Sawmill Residues Research Articles

Exploring sustainable fuel production through thermal behavior analysis using TGA and artificial neural network in the co-pyrolysis of polystyrene and coconut sawmill residue

This study employs Thermogravimetric Analysis (TGA) to explore co-pyrolysis potential using polystyrene (PS) and coconut sawmill residue (CSR) for liquid fuel production. Two distinct degradation stages are observed in CSR-PS blends, mirroring pure CSR samples: the initial phase (200-400°C) decomposes biomass components, while the second stage (400-550°C) targets the synthetic polymer PS within CSR-PS blends. Analyzing thermal degradation parameters reveals insights. 100% PS exhibits the highest weight loss and activation energy, highlighting PS's formidable decomposition. Conversely, 100% CSR shows the lowest weight loss and activation energy due to its organic composition. Artificial Neural Network (ANN) modeling indicates varying correlation accuracies for different blend compositions. Surprisingly, 100% PS exhibits lower correlation accuracy in predicting weight loss compared to the 80% PS blend, which achieves a perfect correlation. Conversely, 100% CSR, with simpler decomposition, has the lowest correlation accuracy. These findings illuminate the complex thermal behavior of CSR-PS blends, emphasizing the distinct degradation characteristics of PS and CSR. Implications extend to material applications and disposal strategies, emphasizing tailored approaches based on blend compositions and thermal profiles. This research advances co-pyrolysis as a sustainable avenue for liquid fuel production, providing insights for future research and practical applications.

Variability in Physical Properties of Logging and Sawmill Residues for Making Wood Pellets

Wood pellets are a versatile ingredient to produce bioenergy and bioproducts. Wood pellet manufacturing in Canada started as a way of using the excess sawdust from sawmilling operations. With the recent dwindling availability of sawdust and the growth in demand for wood pellets, the industry uses more non-sawdust woody biomass as feedstock. In this study, woody biomass materials received from nine wood pellet plants in British Columbia (BC) and Alberta were analyzed for their properties, especially those used for fractionating feedstock to make pellets. Half of the feedstock received at the plants was non-sawdust. Moisture contents varied from 10 to 60% wet basis, with the hog having an average of 50%. Ash contents ranged from 0.3 to 4% dry basis and were highest in the hog fraction. Bulk density varied from 50 to 450 kg/m3, with shavings having the lowest bulk density. Particle density ranged from 359 kg/m3 for infeed mix to 513 kg/m3 for sawdust. In total, 25% of particles received were larger than 25 mm. The extraneous materials (sand, dirt) in the infeed materials ranged from 0.03% to 1.2%, except for one hog sample (8.2%). Plant operators use mechanical fractionation and blending to meet the required ash content. In conclusion, further instrumental techniques to aid in fractionation should be developed.

Diversity of properties of sawmill residues used as feedstock for energy generation

Sawmill residues are used in the power industry, where it accounts for the greatest portion of solid biomass used in combined heat and power plants and heat-generating plants, mainly as chips. This results in increasing demand for this material around the world, which makes the characteristics and variability of sawmill biofuels increasingly important. The objective of this study was to determine the energy-related properties of Pinus sylvestris L. residues depending on the tree growth site (five locations), date of harvest (autumn, winter) and the type of biomass (sawdust, wood slabs). These three factors were found to significantly diversify a large majority of the sawmill residue properties. Sawmill residues had higher LHV compared to the level generally determined for wood (of similar moisture content), and the type of sawmill residue explained to the greatest extent the variability of the largest number of attributes. Wood slabs generally had worse properties than sawdust, and the differences between the forest districts were identical with the influence of the location. In the case of the harvest date, it was found that the source of variability was in fact, inter alia, "nested" in the season of the relative air humidity.

Extractives of Tree Biomass of Scots Pine (Pinus sylvestris L.) for Biorefining in Four Climatic Regions in Finland—Lipophilic Compounds, Stilbenes, and Lignans

The aim of the study was to quantify total extractive contents and lipophilic compounds, stilbenes, and lignans in Scots pine stem wood, stem bark, branch biomass, and sawmill residues in four climatic regions of Finland to evaluate the most optimal sources of extractives for bio-based chemical biorefining and bioenergy products. Data were derived from 78 chip samples from the before-mentioned raw materials, the samples being pooled by tree height position from the sample trees of 42 experimental forest stands, and sawdust lots from 10 log stands. Accelerated solvent extraction (ASE) was employed to determine total extractive contents, followed by gas chromatography with flame ionization detection (GC–FID) to quantify extractive groups and gas chromatography-mass spectrometry (GC–MS) to analyse individual extractive compounds. Resin acids and triglycerides followed by fatty acids were the dominant extractive groups. Resin acids were most abundant in stem wood from final fellings and in sawdust, fatty acids in bark and branch biomass, and triglycerides also in stem wood from thinnings and the top parts of trees. Of the minor extractive groups, stilbenes were the most abundant in stem wood from final fellings and in sawdust, and steryl esters, sterols, and lignans in bark and branch biomass, the two last groups almost missing from other biomass components. Regional differences in the contents of extractive groups were generally small, 1.0−1.5 percentage points at the maximum, but factor analysis distinguished northern and southern regions into their own groups. Bark was the most potential source of fatty acids and sterols in southern Finland, and triglycerides and steryl esters in northern Finland. In stem wood, steryl esters, triglycerides, and lignans decreased and stilbenes increased from north to south. Certain fatty acids and resin acids were more frequent in the north. The results highlighted the importance of focused procurement and efficient sorting of raw materials, purity, unique properties, and feasible isolation techniques for competitive ability as well as large raw material volumes or well-defined value-added products.

Putting Bioenergy With Carbon Capture and Storage in a Spatial Context: What Should Go Where?

This paper explores the implications of siting a bioenergy with carbon capture and storage (BECCS) facility to carbon emission performances for three case-study supply chains using the Carbon Navigation System (CNS) model. The three case-study supply chains are a wheat straw derived BECCS-power, a municipal solid waste derived BECCS-waste-to-energy and a sawmill residue derived BECCS-hydrogen. A BECCS facility needs to be carefully sited, taking into consideration its local low carbon infrastructure, available biomass and geography for successful deployment and achieving a favorable net-negative carbon balance. On average, across the three supply chains a 10 km shift in the siting of the BECCS facility results in an 8.6–13.1% increase in spatially explicit supply chain emissions. BECCS facilities producing low purity CO2 at high yields have lower spatial emissions when located within the industrial clusters, while those producing high purity CO2 at low yields perform better outside the clusters. A map is also generated identifying which of the three modeled supply chains delivers the lowest spatially explicit supply chain emission options for any given area of the UK at a 1 MtCO2/yr capture scale.

Greenhouse gas mitigation potential of replacing diesel fuel with wood-based bioenergy in an arctic Indigenous community: A pilot study in Fort McPherson, Canada

Remote and northern communities surrounded by forested areas are well positioned to use wood-based bioenergy to meet their energy needs and thereby reduce their greenhouse gas (GHG) emissions. However major gaps remain regarding the GHG mitigation potential considering the challenges along the biomass supply chain. Using Fort McPherson, an Indigenous community located in the Northwest Territories (NWT), Canada, we developed a life cycle assessment based model to estimate the potential GHG emission reductions and timing. We also built two main bioenergy scenarios testing 1) wood chips made from locally harvested willow or 2) imported pellets made from sawmill residues including key parameters like transport distances, boiler efficiency, and emission factors. We found that replacing diesel fuel with bioenergy resulted in GHG savings as high as 32,166 t of CO2 eq over 100 years. GHG benefits can be achieved within 0–20 years for local wood chips or 2–37 years for imported sawmill residue pellets. Increases in transport distance and decreases in biomass boiler efficiency resulted in delays in GHG emissions benefits for both local chips and imported pellets. This study shows that the use of local or imported forest biomass to replace diesel in remote northern communities’ energy systems can generate GHG savings within a time-frame that is relevant to current climate change concerns. In addition to GHG mitigation potential, we discuss the socio-economic and environmental factors to take into consideration at the community level when deciding between local or imported biomass supply chains.

Composites from Recycled and Modified Woods—Technology, Properties, Application

The intention of efficient processing and use of less valuable wood species, bio-damaged logs, sawmill residues, cuttings, chips, sawdust, recycled wooden products, and other lignocellulosic raw materials in the production of wood composites is the focus of several scientific research institutes in the world [...]

Chlorine and ash removal from salt-laden woody biomass by washing and pressing

Over 11 million cubic meters of timber were harvested from the coastal forests of British Columbia in 2017. For transport, the logs are usually floated in the water and towed along the coastal waters along Fraser River to sawmills. The submerged timber's chlorine content is up to 100 times higher than the timber harvested from inland. The sawmill residues leftover from cutting the salt-laden timber are unsuitable to be burned in boilers. In this study, ground sawdust, bark, and wood chips of three species: Douglas fir, hemlock, and western red cedar from the Lower Mainland, as well as spruce-pine-fir (SPF) from Vancouver Island, were washed for 5 min using tap water under constant stirring and pressed on a flat metal bed for 30 s using a mechanical hydraulic press. The chlorine content dropped from 2,000–24,000 ppm to below 700 ppm db (dry basis). The low salt biomass meets the ISO 17225-2 quality standard for wood pellets. The chlorine removal efficiency of this treatment method was 88–95%. The reduction in ash content of the washed and pressed samples ranged was 45–85% of the ash in the untreated biomass.

Analysis of dynamic moisture movement within bio-based earth mortars

Understanding moisture movement within building materials is critical for the understanding of how they dynamically respond to their hygrothermal environment. Utilising low embodied energy, hygrothermal materials such as bio-fibers and earth will enable a ‘green solution’ to the current climate change issues surrounding carbon intensive materials such as concrete. Within this research an earth mortar with bio-fibres of 2 types of sheep wool: Wool 1 (W1), Wool 2 (W2) and a Saw Mill Residue (SMR) in addition to a plain, control sample (PL) were cast. Experimentation was completed on these materials to identify Water Vapour Permeability (WVP), Sorption Isotherms and latent heat of sorption. Results demonstrated that for WVP, SMR has the greatest value of WVP (2.2 x10−11 kg.m−1.s−1.Pa−1). PL also had the lowest value (1.4 x10−11 kg.m−1.s−1.Pa−1). For sorption isotherm, over the course of the experiment it can be demonstrated that the incorporation of fibres increases the rate in which the mortars adsorb water molecules. This is particularly highlighted as above 30% RH sample begin to increase in moisture content with this rapidly increasing from approximately 65% RH. Finally, latent heat of sorption analysis demonstrated that a dynamic change in latent heat under differing hygorthermal conditions can be indentified; for all samples, even after 21, 24 h cycles. However, SMR had the lowest quantity of latent heat even by comparison to the PL sample as there is a sustained difference of approximately only 0.5 °C between samples. This establishes that the SMR sample requires less heat energy in order for the water to change to and from vapour and liquid state.

Spatial optimization of multiple biomass utilization for large-scale bioelectricity generation

This study developed a geographical information system-based methodology to maximize the environmental and economic efficiency of large-scale energy plants using different types of biomass. As a precursor to the optimization modelling, multi-criteria spatial analyses and then transport cost optimization are applied taking into account spatial biomass availability and existing road networks, in order to identify optimal biomass energy plant sites for different combinations of biomass types. A geographical information system integrated with a capacitated maximal covering location problem model was employed to assign biomass supply points to biomass energy plants. Capacity limits of the plants and a defined maximum transportation distance were taken into consideration. The resulting information was used to examine major challenges in establishing a large-scale biomass energy plant, biomass supply logistics, environment cost and anticipated traffic congestion. A sensitivity analysis was also carried out to review the influence of plant capacity and maximum transportation distance on economic and environmental sustainability. The proposed methodology was employed utilizing agricultural and forest residues for bioelectricity generation in Queensland, Australia. It was found that 100% bagasse had the highest eco-efficiency for bioelectricity generation from multiple biomass combinations. In contrast, the combination of 70% sawmill residues and 30% forest harvest residues showed the lowest level of traffic congestion (2 trucks per hour). In addition, the impact of traffic congestion of bulky sugarcane residues can be reduced by adding forest residues to the biomass supply. The advantages of the resulting solution are further enhanced when social impacts such as energy security, new income opportunities and job creation are taken into account in addition to the sustainability aspects.

Determination of specific heat capacity of bio-fibre earth mortars stabilised at different relative humidities using Differential Scanning Calorimetry

Understanding the relationship that earth-based mortars have with both water and temperature is imperative to optimise moisture buffering properties. Specific Heat Capacity (Cp) is a key factor to understand the benefits in terms of thermal mass and latent heat. This paper presents the results of bio-based earth mortars (with fibres consisting of two varieties of sheep wool: Wool 1 (W1), Wool 2(W2) and Saw Mill Residue (SMR)) stabilised at 53% and 75% Relative Humidity (RH). Differential Scanning Calorimetry (DSC) according to ISO 11357–4 was used to calculate Cp of the aforementioned mortars. The temperature range of this experiment was that of 0–50 °C with a particular focus on values at 20 °C as this best represented a suitable indoor temperature. From these experiments, the results demonstrate that when stabilised at different RH, the difference in Cp was bio-fibre dependant and had a range between 0.71– 1.01 kJ/kg.K at 53% RH and 0.85–1.14 kJ/kg.K at 75% RH. These differences could potentially be attributed to the materials ability to readily accept water molecules. This emphasised that incorporating bio-fibres to a plain mixture (PL) can increase the Cp by up to 60%; significantly improving the thermal inertia of the building material. By reducing this temperature differential, it will reduce the heating requirements of a building which as consequential carbon reduction and thermal comfort benefits. Overall, SMR has the largest Cp for 75% at 20 °C was 1.141 kJ/kg.K, therefore specifically, this fibre would be the most effective to implement within a building. It also demonstrates the differences of the samples adsorption and absorption of water in differing hygrothermal environments.

When Biomass Electricity Demand Prompts Thinnings in Southern US Pine Plantations: A Forest Sector Greenhouse Gas Emissions Case Study

Increasing demand for woody biomass-derived electricity in the UK and elsewhere has resulted in a rapidly expanding wood pellet manufacturing industry in the southern US. Since this demand is driven by climate concerns and an objective to lower greenhouse gas (GHG) emissions from the electricity sector, it is crucial to understand the full carbon consequences of wood pellet sourcing, processing, and utilization. We performed a comparative carbon life cycle assessment (LCA) for pellets sourced from three mills in the southern US destined for electricity generation in the UK. The baseline assumptions included GHG emissions of the UK’s 2018 and 2025 target electricity grid mix and feedstock supplied primarily from non-industrial private forest (NIPF) pine plantations augmented with a fraction of sawmill residues. Based on regional expert input, we concluded that forest management practices on the NIPF pine plantations would include timely thinning harvest treatments in the presence of pellet demand. The LCA analysis included landscape carbon stock changes based on USDA Forest Service Forest Vegetation Simulator using current USDA Forest Service Forest Inventory and Analysis data as the starting condition of supply areas in Arkansas, Louisiana and Mississippi. We found that GHG emission parity (i.e., the time when accumulated carbon GHG emissions for the bioenergy scenario equal the baseline scenario) is more than 40 years for pellets produced at each individual pellet mill and for all three pellet mills combined when compared to either the UK’s 2018 electricity grid mix or the UK’s targeted electricity grid mix in 2025. The urgency to mitigate climate change with near-term actions as well as increasing uncertainty with longer-term simulations dictated a focus on the next four decades in the analysis. Even at 50% sawmill residues, GHG emission parity was not reached during the 40 years modeled. Results are most likely conservative since we assume a high share of sawmill residues (ranging from 20 to 50%) and did not include limited hardwood feedstocks as reported in the supply chain which are generally associated with delayed GHG emission parity because of lower growth rates.

Evaluation of cement-bonded particleboards produced from mixed sawmill residues

This study evaluates the application feasibility and properties of cement-bonded particleboards produced from mixed tropical hardwood species. Wood residues from a typical sawmill were collected, dried and used in the manufacturing of the cement composites. The wood residues used were from Ceiba pentandra and Gmelina arborea timber species. The residues were mixed in seven ratios in the production of the composite samples. Two control experimental samples containing unmixed residues of each species were also produced. The test carried out on the boards were flexural strength, water uptake properties and wet and dry screw withdrawal resistance. The effect of the wood mix ratio on the board properties was evaluated. The result showed that all properties except the screw withdrawal resistance were significantly influenced by the mix ratios (p < 0.05). The wet and dry screw withdrawal resistance ranged from 1170 to 1770 N and 1360 to 1830 N, respectively. The optimum wood mix ratio for enhancing mechanical performance of the boards was 1:4 of C. pentandra/G. arborea wood residues. Based on the result of this study, the particleboards produced can be used as wood composite ceiling tiles in building applications.

Biochar from sawmill residues: characterization and evaluation for its potential use in the horticultural growing media

Peat remains the primary constituent of horticultural growing media in professional use. However, use of peat in horticultural growing media results in greenhouse gas emissions and biodiversity loss due to excavation of natural peatlands. Biochar is gaining attention as a sustainable alternative to peat use in horticulture. This study examined the potential of biochar produced from a particular type of sawmill residue, as a partial replacement for peat in horticultural growing media. Five treatments including peat only, biochar only, biochar and peat in 1:1, 1:3, and 3:1 (V/V) ratios were assessed. The addition of biochar into growing media increased the pH and EC of the medium. However, physical properties (air-filled porosity and water holding capacity) were negatively affected with the increase in biochar content in the medium. According to the germination test results, biochar significantly improved germination and the shoot and root length of germinated seeds of cress, lettuce and tomato when compared to peat-only and biochar-only treatments. The inclusion of biochar in 25–50% volume ratio improved plant growth parameters compared to peat-only and biochar-only media. Results obtained from this study suggest that sawmill residue offers great potential as a feedstock for biochar production and inclusion of biochar has positive effects on seed germination and plant growth that might compete with modified peat.

Extractives of Stemwood and Sawmill Residues of Scots Pine (Pinus sylvestris L.) for Biorefining in Four Climatic Regions in Finland—Phenolic and Resin Acid Compounds

This study aimed to identify and quantify phenolic and resin acid extractive compounds in Scots pine stemwood and sawmill residues in four climatic regions of Finland to evaluate their most optimal sources for bio-based chemical biorefining and bioenergy products. The sample consisted of 140 trees from 28 stands, and sawdust lots from 11 log stands. NMR for the overall extractive analysis and HPLC for the quantitative estimation of phenolic and resin acid compounds were employed. Correlation analysis, multivariate factor analysis, principle component analysis and multiple linear regression modelling were applied for statistical analysis. HPLC identified 12 extractive compounds and NMR five more resin acids. Pinosylvin (PS), pinosylvin monomethyl ether (PSMME), and partly neolignans/lignans occurred in the largest concentrations. Wood type caused the most variation, heartwood having larger concentrations than sapwood (sawdust between them). Regional differences in the concentrations were smaller, but factor analysis distinguished the northern and the southern regions into their own groups. The results indicated higher concentrations of PS, PSMME, and vanillic acid in southern regions and those of, e.g., PSMME glycoside, lignan 2, and neolignan 1 in northern regions. The rather low concentrations of extractives in stemwood and sawdust imply value-added products, efficient sorting and/or large raw material volumes.

Wood for food: Economic impacts of sustainable use of forest biomass for salmon feed production in Norway

Aquaculture is the fastest growing animal food producing sector in the world with an annual growth rate of 7%. In Norway alone production of this industry is projected to expand from 1.2 million tons today to 5 million tons by 2050, implying a rapid increase in the demand for sustainable salmon feed alternatives to conventional feed resources such as fish meal and fish oil. Yeast produced from nonfood resources such as wood can serve as a high-quality protein source for farmed fish. In this study we analyze how commercial wood-based feed production in Norway using softwood chips from roundwood and sawmill residues will influence wood fiber prices. Such production will have to compete for wood fiber with wood-based bioenergy in particular, and the analyses were done assuming three main scenarios of expected global consumption of wood for bioenergy. The first scenario (Base) assumes a modest use of wood-based bioenergy reflecting the EU climate mitigation target for 2030. The second (MaxEnergy) and third (MaxEnergyLowRes) scenarios assume using bioenergy at a scale sufficient to fulfill IPCC's 2 °C climate mitigation target, with the only difference that in the MaxBio scenario tree stump utilization is allowed in Europe and USA. The bio-economic global partial equilibrium model EFI-GTM was applied to assess the economic impacts. Yeast production from wood in Norway could be able to pay from 37 to 64 euro/m3 of wood delivered mill site, the large variation depending on the yeast production costs other than wood biomass and the price of alternative fish feed resources. Other factors e.g. improved salmon health due to using wood-based yeast and environmental policy regulations of soya meal productions may increase this paying ability. To get 3 million m3 of wood per year during the period 2020–2030 for producing 330 t yeast it would be necessary to pay about 54, 47 and 55 euro/m3 in the scenarios Base, Bio and BioLowRes, respectively. The wood quantity supplied to the salmon feed production from additional Norwegian harvest will be rather low. If production of wood-based yeast for fish feed proves to be viable in Norway, it is likely to be attractive also in other aquaculture regions like North- and South America and Scotland, implying increased wood demand and higher wood prices than estimated above. Microbial ingredients like yeast produced from non-food biomass such as wood, offer potentials for commercial production. However, the present costs of producing yeast from lignocellulosic biomass may still be too high, and there is a need to develop more efficient processes for economic utilization.

Carbonization techniques and wood species influence quality attributes of charcoals produced from industrial sawmill residues in Eastern Cameroon

Cameroon harvests a considerable volume of round wood each year, only a small part of which is used for manufactured products. In recent decades, various charcoal-making initiatives have emerged around industrial timber-processing units, particularly in the eastern region, in order to develop a market for residual biomass. However, the undifferentiated use of these residues obtained from different species often results in products with varying energy potential that are not always appreciated by consumers. Moreover, the physical and chemical characteristics of the charcoal produced are unknown, as are the factors that influence its quality. The aim of this study was to assess the variability of the physical and chemical properties of charcoal produced from industrial sawmill residues in the eastern region of Cameroon using different carbonisation techniques. Three wood species, Ayous, Frake and Movingui, and three types of kilns (traditional, improved traditional and Casamance system) were used. For each species, three bundles of five pieces of wood each were prepared, with an initial moisture content ranging from 28% to 36%. The physical and chemical properties determined were moisture content, apparent density, volatile matter content, fixed carbon content, ash content and Higher Heating Value (HHV). Our results showed that the charcoal properties varied depending on the wood species and types of kilns used. Movingui, with the highest density (0.73 g/cm3), produced charcoal with the lowest moisture content (4.03%) and the highest apparent density (0.42 g/cm3). The lowest volatile matter content (20.32%), the lowest ash content (1.27%) and the highest fixed carbon content (74.95%) were also obtained with this species. All these values were obtained with Movingui charcoal produced with the Casamance system. However, the highest HHV (32.51 MJ/kg) was obtained with charcoal from Ayous, also produced with the Casamance system. On comparing the three charcoaling systems used, the Casamance model yielded the best physical and chemical charcoal properties. All the charcoals studied complied with FAO standards for cooking fuel. The highest HHV obtained with charcoal from Ayous hardwood shows its ability to release large amounts of thermal energy during combustion.&#x0D; &#x0D; Keywords: Charcoal, carbonization technologies, eastern Cameroon, physicochemical properties, industrial sawmills wastes.

Comparative Life Cycle Assessment of Bioenergy Production from Different Wood Pellet Supply Chains

The EU is one of the largest producers and consumers of wood pellets in the world, covering around 36% of the global wood pellet production and around 50% of the global consumption in 2018. The EU wood pellet consumption is expected to further increase in response to the ambitious energy and climate goals for 2030. Currently, wood pellets are mainly produced from sawdust and other sawmill residues; however, other types of forest feedstock are being investigated in order to meet the increasing wood pellet demand and move toward greater energy independence. The aim of this study is to evaluate and compare the environmental impact of different wood pellet supply chains. A comparative cradle-to-grave life cycle assessment is performed considering the following wood feedstock systems: (i) sawdust from sawmill (S1), (ii) roundwood logs (S2), (iii) whole trees from forest thinning operation (S3), and (iv) logging residues produced during forest tree harvesting (S4). The study focuses on Global Warming Potential (GWP), Ozone Depletion Potential (ODP), Photochemical Ozone Creation Potential (POCP), and Human Toxicity Potential (HTP). Results show that S3 displays the lowest figures on all the environmental impact categories considered in this study. Compared to the reference case S1, S3 shows a GWP reduction of 46%, an ODP reduction of 6.6%, a POCP reduction of 14.8%, and HTP reduction of 13.2%. S3 and S4 have lower GWP than S1 and S2, even when the biogenic CO2 emissions are considered. Overall, the life cycle phases that have the highest GWP, POCP, and HTP are the burning phase and the preparation of the material to be pelletized, particularly the drying process. Nevertheless, the main phases that contribute to the ODP are the forest operations and the pellet preparation.

Basic Performance of Tubular Molten Carbonate-Type Direct Carbon Fuel Cells

In order to resolve energy issues, novel technologies for more effective utilization of carbon resources such as biomass and organic waste are needed. Direct carbon fuel cells (DCFCs) are fuel cells utilizing solid carbon as fuel. The total reaction can be expressed as follows. C(s) + O2(g) = CO2(g) (1)DCFCs as well as typical fuel cells are expected to achieve relatively high efficiency even on a small scale. Due to utilizing solid fuel, storage and transportation of fuel are easy. However, conventional DCFCs had two big problems such as the way to continuously supply solid fuel and low cell performance. We have proposed novel tubular molten-carbonate type direct carbon fuel cells (TMC-DCFCs) [1] to resolve those problems. This study investigated basic performance of TMC-DCFCs. We have already developed tubular molten carbonate-type fuel cells (TMCFCs) with comparatively high robustness and good durability against impurities [2,3], and the manufacturing method of them were applied for TMC-DCFCs. Each cell component of TMC-DCFCs was almost same with typical MCFCs. Cathode was NiO-3%MgO, electrolyte matrix was LiAlO2, anode was Ni-2%AlCr and they were formed by slurry coating methods. Electrolyte was 60%Li2CO3-40%Na2CO3 molten carbonate. Activated carbon powders (MD: 43 µm) or carbonized wood powders (MD: 31 µm) was used as solid carbon fuel. A tubular cell was inserted into the mixture of solid carbon fuel and molten carbonate same with electrolyte in the weight ratio of 80/20. In this paper, we refer to the mixing ratio between solid carbon and molten carbonate as “the carbon/carbonate ratio”. Carbonized wood powders were sawmill residues from conifer carbonized at 623 K and included 50.3% of volatile matter, 46.3% of fixed carbon and 3.4% of ash. Therefore, the net fixed carbon/carbonate ratio was 65/35 when using carbonized wood powders. Single cell tests of continuous power generation were conducted for 2 hours and about 0.72 V of cell voltages with 230 mA cm-2 of current densities, which corresponded to over 160 mW cm-2 of power densities, were achieved at 1073 K in both cases using activated carbon and carbonized wood (Fig. 1). TMC-DCFCs had high cell performance and could sufficiently utilize carbonized wood powders as fuel. These results suggested that the change of the carbon/carbonate ratio was permissible to some extent and a small amount of ash hardly affected the cell performance. On the other hand, it is presumed that the contact between the anode and solid carbon might be poor when the carbon/carbonate ratio is too large or the flooding might occur when the carbon/carbonate ratio is too small. Hence, effects of the mixing ratio and ash contents should be investigated in more detail. Furthermore, the stack test using two cells connected in series was conducted at 973 K. The container filled with the fuel mixture was separated into two sections by the alumina board to be electrically insulated. Results of the stack test will be reported at our presentation.

CELL DAMAGE AND BIOMASS OF YELLOW PASSION FRUIT UNDER WATER SALINITY AND NITROGEN FERTILIZATION

ABSTRACT The aimed of this study was to evaluate the attenuating action of nitrogen doses on leaf cell membrane damage, dry biomass production and leaf area in the formation of yellow passion fruit seedlings irrigated with saline water. Treatments were arranged in a randomized block design, in split plots, corresponding to five levels of irrigation water salinity (plot) (ECw) (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of nitrogen fertilization (subplot) (60; 80; 100; 120 and 140% of 300 mg of N dm-3), which were repeated in five blocks. Plants were grown in pots (Citropote®) with a volume of 3,780 mL, which were filled with a mixture of soil, aged bovine manure and sawmill residue (shaving) in a ratio of 2:1:0.5, respectively. Waters with different levels of salinity were applied from 40 to 85 days after sowing, when the plants were in transplanting conditions. At 85 days after sowing, the percentage of cell damage based on electrolyte leakage, variables of dry biomass, leaf area and specific leaf area were evaluated. Increment in irrigation water salinity reduces the biomass accumulation of yellow passion fruit seedlings; The increase in nitrogen dose did not mitigate the effect of salinity, which reduced cell membrane integrity, making the plant more sensitive.