La investigación se inició con un diagnóstico de fincas pertenecientes a la agricultura urbana y suburbana infestadas por Dichrostachys cinerea (L.) Wigth et Arm. Se determinaron en cuatro sistemas ...de uso (dos sistemas infestados por D. cinerea y dos sistemas agrícolas en explotación por 10 años luego de la deforestación del marabú y puesto en cultivo) en la zona de Becerra, finca Los Téllez del municipio Las Tunas. El objetivo fundamental fue valorar indicadores de calidad de los suelos Fersialíticos pardos rojizos sobre granitoides, que reflejen el grado de estabilidad de los suelos bajo el marabú y los cambios ocurridos por las prácticas de uso y manejo. Para evaluar el efecto de los sistemas de manejo sobre los indicadores de calidad de suelo se midieron indicadores químicos, (pH, P, Materia orgánica), físicos, (densidad aparente, contenido en arena, porosidad total) y biológicos, (densidad y biomasa de lombrices). Los resultados mostraron que los sistemas de D. cinerea resultaron los de mayor índice de calidad de los suelos tomando como indicadores materia orgánica, densidad aparente y biomasa de lombrices. Los sistemas cultivados alcanzaron la menor acumulación de carbono orgánico, densidad y biomasa de oligoquetos y porosidad total.
Biomass is the most widely used non-fossil fuel in the world. Biomass resources show a considerable potential in the long-term given the increasing proliferation of dedicated energy crops for ...biofuels. The second edition of Biomass Gasification and Pyrolysis is enhanced with new topics, such as torrefaction and cofiring, making it a versatile resource that not only explains the basic principles of energy conversion systems, but also provides valuable insight into the design of biomass conversion systems. This book will allow professionals, such as engineers, scientists, and operating personnel of biomass gasification, pyrolysis or torrefaction plants, to gain a better comprehension of the basics of biomass conversion. The author provides many worked out design problems, step-by-step design procedures and real data on commercially operating systems. With a dedicated focus on the design, analysis, and operational aspects of biomass gasification, pyrolysis, and torrefaction, Biomass Gasification, Pyrolysis and Torrefaction, Second Edition offers comprehensive coverage of biomass in its gas, liquid, and solid states in a single easy-to-access source. * Contains new and updated step-by-step process flow diagrams, design data and conversion charts, and numerical examples with solutions * Includes chapters dedicated to evolving torrefaction technologies, practicing option of biomass cofiring, and biomass conversion economics * Expanded coverage of syngas and other Fischer-Tropsch alternatives * Spotlights advanced processes such as supercritical water gasification and torrefaction of biomass. * Provides available research results in an easy-to-use design methodology
The grafting technique in tomato production has become popular in many countries in recent years as an alternative to control soil diseases and nematodes, as well as inducing tolerance to stress due ...to abiotic factors. An experiment was carried out in greenhouse conditions, where the effect of the use of grafted plants in tomato fSolanum lycopersicum L.), was evaluated by measuring biomass, fruit yield and content of N, P, K, Ca and Mg. The commercial hybrid Multifort fSolanum lycopersicum × S. habrochaites) was used as root-stock and as scion El Cid, a saladette type fruit hybrid was used. Grafted and ungrafted plants were established, directed to one and two stems. They were arranged using an experimental design of randomized complete blocks. Results indicate an increase in biomass in grafted plants, up to 36% in grafted plants directed to two stems. A larger accumulation of N, K and Ca was detected in grafted plants; in plants with two stems the significant increase was 46, 59.4 and 65.5% of N, K, Ca, respectively, compared with plants that were not grafted at two stems. Fruit yield was significantly improved in grafted plants directed to one and two stems, up to 0.93 and O.79kg/plant, which represented increases of 12.9 and 6.6%, respectively. It is concluded that tomato grafted with Multifort/El Cid modifies its mineral composition and improves yield and biomass accumulation.
A review on biomass as a fuel for boilers Saidur, R.; Abdelaziz, E.A.; Demirbas, A. ...
Renewable & sustainable energy reviews,
06/2011, Letnik:
15, Številka:
5
Journal Article
Recenzirano
Currently, fossil fuels such as oil, coal and natural gas represent the prime energy sources in the world. However, it is anticipated that these sources of energy will deplete within the next 40–50
...years. Moreover, the expected environmental damages such as the global warming, acid rain and urban smog due to the production of emissions from these sources have tempted the world to try to reduce carbon emissions by 80% and shift towards utilizing a variety of renewable energy resources (RES) which are less environmentally harmful such as solar, wind, biomass etc. in a sustainable way. Biomass is one of the earliest sources of energy with very specific properties. In this review, several aspects which are associated with burning biomass in boilers have been investigated such as composition of biomass, estimating the higher heating value of biomass, comparison between biomass and other fuels, combustion of biomass, co-firing of biomass and coal, impacts of biomass, economic and social analysis of biomass, transportation of biomass, densification of biomass, problems of biomass and future of biomass. It has been found that utilizing biomass in boilers offers many economical, social and environmental benefits such as financial net saving, conservation of fossil fuel resources, job opportunities creation and CO
2 and NO
x
emissions reduction. However, care should be taken to other environmental impacts of biomass such as land and water resources, soil erosion, loss of biodiversity and deforestation. Fouling, marketing, low heating value, storage and collections and handling are all associated problems when burning biomass in boilers. The future of biomass in boilers depends upon the development of the markets for fossil fuels and on policy decisions regarding the biomass market.
Langergraber G. 2001 Development of a Simulation Tool for Subsurface Flow Constructed Wetlands. Tietz A., Langergraber G., Sleytr K., Kirschner A., Haberl R. 2007 Characterization of microbial ...biocoenosis in vertical subsurface flow constructed wetlands.
Feedstock cost and cost variability is expected to increase with the number of biorefineries. To quantify this effect, this spatial-economic analysis simulates feedstock cost and cost variability of ...an industry based on corn stover as a function of the number of biorefineries. Results are reported for nine scenarios (a base case and sensitivity analysis of four variables – harvest efficiency, sustainability constraints, opportunity cost, and corn grain yield) under deterministic and stochastic simulations, assuming biorefineries using 658 000 Mg (725 000 tons) year-1 of corn stover in 2019. The resulting supply curves are highly elastic (i.e. little change in cost) for the first 50 of the 121 biorefineries, with price increases in subsequent biorefineries depending on scenario. In the base-case deterministic scenario, weighted-average stover costs are $66 Mg-1 ($60 ton-1), $69 Mg-1 ($62 ton-1), and $156 Mg-1 ($142 ton-1), at the first, 60th, and 121st biorefineries, respectively. The stochastic simulations, subject to observed 30-year corn yield variability, follow a similar pattern, with price distributions that vary by scenario. The base-case stochastic simulations illustrate minimal cost variability for the first 60 biorefineries, but rapid increases in cost variability in the second half of potential biorefineries, with similar patterns observed in the other scenarios. Of the four variables explored, price was most sensitive to harvest efficiency, followed by sustainability constraints, corn yield, and opportunity cost. Results suggest that, under conventional logistics, about half of the US corn stover resource is reliably available with minimum cost increase and variability. Interactive visualization is available at https://doi.org/10.11578/1828779.
In the gasification of an aquatic biomass with He/CO sub(2)/O sub(2), the effects of the concentration of CO sub(2) and O sub(2) in the gasifying agent and the feeding rate on the gasification ...behavior were investigated using a downdraft fixed-bed gasifier at 900 degree C. Using CO sub(2)/O sub(2) as the gasifying agent led to an increase in the conversion to gas and the syngas (CO + H sub(2)) content because the gasification of char with CO sub(2) (C + CO sub(2) arrow right 2CO) and the decomposition of tarry compounds were promoted. Increasing CO sub(2) content led to the increase in the conversion to gas and CO content and the decrease in the H sub(2) content. With increasing O2 content, contents of CO and H sub(2) increased while the conversions to gas remained almost constant. Especially with CO sub(2)/O sub(2) = 45/55 vol.%, the conversion to gas was 94.0 C-mol% and the syngas content exhibited a maximum value of 69.7 vol.%. As the feeding rate was decreased, contents of CO and H sub(2) decreased while the conversion to gas remained almost constant. The nitrogen atoms in the feedstock were mainly converted to form N sub(2). H sub(2)S and COS were the main sulfurous gases. The sulfur content in the char was much higher than that in the feedstock.
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•Lignocellulosic and macroalgae biomasses have been targeted for biochar production.•Co-pyrolysis improves the performance of biomass pyrolysis and biochar properties.•Biochar ...properties are influenced by biomass type & pyrolysis operating conditions.•Co-pyrolysis aids development of multiple biochar properties for various uses.•Morphological & surface compositional changes in biochar require characterization.
Biochar properties are significantly influenced and controlled by biomass feedstock type and pyrolysis operating conditions, and the development of multiple biochar properties for various applications has necessitated the need for blending different feedstocks together. Co-pyrolysis as a potential technology has been proposed to improve the overall performance of biomass pyrolysis and has proved effective in improving biochar properties. Consequently, the combination of lignocellulosic and macroalgae biomasses has been targeted for biochar production and improvement of biochar properties through co-pyrolysis. This paper therefore presents a critical review of biochar production from co-pyrolysis of lignocellulosic and macroalgae biomass (CLMB). It discusses the biomass feedstock selection, characterization, pre-processing and suitability for thermal processing; and analyzes biochar production, characterization and reactor technologies for CLMB. Furthermore, the potential and economic viability of biochar production system from CLMB are highlighted; and finally, the current state and future directions of biochar production from CLMB are extensively discussed.
To investigate large-scale patterns of above-ground and below-ground biomass partitioning in grassland ecosystems and to test the isometric theory at the community level. Northern China, in diverse ...grassland types spanning temperate grasslands in arid and semi-arid regions to alpine grasslands on the Tibetan Plateau. We investigated above-ground and below-ground biomass in China's grasslands by conducting five consecutive sampling campaigns across the northern part of the country during 2001-05. We then documented the root : shoot ratio (R/S) and its relationship with climatic factors for China's grasslands. We further explored relationships between above-ground and below-ground biomass across different grassland types. Our results indicated that the overall R/S of China's grasslands was larger than the global average (6.3 vs. 3.7). The R/S for China's grasslands did not show any significant trend with either mean annual temperature or mean annual precipitation. Above-ground biomass was nearly proportional to below-ground biomass with a scaling exponent (the slope of log-log linear relationship between above-ground and below-ground biomass) of 1.02 across various grassland types. The slope did not differ significantly between temperate and alpine grasslands or between steppe and meadow. Our findings support the isometric theory of above-ground and below-ground biomass partitioning, and suggest that above-ground biomass scales isometrically with below-ground biomass at the community level.
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