal range power plants. As an island continent, Australia is one such region – a previous study estimated that Australia hosts up to 30% of the world’s resource. Here, we make use of a gridded tidal dataset (TPXO9) to characterize the tidal range resource of Australia. We examine the theoretical resource, and we also investigate the technical resource through 0D modelling with tidal range power plant operation. We find that the tidal range resource of Australia is 2004 TWh/yr, or about 22% of the global resource. This exceeds Australia’s total energy consumption for 2018/2019 (1721 TWh/yr), suggesting tidal range energy has the potential to make a substantial contribution to Australia’s electricity generation (265 TWh/yr in 2018/2019). Due to local resonance, the resource is concentrated in the sparsely populated Kimberley region of Western Australia. However, the tidal range resource in this region presents a renewable energy export opportunity, connecting to markets in southeast Asia. Combining the electricity from two complementary sites, with some degree of optimization tidal range schemes in this region can produce electricity for 45% of the year.

Abstract To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed Hydrogen production and End-Uses from CHHP system for the campus using local resources. Following the resource assessment study, the team selects FuelCell Energy DFC1500™ unit as a molten carbonate fuel cell to study of combined heat, hydrogen and power (CHHP) system based on a molten carbonate fuel cell fed by biogas produced by anaerobic digestion. The CHHP system provides approximately 650 kg/day. The total hydrogen usage 123 kg/day on the university campus including personal transportation applications, backup power applications, portable power applications, and other mobility applications are 56, 16, 29, 17, and 5 respectively. The excess hydrogen could be sold to a gas retailer. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas emissions and hydrogen generated is used to power different applications on the university campus.

Abstract The primary objectives of this study are to evaluate the levelized cost of energy (LCOE) for different wave energy conversion strategies and to examine cost reduction pathways such that wave energy conversion projects are competitive, relative to alternative energy industries. The energy production of six different WEC devices was estimated for four sites along the U.S. Pacific coast. The LCOE of pilot-scale wave energy conversion projects was estimated to range between $0.07/kWh and $0.92/kWh higher than the target LCOE of those for early-market offshore wind energy projects. Device capacity factors were generally below the commonly assumed value of 30%. Methods of cost reduction to the target LCOE of $0.30/kWh were explored, including decreasing capital and operational expenditures (CAPEX and OPEX) and increasing annual energy production (AEP) through improvements in the wave energy resource and WEC and WEC array performance, and advanced controls. Results indicate that CAPEX and OPEX should be reduced by at least 45% and AEP should be increased by 200%. A reduction of CAPEX and OPEX by 75%, combined with array evaluation and control strategies capable of increasing AEP by 12%–55% could also result in LCOE for wave energy conversion projects of less than $0.30/kWh.

Abstract With the increasing effects of climate change and high costs of energy, many rural Alaska communities are working to implement local alternative energy solutions to improve energy security. Integrating renewable energy systems can reduce reliance on fossil fuels and subsequently improve food, energy, and water (FEW) security. In this study, wind energy modeling techniques using local airport meteorological data were convolved with community loads to determine the most cost-effective combinations of wind turbine technology and dispatchable loads for improving FEW security in a southwestern Alaska village. This approach is different from wind assessments that exclusively analyze wind resources. A 100 kW wind turbine was determined to be suitable for the community, resulting in a capacity factor of 16.7% and levelized cost of energy (LCOE) of $1.15/kWh, with diminishing returns for higher wind turbine capacity. The results from the dispatchability study indicated that dispatchable loads could handle the intermittency of the wind resource with up to 86% of their annual load met. More work is needed to understand the impact of integrating and scheduling dispatchable loads into the grid in practice.

Abstract It has been recognized that oils derived from microorganism and wastewater sludge are comparable replacements of traditional biodiesel production feedstock, which is energy intensive and costly. Energy balance and greenhouse gas (GHG) emissions are essential factors to assess the feasibility of the production. This study evaluated the energy balance and GHG emissions of biodiesel production from microbial and wastewater sludge oil. The results show that energy balance and GHG emissions of biodiesel produced from microbial oil are significantly impacted by the cultivation methods and carbon source. For phototrophic microorganism (microalgae), open pond system gives 3.6 GJ higher energy gain than photo bioreactor system in per tonne biodiesel produced. For heterotrophic microorganisms, the energy balance depends on the type of carbon source. Three carbon sources including starch, cellulose, and starch industry wastewater (SIW) used in this study showed that utilization of SIW as carbon source provided the most favorable energy balance. When oil extracted from municipal sludge is used for biodiesel production, the energy gain is up to 29.7 GJ per tonne biodiesel produced, which is higher than the energy gain per tonne of biodiesel produced from SIW cultivated microbes. GHG emissions study shows that biodiesel production from microbes or sludge oil is a net carbon dioxide capture process except when starch is used as raw material for microbial oil production, and the highest capture is around 40 tonnes carbon dioxide per tonne of biodiesel produced.

Abstract This paper deals with thermal efficiency enhancement analysis of a solar water heating system with a solar tracker. Made at laboratory-scale, an automated mechanical system enables solar panel rotation and inclination. The control system is programmed to place the solar panels facing the sun throughout the day. Its coordinates by means of the solar height and the azimuthal angle will determine the sun position on the celestial sphere. The thermal behaviour of the solar water heating system is developed with energy balance on solar panels, heat exchanger and storage system. The solar irradiation intensity is measured by a pyranometer placed in the plan of the solar panels. Comparison between experimental results obtained for fixed inclinations of solar panels and those obtained with the solar tracker shows a 40% gain of overall stored thermal energy. The energy gain depends on the season. The low inclinations are still favourable in summer while in winter they are higher inclinations are needed.

While fossil energy prices remain relatively low and agricultural prices are maintained at a relatively high level as a result of production costs, the use of purpose grown crops as a source of fuels requires subsidies, tax support or other financial incentives to be viable. In the short term, the use of agricultural and forest raw materials as industrial raw materials for production of higher value products appears more attractive. However, simple substitution of a petroleum-based product by one derived from plants is seldom possible. Options are reviewed, covering both established commercial activities (such as starch, vegetable oil, paper-pulp and natural fibres), as well as the extensive research and development activities that should lead to new crops, new products and new markets.

Abstract Dust accumulation on glass plates with different tilt angles and associated reductions in solar transmittance have been experimentally investigated over a period of 1 year under the climate conditions of the Minia region, middle of Egypt. The glass plates were never cleaned during the experiment duration of 1 month to allow dust to accumulate. The results showed that the fractional reduction in glass normal transmittance depends strongly on dust deposition in conjunction with plate tilt angle, as well as on the exposure period and site climate conditions. Based on the data obtained, an empirical correlation, accurate to ±6%, is developed which allows for the calculation of the reduction in glass transmittance for a given tilt angle after a number of days of exposure to the atmosphere. For design purposes and in the absence of any specific data, the literature comparisons encourage the use of the correlation for other neighboring regions along the desert belt that extends from the Atlantic Ocean to the Persian Gulf. For moderately dusty places, weekly cleaning of the glass covers of solar panels is strictly recommended as part of the maintenance routine, but equipment should be cleaned immediately after a dust storm to retain nominal operating efficiency.

Abstract This literature review was built upon recently published articles on Life Cycle Assessments (LCAs) of agricultural biogas plants, to: enhance understanding of the relevant literature in the field and the related question by readers worldwide. It was designed to highlight methodological issues and impact indicators, which best represent this research field; consequently, they should be considered in performing environmental assessments of agro-biogas derived energy systems. The literature review highlighted the wide variability of environmental results due to the ways the feedstock mixtures were produced, managed, and supplied; and due to the regions in which the anaerobic digesters were located and operated. Differences were found to be related to the aim and function of the study and to the methodological approach used, especially for the development of the environmental impact assessments. Other differences resulted from the ways the energy produced was utilised, whether it was used as an input to the natural gas national grid, and/or if it was used within the production system. The authors of this review concluded that, although much progress has been made, many unsolved challenges and methodological choices must be addressed to further improve the robustness of LCA in relation to AD and to related approaches.