Biomass Pellet Production Research Articles

Biogas and biomass pellet production from water hyacinth

The prime objective of this paper was to produce the biogas and biomass pellets from water hyacinth. The leaf and petiole were chopped, grind, squeezed and then separated into two parts as squeezed out juice and remaining fiber. The squeezed out water as water hyacinth juice (SWWH) was used to produce biogas with microorganisms at a ratio of 1: 1 (8 liters of SWWH/8 liters of microorganisms). Water hyacinth fiber (WHF), with a moisture content of 10.57% wet basis, was used to produce biomass pellets. The results showed that a total of 458.44 liters of biogas was produced from SWWH with microorganisms consisting of 68.67% CH4, 18.23% CO2, and 13.10% other gases. Specific methane yield and the potential to biodegrade methane were 237.37 L CH4/kgVSadded and 51.89%, respectively. Test results of biomass pellets from water hyacinth with water ratio of 10:90 indicated that the bulk density, diameter, durability, fines content, length, and moisture of the pellets met the criteria of the US Standards (PFI standard), except for inorganic ash and chloride contents.

Effect of extractives on the physicochemical properties of biomass pellets: Comparison of pellets from extracted and non-extracted sycamore leaves

Physicochemical properties of biomass pellets were compared following their preparation from extracted and non-extracted sycamore leaves. The goal was to achieve high-quality biomass pellets. Batches of pellets were prepared at different moisture contents and pressure. The properties, including pellet density, diametric compressive strength, and combustion performance, were analyzed. Pellets produced from extracted leaves had higher pellet density (between 1125 and 1250 kg·m-3) compared to those made from non-extracted leaves. In addition, data of the combustion experiment showed more weight loss in extracted leaves’ pellets and a higher burning rate (9.54%·min-1) than that of non-extracted leaves’ pellets (8.47%·min-1). Also, the pellets made from extracted leaves could be ignited and burned easily compared to non-extracted leaves. However, the diametric compressive strength was not always higher in extracted leaves’ pellets compared to non-extracted. In general, it was concluded that extraction could increase the pellet density and improve combustion performance but did not fit the purpose to increase the diametric compressive strength. The analysis and conclusions can provide a reference for the production of high-quality biomass pellets.

Socioeconomic Aspects of the Forests in Portugal: Recent Evolution and Perspectives of Sustainability of the Resource

Portuguese forests have always played an essential role in the socioeconomic development of national rural areas, but also in several forest-based industrial sectors, such as the cork, pulp and paper, and wood panels industries. In addition to these dominant sectors, there are also several other uses for forest timber, such as being the major raw materials to the production of furniture or devoted to the growing biomass pellets production industry. This review article presents the evolution of the forest industrial sector throughout the recent past, and its impact on the development of the rural environment, from a socioeconomic perspective, namely concerning the jobs and value-added creation, as well as the importance of the forest in national industrial development. It shows the importance of sustainable forest management for the development of the rural environment, as an essential sector for the creation of wealth and for the establishment of populations in the interior regions of the country.

Effect of sodium carboxymethyl cellulose addition on particulate matter emissions during biomass pellet combustion

Sodium carboxymethyl cellulose (CMC) can be used as a cost-effective and environmentally friendly binder in the pelletizing process for production of biomass pellets with good quality. However, the effect of its addition on the emission of particulate matters (PM) during the combustion process, are still not clear. In this study, four typical biomass fuels, cotton stalk, cornstalk, camphorwood and rice husk, were used to investigate the effect of the addition of 5 wt% CMC in the biomass pellets on PM emissions during the combustion process. In the case of pure CMC combustion, a large amount of PM mainly with PM2.5 were generated, which was associated to the evaporation and condensation of NaOH and Na2CO3. The PM10 emission from the combustion of the four biomass fuels varied from 9.72 mg/Nm3 to 23.12 mg/Nm3 with mainly PM1. The addition of 5 wt% CMC in cotton stalk, corn stalk and camphorwood significantly increased the PM emissions due to the evaporation and subsequent condensation of Na-containing species, e.g. NaCl, Na2SO4, NaOH and Na2CO3. For rice husk, the addition of CMC hardly affected PM1 emission due to the dominated SiO2 component in rice husk ash, which reacted with the Na-containing species from the combustion of CMC and facilitated the formation of coarse ash particles and the reduction of PM1 emission. Although the addition of CMC in biomass fuels can greatly enhance the pellets qualities, its addition increases the PM emissions to varying degree. Therefore, in the industrial application of CMC to biomass densification, countermeasures such as mixing of high Si-containing rice husk or SiO2-rich minerals with biomass fuels should be taken to alleviate the PM issues resulting from the introduction of CMC.

Biomass pellets for power generation in India: a techno-economic evaluation

Modern bioenergy is being recognized as an increasingly important low-carbon resource by policy-makers around the world to meet climate policy targets. In India also, there is a clear recognition of the significant role of bioenergy in electricity generation as well as in other applications. In this study, a preliminary attempt has been made to assess the techno-economic feasibility of biomass pellets-based power (BPBP) generation in India. Surplus availability of biomass feedstock from agriculture and forestry/wasteland sector is estimated at 242 million tonnes (Mt) for 2010–11 and is expected to rise to 281 Mt in 2030–31 due to increased crop production and associated waste/residue availability. In terms of related capacity, the potential of BPBP projects is estimated at 35 GW for 2030–31. The associated carbon dioxide mitigation potential resulting from the substitution of coal is estimated at 205 Mt in 2030–31 if the entire biomass surplus is to be diverted for power generation. The levelized cost of electricity is estimated at €0.12 per kWh for BPBP projects as compared to €0.10 per kWh for imported coal based power plants. For states with the lower tariff for biomass power, the break-even price of carbon for BPBP projects is estimated at €18 per tonne. Additionally, BPBP projects will generate employment of more than 5 million person-months in the construction of biomass power plants and over 200,000 full-time employments in the operation of BPBP plants and in the production of biomass pellets.

Effect of minerals and binders on particulate matter emission from biomass pellets combustion

In this study, the effect of minerals and binders on the emission characteristics of particulate matter (PM) from biomass pellets combustion is investigated using a fixed bed combustor combined with a Dekati low pressure impactor (DLPI). It was found that densification reduced PM emission as the pellets hindered the release of alkali metals in comparison to the bulk biomass. The generation of PM1 was mainly due to the homogeneous condensation and heterogeneous coagulation of alkali chlorides and sulfates. Alkaline earth metals and Si played a dominant role in the formation of PM10. Diatomite in mineral additives could effectively reduce the emission of PM1, while the binders showed no inhibitory effect on the PM emission. Composite additives prepared with carboxymethyl cellulose (CMC) and diatomite showed a positive synergistic effect in reducing the emissions of PM1 with the optimum CMC/diatomite ratio of 1:4. The results showed that composite additives of minerals and binders are excellent choices for the industrial production of biomass pellets from the view of increasing pellet quality and reducing PM emission.

Techno-economic evaluation of integrating torrefaction with anaerobic digestion

In recent days, the interest on torrefaction is increasing owing to its ability to improve biomass properties to a level of competing with coal. However, its techno-economic feasibility still need to be optimized. Integrating torrefaction with other thermochemical and biochemical processes could be a feasible option to improve the performance of the torrefaction process. In that regard, this study evaluates the techno-economic feasibility of integrating the torrefaction with anaerobic digestion (AD). In addition, new process configurations were studied to identify the possible heat energy recovery options. Technical feasibility was tested through mass and energy balance at each process unit. The economic indicators such as net present value (€), minimum selling price and internal rate on return (%) were used to evaluate the economic performance. At 10 t/h of torrefied biomass pellets production capacity, the estimated bio-methane production from AD was 369 m3/h. The economic evaluation shows that the minimum selling price of the torrefied biomass to reach the breakeven could be reduced from 199 €/t for standalone torrefaction to 185 €/t in case of torrefaction integrated with AD. The sensitivity analysis shows that feedstock and total capital investment were the most sensitive input parameters. This study shows that integrating the torrefaction with AD has better technical and economic feasibility than standalone torrefaction.

Adsorption of furfural from torrefaction condensate using torrefied biomass

Torrefaction is a biomass energy densification process that generates a major byproduct in the form of torrefaction condensate. Microbial conversion of torrefaction condensate could be an attractive option for energy integration within torrefaction process. However, torrefaction condensate contains several compounds, such as furfural, 5-hydroxymethylfurfural and guaiacol that are inhibitory to microbes. In this study, for the first time, we reported detoxification of torrefaction condensate, by removing the major inhibitory compound furfural, using torrefied biomass and later used the detoxified torrefaction condensate for anaerobic digestion. The effect of varying torrefaction temperature (225–300°C), torrefied biomass dosage (25–250g/L), initial pH (2.0–9.0), and contact time (1–12h) on furfural adsorption was studied with batch adsorption experiments. The furfural adsorption on torrefied biomass was best represented by pseudo second order kinetic model. The adsorption of furfural and other inhibitory compounds on torrefied biomass was likely a hydrophobic interaction. A maximum of 60% of furfural was adsorbed from torrefaction condensate containing 9000mgfurfural/L using 250g/L of torrefied biomass in batch adsorption. For, column (20mm internal diameter and 200mm bed height), the saturation time for furfural adsorption was around 50min. Anaerobic digestion of the detoxified torrefaction condensate shows that the lag phase in methane production was reduced from 25d to 15d for 0.2 volatile solid (VS)substrate:VSinoculum loading. The study shows that torrefaction condensate can be effectively detoxified using torrefied biomass for microbial conversion and can be integrated within the torrefied biomass pellet production process.

Evaluation of straw with absorbed glycerol thermal degradation during pyrolysis and combustion by TG-FTIR and TG-GC/MS

Despite the interest in second generation biofuels produced from straw, an increased attention on the by-products (glycerol) of the biodiesel production still remains. With the increase of biodiesel production year by year, new possibilities for glycerol utilization attract more attention. One possible use of glycerol is as a binder material for straw or other biomass pellets production. Thermal behaviour of straw pellets containing 0 and 14wt% of glycerol was analysed using a Netzsch STA 449 F3 Jupiter thermal analyser. The scope of this work is investigation of formation and development of the most toxic carbonyl group compounds (with special focus on acrolein, propane, formaldehyde, acetaldehyde) during combustion and thermal destruction of straw pellets depending on the absorbed amount of raw glycerol, atmosphere and heating rate by thermogravimetric (TG) and evolved gas analysis (TG-FTIR and TG-GC/MS) methods. Possible pathways of main carbonyl products formation were analysed. Evolved gas analysis by Fourier transform infrared spectroscopy (FTIR) and Gas chromatography–mass spectrometry (GC/MS) methods revealed the maximum absorbance of alcohol at the wavelength of 1055cm−1 and the increasing abundance of ion current of m/z=61 which corresponds mainly to glycerol. Besides, analysis of the formation of aldehydes showed that the addition of the glycerol to the straw does not stimulate the excessive formation of toxic and unwanted emissions.

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.

Geoffroea decorticansfor Biofuels: A Promising Feedstock

In this work, chañar (Geoffroea decorticans) fruit is evaluated as a potential feedstock for biodiesel and biomass pellets production with reference to some relevant properties. The fatty acid profile of this oil (83% unsaturated acids) is found to be comparable to similar seed oils which have been attempted for biodiesel production. As a result, the methyl esters (biodiesel) obtained from this oil exhibits high quality properties. Chañar biodiesel quality meets all other biodiesel international standards (ASTM D6751 and EN 14214). Moreover, the husk that surrounds the kernel showed a high potential for usage as densified solid fuels. The results demonstrate that chañar husks pellets have a higher calorific value when compared with other biomass pellets, typically, approximately 21 MJ kg−1with 1.8% of ashes (which is equivalent to that obtained from the combustion of pellets produced from forest wastes). This study indicates that chañar can be used as a multipurpose energy crop in semiarid regions for biodiesel and densified solid fuels (pellets) production.

Steam-treated wood pellets: Environmental and financial implications relative to fossil fuels and conventional pellets for electricity generation

Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM10). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kWh vs. $0.16/kWh). Impacts of retrofit infrastructure become increasingly significant at lower generating station capacity factors, further favouring steam-treated pellets for both environmental and financial metrics.

Effect of Carboxymethyl Cellulose Binder on the Quality of Biomass Pellets

Quality and energy efficiency are two critical concerns associated with the production of biomass pellets. This study elaborates methods to improve the quality of biomass pellets by using a new additive solution (carboxymethyl cellulose (CMC)) and its influence on pellet physical and mechanical properties during the densification of three types of agricultural waste (cotton stalks, wheat straw, and rape straw). Simultaneously, the cohesion and binding mechanisms were analyzed with attenuated total reflectance infrared spectra (ATR-FTIR) and light microscopy (LM). The results show that adding CMC lowers the energy consumption and increases the pellet quality by improving relaxed density, compressive strength, and durability for cotton stalks and wheat straw. However, adding CMC to rape straw decreased the pellet quality. Our results showed that addition of CMC leads to electrostatic forces among the particles that might be responsible for the cohesion strength of biomass pellets, which may be attributed to...

Complementary effects of torrefaction and co-pelletization: Energy consumption and characteristics of pellets

In this study, complementary of torrefaction and co-pelletization for biomass pellets production was investigated. Two kinds of biomass materials were torrefied and mixed with oil cake for co-pelletization. The energy consumption during pelletization and pellet characteristics including moisture absorption, pellet density, pellet strength and combustion characteristic, were evaluated. It was shown that torrefaction improved the characteristics of pellets with high heating values, low moisture absorption and well combustion characteristic. Furthermore, co-pelletization between torrefied biomass and cater bean cake can reduce several negative effects of torrefaction such as high energy consumption, low pellet density and strength. The optimal conditions for energy consumption and pellet strength were torrefied at 270°C and a blending with 15% castor bean cake for both biomass materials. The present study indicated that compelmentary performances of the torrefaction and co-pelletization with castor bean cake provide a promising alternative for fuel production from biomass and oil cake.

Values for particle-scale properties of biomass briquettes made from agroforestry residues

The production of biomass pellets and briquettes from agroforestry residues has increased rapidly in recent years. The design of machines, equipment and the infrastructure necessary for the handling, transport and storage of these products has been an engineering challenge since, when moving, biomass does not usually flow as easily as other granular materials. The discrete element method (DEM) provides a means of studying the handling and silo discharge behaviour of granular solids as well as the distribution of the pressures exerted by such materials in silos. However, the development of such models requires certain properties of the particles in question to be known. The present work experimentally determines the true density, Young's modulus of elasticity (axial and radial), the particle–particle restitution coefficient and the particle–wall friction coefficient—all variables that must be known in the construction of DEM models—for briquettes made from maize stalk, maize stalk plus pine wood chips, rice husk, vine shoots, rape straw, cereal straw and sawdust plus cereal straw.

The Feasibility of Biomass Pellets Production in Portugal

The production of pellets represents the possibility of using different biomass residues in a standardized fuel. In this article, the economic feasibility of pellets production is analyzed in the Portuguese scenario according to the key indicators of biomass availability, costs, and legal framework. The potential of biomass residues in Portugal is significant and mainly from forestry. However, several limitations to its utilization for pellets production may arise since they are already put to other uses, such as biomass power plants. The combination of the biomass power plants with pellet production plants seems to be the best option for pellet production in the actual Portuguese scenario. The main constrains for the pellets market has been to convince small-scale customers that pellets are a good alternative fuel, mainly due to the investment needed and the strong competition in terms of fuel price with natural gas. These market problems need incentives at a political level bringing the value added tax for the same level of natural gas.

Technical and economic assessment for the production of torrefied ligno-cellulosic biomass pellets in the US

Manufacturing and trade of wood pellets in the United States (US) has seen an exponential growth in the last few years, triggered by its potential utilization in applications typically dominated by fossil fuels, such as heat, power, and combined cycle generation. This combination holds the promise of delivering a high density, high heat value fuel, making it a better substitute for coal and other fossil fuels. This combined process exists only at pilot-plant levels. Scale-up of the technology and feasibility of such projects remain largely unexplored. This research developed a techno-economic model for the production of torrefied wood pellets, considering critical production parameters, and evaluating sensitivity to changes in CAPEX (Capital Expenditure), biomass delivered costs, labor, and energy consumption of a facility, evaluated through a case-study. Results indicated that biomass delivered costs and depreciation are the most significant factors influencing production with CAPEX being the most sensitive variable due to high investments in torrefaction reactors. The selection of different torrefaction technologies, and adequate binders, may represent a major improvement in the feasibility of a project by reducing capital costs drastically. Back-calculated price for torrefied wood pellets is $261/metric ton (100,000 metric tons/year facility), and delivered price may reach $282/metric ton, a similar cost compared to regular pellets. Preliminary analysis of carbon credits as additional income may considerably increase the likeability of the business, and further enhance profitability.

Potential availability of non-woody biomass feedstock for pellet production within the Republic of Ireland

The threat of increasing fuel prices and climate change necessitates the need for clean, renewable and independent energy sources. A GIS ( G eographical I nformation S ystems) model was developed using ArcGIS 9.2 to analyze the availability of non-woody biomass (wheat, oat, barley and rape straw, willow and miscanthus) for pellet production in Ireland. Utilization within the heating and electricity sector would displace currently used fossil fuels with cleaner, carbon neutral non-woody residues. The total hectares of biomass within Ireland were computed and the biomass yield determined. The greatest potential source of biomass for pelleting is cereal straw. Within the Republic of Ireland the South-East, South-West and Mid-East of Ireland have the greatest biomass yield for pellet production and likely to be most economically viable. Non-woody biomass has a realistic potential to displace fossil fuels within the heating and electricity sector resulting in CO 2 mitigation. Keywords: Biomass pellet production, Non-woody biomass, GIS analysis, Renewable energy source, CO 2 mitigation DOI: 10.3965/j.issn.1934-6344.20 1 0.0 1 .0-0 Citation: Anthony Nolan, Kevin Mc Donnell, Ger J. Devlin, John P. Carroll , John Finnan. Potential a vailability of n on- w oody b iomass f eedstock for p ellet p roduction within the Republic of Ireland. Int J Agric & Biol Eng, 20 1 0; 3 ( 1 ): <span style=line-height: 140%; font-family:

Economic Analysis of Manufacturing Costs of Pellet Production in the Republic of Ireland Using Non-Woody Biomass~!2009-07-23~!2009-12-22~!2010-03-02~!

An economic analysis of a non-woody biomass pelleting process was performed for conditions in the Republic of Ireland. The analysis considered the establishment, harvest, storage and drying costs of the feedstock's on-farm, together with transportation costs to the processing plant and the costs associated with the pelleting process. Capital and operating costs of the pelleting process were estimated at several plant capacities - 6t / h, 8t / h and 10t / h. The pellet production cost for the base case scenario of 8t / h was � 102 / t of pellets produced. By decreasing production capacity to 6t / h an increase in the production cost of � 10 / t was experienced while increasing capacity to 10t / h resulted in a decrease of � 6 / t in the production cost of pellets. The cost of the raw material is the largest cost component (66%) of the total pellet production cost. Other major cost factors include pelleting and cooling plant (11%), straw grinding plant (10%) and personnel costs (9%). Considering current energy prices the equivalent energy cost of � 7 / GJ (excluding profit margins) the potential production of non-woody biomass pellets competes favourably with oil and gas and was found to be economically viable.

The relationship between bulk density and energy input, in biomass pellet production

The relationship between bulk density and energy input, in biomass pellet production