Sawmill Residues Research Articles

Physicochemical characterisation of bio-based insulation to explain their hygrothermal behaviour

The utilisation of bio-based building materials as hygric buffers has received recent research interest due to their moisture sorption and thermal behaviours which are positive for indoor comfort. Their hygrothermal properties are known but not fully understood, especially when these bio-based materials are exposed to frequent indoor relative humidity (RH) levels. For the first time, it is identified the characteristics at a micro-level responsible for the hygrothermal performance. Bio-based samples utilised within this paper are: Saw Mill Residue (SMR), Wool 1 (W1), Wool 2(W2), Wood Pellets (WP), Straw (STW) and Wood Wool Board (WWB). Results included thermal analysis (DSC, TGA, DTG), chemical analysis (FTIR) and optical microscopy (SEM) to understand and compare how these bio-based materials behave when stabilised at 53% and 75% RH. For cellulose based samples it was demonstrated that in a dynamic hygrothermal environment SMR and WP are the most hygrothermal stable and for keratin-based materials, W1 is the most stable. For the keratin-based samples when conditioned at 75%, as per the intensity of FTIR spectra, the regularity of molecular chain, W2 has the more ordered material structure but W1 is affected more in terms of hydroxyl absorbance from the spectra. These experiments give a greater insight into the dynamic way in which RH affects the thermal stability of samples. This research paper outlines fundamental differences within materials physical properties and chemical reactions. From the 6 different materials that were used, SMR was demonstrated to be the most thermally stable sample overall.

Hybrid optimization-simulation for integrated planning of bioenergy and biofuel supply chains

Traditionally, biomass supply chain planning has been done hierarchically at the strategic, tactical, and operational levels. Hierarchical planning might result in inconsistent or infeasible solutions at lower planning levels because short-term variations, e.g., those in biomass supply and demand, are not considered in long-term plans. To address this issue, an integrated strategic, tactical, and operational plan is developed in this paper in to consider the variations and details of lower planning levels. The integrated plan is developed as a hybrid model based on the recursive optimization-simulation approach. The optimization model integrates the strategic and tactical plans, while the simulation model incorporates the variations at the operational level. A procedure is developed to adjust the plans according to the variations in the model parameters using a feedback mechanism between the operational and the strategic/tactical level plans. The hybrid model is applied to a case study in British Columbia, Canada. The results show that the operational level variations and constraints could affect the long-term investment decisions and their profitability. For the given case study, the operational level variations decreased the estimated net present value by 21% due to the higher demand for logging residues. However, compared with the initial solution considered in the hybrid model, the final solution has a 17% higher net present value. The final design from the hybrid model suggests small-scale bioenergy and biofuel conversion facilities rather than large-scale ones as their demand for biomass could be met using more sawmill residues and less roadside logging residues.

The impact of forest disturbances on residual biomass supply: A long-term forest level analysis

Residual forest biomass is an attractive feedstock for bioenergy production due to its abundance and renewability. However, natural forest disturbances such as wildfire and insect infestation cause unpredictable fluctuations in supply, disrupting long-term procurement plans for delivering feedstock to biorefineries. This study proposes a method to assess the impact of disturbances on long-term supply of residual forest biomass. The method was integrated within a framework of forest management planning for timber production, reflecting current reality of commercially-managed forests. The method was implemented to a case study in eastern Canada focusing on the two most prevalent forest disturbances, wildfire and spruce budworm (Choristoneura fumiferana [Clemen]) infestation. Nine scenarios were considered, with disturbance rates ranging from 0 to 1.6% yr−1 (predicted maximum). Residual biomass considered in this study were (i) logging residue, (ii) salvage biomass, and (iii) sawmill residue. The results show that, as the disturbance rate increases, the area available for timber harvest decreases, leading to a reduction in logging and sawmill residues. In the highest disturbance rate scenario, logging and sawmill residue decreases by almost 40%. Collection of salvage biomass can make up for the reduction, redeeming approximately 20% of the loss. Our method complements the conventional timber production planning process, allowing quantification of residual biomass supply in the face of uncertain natural disturbances due to climate change. The proposed method should support managers in their effort to maintain robust supply chains, while facilitating the adoption of the principles of circular economy.

A carbon footprint assessment of multi‐output biorefineries with international biomass supply: a case study for the Netherlands

AbstractThe efficient use of lignocellulosic biomass for the production of advanced fuels and bio‐based materials has become increasingly relevant. In the EU, regulatory developments are stimulating the mobilization and production of bio‐based chemicals / materials and biofuels from lignocellulosic biomass. We used an attributional life‐cycle assessment approach based on region‐specific characteristics to determine the greenhouse gas emissions (GHG) performance of different supply‐chain configurations with internationally sourced lignocellulosic biomass (stem wood, forest residues, sawmill residues, and sugarcane bagasse) from the USA, the Baltic States (BS), and Brazil (BR) for the simultaneous production of lactide and ethanol in a biorefinery located in the Netherlands (NL). The results are compared with a biorefinery that uses locally cultivated sugar beets. We also compared GHG emissions savings from the supply‐chain configurations with the minimum GHG saving requirements in the revised Renewable Energy Directive (RED II) and relevant fossil‐based counterparts for bio‐based materials. The GHG emissions ‘from cradle to factory gate’ vary between 692 g CO2eq/kglactide (sawmill residues pellets from the BS) and 1002 g CO2eq/kglactide (sawmill chips from the USA) for lactide and between 15 g CO2eq/MJethanol (sawmill residues pellets from the BS) and 28 g CO2eq/MJethanol (bagasse pellets from BR) for ethanol. Upstream GHG emissions from the conversion routes have a relatively small impact compared with biomass conversion to lactide and ethanol. The use of woody biomass yields better GHG emissions performance for the conversion system than sugarcane bagasse or sugar beets as result of the higher lignin content that is used to generate electricity and heat internally for the system. Only the sugar beet from the NL production route is able to comply with RED II GHG savings criteria (65% by 2021). The GHG savings from polylactide acid (a derivate of lactic acid) are high and vary depending on choice of fossil‐based counterpart, with the highest savings reported when compared to polystyrene (PS). These high savings are mostly attributed to the negative emission credit from the embedded carbon in the materials. Several improvement options along the conversion routes were explored. Efficient feedstock supply chains (including pelletization and large ocean vessels) also allow for long‐distance transportation of biomass and conversion in large‐scale biorefineries close to demand centers with similar GHG performance to biorefineries with a local biomass supply. © 2019 The Authors. Biofuels, Bioproducts, and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Thermodynamic model of fast pyrolysis bio-oil advanced distillation curves

Fast pyrolysis bio-oil (FPBO) is a complex organic liquid with over 1000 organic compounds. Therefore, little research exists on the prediction and modelling of liquid physicochemical properties and vapour-liquid phase behaviour. A thermodynamic model of the FPBO vapour-liquid equilibrium (VLE) in distillation will improve the understanding of bulk and FPBO fraction properties, and therefore, aid in the enhancement of FPBO for desired applications, such as condensation of pyrolysis vapours, fractionation, and evaporation during combustion. FPBO produced at 450 °C from softwood sawmill residues at a feed rate of 4 kg/h (~20 s residence time) in a pilot-scale auger reactor was distilled in an advanced distillation curve (ADC) apparatus at atmospheric pressure and at a vacuum of 5 kPa (abs). The ADC equipment allows for the data collection of true thermodynamic state points, including vapour phase composition data. UNIQUAC was the selected equation of states (EoS) to model FPBO distillation VLEs in a 20–flash series in VMGSim™. A surrogate mixture of water, 3,4,4′-biphenoltriol (pyrolytic lignin), inert solids, and multiple organic components was used to model and predict the VLE and consequently bulk physicochemical properties. It was found that GC-FID composition data (in area%), water content (Karl Fisher titration), distillation residue, and solid content were sufficient to inform the model (surrogate composition). This work improved the understanding of FPBO phase behaviour, composition, and bulk properties. The method allows for the identification of target components and fractions to enhance FPBO quality for desired applications.

Influence of diameter and quality of beech logs on the potential energy of sawmill residues

The influence of log diameter and log quality were studied relative to the potential heat energy produced from wood residue. Research was conducted on beech sawmill logs (30 cm to 49 cm in diameter and 4 m in length) of different qualities. Logs with greater diameters and of better quality increased the amount of products and decreased the amount of residue. A decrease in the diameter and quality of beech logs increased the total energy capacity, ranging between 840 kWh/m3 (highest quality logs, 40 cm to 49 cm in diameter) and 1,350 kWh/m3 (lower quality logs, 30 cm to 34 cm in diameter). Drying the lumber produced from logs of small diameters used less than 10% of the potential heating energy. However, logs of 40 cm to 49 cm in diameter increased this usage to 33%. When burner losses and drying energy losses were calculated, there was approximately 430 kWh/m3 to 960 kWh/m3 of leftover energy. This could be used for various purposes or it could be sold. The amount of obtained energy was influenced more by log diameter than by the log quality.

Life cycle assessment of forest-based biomass for bioenergy: A case study in British Columbia, Canada

Large quantities of residual forest-based biomass, including harvesting and sawmill residues, are available in British Columbia, Canada. They can be used to generate bioenergy. Currently, harvesting residues are burned to reduce fire hazard, and private and remote sawmills’ residues are either burned or landfilled. While previous studies assessed the impact of bioenergy production from residual forest-based biomass on global warming, this life cycle assessment includes a comprehensive set of ten impact categories. Adopting a case study in a region in British Columbia, a life cycle model is applied to three locations considering four combustion and gasification technologies with different capacities (0.5 MW, 2 MW, 3 MW and 5 MW) and product outputs (electricity and/or heat). Most bioenergy supply chain scenarios showed improved environmental performance due to avoided uncontrolled combustion of residues and avoided fossil fuel combustion, particularly in the categories of acidification (+1% to -71%), eutrophication (-2% to -85%), fossil resource depletion (-2% to -84%), respiratory effects (0% to -96%), and photochemical ozone formation (+3% to -59%). Benefits were larger at locations dependent on fossil energy compared to locations dependent on hydropower. In contrast, ecotoxicity values increased in most scenarios (+460% to -11%), due to wood ash disposal. Results confirmed conversion efficiency and wood ash disposal as influencing factors in bioenergy supply chains for the investigated region, but showed a minor influence of the feedstock procurement distance. Moreover, the results emphasized the high contribution of uncontrolled burnings to the overall environmental impact of the forest biomass supply chains.

Physicochemical Approach To Blend Biomass

A physicochemical methodology for blending biomass to solve ash agglomeration in combustion processes has been used. The method is based on prediction of high melting point compounds by phase diagram and FactSage calculations coupled with experiments at laboratory and pilot scales. Experimental validation of the calculations was carried out by annealing at 1000 °C followed or not by air quenching at the laboratory scale, using either compressed ash or biomass pellets. Samples were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and powder X-ray diffraction. Two biomasses, oak bark, a sawmill residue, and wheat straw, an agricultural residue, were selected on the basis of their ash composition (rich in Ca, K, or Si). Several mixtures were selected with a minimum of the liquid phase calculated by thermodynamic equilibrium. The results show that the chemical reaction was obtained after annealing because new phases were obtained, whereas they were absent from the ashes of single biomasses. The mixture is not simply a dilution. A slightly smaller chemical reaction was observed in biomass pellets than in compressed ash. These results agree with the predictions, except for the K₂Ca₆Si₄O₁₅ ternary compound, absent from the thermodynamic databases but clearly identified in the ash of the 50:50 wheat straw/oak bark mixture. To our knowledge, it is the first time that this phase has been observed in biomass ashes. It has been recently observed in phase equilibria and crystallographic studies. This underlines the interest of the predictions but also the need to improve existing thermodynamic databases, especially on the CaO–K₂O–SiO₂ system.

Application of biochar for acid gas removal: experimental and statistical analysis using CO2.

Acid gases such as carbon dioxide and hydrogen sulfide are common contaminants in oil and gas operations, landfill gases, and exhaust stacks from power plants. While there are processes currently used to treat these effluents (e.g., amine absorption and adsorption using zeolite), many of these processes require high energy, space, and hazardous chemicals. Removal using biochar derived from the fast pyrolysis of forestry residues represents a more sustainable option. In this study, adsorption using CO2 as a surrogate for acid gases was investigated using various biochars produced from fast pyrolysis of sawmill residues. Response surface methodology was used to determine operating conditions for maximum adsorption and assess interaction of the adsorption parameters, i.e., temperature, inlet feed flow rate, and CO2 concentration, on biochar adsorption capacity. The Freundlich isotherm best represented the equilibrium adsorption, and the kinetic model was pseudo first-order. Thermodynamic analysis indicated the adsorption process was spontaneous and exothermic. The biochar had better adsorption capacity relative to commercial zeolite. Our results suggested that biochar could be used as a sustainable and cost-effective option for contaminant removal from acid gases produced in landfill gas treatment, fossil fuel extraction, and/or combustion.

Sustainable bio-based earth mortar with self-healing capacity

This paper describes the hygrothermal and mechanical properties and self-healing capacity of a sustainable bio-based mortar repair system for earth construction. There is currently limited characterisation of materials that directly compare earth, bio-fibres and self-healing behaviour. Additionally, the thermal performance of self-healing materials has been under-researched. Both prismatic and 0.1 m × 0.1 m samples were cast with plain mixes, saw mill residue (SMR), straw, wool and wood pellets. Executing both structural and hygrothermal experimentation provided an indication of the performance and durability of the samples. The bio-based agent added to the bio-based composite consisted of bacteria. Adding the bio-based agent to an earth matrix with (wheat) straw, (sheep) wool, SMR and wood pellets showed promising results for the hygric properties, as the initial water adsorption and absorption were lessened. The thermal conductivity was reduced from 0.32 to 0.23 W/m.K when bio-based agents were combined into the earth-based mix design with SMR. Overall, it is evident that out of all ten mix designs, bio-SMR provided the best environmental conditions for the bio-agent.

Hydrolysis of Corn Stalk Enzymatics using Cellulation Enzyme as an Efforts to Increase Reducing Sugar Levels

Bioethanol can be processed from various types of starchy plants (cassava, corn, seed sorghum, sago), sugary plants (sugar cane, sweet sorghum, beets) as well as cellulose (straw, sawmill residue, bagasse, soybean seed skin). Cellulose is the main constituent of plant cells and is an abundant organic compound on earth. Cellulose material which is not a food ingredient can be used as bioethanol raw material. One of them is corn stalk waste. Corn stalk waste is obtained from the corn harvest. In the corn harvest, there is a cellulose waste that can be utilized, including corn leaves and corn cobs. This study aims to utilize corn stalk waste to obtain optimum reducing sugar levels using variations in cellulase enzyme concentration and hydrolysis time. Before the hydrolysis process, initial processing is carried out using alkaline solutions, namely NaOH, for the delignification process. The variables used in the study include: cellulase enzyme concentration: 2%; 2.5%; 3%; 3.5%; 4% and hydrolysis time: 6, 8 and 10 hours. The effect of Physical treatment and Chemical treatment affect the levels of Lignin and cellulose. After the corn stalk waste has undergone physical and chemical treatment using 10% NaOH, there is a decrease in lignin levels from 12% to 4% and there is an increase in cellulose levels from 40% to 75%. While for the best result is obtained at the enzyme concentration of 3.5% with hydrolysis time of 10 hours which produces a reducing sugar of 2214.900 mg/L.

Economic and Environmental Analysis of Pellets’ Production in Rio Pardo Watershed, Brazil

ABSTRACT Economic and environmental aspects of residues energetic use in Brazil are extremelly important. In one hand, the country is today a recognized bioenergy producer in a global scenario; on the other, it is still struggling to provide a reliable renewable energy supply to rural communities. Local demand could be supplied through small investments using local forest mill residues as feedstock to produce value-add bio-based energy fuels. Therefore, this work aims at evaluating wood pellets production as an alternative source for supplying regional heat demand for drying grains and tobacco in the Rio Pardo Watershed (RPW), Brazil. It presents techno-economic analysis and risk assessment for a pellet plant supplied by sawmill residues available at the RPW. The results showed the economic feasibility of pellets production in the RPW. The pellets can be a clean, renewable alternative energy source to firewood for supplying farms demand for drying grains and tobacco.

Influence of the Composition on the Exploitation Properties of Combined Medium Density Fibreboards Manufactured with Coniferous Wood Residues

One of the main disadvantages of medium density fibreboards (MDF) in comparison with particleboards is the higher price of the panels, due to the energy-intensive defibration process. Studies on the possibilities for replacing some part of the wood fibre mass in the composition of MDF with coniferous sawmill residues (shavings) obtained from bandsaw, are presented in this article. The experimental plan is designed using the McLean and Anderson method for studying the properties of multi component systems in the presence of constraints on the components. The content of coniferous wood shavings varies up to 40%. The panels are manufactured with a density of 720 kg.m-3. The content of urea-formaldehyde resin varies from 8 to 14% in order to compensate the negative impact of the inclusion of coniferous wood shavings in the composition of the manufactured MDF panels. The main exploitation properties of the panels are determined. Experimental and statistical models on the influence of the studied factors are obtained by applying stepwise regression and optimization is performed to obtain the best exploitation properties of MDF panels. As a result of the study it was determined that in order to achieve the values of MDF properties, required by the respective standards, the maximum permissible content of coniferous wood shavings should be up to 10.6%, in which case the content of urea-formaldehyde resin should be above 10%. If the content of urea-formaldehyde resin is below 10%, the maximum permissible content of coniferous wood shavings should be up to 5%.

ENERGETIC VALORIZATION OF SAWMILL RESIDUES THROUGH SLOW PYROLISIS PROCESS

Brazil is a large producer of sawmill wastes, commonly used to supply boilers and produce energy. In order to reduce unwanted characteristics of the material, thermochemical conversions through carbonization is an alternative. The aim of this study is to characterize the energetic proprieties of raw biomass and pyrolyzed biomass of sawmill residues. In order to analyze the environmental impact in the emission of pyrolysis gases, the behavior of gases during the thermic treatment was determined. Eucalyptus sp. and Pinus sp. residues slow pyrolysis was performed in an electric kiln, whose gases were conducted through a condensable gas recovery system and an online gas analyzer. The charcoal, bio-oil and non-condensable gases yields were estimated. The wood’s and charcoal’s proximate analysis (extractives, lignin, holocellulosis, ash content), higher heating value, equilibrium moisture and density were appraised. The wood’s chemical components were esteemed. Hardwood and softwood’s charcoal presented several differences, especially in yields due to types of lignin. Hardwoods produce a higher amount of acetic acid in slow pyrolysis. This acid was converted, mainly, in carbon dioxide and e a minor extent in methane and carbon monoxide. The gas release was affected by the temperature and wood’s composition. The main gases resulting from the slow pyrolysis of wood are CO2, CO, CH4, H2. The emission of this gases to the atmosphere in addition to increasing the environmental impact caused by the industry is still a waste of energy that could be harnessed more efficiently. Pyrolysis increased the energetic characteristics of sawmill waste. However, in spite of the advantages of carbonization, ways to mitigate the emission of gases emitted in an operational scale should be evaluated.

Preparation and Characterization of Combed Sawmill Slab Residues from Chinese Fir and its Scrimber

To effectively utilize sawmill slab residues, self-manufactured combing equipment was used to transform residues into individual bundle sticks. The scrimber was prepared from Chinese fir by hot pressing the resulting bundle sticks. In this study, the combing process and effects of density on the mechanical and physical properties of the scrimber were investigated. The morphology of the scrimber was tested with computed tomography. The results showed that a rotary speed of 120 rpm for the coarse roller and a rotary speed of 360 rpm for the fine roller combed along the grain were the optimum combing parameters to prepare a uniform individual bundle of sticks. The moisture content of the feeding sawmill residues was above 30%. The scrimber prepared via bundle sticks is a new type of structural scrimber, and the density of the scrimber influenced the physical and mechanical properties. As the scrimber density increased, the modulus of rupture, modulus of elasticity, and internal bond gradually increased, while the 24-h thickness swell decreased. The studied method enhanced the density and improved the physical and mechanical properties. The striped structural characteristic of the scrimber was evident, and the density distribution varied for different faults.

Assessing the potential impact of a biorefinery product from sawmill residues on the profitability of a hardwood value chain

Due to the high amount of low-quality hardwoods harvested during selection cuts, the forest industry has been facing a decline in profit margins. One possible solution for utilizing the low-quality raw material is the production of extracts. The objective of this work was to estimate to what extent the inclusion of betulin in the traditional wood products portfolio could extend the profitability of a hardwood value chain. The profitability of a selection cut was assessed from the sawmill perspective, followed by an evaluation of the potential financial gain of producing betulin. Finally, the inclusion of betulin in a value chain was assessed. Results showed that the profitability of selection cuts was very low in some forest stands. The sensitivity analysis demonstrated that, among selected costs and revenues, profit was more sensitive to variations in the value of coproducts. If a fraction of coproducts volume was used to extract betulin, it would be sufficient to generate enough revenue to offset the total costs; however, a major constraint was the small size of the current betulin market, with annual sales not exceeding 1000 kg. Despite that, results demonstrate the potentially strong contribution of high value added extracts to the profitability of the forest value chain.

A modeling framework for the optimal forest supply chain design considering residues reuse

In the forest industry, large volumes of residues are generated during the harvesting and lumber production, whose re-use can increase the economic opportunities in this industry. In this sense, they can be used as raw material for some products (pellets, wood panels, among others) or as fuels for energy production. Due to the great number of available production alternatives and involved elements, a supply chain approach is appropriate to address this problem. Then, taking into account the particular conditions of the forest industry in Argentina, a mixed integer linear programming formulation is proposed in order to obtain the optimal design of the forest supply chain emphasizing the appropriate use of forest and wood residues. The model determines the location and size of each production facility, the amounts of products and residues to be generated, and all the material flows between forest sites and plants, between plants, and between plants and customers, in order to maximize the total benefit. This approach is suggested as a tool to analyze the optimal configuration of the forest supply chain by assessing the viability of different production alternatives. Through the different considered scenarios, it can be concluded that a strategic design for the forest supply chain is required in order to achieve an efficient use of harvest and sawmill residues.

Evaluating Economic Alternatives for Wood Energy Supply Based on Stochastic Simulation

Productive forests, as a major source of biomass, represent an important pre-requisite for the development of a bio-economy. In this respect, assessments of biomass availability, efficiency of forest management, forest operations, and economic feasibility are essential. This is certainly the case for Mexico, a country with an increasing energy demand and a considerable potential for sustainable forest utilization. Hence, this paper focuses on analyzing economic alternatives for the Mexican bioenergy supply based on the costs and revenues of utilizing woody biomass residues. With a regional spatial approach, harvesting and transportation costs of utilizing selected biomass residues were stochastically calculated using Monte Carlo simulations. A sensitivity analysis of percentage variation of the most probable estimate in relation to the parameters price and cost for one alternative using net future analysis was conducted. Based on the results for the northern region, a 10% reduction of the transportation cost would reduce overall supply cost, resulting in a total revenue of 13.69 USD/m3 and 0.75 USD/m3 for harvesting residues and non-extracted stand residues, respectively. For the central south region, it is estimated that a contribution of 16.53 USD/m3 from 2013 and a total revenue of 33.00 USD/m3 in 2030 from sawmill residues will improve the value chain. The given approach and outputs provide the basis for the decision-making process regarding forest utilization towards energy generation based on economic indicators.

Biochar feedstock and pyrolysis temperature effects on leachate: DOC characteristics and nitrate losses from a Brazilian Cerrado Arenosol mixed with agricultural waste biochars

Dissolved organic carbon (DOC) leached from Brazilian Cerrado Arenosols can lead to carbon (C) losses and lower soil fertility, while excessive nutrient, e.g. nitrate (NO3−), leaching can potentially cause water contamination. As biochar has been shown to stabilize C and retain soil nutrients, a greenhouse experiment was conducted to test different biochars’ contributions to DOC and NO3− leaching from a sandy soil. Biochars were made from four local agricultural waste feedstocks (cotton residue, swine manure, eucalyptus sawmill residue, sugarcane filtercake) pyrolysed at 400, 500 and 600 °C. Biochar was mixed with soil at 5% weight in pots and maize seeds planted. Leachate was collected weekly for six weeks and analyzed for DOC and NO3− concentrations, while fluorescence spectroscopy with parallel factor analysis (PARAFAC) was used to interpret DOC characteristics. Cotton and swine manure biochar treatments had higher DOC and NO3− losses than eucalyptus biochar, filtercake biochar, and control treatments. Cotton and swine manure biochar treatments at high temperatures lost mostly terrestrial, humified DOC, while swine manure, filtercake, and eucalyptus biochars at low temperatures lost mostly labile, microbially-derived DOC. Through the practical use of fluorescence spectroscopy, our study identified filtercake and eucalyptus biochars as most promising for retaining DOC and NO3− in a Cerrado Arenosol, potentially reducing stable C and nutrient losses.

An economic analysis of the carbon benefits of sawmill residues' use in South Korea

Abstract In this study, a methodological basis is used to analyze the carbon economic effects of sawmill residue use. The usage of sawmill residues, which is classified in two main categories: energy source and base material for products, leads to different economic effects and benefits. When analyzing the economic effects of using wood as an energy source, the benefits stem from reduced carbon emissions and related costs. When sawmill residues are used as a base material, the primary usage relates to construction materials and household goods. The economic effects are analyzed and calculated in terms of the amount and interest rates of carbon retained in the base material. This study predicts the total economic effects of the carbon sinks stored within the system boundaries of construction materials and household goods until 99.9% of the stored carbon sinks are released. The results demonstrate that the economic benefits of sawmill residues are substantial, but differ based on the type of use. The economic benefits of using sawmill residues as a base material increase with time and match the benefits of using the residues as an energy source—when used for construction purpose, the economic benefits reach that of using wood as an energy source in 13 years and for household goods purpose in 16 years. More specifically, the dollar value per ton of sawmill residues is USD 9.85 when used as an energy source, USD 15.94 as a construction material (for 33 years), and USD 10.95 as a base material (for 30 years) for household goods. The economic benefits of the base material use eventually surpass the economic benefits of energy use. The findings illustrate that base material usage of sawmill residues leads to more economic benefits from a long-term perspective; the specific numbers may differ by country, but our methodology provides an appropriate guideline for other countries and situations.