scholarly journals Utilization of Barley Straw as Feedstock for the Production of Different Energy Vectors

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 726
Author(s):  
Merlin Raud ◽  
Lisandra Rocha-Meneses ◽  
Daniel J. Lane ◽  
Olli Sippula ◽  
Narasinha J. Shurpali ◽  
...  

During the bioethanol production process, vast amounts of residues are generated as process waste. To extract more value from lignocellulosic biomass and improve process economics, these residues should be used as feedstock in additional processes for the production of energy or fuels. In this paper, barley straw was used for bioethanol production and the residues were valorized using anaerobic digestion (AD) or used for the production of heat and power by combustion. A traditional three-step bioethanol production process was used, and the biomass residues obtained from different stages of the process were analyzed. Finally, mass and energy balances were calculated to quantify material flow and assess the different technological routes for biomass utilization. Up to 90 kg of ethanol could be produced from 1 t of biomass and additional biogas and energy generated from processing residues can increase the energy yield to over 220%. The results show that in terms of energy output, combustion was the preferable route for processing biomass residues. However, the production of biogas is also an attractive solution to increase revenue in the bioethanol production process.

e-xacta ◽  
2018 ◽  
Vol 11 (2) ◽  
pp. 31
Author(s):  
José Izaquiel Santos da Silva ◽  
Edilailsa Januário de Melo ◽  
Eduardo De Paulo Ferreira ◽  
Mariana Freitas Moura ◽  
Shirley Caroline Nascimento

<p><em>O biodiesel vem sendo amplamente utilizado no mercado atual como uma alternativa de substituição aos combustíveis fósseis finitos. No final de sua produção, 10% da corrente de saída do processo é composta de glicerol. A conversão deste glicerol em hidrogênio é uma alternativa que visa agregar valor econômico a este subproduto. Sendo assim, este trabalho apresenta um estudo da reforma em fase aquosa de glicerol, subproduto de um processo de produção de biodiesel, utilizando catalisador de platina suportados em Al<sub>2</sub>O<sub>3</sub> para produção de hidrogênio. Para isto, os balanços de massa e energia foram analisados, onde os resultados mostraram uma corrente final constituída de hidrogênio e 4,66% de CO<sub>2</sub>,</em> <em>impactando em baixos gastos energéticos e gerando resíduos menos poluentes se comparados as rotas de reforma mais tradicionais empregadas na indústria</em><em>.</em></p><p><em> </em></p><p><em>Abstract</em></p><p><em> Biodiesel is being widely used in the current market in place of fossil fuels. At the end of its production process, 10% of the output stream is comprised of glycerol. The conversion of this glycerol into hydrogen is an alternative that can add economic value to the by-product. This paper presents a study of the aqueous-phase reforming of glycerol, by product of a biodiesel production process, over platinum catalysts supported on Al<sub>2</sub>O<sub>3</sub> for hydrogen production. For this, the mass and energy balances were analyzed, where the results showed a final current constituted of hydrogen and only 4.66% of CO<sub>2</sub>, impacting on low energy costs and the generation of less polluting residues when compared to the used in industry.</em></p>


2019 ◽  
pp. 646-654
Author(s):  
Jan Iciek ◽  
Kornel Hulak ◽  
Radosław Gruska

The article presents the mass and energy balances of the sucrose crystallization process in a continuous evaporating crystallizer. The developed algorithm allows to assess the working conditions of the continuous evaporating crystallizers and the technological and energy parameters. The energy balance algorithm takes into account the heat released during the crystallization of sucrose, which was analyzed in this study, heat losses to the environment and heat losses due the vapor used for inert gas removal.


ChemSusChem ◽  
2012 ◽  
Vol 6 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Christos K. Nitsos ◽  
Konstantinos A. Matis ◽  
Kostas S. Triantafyllidis

2017 ◽  
Vol 106 ◽  
pp. 59-64 ◽  
Author(s):  
E. Oropeza-De la Rosa ◽  
L.G. López-Ávila ◽  
G. Luna-Solano ◽  
D. Cantú-Lozano

Author(s):  
К.Н. Привалова ◽  
Р.Р. Каримов

Исследования по определению энергетической эффективности пастбищных систем со злаковыми и бобово-злаковыми травостоями проведены в Федеральном научном центре кормопроизводства и агроэкологии им. В. Р. Вильямса. В статье приведены результаты агроэнергетической оценки многовариантных пастбищных систем со злаковыми травостоями, созданными в 1946 году. Даны количественные показатели по сбору обменной энергии, совокупным затратам на её производство, окупаемости затрат в зависимости от системы ведения пастбищ. Изучена эффективность совокупных затрат в виде овеществлённого труда (на семена, удобрения, сельскохозяйственные машины, средства огораживания загонов и прочее) и живого труда (работы трактористов, пастухов и строителей и др.). Обоснована высокая агроэнергетическая эффективность изучаемых пастбищных систем благодаря мобилизации в продукционный процесс природных факторов, долевое участие которых в структуре производства обменной энергии составило 69–84%. Природные факторы, участвующие в продукционном процессе луговых агроэкосистем, характеризуются большим разнообразием. Это не только использование солнечной энергии и азотфиксация бобовыми травами, но и долголетие травостоев, самовозобновление фитоценозов, дерновообразовательный процесс (повышение плодородия почвы), получение дешёвого корма и улучшение здоровья животных при летнем выпасе. Роль возобновляемых природных факторов выявлена на основе балансового метода, принятого в экономике (по разнице сбора обменной энергии и антропогенных затрат). Благодаря ведущей роли природных факторов в структуре произведённой продукции агроэнергетический коэффициент окупаемости совокупных затрат антропогенной энергии (АК) за счёт сбора обменной энергии достигал 3–6 раз в среднем за 45 лет. Разработанные в результате долголетних исследований многовариантные энергосберегающие пастбищные системы обосновывают возможность рекомендовать их производству с учётом применения различного уровня энергозатрат. Ключевые слова: культурные пастбища, системы ведения, долголетние травостои, сбор обменной энергии, совокупные антропогенные затраты, окупаемость затрат. The investigation was conducted at the Federal Williams Research Center of Fodder Production and Agroecology and was aimed at testing energy efficiency of gramineous and legume-gramineous swards. This article presents the results obtained on pasture ecosystems with gramineous planted in 1946. Exchange energy yield, total production costs and economic effectiveness were analyzed. Total production costs comprised costs for seeds, fertilizers, machinery, construction materials, labor, etc. Introduction of natural factors into the production process resulted in higher energy efficiency. Their share amounted to 69–84% in the final exchange energy yield. There are a lot of natural factors that affect grass productivity such as solar energy, nitrogen-fixation, sward longevity and regeneration, soil fertility, low-cost feed production, and livestock health. The value of natural factors was determined according to the balance method (by the difference between exchange energy yield and anthropogenic costs). Since environmental factors had a leading role in the production process, the return rate raised by 3–6 times for 45 years due to exchange energy increase. Therefore, pasture ecosystems developed can be recommended for a large-scale forage production.


2019 ◽  
Vol 120 ◽  
pp. 144-155 ◽  
Author(s):  
Andrea Maria Rizzo ◽  
Marco Pettorali ◽  
Renato Nistri ◽  
David Chiaramonti

2017 ◽  
Vol 11 (6) ◽  
pp. 2799-2813 ◽  
Author(s):  
Colin R. Meyer ◽  
Ian J. Hewitt

Abstract. Meltwater is produced on the surface of glaciers and ice sheets when the seasonal energy forcing warms the snow to its melting temperature. This meltwater percolates into the snow and subsequently runs off laterally in streams, is stored as liquid water, or refreezes, thus warming the subsurface through the release of latent heat. We present a continuum model for the percolation process that includes heat conduction, meltwater percolation and refreezing, as well as mechanical compaction. The model is forced by surface mass and energy balances, and the percolation process is described using Darcy's law, allowing for both partially and fully saturated pore space. Water is allowed to run off from the surface if the snow is fully saturated. The model outputs include the temperature, density, and water-content profiles and the surface runoff and water storage. We compare the propagation of freezing fronts that occur in the model to observations from the Greenland Ice Sheet. We show that the model applies to both accumulation and ablation areas and allows for a transition between the two as the surface energy forcing varies. The largest average firn temperatures occur at intermediate values of the surface forcing when perennial water storage is predicted.


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