Alternative Biomass Research Articles

Kiwi Clear‐Cut: First Evaluation of Recovered Biomass for Energy Production

Among the various types of agricultural waste, significant amounts of energy can be obtained from woodchips derived from comminuted pruning residues. This study aimed to assess the feasibility of using kiwi orchard clear-cut biomass for energy production. The field trial was conducted in a commercial kiwi (Actinidia chinensis) orchard located in Northwest Italy. We evaluated the biomass yield, woodchip quality, energy consumption, and economic sustainability of this practice. Processed data determined the available biomass to be 20.6 tonnes dry matter ha−1. Woodchip analysis showed a biomass moisture content of 53% and a relatively low heating value of about 7.5 MJ·kg−1. Furthermore, the average ash content was 2.4%. Production cost was 99.6 €·t−1 dry matter, which was slightly less than the market price of 100 €·t−1 dry matter for woodchips. In summary, kiwi clear-cut recovered biomass may be a valid alternative biomass source.

Biodiesel production from Neochloris oleoabundans by supercritical technology

Oleaginous microalgae have been proposed as a sustainable alternative biomass to produce biodiesel in order to substitute conventional vegetable oils derived from oilseed crops. Particularly, recent studies pointed out the potential of N. oleoabundans, cultured in seawater or in anaerobically digested dairy manure, to produce triglycerides with high content of monounsaturated fatty acids. The supercritical technology has been recognized as a green sustainable alternative to transform biomass into valuable products. Thus, the aim of the present wok was to study the direct supercritical alcohol processing of partially dried N. oleoabundans biomass and later reaction products fractionation by supercritical CO2 or liquid n-hexane. A direct alcoholysis of microalgae biomass was carried out at different temperatures (250°C and 280°C) and increasing reaction times in order to evaluate the fatty acid ester production. Bio-oils from microalgae with up to 35wt.% fatty acid esters were obtained by two fold extraction with n-hexane. Conversely, supercritical CO2 fractionation produced upgraded bio-oils with up to 74wt.% of fatty acid esters content.

Pembuatan Bioetanol Berbahan Baku Kertas Bekas menggunakan Metode Hidrolisis Asam dan Fermentasi

The enormous global daily consumption of liquid fuels is of the order of 80 million barrels/day (equivalent of 12.7 million m3/day). The sugar cane area required to produce the same volume of ethanol about 700 million hectares, assuming a yield of 6.5 m3/ha/year of ethanol. This study focus to use the second generation feedstock for bioethanol production. Waste papers have cellulose biomass in high percentage so that can be used as potential alternative biomass feedstock to convert bioethanol. Alkaline delignification was conducted by sodium hydroxide (NaOH) and then hydrolyzed using sulfuric acid (H2SO4) diluted with various concentrations (2%, 2.5%, 3%, 3.5%, 4%, and 5% (v/v) and then fermentation was carried out by Saccharomyces cereviciae with the variation fermentation time (4 days, 5 days, 6 days, 7 days, and 8 days). Ethanol will be produced after separated using evaporation process. The results for the paper inked with the highest ethanol content of 6,12 % (v/v) was obtained at a concentration of 4% sulfuric acid (v / v) and 7 days fermentation time. While the paper without ink obtained the highest ethanol content of 8,13 % (v / v) sulfuric acid at a concentration of 4% (v/v) and 7 days fermentation time

Integrated design and sustainable assessment of innovative biomass supply chains: A case-study on miscanthus in France

Cost-efficient, environmental-friendly and socially sustainable biomass supply chains are urgently needed to achieve the 2020 targets of the Strategic Energy Technologies-Plan of the European Union. This paper investigated technical, social, economic, and environmental barriers to the development and innovation of supply chains, taking into account a large range of parameters influencing the performances of biomass systems at supply chain scale. An assessment framework was developed that combined economic optimization of a supply chain with a holistic and integrated sustainability assessment. The framework was applied to a case-study involving miscanthus biomass in the Burgundy region (Eastern France) to compare alternative biomass supply chain scenarios with different annual biomass demand, crop yield, harvest timing and densification technologies. These biomass supply chain scenarios were first economically optimized across the whole supply chain (from field to plant gate) by considering potential feedstock production (from a high-resolution map), costs, logistical constraints and product prices. Then sustainability assessment was conducted by combining recognized methodologies: economic analysis, multi-regional input-output analysis, emergy assessment, and life-cycle assessment. The analysis of the case study scenarios found that expanding biomass supply from 6,000 to 30,000tons of dry matter per year did not impact the profitability, which remained around 20€perton of biomass procured. Regarding environmental impacts, the scenario with the lowest feedstock supply area had the lowest impact per ton due to low economies of scale. Mobile briquetting proved to be also a viable economic option, especially in situations with a considerable scattering of the crop production and expensive transportation logistics. By highlighting hot-spots in terms of economic, environmental and social impacts of biomass supply systems, this study provides guidance in the supply chain optimization and the design of technological solutions tailored to economic operators as well as other stakeholders, such as policy makers.

Response surface optimization, modeling and uncertainty analysis of mass loss response of co-combustion of sewage sludge and water hyacinth

The present study aims at quantifying mass loss percentage (MLP, %) predictions and their stochastic uncertainty when co-combustion of sewage sludge (SS) and water hyacinth (WH) are applied as alternative biomass materials under different blend ratios (BR), heating rates (HR, °C/min) and temperatures (T, °C). Optimization and validation of experimental data through Box–Behnken design pointed to 630.9°C for T, 60.1% SS for BR, and 29.9°C/min for HR as the optimal co-combustion parameters to achieve the maximum MLP of 92.4%. Monte Carlo (MC) simulations were used to quantify uncertainty in MLP predictions of the best-fit multiple non-linear regression (MNLR) model derived from the entire experimental data as a function of MC-generated T as the only continuous predictor of the MNLR. Mean MLP value of the MNLR predictions was higher by 19% than that of the MC-simulated T whose mean was higher by only 1% than mean measured T. Incorporating the uncertainty estimation based on Monte Carlo simulations with response surface approach for co-combustion of SS and WH was one of the main novel contributors of the present study to related literature.

Fodder radish cake (Raphanus sativus L.) as an alternative biomass for the production of cellulases and xylanases in solid-state cultivation

Fodder radish cake (Raphanus sativus L.) as an alternative biomass for the production of cellulases and xylanases in solid-state cultivation

Sustainable network design for multi-purpose pellet processing depots under biomass supply uncertainty

This study develops a two-stage stochastic mixed-integer programming model to manage multi-purpose pellet processing depots under feedstock supply uncertainty. The proposed optimization model would help to minimize cost and mitigate emissions from the supply chain network. We consider three alternative Biomass Processing and Densification Depot (BPDD) technologies; namely, conventional pellet processing, high moisture pellet processing, and ammonia fiber expansion. These three technologies pre-process/pre-treat and densify different types of biomass into more highly densified intermediate products for different markets in order to improve movability and overall supply network performance in terms of costs and emissions. A hybrid decomposition algorithm was developed that combines Sample Average Approximation with an enhanced Progressive Hedging (PH) algorithm to solve this challenging NP-hard problem. Some heuristics such as Rolling Horizon (RH) heuristic, variable fixing technique were later applied to further enhance the PH algorithm. Mississippi and Alabama were selected as a testing ground and ArcGIS was employed to visualize and validate the modeling results. The results of the analysis reveal promising insights that could lead to recommendations to help decision makers achieve a more cost-effective environmentally-friendly supply chain network.

Alternative biomass strategies for bioenergy: implications for bird communities across the southeastern United States

AbstractConcerns over energy demands and climate change have led the United States to set ambitious targets for bioenergy production in the coming decades. The southeastern United States has had a recent increase in biomass woody pellet production and is projected to produce a large portion of the nation's cellulosic biofuels. We conducted a large‐scale, systematic comparison of potential impacts of two types of bioenergy feedstocks – corn (Zea mays) and pine (Pinus spp.) – on bird communities across the southeastern United States. In addition, we evaluated three biomass alternatives for woody biomass from pine plantations: thinning, residue harvest, and short‐rotation energy plantations (SREPs). We conducted transect counts for birds in eight different land uses across the region (85 sites), including corn fields, reference forest, and plantation forests, 2013–2015. We then used hierarchical occupancy models to test the effect of these biomass alternatives on 31 species. Across all species, birds had lower rates of occupancy in corn fields compared to pine stands. Thinning had positive effects on the average occupancy across species, while residue harvest and the potential conversion of conventional plantations to SREPs had negative effects. Cavity nesters and species with bark‐gleaning foraging strategies tended to show the strongest responses. These results highlight the potential negative effects of corn as an energy crop relative to the use of pine biomass. In addition, harvesting biomass via thinning was a bird‐friendly harvest method in comparison with other alternatives. While SREPs may negatively impact some bird species, previously reported yields emphasize that they may provide an order of magnitude greater yield per unit area than other alternatives considered, such that this land‐use practice may be an important alternative to minimize the bioenergy impacts across the landscape.

Emissions and ash behavior in a 500 kW pellet boiler operated with various blends of woody biomass and peat

Due to the increasing utilization of wood-based raw materials, there is growing interest in the use of alternative biomass raw materials for biomass pellet production. However, the utilization of these new raw materials may significantly increase particle emissions from small boilers, which can cause adverse effects on human health and the environment. In this study, the effects of biomass raw materials on particle and gaseous emissions and ash behavior were studied in a real-world operating 500kW reciprocating grate boiler. The studied fuels were pellets, which consisted of softwood stem, bark, peat and various mixtures of these materials. The emission factors of the fine particles (PM1) ranged between 11 and 26mg/MJ, which were primarily determined by alkali metal release from the fuel. The co-firing of peat with wood significantly decreased PM1 emissions. This decrease was observed because of the high silicate content in peat, which led to alkali silicate formation during co-combustion and, consequently, the retention of alkali metals in the bottom ash. In contrast, the release of trace metals into the fine particle fraction was independent of the fuel ash composition with the exception of Cu. The emissions of As, Cd, Pb, Tl, and Zn were linearly dependent on their concentrations in the fuel. The highest release rates, which were between 40% and 60%, were observed for zinc and lead. Zinc formed the majority of the total PM1 heavy metal emissions, and zinc emissions were especially high in bark combustion. On the basis of these results, fuel composition based indexes were derived for predicting particle emissions. The results highlight the importance of both the fuel alkali metal content and alkali metal/silicate ratio in the formation of fine particles with fuels that consist of woody biomass and peat.

Pelletized Composite Wood Fiber Mixed with Plastic as Advanced Solid Biofuels: Thermo-Chemical Analysis

Biomass pellets, as renewable multifunctional resources, cannot only be exploited for heating and power generation but also for greenhouse carbon dioxide enrichment. Composite pellets of plastics and wood fibers are one of the industrialized alternative biomass with improved multiphysical properties. In this study, thermal and chemical analysis along with the scanning electron microscope imaging were implemented. The bio-based fibers were mixed with several volume fractions of plastic in the form of pelletized advanced solid fuel. The pristine fiber pellet containing no plastic was tested as a baseline for the thermo-chemical properties of composite wood pellets. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used for the thermal analysis of pelletized samples. The TGA results were used to explore the thermal reactivity of fibers and plastics under high temperature conditions. The DSC results showed that the glass transition of the composite pellets, taking place under endothermic reactions, was activated by increasing the plastic content of composite pellets. Thermal conductivity of composite pellets was measured using the Hot-Disk transient plane source (TPS) technique. The TPS results showed that a composite pellet with a higher volume-fraction of plastics possessed a lower thermal conductivity. This is due to the lower thermal conductivity of shredded plastics than the blended fibers in the matrix of the pellets. The presence of plastic changed the thermal behavior of fiber by enhancing the energy content of composite pellets while altering the chemical composition of gas emission during the thermo-chemical conversion of biomass. Finally, the results of pelletized fiber-plastic composites were compared with undensified fibers and plastics to identify the accessible boundaries for the thermo-chemical properties of fiber-plastic solid fuels. The results of this study helped to improve the efficiency of the thermo-chemical conversion of the composite pellets through understanding the thermo-chemical behavior of the biomass within the reactor.

Enzymatic hydrolysis of mercerized and unmercerized sisal pulp

Enzymatic saccharification of sisal cellulosic pulp has been investigated. Brazil leads global production of lignocellulosic sisal fiber, which has high cellulose content, an important property for producing glucose via saccharification. Hence, sisal pulp can be a good alternative for use in biorefineries. Prior to enzymatic hydrolysis, the starting pulp [85 ± 2% α-cellulose, 15 ± 2% hemicelluloses, 1.2 ± 2% insoluble lignin, viscometric average molar mass (MMvis) 19,357 ± 590 g mol−1, crystallinity index (CI) 74%] was pretreated with alkaline aqueous solution (mercerization, 20 g of pulp L−1, 20% NaOH, 50 °C). The changes in the properties of the cellulosic pulp during this pretreatment were analyzed [α-cellulose content, MMvis, CI, pulp fiber dimensions, and scanning electron microscopy (SEM)]. The unmercerized and mercerized (97.4 ± 2% α-cellulose, 2.6 ± 2% hemicelluloses, 0.3 ± 0.1% insoluble lignin, MMvis 94,618 ± 300 g mol−1, CI 68%) pulps were subjected to enzymatic hydrolysis (48 h, commercial cellulase enzymes, 0.5 mL g−1 pulp); during the reactions, aliquots consisting of unreacted pulp and liquor were withdrawn from the medium at certain times and characterized (unreacted pulp: MMvis, CI, fiber dimensions, SEM; liquor: high-performance liquid chromatography). The changes in pulp properties observed during mercerization facilitated access of enzymes to cellulose chains, and the yield of the hydrolysis reaction increased from 50.2 (unmercerized pulp) to 89.0% (mercerized pulp). These initial results for enzymatic hydrolysis of sisal pulp indicate that it represents a good alternative biomass for bioethanol production.

A cost-benefit analysis of a pellet boiler with electrostatic precipitator versus conventional biomass technology: A case study of an institutional boiler in Syracuse, New York

BackgroundBiomass facilities have received increasing attention as a strategy to increase the use of renewable fuels and decrease greenhouse gas emissions from the electric generation and heating sectors, but these facilities can potentially increase local air pollution and associated health effects. Comparing the economic costs and public health benefits of alternative biomass fuel, heating technology, and pollution control technology options provides decision-makers with the necessary information to make optimal choices in a given location. MethodsFor a case study of a combined heat and power biomass facility in Syracuse, New York, we used stack testing to estimate emissions of fine particulate matter (PM2.5) for both the deployed technology (staged combustion pellet boiler with an electrostatic precipitator) and a conventional alternative (wood chip stoker boiler with a multicyclone). We used the atmospheric dispersion model AERMOD to calculate the contribution of either fuel-technology configuration to ambient primary PM2.5 in a 10km×10km region surrounding the facility, and we quantified the incremental contribution to population mortality and morbidity. We assigned economic values to health outcomes and compared the health benefits of the lower-emitting technology with the incremental costs. ResultsIn total, the incremental annualized cost of the lower-emitting pellet boiler was $190,000 greater, driven by a greater cost of the pellet fuel and pollution control technology, offset in part by reduced fuel storage costs. PM2.5 emissions were a factor of 23 lower with the pellet boiler with electrostatic precipitator, with corresponding differences in contributions to ambient primary PM2.5 concentrations. The monetary value of the public health benefits of selecting the pellet-fired boiler technology with electrostatic precipitator was $1.7 million annually, greatly exceeding the differential costs even when accounting for uncertainties. Our analyses also showed complex spatial patterns of health benefits given non-uniform age distributions and air pollution levels. ConclusionsThe incremental investment in a lower-emitting staged combustion pellet boiler with an electrostatic precipitator was well justified by the population health improvements over the conventional wood chip technology with a multicyclone, even given the focus on only primary PM2.5 within a small spatial domain. Our analytical framework could be generalized to other settings to inform optimal strategies for proposed new facilities or populations.

다양한 바이오매스의 분쇄도 실험을 통한 미분탄 화력발전 적용가능성 연구

기후 변화 대응을 위한 온실가스 감축 측면에서, 석탄화력발전소에서 바이오매스 사용량은 계속하여 증가되어 왔다. 파리 협정 이후 온실가스 감축 목표치가 더욱 구체화되면서 바이오매스 사용은 급격히 더 많아질 것으로 예상된다. 미분탄 석탄 화력발전에서 바이오매스 혼소시 가장 큰 문제점 중 하나는 바이오매스의 미분성이 석탄에 비해 훨씬 낮다는 것으로, 이를 해결하기 위해 가장 먼저 바이오매스의 미분성 측정 방법을 확립하는 작업이 필요하다. 석탄의 경우 HGI (hardgrove grindability index)측정 장치를 통해 분쇄도 측정이 가능하여 이를 표준으로 삼고 있지만, 바이오매스의 경우 표준 측정 방법이 확립되어있지 않다. 본 연구에서는 볼 밀과 입자 크기별 분포량을 이용한 석탄과 바이오매스의 분쇄 실험을 진행하였다. 실험에는 석탄 1종과 바이오매스 6종을 사용하였다. 분쇄시간에 따른 입자 분포량을 비교하고, <TEX>$75{\mu}m$</TEX> 이하 입자 분포량으로 분쇄도를 평가하였다. 실험결과 반탄화 바이오매스 TBC (torrefied biomass chip)와 TWP (torrefied wood chip)는 발전용 사용적합 기준에 대해 대략적으로 70%의 값을 나타냈다. 다른 바이오매스들의 경우 반탄화 바이오매스와 비교했을 때 분쇄성이 훨씬 더 낮은 결과를 보였다. TBC와 TWP는 수분이 감소하고 섬유질 구조가 분해되는 반탄화 과정을 통해 분쇄가 향상되었다. 또한 분쇄도가 높은 반탄화 바이오매스가 소모전력이 낮게 측정되었다. 본 연구를 통해 바이오매스의 석탄화력발전 적용을 위한 표준화 작업의 기초 자료들을 확보할 수 있다. Recently usage of biomass is increased in pulverized coal power plants for reduction of <TEX>$CO_2$</TEX> emission. Many problems arise when thermal share of the biomass is increased, and milling of the biomasses is one of the most important problems due to their low grindability when existing coal pulverizer is used. Grindability of coal can be measured through the HGI (Hardgrove grindability index) equipment as a standard, but method of measuring biomass grindability has not been established yet. In this study, grinding experiment of coal and biomass was performed using a lab-scale ball mill. One type of coal (Adaro coal) and six biomasses (wood pellet (WP), empty fruit bunch (EFB), palm kernel shell (PKS), walnut shell (WS), torrefied wood chip (TBC) and torrefied wood pellet (TWP)) were used in the experiment. Particle size distributions of the fuels were measured after being milled in various pulverization times. Pulverization characteristics were evaluated by portion of particles under the diameter of <TEX>$75{\mu}m$</TEX>. As a result, about 70% of the TBC and TWP were observed to be pulverized to sizes of under <TEX>$75{\mu}m$</TEX>, which implies that they can be used as alternative biomass fuels without modification of the existing mill. Other biomass was observed to have low grindability compared with torrefied biomass. Power consumption of the mill for various fuels was measured as well, and the results show that lower power was consumed for torrefied biomasses. This result can be used for characterization of biomass as an alternative fuel for pulverized coal power plants.

The carbon footprints of alternative value chains for biomass energy for cooking in Kenya and Tanzania

Due to its availability and affordability for poorer populations, wood-based biomass energy remains vital in meeting local energy demands – especially for cooking fuel – in many regions of the developing world. However, increasing feedstock scarcity (e.g. due to deforestation) coupled with the negative socio-economic and environmental outcomes of inefficient production and consumption technologies make it imperative to identify alternative energy solutions that benefit people without harming the environment. Indeed, tackling energy poverty is crucial to efforts aimed at meeting sustainable development goals at the household level. However, interventions aimed at reducing energy poverty must simultaneously seek solutions that might reduce people’s carbon footprint. Carbon footprints, or the amounts of greenhouse gas emissions linked to particular activities, are associated with climate change and its impacts. Globally, calls have intensified to reduce the carbon footprint of energy use, including use of biomass fuels. Locally, climate change issues are increasingly seen as posing particular threats to already vulnerable communities. The present paper evaluates the carbon footprints of alternative biomass energy solutions for cooking, as one key aspect of their environmental performance. It compares the carbon footprints of firewood, charcoal, biogas, jatropha oil, and crop residue briquettes. The research focuses on selected technologies for biomass energy production and consumption in two case study sites in rural and urban contexts of Kenya and Tanzania. Carbon footprinting is applied as a methodological approach to evaluating technological options for sustainable development in developing economies undergoing rapid population growth, urbanization, and industrial development. Results indicate that the unimproved charcoal value chain has a big carbon footprint. The value chain for jatropha oil appears to hold the greatest potential for carbon footprint reductions, as long as the feedstock is grown in the form of hedges around plots. However, the limited yield potential of hedges calls into question the economic viability of this solution. Results further show that carbon footprinting can help to raise awareness and inform stakeholders and decision-makers about alternative, environmentally more suitable biomass energy value chains. However, any assessment of the overall sustainability of these value chains should also integrate socio-economic aspects and factors influencing adoption.

Effect of biomass pretreatment on the product distribution and composition resulting from the hydrothermal liquefaction of short rotation coppice willow

A major challenge for the implementation of hydrothermal liquefaction (HTL) as a continuous process is the formulation of lignocellulosic feedstock, which is prone to phase separation into water and biomass parts when pressurized. One approach to remedy such phase separation is to reduce the dry matter content; however, as this approach is detrimental to process cost efficiency, designing an appropriate pretreatment step to ensure pumpability at high dry matter content is preferable. This paper evaluated the effect of various pretreatment methods on product distribution and composition resulting from the HTL of willow and proposes short rotation coppice as an alternative biomass feedstock for biofuels production. Alkaline–thermal pretreatment, besides making high dry matter pumpable feedstock slurries, also led to an increase in the production of the bio-crude product with an oxygen content lower than 8wt% and a higher concentration of aromatics and phenolic compounds.

Multi-objective optimization of biomass based ammonia production - Potential and perspective in different countries

More environmentally-benign processes are required for the production of important chemicals such as ammonia. Techno-enviro-economic studies that utilize process modeling and optimization play a decisive role in predicting the viability of these processes, but they tend to focus on a single geographical location. This limits the usefulness of the results from such studies, because it is hard to compare results for different feedstock and location factors. Thus, the present study compares the economics and environmental potential of several variations of a novel biomass-based ammonia production process in different locations. The process is simulated for three biomass feedstocks grown in Australia, Brazil, and India. A comprehensive economic analysis and life cycle assessment is performed for the different process variants. A Multi-Objective Optimization (MOO) approach is used to minimize the manufacturing costs and the environmental impacts of the biomass-to-ammonia process specific to each feedstock and country. The Indian scenario was found to be the most favorable economically, whereas the Brazilian scenario had the lowest greenhouse gas potential. The results demonstrate that each type of biomass is specific to its location and both the economic and environmental profiles are strongly related to the location. The results of the individual studies are superimposed to provide a Global Pareto Front for the cost and environmental impact of the production of ammonia from biomass. This provides a very useful resource for future researchers who can compare results for alternative biomass, locations and processes.

Biomass sources for thermal conversion. Techno-economical overview

The constant increase in the use of biomass fuels has raised prices of the most common commercial products and consequently seeking for new alternative biomass resources for thermal conversion, like some industrial and agricultural wastes, becomes an interesting issue. To this aim, thirteen alternative raw biomass samples were analyzed and compared with briquette, wood pellets, and charcoal. Their proximate, ultimate and calorimetric analysis and physical properties data have been considered. In the same way gaseous emissions, ash composition, deposition and corrosion tendencies were evaluated. In addition to these intrinsic and environmental parameters, a general economic study, based on our previously obtained data, has been developed. Some of the selected samples, like almond shell and especially olive stone, seem to be optimum biomass resources to use instead of wood pellets, charcoal or briquettes in grate boilers, while some others require pretreatment to improve their characteristics and make them suitable alternatives to be considered in a short term future.

Hydrogen production by biomass gasification

Hydrogen could be the important energy sources of the next period provided that its production, transportation, and storage are solved. In this paper review of the production of hydrogen from lignocellulosic feedstock is given. The process is analyzed in all its phases and alternative solutions. Two different, alternative biomass gasification process - direct and indirect, and two different, alternative reforming model - partial oxidation and steam reforming are described. Gas cleaning is also provided with two different, alternative concepts - cold and hot cleaning. Conversion of the working gas and the separation of hydrogen from CO2 and other impurities are still used as a method in the tubular membrane reactor - all in one place which significantly reduced the cost of 1 kg of hydrogen. In all these processes is especially taken into consideration on the integration of energy in the process, which is also significantly contributed to the better price of hydrogen.

Rendimento de hidrólise e produção de etanol lignocelulósico a partir de biomassa de capim elefante

Due to search for alternative biomasses, that are easy to access, low cost and high in cellulose concentration, for the production of 2nd generation ethanol - or lignocellulosic - this study was carried out with Pennisetum purpureum, known as elephant grass. The study was conducted to determine the chemical composition of elephant grass forage to evaluate its use in the production of lignocellulosic ethanol. The elephant grass stems were reaped in the experimental area of Feira Agrotecnologica de Palmas (AGROTINS) on august 2015. The results have shown that the elephant grass presented approximately 60% cellulose, demonstrating the potential use of this biomass to obtain reducing sugars. The biomass underwent chemical pretreatment before the enzymatic hydrolysis step using commercial cellulase enzyme Cellic CTEC2. After hydrolysis, gave a 54% yield of reducing sugars, which has shown a yield of 53,9% in the hydrolysis. In addition, the yield for ethanol production was 87,8%. Due to this, it is possible to assure that the elephant grass biomass has a great potential as cellulose source, therefore it can be used as an alternative that is cheap and huge in availability to the production of lignocellulosic ethanol.

Knock characteristics of SI engine fueled with n-butanol in combination with different EGR rate

Knock is one of the main obstacles for optimizing combustion process of SI engines fueled with alternative biomass fuel n-butanol. In this paper, knock characteristic of SI engine fueled with n-butanol and RON 92 gasoline is studied on a single cylinder SI engine. The onset timing, intensity and frequency of knock for these two fuels at different EGR rate are compared. Additionally, the effects of different compression ratios and intake pressures on knock intensity of SI engine are also studied and results are presented. The study results show that EGR can decrease knock intensity and delay knock onset timing due to its cooling and dilution effects. It is observed under a low EGR rate of 3%, knock intensity of n-butanol is significantly reduced whereas combustion pressure has negligible change. The probability distribution of n-butanol knock intensity is more concentrated compared with that of gasoline under a given EGR rate, which indicated n-butanol had smaller combustion variations. The application of EGR on high intake pressure and high compression ratio n-butanol engine can effectively suppression knock combustion.