Mechanical Durability and Grindability of Pellets after Torrefaction Process

Renewable energy sources and their part in the global energy mix are beneficial to energy diversification and environment protection. However, raw biomass is characterized by low heating value, hydrophilic properties, various mechanical durability, and the logistic challenges related to transportation and storage. One frequently used process of combined biomass valorization is torrefaction and pelletization, which increase the heating value, homogeneity, and hydrophobicity of the fuel. However, industrial clients need fuel characterized by favorable grindability, whereas, the individual clients (householders) need fuel with high mechanical durability. Due to the different expectations of final customers regarding biomass fuel properties, it is necessary to investigate the influence of the torrefaction on the mechanical durability of the pellets. In this paper, five various types of pellets and their torreficates (obtained at a temperature of 200 and 300 °C) were examined. Then the mechanical durability index DU and the grindability of the untreated and torrefied pellets were determined. The results indicated that the mechanical durability of untorrefied pellets is significantly greater than torrefied pellets. Interestingly, no significant differences in mechanical durability between torrefied pellets at 200 and 300 °C were observed, For sunflower husk pellets, the DU index amounted to 95.28 ± 0.72 (untorrefied), 47.22% ± 0.28% (torrefied at 200 °C), and 46.34% ± 0.72% (torrefied at 300 °C). Considering the grindability, as the treatment temperature increased the energy demand for grindability decreased. For example, the grindability of pine tree pellets was 15.96 ± 3.07 Wh·kg−1 (untreated), 1.86 ± 0.31 Wh·kg−1 (torrefied at 200 °C), and 0.99 ± 0.17 Wh·kg−1 (torrefied at 300 °C). The highest difference between raw and torrefied pellets was determined for beetroot pomace pellet: 36.31 ± 2.06 Wh·kg−1 (untreated), 3.85 ± 0.47 Wh·kg−1 (torrefied at 200 °C), and 1.03 ± 0.12 Wh·kg−1 (torrefied at 300 °C).

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Storage and Upgrading of Biogas by Physicochemical Purification in a Sudano-Sahelian Context

Energies ◽

10.3390/en14185855 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5855

Author(s):

Djomdi ◽

Leonel Junior Mintsop Nguela ◽

Hamadou Bakari ◽

Hamadou Fadimatou ◽

Gwendoline Christophe ◽

...

Keyword(s):

Energy Demand ◽

Biogas Production ◽

Renewable Energy Sources ◽

Storage System ◽

Dark Fermentation ◽

Steel Wool ◽

Heating Value ◽

Volatile Organic ◽

And Storage

The global energy trends are currently dominated by a massive use of fossil non-renewable energy sources which are progressively depleting. In this way, the production of second-generation biogas production from organic wastes by the dark fermentation process offers, therefore, an attractive solution to diversify the present energy mix. The development of biogas production units has led to an increase in the quantity of biomethane, but it contains impurities. A biomethane purification and storage system was developed in this work to improve the quality of this biofuel. Solutions were first developed to capture carbon dioxide, hydrogen sulfide, water, and volatile organic compounds found in the initial biogas. These solutions were based on a system of purification made up of water absorption reactions and iron oxide, activated charcoal, and steel wool adsorption. Thus, the biomethane obtained after purification has been stored in an inflatable balloon before being compressed into a refrigerant bottle of R134a. The treatment system was used to release a biogas with 95 % biomethane and a law heating value (LHV) of 54 MJ/kg after purification. It also emerges that purification of 2 m3 of biogas requires 0.15 m3 of water at 20oC to produce 1.4 m3 of biomethane. This biomethane can meet an energy demand of 1624 Wh or 0.2 m3 of daily biomethane requirements. The system as a whole can allow customers with a biodigester to produce their own energy (cooking or electric) while reducing the production of green-house gases in the atmosphere.

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Burning Resistance of Lignitic Coals Under Oxygen-Enriched Conditions

Journal of Energy Resources Technology ◽

10.1115/1.4046080 ◽

2020 ◽

Vol 142 (8) ◽

Cited By ~ 1

Author(s):

Ozlem Uguz ◽

Hanzade Haykiri-Acma ◽

Serdar Yaman

Keyword(s):

Horizontal Tube ◽

Treatment Temperature ◽

Low Grade ◽

Combined Effects ◽

X Ray Diffraction ◽

Heating Value ◽

Inorganic Matter ◽

O2 Concentration ◽

Effects Of Temperature ◽

The Individual

Abstract Oxygen-enriched air combustion of low-grade fuels with high inorganic matter is of great interest due to the efficient burning of such fuels and mitigation of emissions. For this purpose, this study aims to investigate the combined effects of oxygen enrichment and temperature on burnout levels. The oxygen-enriched air combustion performance of two Turkish lignites with different geological ages (early Miocene-Pliocene period Kutahya-Tuncbilek (KT) lignite and Pleistocene period Adiyaman-Golbasi (AG) lignite) was investigated in a horizontal tube reactor. The lignite samples were heated slowly (10 °C/min) to the temperatures of 200–600 °C for AG lignite and 200–800 °C for KT lignite under N2/O2 atmospheres with O2 ratios of 21, 30, 40, and 50 vol%. The solid residue remained after this oxidative heat treatment was characterized by proximate/ultimate analyses, higher heating value, (HHV) thermal analysis, Fourier transform infrared spectroscopy, (FTIR) X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. It was concluded that AG lignite that is relatively younger lignite is more susceptible to the O2-enriched conditions as the treatment temperature or O2 concentration increases. It was also determined that the combined effects of temperature and O2 concentration are much more profound than the individual effects of these parameters.

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Evaluation of selected properties of briquettes from recovered paper and board

Research in Agricultural Engineering ◽

10.17221/61/2013-rae ◽

2016 ◽

Vol 61 (No. 2) ◽

pp. 66-71 ◽

Cited By ~ 6

Author(s):

M. Brožek

Keyword(s):

Renewable Energy ◽

Energy Demand ◽

Renewable Energy Sources ◽

Calorific Value ◽

Energy Sources ◽

Rapid Decline ◽

Gross Calorific Value ◽

Weight Density ◽

Mechanical Durability ◽

Oil And Natural Gas

Worldwide increasing energy demand is today permanently covered by a majority of non-renewable energy sources, namely by coal, crude oil and natural gas. This causes the rapid decline of their reserves and the time gets near when they will be run out. Therefore in the last years the exploitation of renewable energy sources has been permanently preferred. One of alternative fuel forms is fuel on the basis of paper waste. In this paper the results of tests are published, which were carried out using six sorts of recovered paper and board (group and grade 1.05, 1.06, 2.02, 2.05, 2.07 and 2.08 according to CSN EN 643:2002), pressed into the form of briquettes. During the tests following briquettes parameters were watched: moisture content, ash amount, gross calorific value, length and diameter, weight, density, rupture force and mechanical durability. It was proved that briquettes made from recovered paper and board compared with briquettes from wood waste are of high density, high mechanical durability and for their rupture, relatively high force is necessary. But at the same time they have high ash amount and low gross calorific value.

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Direct ammonia fueled solid oxide fuel cells: A comprehensive review on challenges, opportunities and future outlooks

International Journal of Energy Technology ◽

10.32438/ijet.203011 ◽

2020 ◽

pp. 70-91 ◽

Cited By ~ 1

Author(s):

Molla Asmare ◽

Mustafa Ilbas

Keyword(s):

Electric Power ◽

Energy Demand ◽

Renewable Energy Sources ◽

Clean Energy ◽

Performance Comparison ◽

Optimum Operating ◽

Practical Implementation ◽

Human Society ◽

Energy Access ◽

Green Fuel

Nowadays, the most decisive challenges we are fronting are perfectly clean energy making for equitable and sustainable modern energy access, and battling the emerging alteration of the climate. This is because, carbon-rich fuels are the fundamental supply of utilized energy for strengthening human society, and it will be sustained in the near future. In connection with this, electrochemical technologies are an emerging and domineering tool for efficiently transforming the existing scarce fossil fuels and renewable energy sources into electric power with a trivial environmental impact. Compared with conventional power generation technologies, SOFC that operate at high temperature is emerging as a frontrunner to convert the fuels chemical energy into electric power and permits the deployment of varieties of fuels with negligible ecological destructions. According to this critical review, direct ammonia is obtained as a primary possible choice and price-effective green fuel for T-SOFCs. This is because T-SOFCs have higher volumetric power density, mechanically stable, and high thermal shocking resistance. Also, there is no sealing issue problem which is the chronic issues of the planar one. As a result, the toxicity of ammonia to use as a fuel is minimized if there may be a leakage during operation. It is portable and manageable that can be work everywhere when there is energy demand. Besides, manufacturing, onboard hydrogen deposition, and transportation infrastructure connected snags of hydrogen will be solved using ammonia. Ammonia is a low-priced carbon-neutral source of energy and has more stored volumetric energy compared with hydrogen. Yet, to utilize direct NH3 as a means of hydrogen carrier and an alternative green fuel in T-SOFCs practically determining the optimum operating temperatures, reactant flow rates, electrode porosities, pressure, the position of the anode, thickness and diameters of the tube are still requiring further improvement. Therefore, mathematical modeling ought to be developed to determine these parameters before planning for experimental work. Also, a performance comparison of AS, ES, and CS- T-SOFC powered with direct NH3 will be investigated and best-performed support will be carefully chosen for practical implementation and an experimental study will be conducted for verification based on optimum parameter values obtained from numerical modeling.

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Techno-Economic Analysis of a Novel Hydrogen-Based Hybrid Renewable Energy System for Both Grid-Tied and Off-Grid Power Supply in Japan: The Case of Fukushima Prefecture

Applied Sciences ◽

10.3390/app10124061 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4061 ◽

Cited By ~ 3

Author(s):

Naoto Takatsu ◽

Hooman Farzaneh

Keyword(s):

Renewable Energy ◽

Energy Demand ◽

Renewable Energy Sources ◽

Economic Assessment ◽

Energy System ◽

Modeling Framework ◽

Integrated Simulation ◽

Hybrid Renewable Energy System ◽

Renewable Energy System ◽

Hybrid Renewable Energy

After the Great East Japan Earthquake, energy security and vulnerability have become critical issues facing the Japanese energy system. The integration of renewable energy sources to meet specific regional energy demand is a promising scenario to overcome these challenges. To this aim, this paper proposes a novel hydrogen-based hybrid renewable energy system (HRES), in which hydrogen fuel can be produced using both the methods of solar electrolysis and supercritical water gasification (SCWG) of biomass feedstock. The produced hydrogen is considered to function as an energy storage medium by storing renewable energy until the fuel cell converts it to electricity. The proposed HRES is used to meet the electricity demand load requirements for a typical household in a selected residential area located in Shinchi-machi in Fukuoka prefecture, Japan. The techno-economic assessment of deploying the proposed systems was conducted, using an integrated simulation-optimization modeling framework, considering two scenarios: (1) minimization of the total cost of the system in an off-grid mode and (2) maximization of the total profit obtained from using renewable electricity and selling surplus solar electricity to the grid, considering the feed-in-tariff (FiT) scheme in a grid-tied mode. As indicated by the model results, the proposed HRES can generate about 47.3 MWh of electricity in all scenarios, which is needed to meet the external load requirement in the selected study area. The levelized cost of energy (LCOE) of the system in scenarios 1 and 2 was estimated at 55.92 JPY/kWh and 56.47 JPY/kWh, respectively.

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A Sizing Method for PV–Battery–Generator Systems for Off-Grid Applications Based on the LCOE

Energies ◽

10.3390/en14071988 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1988

Author(s):

Ioannis E. Kosmadakis ◽

Costas Elmasides

Keyword(s):

Renewable Energy ◽

Energy Demand ◽

Renewable Energy Sources ◽

Temporal Distribution ◽

Electrical Energy ◽

Optimal Number ◽

Diesel Generator ◽

Levelized Cost Of Electricity ◽

Sufficient Power ◽

Battery Energy

Electricity supply in nonelectrified areas can be covered by distributed renewable energy systems. The main disadvantage of these systems is the intermittent and often unpredictable nature of renewable energy sources. Moreover, the temporal distribution of renewable energy may not match that of energy demand. Systems that combine photovoltaic modules with electrical energy storage (EES) can eliminate the above disadvantages. However, the adoption of such solutions is often financially prohibitive. Therefore, all parameters that lead to a functionally reliable and self-sufficient power generation system should be carefully considered during the design phase of such systems. This study proposes a sizing method for off-grid electrification systems consisting of photovoltaics (PV), batteries, and a diesel generator set. The method is based on the optimal number of PV panels and battery energy capacity whilst minimizing the levelized cost of electricity (LCOE) for a period of 25 years. Validations against a synthesized load profile produced grid-independent systems backed by different accumulator technologies, with LCOEs ranging from 0.34 EUR/kWh to 0.46 EUR/kWh. The applied algorithm emphasizes a parameter of useful energy as a key output parameter for which the solar harvest is maximized in parallel with the minimization of the LCOE.

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Chemical Characterization of Microcystis aeruginosa for Feed and Energy Uses

Energies ◽

10.3390/en14113013 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3013

Author(s):

Larissa Souza Passos ◽

Éryka Costa Almeida ◽

Claudio Martin Pereira de Pereira ◽

Alessandro Alberto Casazza ◽

Attilio Converti ◽

...

Keyword(s):

Microcystis Aeruginosa ◽

Animal Feed ◽

Renewable Energy Sources ◽

Chemical Characterization ◽

Cyanobacterial Blooms ◽

Energy Sources ◽

Carbohydrate Source ◽

Heating Value ◽

Adverse Health Effects ◽

Degradation Reactions

Cyanobacterial blooms and strains absorb carbon dioxide, drawing attention to its use as feed for animals and renewable energy sources. However, cyanobacteria can produce toxins and have a low heating value. Herein, we studied a cyanobacterial strain harvested during a bloom event and analyzed it to use as animal feed and a source of energy supply. The thermal properties and the contents of total nitrogen, protein, carbohydrate, fatty acids, lipid, and the presence of cyanotoxins were investigated in the Microcystis aeruginosa LTPNA 01 strain and in a bloom material. Microcystins (hepatotoxins) were not detected in this strain nor in the bloom material by liquid chromatography coupled to mass spectrometry. Thermogravimetric analysis showed that degradation reactions (devolatilization) initiated at around 180 °C, dropping from approximately 90% to 20% of the samples’ mass. Our work showed that despite presenting a low heating value, both biomass and non-toxic M. aeruginosa LTPNA 01 could be used as energy sources either by burning or producing biofuels. Both can be considered a protein and carbohydrate source similar to some microalgae species as well as biomass fuel. It could also be used as additive for animal feed; however, its safety and potential adverse health effects should be further investigated.

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Electric Mobility in Cities: The Case of Vienna

Energies ◽

10.3390/en14010217 ◽

2021 ◽

Vol 14 (1) ◽

pp. 217

Author(s):

Amela Ajanovic ◽

Marina Siebenhofer ◽

Reinhard Haas

Keyword(s):

Electric Vehicles ◽

Future Development ◽

Urban Areas ◽

Energy Demand ◽

Renewable Energy Sources ◽

Road Transport ◽

Electric Mobility ◽

Policy Framework ◽

The Future ◽

Historical Developments

Environmental problems such as air pollution and greenhouse gas emissions are especially challenging in urban areas. Electric mobility in different forms may be a solution. While in recent years a major focus was put on private electric vehicles, e-mobility in public transport is already a very well-established and mature technology with a long history. The core objective of this paper is to analyze the economics of e-mobility in the Austrian capital of Vienna and the corresponding impact on the environment. In this paper, the historical developments, policy framework and scenarios for the future development of mobility in Vienna up to 2030 are presented. A major result shows that in an ambitious scenario for the deployment of battery electric vehicles, the total energy demand in road transport can be reduced by about 60% in 2030 compared to 2018. The major conclusion is that the policies, especially subsidies and emission-free zones will have the largest impact on the future development of private and public e-mobility in Vienna. Regarding the environmental performance, the most important is to ensure that a very high share of electricity used for electric mobility is generated from renewable energy sources.

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Crystal growth of clathrate hydrate formed with H2 + CO2 mixed gas and tetrahydropyran

Scientific Reports ◽

10.1038/s41598-021-90802-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Meku Maruyama ◽

Riku Matsuura ◽

Ryo Ohmura

Keyword(s):

Crystal Growth ◽

Synthesis Gas ◽

Water System ◽

Hydrate Formation ◽

Growth Dynamics ◽

Operating Conditions ◽

Mixed Gas ◽

Thermodynamic Conditions ◽

The Individual ◽

And Storage

AbstractHydrate-based gas separation technology is applicable to the CO2 capture and storage from synthesis gas mixture generated through gasification of fuel sources including biomass. This paper reports visual observations of crystal growth dynamics and crystal morphology of hydrate formed in the H2 + CO2 + tetrahydropyran (THP) + water system with a target for developing the hydrate-based CO2 separation process design. Experiments were conducted at a temperature range of 279.5–284.9 K under the pressure of 4.9–5.3 MPa. To simulate the synthesis gas, gas composition in the gas phase was maintained around H2:CO2 = 0.6:0.4 in mole fraction. Hydrate crystals were formed and extended along the THP/water interface. After the complete coverage of the interface to shape a polycrystalline shell, hydrate crystals continued to grow further into the bulk of liquid water. The individual crystals were identified as hexagonal, tetragonal and other polygonal-shaped formations. The crystal growth rate and the crystal size varied depending on thermodynamic conditions. Implications from the obtained results for the arrangement of operating conditions at the hydrate formation-, transportation-, and dissociation processes are discussed.

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Optimal Planning and Operation of a Residential Energy Community under Shared Electricity Incentives

Energies ◽

10.3390/en14082045 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2045

Author(s):

Pierpaolo Garavaso ◽

Fabio Bignucolo ◽

Jacopo Vivian ◽

Giulia Alessio ◽

Michele De Carli

Keyword(s):

Renewable Energy ◽

Power Distribution ◽

Energy Demand ◽

Renewable Energy Sources ◽

Energy System ◽

Distribution Networks ◽

Building Envelope ◽

Net Energy ◽

Technical Equipment ◽

Optimal Planning

Energy communities (ECs) are becoming increasingly common entities in power distribution networks. To promote local consumption of renewable energy sources, governments are supporting members of ECs with strong incentives on shared electricity. This policy encourages investments in the residential sector for building retrofit interventions and technical equipment renovations. In this paper, a general EC is modeled as an energy hub, which is deemed as a multi-energy system where different energy carriers are converted or stored to meet the building energy needs. Following the standardized matrix modeling approach, this paper introduces a novel methodology that aims at jointly identifying both optimal investments (planning) and optimal management strategies (operation) to supply the EC’s energy demand in the most convenient way under the current economic framework and policies. Optimal planning and operating results of five refurbishment cases for a real multi-family building are found and discussed, both in terms of overall cost and environmental impact. Simulation results verify that investing in building thermal efficiency leads to progressive electrification of end uses. It is demonstrated that the combination of improvements on building envelope thermal performances, photovoltaic (PV) generation, and heat pump results to be the most convenient refurbishment investment, allowing a 28% overall cost reduction compared to the benchmark scenario. Furthermore, incentives on shared electricity prove to stimulate higher renewable energy source (RES) penetration, reaching a significant reduction of emissions due to decreased net energy import.

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