scholarly journals Can Agriculture Balance Its Energy Consumption and Continue to Produce Food? A Framework for Assessing Energy Neutrality Applied to French Agriculture

2018 ◽  
Vol 10 (12) ◽  
pp. 4624 ◽  
Author(s):  
Souhil Harchaoui ◽  
Petros Chatzimpiros
Keyword(s):  
Energy Recovery ◽  
Fossil Fuels ◽  
Crop Residues ◽  
Energy Transition ◽  
High Energy ◽  
Net Energy ◽  
External Energy ◽  
Recovery Potential ◽  
Very High Energy ◽  
Internal Sources

In the context of energy transition, agriculture is facing a double challenge, which is to reduce its fossil fuel dependency and provide—in addition to food—bioenergy to society for substitution to fossil fuels. The feasibility of this challenge depends on whether agriculture can achieve energy neutrality, meaning to balance its consumption of external energy by energy recovery from internal sources. Livestock feed is a major determinant in this balance. We use France as a demonstration case of the changing role of feed in the long-term agricultural energy metabolism and the challenge of reaching energy neutrality. Results show that current agriculture is structurally energy deficient to such an extent that its functional energy requirements almost equal its final produce. The energy recovery potential from crop residues and manure could at best cover the primary biomass equivalent of the external energy inputs to agriculture. Only a suppression of feed from cropland combined with very high energy recovery from agricultural residues could allow achieving energy neutrality and making agriculture a net energy source to society.

scholarly journals Experimental Investigation of Thermal Characteristics of Kiwira Coal Waste with Rice Husk Blends for Gasification

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Deodatus Kazawadi ◽  
Geoffrey R. John ◽  
Cecil K. King’ondu
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Rice Husk ◽  
Energy Recovery ◽  
Fossil Fuels ◽  
High Energy ◽  
Coal Waste ◽  
Rice Husks ◽  
Weight Percentage ◽  
Thermal Stability Of

Eminent depletion of fossil fuels and environmental pollution are the key forces driving the implementation cofiring of fossil fuels and biomass. Cogasification as a technology is known to have advantages of low cost, high energy recovery, and environmental friendliness. The performance/efficiency of this energy recovery process substantially depends on thermal properties of the fuel. This paper presents experimental study of thermal behavior of Kiwira coal waste/rice husks blends. Compositions of 0, 20, 40, 60, 80, and 100% weight percentage rice husk were studied using thermogravimetric analyzer at the heating rate of 10 K/min to 1273 K. Specifically, degradation rate, conversion rate, and kinetic parameters have been studied. Thermal stability of coal waste was found to be higher than that of rice husks. In addition, thermal stability of coal waste/rice husk blend was found to decrease with an increase of rice husks. In contrast, both the degradation and devolatilization rates increased with the amount of rice husk. On the other hand, the activation energy dramatically reduced from 131 kJ/mol at 0% rice husks to 75 kJ/mol at 100% rice husks. The reduction of activation energy is advantageous as it can be used to design efficient performance and cost effective cogasification process.

Net Energy and CO2 Emissions Analysis of Using MRF Residue as Solid Recovered Fuel at Coal Fired Power Plants

2012 ◽  
Author(s):  
Alex C. Breckel ◽  
John R. Fyffe ◽  
Michael E. Webber
Keyword(s):  
Waste Management ◽  
End Of Life ◽  
Energy Recovery ◽  
Power Plants ◽  
Fossil Fuels ◽  
Management Practices ◽  
High Energy ◽  
Moderate Degree ◽  
Management Hierarchy ◽  
The U.S

According to the waste management hierarchy published by the U.S. EPA, waste reduction and reuse are the most preferred modes of waste management, followed by recycling, energy recovery and lastly disposal. As many communities in the U.S. work towards sustainable waste management practices, recycling tends to be a cost-effective and common solution for handling municipal solid waste. With the introduction of single-stream recycling and automated materials recovery facilities (MRFs), where commingled recyclables are sorted into various commodity streams for sale to recycling facilities, recycling rates have steadily climbed in recent years. Despite increasing total recycling rates, contamination and diminishing returns for higher recovery ratios causes MRFs to landfill 5–25% of the incoming recycling stream as residue. This residue stream is composed primarily of plastics and fiber, both of which have high energy content that could be recovered instead of buried in a landfill. Plastics in particular are reported to have heat contents similar to fossil fuels, making energy recovery a viable end-of-life pathway. Sorting, shredding and densifying the residue stream to form solid recovered fuel (SRF) pellets for use as an alternative fuel yields energy recovery, displaced fossil fuels and landfill avoidance, moving more disposed refuse up the waste management hierarchy. Previous studies have shown that plastic, paper, and plastic-paper mixes are well suited for conversion to SRF and combustion for energy production. However, these studies focused on relatively homogenous and predictable material streams. MRF residue is not homogenous and has only a moderate degree of predictability, and thus poses several technical challenges for conversion to SRF and for straightforward energy and emissions analysis. This research seeks to understand the energetic and environmental tradeoffs associated with converting MRF residue into SRF for co-firing in pulverized coal power plants. A technical analysis is presented that compares a residue-to-SRF scenario to a residue-to-landfill scenario to estimate non-obvious energy and emissions tradeoffs associated with this alternative end-of-life scenario for MRF residue. Sensitivity to key assumptions was analyzed by considering facility proximity, landfill gas capture efficiency, conversion ratio of residue to SRF and the mass of residue used. The results of this study indicate that the use of MRF residue derived SRF in coal fired steam-electricity power plants realizes meaningful reductions of emissions, primary energy consumption, coal use and landfill deposition.

Biomass as an energy source for the midwestern U.S.

1992 ◽  
Vol 7 (3) ◽  
pp. 137-144 ◽  
Author(s):  
D. R. Keeney ◽  
T. H. DeLuca
Keyword(s):  
Energy Source ◽  
Energy Balance ◽  
Rural Communities ◽  
Alternative Energy ◽  
Fossil Fuels ◽  
Crop Residues ◽  
Biomass Energy ◽  
Energy Resources ◽  
Net Energy ◽  
Seed Crops

AbstractRecognition of the environmental costs of fossil fuels coupled with concern over their depletion within the next few decades has broadened the search for alternative energy resources, including biomass energy. Ethanol produced from corn (Zea mays L.) grain currently is the primary form of biomass energy produced in the Midwest, but its net energy balance commonly is negative when corn grain is produced under conventional practices. Reducing fossil fuel inputs, particularly for nitrogen fertilizer, will improve the energy balance, but more substantial improvements involve increased efficiency of ethanol production. An alternate source involves fermentation of crops such as sweet sorghum (Sorghum bicolor [L.]Moench).Other potential biomass energy resources for the Midwest include oils extracted from seed crops, methane from waste digestion, and combustion, gasification or fermentation of woody and herbaceous crops and crop residues. These resources may serve as an energy supplement or a useful energy source for individual farms, households or rural communities. Biomass energy systems in Midwest agriculture must be evaluated regarding their long term environmental impacts and their sustainability. Externalities that must be considered include surface and ground water pollution, soil erosion, and economic and social benefits to the rural community.

BP Global Energy Outlook 2030

2013 ◽  
pp. 109-128 ◽  
Author(s):  
C. Rühl
Keyword(s):  
Emerging Economies ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Net Energy ◽  
Global Energy ◽  
The Past ◽  
Market Shares ◽  
The Us ◽  
Almost All ◽  
Oil Gas

This paper presents the highlights of the third annual edition of the BP Energy Outlook, which sets out BP’s view of the most likely developments in global energy markets to 2030, based on up-to-date analysis and taking into account developments of the past year. The Outlook’s overall expectation for growth in global energy demand is to be 36% higher in 2030 than in 2011 and almost all the growth coming from emerging economies. It also reflects shifting expectations of the pattern of supply, with unconventional sources — shale gas and tight oil together with heavy oil and biofuels — playing an increasingly important role and, in particular, transforming the energy balance of the US. While the fuel mix is evolving, fossil fuels will continue to be dominant. Oil, gas and coal are expected to converge on market shares of around 26—28% each by 2030, and non-fossil fuels — nuclear, hydro and renewables — on a share of around 6—7% each. By 2030, increasing production and moderating demand will result in the US being 99% self-sufficient in net energy. Meanwhile, with continuing steep economic growth, major emerging economies such as China and India will become increasingly reliant on energy imports. These shifts will have major impacts on trade balances.

Strong interactions at very high energy

1964 ◽  
Vol 82 (1) ◽  
pp. 3-81 ◽  
Author(s):  
Evgenii L. Feinberg ◽  
Dmitrii S. Chernavskii
Keyword(s):  
High Energy ◽  
Strong Interactions ◽  
Very High Energy ◽  
Very High

Assessing desalination as a sustainable alternative using a multiple criteria decision support model

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
M. B. Fernandes ◽  
M. C. Almeida ◽  
A. G. Henriques
Keyword(s):  
Decision Support ◽  
Energy Production ◽  
Fossil Fuels ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
High Energy ◽  
Economic Benefits ◽  
Multiple Criteria ◽  
Water Production ◽  
Decision Support Model

Desalination technologies provide an alternative for potable water production, having significant potential for application where fresh water scarcity exists. Potential benefits have to be balanced with other factors, such as high costs, high energy consumption, and significant environmental impacts, for the understanding of real risks and gains of desalination within the context of integrated water resources management. Multiple factors can be considered when analysing the viability of a desalination project but often a limited approach is used. The complexity in the analysis lies in finding the alternatives that obey to multiple objectives (e.g. reduced environmental impact, social acceptance, less cost associated). In this paper, development of a methodology based on multiple criteria decision support system for the evaluation and ranking the potential of desalination technologies is described and applied to a Portuguese case study. Relevant factors to the selection of desalination technologies were identified using SWOT analysis and the MACBETH (Measuring Attractiveness by a Categorical Based Evaluation Technique) approach was applied. Technical alternatives considered include reverse osmosis and multi-effect desalination (MED), together with energy production by fossil fuels or solar energy. Production of water by conventional approaches was also considered. Results, for non-economic benefits, show higher score for MED solar but, in the cost-benefit analysis, conventional methods of water production have higher ranking since costs of renewable energies are not yet competitive. However, even if not preferred in economic terms, desalination is ranked significantly above the conventional approaches for non-economic criteria.

Transportation: Fuel Energies

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Energy Density ◽  
Fossil Fuels ◽  
High Energy ◽  
Ease Of Use ◽  
Low Energy ◽  
High Energy Density ◽  
Nuclear Fuels ◽  
Liquid Hydrocarbons ◽  
Transportation Fuel ◽  
Journey Time

Transportation efficiency can be measured in terms of the energy needed to move a person or a tonne of freight over a given distance. For passengers, journey time is important, so an equally useful measure is the product of the energy used and the time taken for the journey. Transportation requires storage of energy. Rechargeable systems such as batteries have very low energy densities as compared to fossil fuels. The highest energy densities come from nuclear fuels, although, because of shielding requirements, these are not practical for most forms of transportation. Liquid hydrocarbons represent a nice compromise between high energy density and ease of use.

scholarly journals Multi-Country Scale Assessment of Available Energy Recovery Potential Using Micro-Hydropower in Drinking, Pressurised Irrigation and Wastewater Networks, Covering Part of the EU

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  
Keyword(s):  
Drinking Water ◽  
Northern Ireland ◽  
Energy Recovery ◽  
Large Scale ◽  
Significant Proportion ◽  
Value Added ◽  
Cost Effective ◽  
Net Energy ◽  
Water Networks ◽  
Scale Assessment

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.

Sign in / Sign up

Export Citation Format

Share Document