scholarly journals Energy crops and renewable energy: overall and process efficiency

2008 ◽  
pp. 1-6
Author(s):  
Winfried Schäfer
Keyword(s):  
Renewable Energy ◽  
Crop Production ◽  
Energy Input ◽  
Fossil Fuels ◽  
Energy Crops ◽  
Process Efficiency ◽  
Energy Crop ◽  
Overall Efficiency ◽  
Carbon Hydrates ◽  
Energy Surplus

Introduction and Objectives The crop scientist focuses his research on high quantity and quality of yield based on a sustainable tilth. The engineer is interested in maximisation of the process efficiency. He interprets the crop scientist’s ap-proach as maximisation of photosynthesis efficiency. Objective of this paper is to support the assessment of energy crop production applying engineering sciences methods in energy accounting. Methods and results The sustainability of energy crop production is assessed by calculating the overall efficiency using rape as example. The results show that the high process energy efficiency of the rapeseed cultivation fosters com-mon acceptance of rape as energy crop. Even under Finnish climate conditions, exergy of rape crop ex-ceeds up to 11-times the energy input for production and exergy of seed up to 3.7 times. Conversion of rapeseed into fuel decreases the energy surplus. Rape methyl ester (RME) delivers still 1.2-fold the energy input for cultivation and conversion. The whole rape crop (root, straw, seed) contains 3 to 6 ‰ of the overall energy input, RME 1 to 2 ‰ only. Animal production converts rape meal feed into manure, which is suitable for anaerobic digestion together with glycerine. The biogas augments the overall efficiency additionally 0.2 to 0.5 ‰. Rape cultivation requires a 4 to 7-year crop rotation. This and the low overall efficiency make it difficult in Finland to achieve energy self-sufficiency replacing diesel fuel by RME. The technical efficiency of the photosynthesis limits the maximum energy yield and reaches up to 0.8 % in Finland. By comparison, the efficiency of a photovoltaic collector is 165 to 248-fold better than the con-version efficiency of biomass or biogas produced from rapeseed and rape straw into electric power. The efficiency of the thermal collector exceeds heat production from burning the rape crop 157 to 443-fold. However, storage and continuous production of power and heat from sun energy is very limited. For that reason, the storage of sun energy in liquid carbon hydrates is subject of present research. Conclusion Energy crop production is captivating with many win-win situations: environmentally neutral bio-fuels replace polluting fossil fuels, farmers get better prices for energy crops, the agrochemical industry gains from intensification of energy crop production, and turn over of power industry grows due to increasing energy consumption to produce agrochemicals and to process biomass into fuel. As a following, the state tax income improves too. However, better prices for mainstream energy crops may trigger export of envi-ronmental pollution at the expense of food production because higher overall efficiency in tropical coun-tries favours the import of organic raw material for bio fuel production. Yet, high process efficiencies of technical processes to convert biomass into fuel justify the production of renewable energy from organic waste and residues. Thus, agriculture should not focus on energy crop production but produce high quality food environment-friendly. The overall efficiency of energy production from energy crops will never be competitive with solar techniques. Solar collectors replace fossil fuels for heat production outside agricul-ture already now sustainable and more efficient. Research on solar-technical processes to produce liquid carbon hydrates from methane, carbon dioxide, and water powered by solar energy without diversion into photosynthesis offers much a greater potential than research on energy crop production. As a measure for sustainability of renewable energy production, the energy surplus from sun energy conversion per capita and square meter is proposed.

scholarly journals Research Regarding the Evaluation of Potential Land Suitable for Energy Crop Production (Biomass) in Cluj County

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Aurel ŞANDOR ◽  
Avram FIŢIU ◽  
Dana-Adriana ILUŢIU-VARVARA
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Renewable Energy ◽  
Crop Production ◽  
Energy Crops ◽  
Energy Crop ◽  
Agricultural Lands ◽  
Short Term ◽  
Term Energy ◽  
Potential Land

The paper presents research regarding the evaluation of potential land suitable for energy crop production in order to obtain biomass as a renewable energy source. Statistic data is presented regarding the evolution of the fancier fund use, starting from 1990, until 2007, in form of pastures, vineyards and orchards, hayfields and inferior category arable lands. On the bases of the use rate of these types of land, land areas were estimated available for biomass type energy crops, at the level of Cluj County. The study proposes the identification of the lands suitable for short term energy crops, like agricultural lands from the inferior category or from the degraded and unproductive lands category.

scholarly journals Bioenergy production: are the objects realistic??

2008 ◽  
pp. 53-58
Author(s):  
Margit Csipkés
Keyword(s):  
Food Production ◽  
Crop Production ◽  
Maximum Level ◽  
Energy Crops ◽  
Plant Production ◽  
Energy Crop ◽  
The North ◽  
National Market ◽  
Energy Plant ◽  
Energy Economy

Currently we do not have the possibility to define our energy reserves, since we do not know the magnitude of extant material resources. The known petroleum (crude) supply will be sufficient for about 100 years at the longest, and according to the latest estimates in 2008 we will reach and even exceed the maximum level of oil extraction, and after this it is going to decrease.Hungary has good givens to go upon the way of sustainable energy economy according to experts, however a coherent government policy that lasts for not just one period is essential, and a sound economic- and agricultural policy is needed as well. According to the FVM’s under-secretary in Hungary more than 1 million hectares can be disposable for energy crop production. This would mean that 20 percent of the fields would be taken away from food production and on these fields energy crops would be grown. But we also have to take into consideration that the increase in energy plant production could happen at the expense of food production. If we would like to ensure the food for Hungary’s population from national sources we have to make calculations in determining energy need. In my research I set out the objective to determine the level of that specific turnover and marginal cost which supports the profitability of grain cultivation. With these indicators it is possible to analyze the economy and competitiveness of growing energy crops in the region of the North Plain. The alternatives of using cereals and rational land use should be also considered. A developing bio-fuel program can be a solution for the deduction of excess grain that is typical in Hungary for several years in the cereals sector. The pressure on the national market caused by excess grain can be ceased or moderated, and therefore the storage problems would decrease as well.

scholarly journals Energy efficiency of fossil and renewable fuels

2016 ◽  
pp. 1-7
Author(s):  
Winfried Schäfer
Keyword(s):  
Renewable Energy ◽  
Co2 Emissions ◽  
Energy Supply ◽  
Energy Input ◽  
Fossil Fuels ◽  
Energy Intensity ◽  
Fossil Fuel ◽  
Energy Output ◽  
Engine Fuel ◽  
Wide Range

Assessment results of renewable energy supply in agriculture and forestry are often questionable because 1. the methodology does not describe the nature dependent conditions of agricultural production, 2. there is no standard system boundary, 3. thermodynamic laws are violated and/or ignored, 4. direct and embodied energy is mixed, 5. the mainstream life cycle analysis (LCA) takes downstream and upstream inputs arbitrarily into consideration, depending on the research objectives and the research-funding agency. Thus, the calculation results neglect a wide range of specific energy input figures of upstream and down-stream factors outside farm level resulting in non-comparable figures. The EROI describes the ratio between energy output and input. The advantage of this measure is that energy input and output of fuel supply as well as the resulting CO2 emissions are comparable. There are no standards to calculate the indirect energy input of commodities and services hidden in monetary inputs (insurances, rent for land, subsidies and fees etc.). They are usually excluded because procedures to handle them as energy input are rare. The easiest way to quantify the indirect energy is the use of the energy intensity (EI). Multiplying the price of any good or service with the energy intensity results in a rough estimation of energy embodied in the good or service. Applying the EROI and the EI to compare the efficiency of fossil and renewable energy supply released the following results: Substitution of fossil fuels by renewable ones causes always additional costs. Most known renewable energy supply techniques need more energy than fossil fuel exploitation. Polluting the environment is - for the time being – the most competitive alternative. Renewable engine fuel, produced from biomass, is not competitive with fossil fuels in terms of EROI. The energy of one ha biomass may substitute gasoline to drive a car 40 000 km with biogas. Electric power harnessed from one ha solar panels enables to drive an electric vehicle 5 000 000 km applying the same calculation method. The most efficient way to mitigate CO2 emissions is to include the entropy of agricultural products in energy policy decision making. Albeit wood has a high EROI, processing fuels from wood of low entropy makes no sense: Producing a table from a tree and burning the residues and the table at the end of its lifetime renders the same energy gain as using the tree for fuel only. The EROI of fossil fuels remains probably on high level during the next 50 to 100 years. Oil and gas will be replaced by coal, in Finland also by nuclear power, peat and wood. Although biomass is more renewable than fossil fuels, its EROI is lower and substitution will not reduce CO2 emissions. Climate change may force humankind to reduce fossil fuel consumption. The only sustainable way to achieve this is reduction of fossil fuel exploitation.

Forcing Germany's renewable energy targets by increased energy crop production: A challenge for regulation to secure sustainable land use practices

2014 ◽  
Vol 36 ◽  
pp. 296-306 ◽  
Author(s):  
Gerd Lupp ◽  
Reimund Steinhäußer ◽  
Anja Starick ◽  
Moritz Gies ◽  
Olaf Bastian ◽  
...  
Keyword(s):  
Land Use ◽  
Renewable Energy ◽  
Crop Production ◽  
Sustainable Land Use ◽  
Energy Crop ◽  
Land Use Practices

scholarly journals Potential Use of Copper-Contaminated Soils for Hemp (Cannabis sativa L.) Cultivation

Environments ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 111
Author(s):  
Giulia Quagliata ◽  
Silvia Celletti ◽  
Eleonora Coppa ◽  
Tanja Mimmo ◽  
Stefano Cesco ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Fossil Fuels ◽  
Cannabis Sativa ◽  
Sulfur Metabolism ◽  
Energy Crops ◽  
Energy Crop ◽  
Edaphic Conditions ◽  
Alternative Sources ◽  
Mitigate Climate Change ◽  
Copper Contaminated

To mitigate climate change, reducing greenhouse gas emissions can be achieved by decreasing the use of fossil fuels and increasing that of alternative sources, such as energy crops. However, one of the most important problems in the use of biomass as a fuel is that of changing soil use and consumption, leading to competition with food crops. We addressed the topic by evaluating the possibility to exploit contaminated areas for energy crops cultivation. Indeed, soil contamination makes land inappropriate for cultivation, with damaging consequences for ecosystems, as well as posing serious health hazards to living beings. Specifically, this work aimed to evaluate the ability of hemp (Cannabis sativa L.) plants to grow on a copper (Cu)-contaminated medium. In addition, the effectiveness of an environment-friendly treatment with sulfate in improving plant ability to cope with Cu-induced oxidative stress was also explored. Results showed that plants were able to grow at high Cu concentrations. Therefore, hemp could represent an interesting energy crop in Cu-contaminated soils. Although the response of Cu-treated plants was evidenced by the increase in thiol content, following modulation of sulfur metabolism, it remains to be clarified whether the use of exogenous sulfate could be an agronomic practice to improve crop performance under these edaphic conditions.

scholarly journals Tools of promoting „energy-crops”

2008 ◽  
pp. 47-52
Author(s):  
Attila Kondor ◽  
József Antal
Keyword(s):  
Renewable Energy ◽  
Nuclear Energy ◽  
Fossil Fuel ◽  
Renewable Energy Sources ◽  
Energy Crops ◽  
Energy Crop ◽  
Soil Conditions ◽  
Short Rotation ◽  
Energy Plantations ◽  
Low Rate

The utilisation of renewable energy sources have come to front with the decreasing fossil fuel stocks, the unsolved problems and fears of nuclear energy and so the cumulating energy dependence. In Hungary the potential of biomass is the largest in renewable energy sources.During our examinations, we analysed the promotion of producing energy crops in Szabolcs-Szatmár-Bereg county. With the examination of the territories involved in energy crop subsidies it can be stated that the energy crop subsidy had its promoting role only on those areas where because of the bad soil conditions the energy crop producing is more profitable than other alternative (non energy) crops.The expected growth rate of energy plantations will be low, according to the low rate of subsidy intensity (40-60%). The uncertainty of direct area payments decreases the calculability that cuts back the favour of investment in short rotation forestry planting.

Energy After COVID

2020 ◽  
Vol 119 (820) ◽  
pp. 317-322
Author(s):  
Michael T. Klare
Keyword(s):  
Renewable Energy ◽  
Electric Vehicles ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
White Collar ◽  
Peak Oil ◽  
Business Travel ◽  
Reduce Energy Consumption ◽  
The Cost ◽  
Energy Companies

By transforming patterns of travel and work around the world, the COVID-19 pandemic is accelerating the transition to renewable energy and the decline of fossil fuels. Lockdowns brought car commuting and plane travel to a near halt, and the mass experiment in which white-collar employees have been working from home may permanently reduce energy consumption for business travel. Renewable energy and electric vehicles were already gaining market share before the pandemic. Under pressure from investors, major energy companies have started writing off fossil fuel reserves as stranded assets that are no longer worth the cost of extracting. These shifts may indicate that “peak oil demand” has arrived earlier than expected.

Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Made Dirgantara ◽  
Karelius Karelius ◽  
Marselin Devi Ariyanti, Sry Ayu K. Tamba
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
Key Words ◽  
Critical Analysis ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Proximate Analysis ◽  
Heating Value ◽  
Bomb Calorimeter ◽  
Hhv Prediction

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat  Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate 

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