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This study chose Oak woodchips and gravel as media filter to enhance the denitrification in the bioretention system (saturated zone 7.7 L) treating synthetic stormwater runoff. It revealed that the denitrification process mainly occurred during the drying phase and enlarging volume of saturated zones to retain more stormwater during storm event was the direct method to promote nitrogen removal of the bioretention system. Nevertheless, it was noted that the nitrogen and dissolved organic carbon would be released into the effluent during the wetting period. The denitrification rate with different nitrate nitrogen (NO3–N) concentrations did not show the obvious change with zero order kinetics constant of 2.91 mg/L∙d on average. Furthermore, it confirmed that woodchips were degraded and converted to volatile fatty acids (VFAs), especially acetic acid as carbon source, further utilized by the denitrifying bacteria, such as Dechloromonas, Acidoborax, Pseudomonas, Denitratisoma and Acinetobacter. In addition, genera of Lachnospiraceae and Lactobacillus, which had the ability to degrade the macromolecular organic components into low molecular VFAs, were observed in the woodchips bioretention system.

Floating constructed wetlands (FCWs) have attained tremendous popularity for water purification purposes. However, FCW functions establishment in nutrients removal from carbon-limited wastewater, especially in cold weather, is still a challenge. Here, two drinking water treatment residual (DWTR) based biocarriers (B-I: DWTR cakes, B-II: DWTR cakes combined with woodchips) have been augmented into FCW to enhance the nutrients (N and P) removal performance. Compared to the traditional FCW, the intensified FCWs simultaneously achieved higher N and P removal efficiencies, with average pollutants removal of 52.16 ± 11.51% for TN and 92.72 ± 1.61% for TP in FCW-I and 57.65 ± 9.43% for TN and 92.17 ± 2.55% for TP in FCW-II, respectively, while their removal in FCW-III of 27.74 ± 7.11% for TN and 17.91 ± 9.27% for TP. B-II performed best in overcoming the negative influence of low temperature in nutrients removal. Mass balance budget indicated that most P was enriched in DWTR based biocarriers. Thus it is feasible to recycle and recover P from the surface water. Furthermore, P in the sediment can be changed from active P to stable P, mitigating the internal P release risk. This study can help to expand the understanding of the intensified FCWs and promote the practical application of FCWs.

For the pulping process in a pulp & paper plant that uses woodchips as raw material, the moisture content (MC) of the woodchips is a major process disturbance that affects product quality and consumption of energy, water and chemicals. Existing woodchip MC sensing technologies have not been widely adopted by the industry due to unreliable performance and/or high maintenance requirements that can hardly be met in a manufacturing environment. To address these limitations, we propose a non-destructive, economic, and robust woodchip MC sensing approach utilizing channel state information (CSI) from industrial Internet-of-Things (IIoT) based Wi-Fi. While these IIoT devices are small, low-cost, and rugged to stand for harsh environment, they do have their limitations such as the raw CSI data are often very noisy and sensitive to woodchip packing. To address this, statistics pattern analysis (SPA) is utilized to extract physically and/or statistically meaningful features from the raw CSI data, which are sensitive to woodchip MC but not to packing. The SPA features are then used for developing multiclass classification models using various linear and nonlinear machine learning techniques to provide potential solutions to woodchip MC estimation for the pulp and paper industry. This work also demonstrates that classification accuracy alone is not a good performance metric for industrial applications, and the practical implications of misclassification must also be considered.

There is a growing demand for alternative forms of energy that could firstly replace fossil fuels, with the environmental advantages resulting therefrom, but that could be as well economically more beneficial by allowing companies to obtain competitive advantages from the aforementioned alternative forms of energy. In this sense, the use of waste to produce thermal energy is presented as an alternative worthy of study. In this paper, an analysis is made of the use of waste from the textile industry, more precisely cotton waste, which is used as a renewable resource for the production of thermal energy. After the characterization of the waste, the energetic potential is determined comparatively to other fuels such as woodchips and wood pellets. A comparative economic assessment with other fuels is carried out. The obtained results show that the cotton briquettes have a heating value of 16.80 MJ/kg and a cost of 0.006 €/kWh when used as fuel. This predicts an annual reduction in fuel cost of 80, 75 and 70% when compared with fuel-oil, wood pellets and wood chips, respectively. Thus, the use of cotton waste could be a viable alternative, economically and environmentally, to produce thermal energy.

A denitrification bed is a system that can reduce the nitrate concentration in subsurface drainage water. There is a need to investigate the carbon quality of old woodchips to gain a better understanding of the effect of age on woodchip properties. The objectives of this study were to characterize the carbon quality and carbon to nitrogen (C/N) ratio of aged woodchips and to examine the suitability of a denitrification bed for a replicated experiment. To achieve these goals, we excavated four-year-old woodchips along the length of a 106.4 m long denitrification bed near Willmar, Minnesota, and analyzed them for particle size, C/N ratio, and carbon quality. Particle size analysis showed similarities from 12.5 to 106.4 m along the bed. We found a mean C/N ratio ranging from 58.4 ±3.17 to 153.4 ±9.57 (smallest at the inlet). The mean lignocellulose index (LCI, a measure of carbon quality) of the four-year-old woodchips ranged from 0.47 to 0.57 (highest at the inlet). The woodchip particle sizes, C/N ratios, and LCI from 25.9 to 106.4 m along the bed length were similar. In conclusion, the C/N ratio and LCI of the four-year-old woodchips showed effects of decomposition and increased woodchip carbon recalcitrance over time, respectively. Keywords: Denitrifying bioreactor, Tile drainage, Water quality, Woodchip bioreactor.

Artificial drainage is a common agricultural practice in Lithuania. In this country, the total drained land area occupies 47% of the total land area and 87% of the agricultural land area. Therefore, this article presents recent research findings on agricultural drainage in Lithuania related to the practices designed to reduce nutrient, i.e., nitrogen (N) and phosphorus (P), losses from the soil via tile drainage and transport in open drains. Temporal changes in tile drainage flow over the last four decades are also discussed in this article. The results from experiments with controlled drainage practices in Lithuania showed promise. Compared to conventional drainage, controlled drainage reduced inorganic N by 42% to 77% and reduced total P by 34% to 72%. The reduced loads were the result of reduced drainage outflow. Moreover, research on the effects of additives in drainage trench backfills showed that woodchips, chopped straw, and lime additives mixed in the drainage trench backfill led to reductions in NO3-N concentrations of 78%, 69%, and 52%, respectively, in the drainage water. The addition of lime to drainage trench backfill reduced PO4-P concentrations in the drainage water by 39%, while woodchips and chopped straw increased the concentrations by 11% and 22%, respectively. It was determined that NO3-N in the drainage water was removed most effectively by woodchips and that PO4-P was removed most effectively by the addition of lime. The experiments with reactive filter materials used as in-ditch measures to remove phosphorus showed that the filter materials can be ranked as follows based on their P removal efficiencies: Polonite > slag > Filtralite-P > dolomite chips. Polonite had an advantage over the other tested materials due to its higher porosity, low sensitivity to clogging, and greater permeability. Laboratory-scale experiments using denitrification bioreactors filled with three types of woodchips (deciduous, coniferous, and mixed) showed no significant differences in NO3-N removal efficiency among the three materials. However, the tests showed that woodchip media are capable of achieving higher NO3-N removal rates due to higher flow rates. Therefore, better optimization and proper evaluation of the effects of hydraulic retention time are needed to improve the design of denitrifying woodchip bioreactors. Keywords: Agricultural drainage, Controlled drainage, Denitrifying bioreactors, Drainage trench backfills, In-ditch filters.

Detrital soil contamination during wood harvesting cannot be avoided without a further cleaning step. The objective of the current study was to determine the effect of Piedmont soil on pinewood pyrolysis products. Ash content was varied at 0.56%, 1.16%, 2.77%, 4.40%, 6.87%, 8.35%, and 15.52% by adding soil to woodchips to mimic the highly soil-contaminated biomass that can be found in biorefineries. This study found that bio-oil yield decreased from 47.1% to 26.3% with an increase in ash content from 0.56% to 15.52%. However, the oxygen content of the bio-oil decreased and the carbon content increased, which led to an increase in heating value from 22.5 to 24.9 MJ kg-1. Inorganics in the soil aided in the catalytic cracking and dehydration reactions for bio-oil formation. A slight increase in the total acid number (106 to 117 mg KOH g-1) and water content (20.72% to 24.99%) was observed with more soil inclusion in the pyrolysis. The effect of soil on biochar O/C and H/C ratios was minimal even though the heating value decreased with an increase in soil content. This study showed that soil (4%wt to 7%wt) in the biomass assisted in deoxygenating the bio-oil and lowered the total mass yield while keeping the total energy yield almost constant. Keywords: Fast pyrolysis, Pinewood, Pinus taeda, Soil, Thermochemical conversion.

The Agaricus blazei strain (KUMB 1221) from Forest Production Control Laboratory, Kyushu University was grown on the basal media of compost mixed with selected agro-residues (sawdust, woodchips and corncob) in the ratio of 25%, 50%, 75% and 100% (by weight). The data was collected on the colony diameter of mycelial growth, days required for spawn run (colonization), days required for primordial formation, whiteness measurement, days required for fruit body formation, number, size and fresh weight of mushrooms, biological efficiency (BE) and mushroom production (MP). It was observed that the mycelial growth showed two types of mycelia according the level of mycelial density; compact (C) and somewhat compact (SC). The fastest spawn run (17 days) was found in woodchips (50%) among all the different treatments while the least spawn run took 26 days in corncob (75%). Sawdust substrates promoted longer days for primordial formation and fruit body development, if compared with woodchips substrates and corncob substrates. With regard to yield, 100%, 75% and 50% mixture with compost were superior to 25% mixture with compost in each group of selected agro-residues and it indicated that adding more compost gave the increased yield. Interestingly, it was noted that mushroom size on compost (100%) was double to the mushroom size of other treatments. In conclusion, it was clearly showed that compost (100%), woodchips (25%) and corncob (25%) could produce better yields among all treatments, and it was also possible to obtain acceptable yields of good quality almond mushroom using main substrates of compost mixed with different agro-residues at various concentrations.

Biochar has received increased attention in environmental applications in recent years. Therefore, three pilot-scale denitrifying bioreactors, one filled with woodchips only and the other two enriched with 10% and 20% by volume of biochar from deciduous wood, were tested under field conditions for the removal of nitrate (NO3-N) and phosphate (PO4-P) from tile drainage water in Lithuania over a 3-year period. The experiment showed the possibility to improve NO3-N removal by incorporating 20% biochar into woodchips. Compared to the woodchips only and woodchips amended with 10% biochar, the NO3-N removal effect was particularly higher at temperatures below 10.0 °C. The results also revealed that woodchips alone can be a suitable medium for PO4-P removal, while the amendment of biochar to woodchips (regardless of 10% or 20%) can lead to large releases of PO4-P and other elements. Due to the potential adverse effects, the use of biochar in woodchip bioreactors has proven to be very limited and complicated. The experiment highlighted the need to determine the retention capacity of biochar for relevant substances depending on the feedstock and its physical and chemical properties before using it in denitrifying bioreactors.

Biochar has been shown to improve soil quality and crop yields. Furthermore, thanks to its high carbon content (C) and stable chemical structure, biochar can sequester C in the soil for a long time, mitigating climate change. However, the variability in published biochar stability in the soil makes verifying this trait under different environmental and agricultural conditions necessary. Moreover, most of the published literature refers to short-term incubation experiments, which are considered to not adequately represent long-term dynamics under field conditions. This article reports the results of a field experiment carried out in a vineyard near Merano, northern Italy, where the stability of woodchips biochar in soil, its impact on the total soil C stocks as well as on the original soil organic C (priming effect) were studied over two years. Vineyard soil (Dystric Eutrochrept) was amended with biochar (25 and 50 t ha−1) alone or together with compost (45 t ha−1) and compared with unamended control soil. Two methods assessed the stability of biochar in soil: the isotopic mass balance approach and the quantification of Benzene PolyCarboxylic Acids (BPCAs), molecular markers of biochar. The amount of C in the soil organic matter (SOM-C) was determined in the amended plots by subtracting the amount of biochar-C from the total soil organic C stock, and the occurrence of priming effect was verified by comparing SOM-C values at the beginning and at the end of the experiment. Results did not show any significant biochar degradation for both application rates, but results were characterized by a high variation. The application of 50 t ha−1 of biochar significantly increased soil C stock while no effect of biochar on the degradation of SOM-C was observed. Results were confirmed in the case of biochar application together with compost. It can be concluded that the use of woodchips biochar as a soil amendment can increase soil C content in the medium term. However, further analyses are recommended to evaluate the impact of biochar on climate change mitigation in the long term.

The environmental impacts of cement and concrete industries are increasingly taken into consideration by regulatory agencies and new solutions must be found to turn into more sustainable productions. The use of waste materials as partial replacement of cement and/or aggregates or also as fillers into cement-based admixtures is a possible way to reduce the related negative impacts, such as carbon dioxide emissions and raw materials consumption. This work explores the possibility of using biochar, a carbon-rich and porous solid by-product resulting from thermochemical conversion of residual biomass under controlled conditions, as filler in concrete for structural use. The biochar used in this study derives from a commercial plant, which produces energy from pyro-gasification of woodchips. Biochar is at first chemically and morphologically characterized, then it is added as filler in concrete in different percentages, up to 10% by weight of cement. The effects of its introduction on fresh and hardened physical and mechanical properties of concrete, as well as on the internal matrix microstructure, are evaluated and compared to a reference concrete. Different curing conditions (wet and dry) and curing times (up to 365 days) are processed, also in order to evaluate biochar effect on concrete in terms of internal curing action and long-term behavior.

In the present work, the H2O2 bleaching with the substitution of 50 wt% NaOH by MgO as the alkali source in the high-consistency (HC) retention stage of mixed triploid poplar (Populus tomentosa Carr.) and acacia (Acacia confusa Merr.) woodchips P-RC APMP (preconditioning followed by refiner chemical treatment, alkaline peroxide mechanical pulp) was conducted. Meanwhile, the related bleaching reaction kinetics was well established. The obtained high-yield pulp presented a higher bleaching yield, improved bulk, favorable brightness and physical properties in comparison with the obtained pulp using 100 % NaOH as the alkali source. Most importantly, the chemical oxygen demand (COD) of the bleaching effluent was greatly decreased. The established bleaching kinetic equation is as following: dw dt = K [ H 2 O 2 ] 3.63 [ NaOH ] 1.08 [ MgO ] 0.57 [ Na 2 SiO 3 ] 0.05 w − 1.89 K = A·e –E/RT where the activation energy E =57.2 kJ/mol. It demonstrates that the bleaching reaction rate greatly depends on the concentration of primary bleaching reagents. The magnitude of the dependent extent is [H2O2] > [NaOH] > [MgO] > [Na2SiO3]. The rapid rise of the pulp brightness increment occurred in the first 35 min in the bleaching reaction.

Proper disposal of animal mortalities is essential in preventing disease transmission and protecting air and water quality. Composting is often used to manage both routine and diseased poultry mortalities. The objectives of this pilot-scale study were to test if adding wood-based biochar to poultry mortality compost could 1) increase compost temperatures, 2) reduce ammonia emissions, 3) decrease leachate’s organic content, and 4) enhance the nutrient content of the final compost. Biochar ratios at 0, 1, 5, 10, and 15% (fresh weight) were co-composted with chicken mortalities and woodchips for 11 weeks (three heating cycles). Results indicated that the biochar amendment significantly increased (3.4–7 °C) the maximum temperatures reached during the composting compared to those of control test units without biochar. Biochar amendments at 5, 10, and 15% resulted in the prolonged periods of temperature over 67 °C to inactivate the highly pathogenic Avian influenza (H7N1), and a reduced cumulative chemical oxygen demand of the leachate by 80.4 ± 3.07%, on average. Biochar amendment at 10 and 15% significantly reduced the cumulative ammonia emissions by 40.4% and 56.8%, respectively. Biochar amendment at 15% increased (34.7%) the total nitrogen content of the final compost. It was concluded that adding biochar, at a minimum of a 5% ratio, is recommended to improve the poultry mortality composting process.

This study compares the life cycle energy consumption and greenhouse gas (GHG) emissions of electricity generation from bio-coals produced from various biomass feedstocks via dry torrefaction (DT) and wet torrefaction (WT) processes. Wheat straw, pine woodchips, grape pomace, manure and algae are the main feedstocks evaluated. The energy consumption and the associated GHG emissions at each life cycle stage were calculated. The main stages included are in-field preparation, feedstocks transportation to torrefaction plant, torrefaction process, bio-coal transportation to power plant, and power plant operations. The results show that all pathways are competitive with coal-based electricity in terms of GHG emissions except pathways with algae as feedstock and manure biochar-based electricity generation. Among the pathways, electricity generation from pine woodchips biochar appears to be the best option, with an 82% GHG emissions reduction compared to coal-derived electricity, followed by wheat starw biochar and grape pomace hydrochar with 80% and 75% emission reductions, respectively. Electricity generation from wheat straw biochar, pine woodchips biochar, and grape pomace hydrochar lead to the highest net energy ratios (NERs) of 4.19, 3.58, and 2.59, respectively. The results also show that the combustion of the biomass for supplying electricity used in the plant decreases GHG emissions in all pathways particularly in WT ones. Sensitivity analysis of using different emissions allocation methods, transportation distances to torrefaction plant and to power plant, emission factor of electricity consumed, and quantity of natural gas consumed were aslo conducted. The developed information is novel and can be used for investment decisions and policy formulation around the world.

In Chile, the demand for pellets has increased considerably in the last years. However, woodchips and sawdust from Pinus radiata which are the traditional materials used for its confection are not always available, making it necessary to investigate other biomass sources complementary. In this study, the residue from corn milling (corn dust) in a maximum distance of 49 km from the pellet production company was analyzed and evaluated as a biomass source. The physical-mechanical and energetic properties of this material were analyzed, then the quality of the pellets created with different percentages of this and P. radiata sawdust was determined. The company requires 10,000 tons of material for its production at a cost of US$80,000 annually. Its distance from the sources of P. radiata sawdust causes it to make them pay US$ 8 t −1 for the material compared to US$ 3 t −1 that companies close to the sources pay, affecting its competitiveness. It was determined that the test tube 50M/50PR meets all the quantitative, qualitative and economic requirements. The acquisition of the 5000 tons required would generate a cost of US$5800 in transporting this material to the plant, this way the company would save US$34,200 in its operational costs annually.

This study investigates the formation and removal of PCDD/Fs and dl-PCBs in two woodchips boilers during different operating periods. Results indicate that combustion condition affects PCDD/F and dl-PCB formation within the woodchip combustion process. PCDD/F and dl-PCB concentrations during the start-up period are much higher than those measured during normal operation and shut-down periods due to unstable combustion. PCDD/F and dl-PCB concentrations at APCDs inlet of Plant A are significantly higher than that of Plant B due to the lower combustion temperature (500–850 °C) compared with Plant B (850–925 °C). Major PCDD/F congeners at APCDs inlet of both plants during normal operation are O 8 CDD, 1,2,3,4,6,7,8-H 7 CDD and 1,2,3,4,6,7,8-H 7 CDF, while major dl-PCBs are TeCB-77, PeCB-118 and PeCB-126. The removal efficiencies of PCDD/F and PCBs achieved with the APCDs of Plant A are 95.6% and 88.6%, respectively, while those of Plant B are 99.3% and 94.9%. Possibly, the AC concentration of Plant A exceeds the optimal AC concentration and, PCDD/Fs and dl-PCBs might be formed because the AC injected can supply additional reaction area and carbon source. Also, this may be due to different operating temperatures of APCDs, which affects removal efficiency of PCDD/F and dl-PCB congeners. The emission factors (PCDD/Fs + dl-PCBs) of Plants A and B are calculated as 17.86 and 1.25 μ g I-TEQ/ton, respectively. Concentrations of PCDD/Fs in the BF ash of Plants A and B during normal operation are measured as 98.57 and 38.06 ng I-TEQ/g, which are significantly higher than the standard limit (1.0 ng I-TEQ/g) promulgated by Taiwan EPA.

Denitrifying bioreactors are increasingly being used for nitrate removal from agricultural drainage water. Filled with carbon substrates, often woodchips, denitrifying bioreactors provide a favorable anaerobic environment for denitrification. Despite performing well in loess soils in the Midwestern United States, field bioreactors have not yet been evaluated in shallow soils over glacial till that are characteristic for the Northeastern United States. This study, therefore, investigates the performance of bioreactors and provides design criteria for shallow soil with flashy discharges. Paired bioreactors, one filled with woodchips and one with a mixture of woodchip and biochar, were installed in tile drained fields in three landscapes in New York State. The bioreactors were monitored for a three-year period during which, the flow rate, temperature, nitrate ( N O 3 − − N ), sulfate ( S O 4 2 − − S ) and dissolved organic carbon (DOC) were measured. Results showed that the average N O 3 − − N removal efficiency during the three years of observations was about 50%. The N O 3 − − N removal rate ranged from 0 in winter to 72 g d−1 m−3 in summer. We found that biochar was only effective during the first year in enhancing denitrification, due to the ageing. An index for carbon availability related to N O 3 − − N removal was developed. During winter, availability of the DOC was a limiting factor in bioreactor performance. Finally, to aid in the design of bioreactors, we developed generalizable relationships between the removal efficiency and hydraulic retention time and temperature.

The life cycle energy consumption and greenhouse gas (GHG) emission performances of forest biomass-derived oxymethylene ether (OME) synthesis used as a diesel additive are analyzed in this study. OME, a new alternative liquid fuel, has great miscibility with conventional fuels like diesel. OME can reduce combustion emissions significantly when used as a diesel additive without any modification to the engine. A data-intensive spreadsheet-based life cycle assessment (LCA) model was developed for OME synthesis from woodchips derived from two different kinds of forest biomass, whole tree and forest residue. Woodchip harvesting, chip transportation, chemical synthesis of OME from biomass-derived syngas, OME transportation to blending, and vehicle combustion of this transportation fuel were considered in the system boundary. The results show that the whole tree pathway produces 27 g CO2eq/MJ of OME, whereas the forest residue pathway produces 18 g CO2eq/MJ of OME over 20 years of plant life. The difference is mainly due to some emissions-intensive operations involved in biomass harvesting and biomass transportation such as skidding, road construction, etc., in the whole tree pathway. Also, vehicle combustion was found to be the most GHG-intensive unit for both pathways. OME combustion in a vehicle accounts for about 77% and 83% of the total life cycle GHG emissions for the whole tree and forest residue pathways, respectively. This study also compares the diesel life cycle emission numbers with the life cycle emissions of OME derived from forest biomass, and it was observed that GHG emissions can be reduced by 20–21% and soot (black carbon) emissions can be reduced by 30% using a 10% OME blended diesel as a transportation fuel compared with conventional diesel.

In this study, the pre-hydrolysis liquor (PHL) was recycled during aspen chip water pre-hydrolysis, and the effects of PHL recycling on the extraction and accumulation of the hemicellulosic saccharides especially that with high molecular weight in the PHL were studied. The results showed that the concentration of hemicellulose saccharides in PHL depended on the pre-hydrolysis temperature and PHL recycling times. Compared to the unrecycled PHL, the concentration of hemicellulosic saccharides in PHL increased significantly when recycling PHL once or twice at 170°C. Furthermore, the amount of high-molecular-weight hemicelluloses (HMHs) in PHL recycled once at 170°C increased from 2.58g/L (unrecycled) to 6.18g/L, but the corresponding average molecular weight of HMHs decreased from 9.2kDa to 7.6kDa. The concentration of hemicellulosic saccharides in PHL decreased with PHL recycling time at 180°C, accompanied by the formation of a significant amount of furfural.

In Vietnam, planted forests account for > 26% of total forest area, with approximately two-thirds of the plantation area managed by smallholders and 80% of plantation wood used for woodchip production. With increasing demand for timber for the construction and furniture industry, the Vietnam Government is seeking to encourage growers to increase the rotation age of plantations and produce higher quality timber so that it can meet its 2020 furniture export targets. Progress on this goal is however slow, with growers unsure about the financial case for increasing rotation age. Using a case study of the Ben Hai State Forestry Company (SFC), we compare financial returns from acacia plantations by the rotation ages of 5, 6 and 10 years. The 5 year rotation is for the sole purpose of producing woodchips whilst 6 and 10 year rotations produce both timber and woodchips. Results show that all three types of plantation produce positive returns but the return from 10 year rotation plantations (in terms of NPV and IRR) is much higher than those of others. By increasing the rotation age by 1 year (6 years total) and 5 years (10 years total) from the common practice of 5 years, the net present values from the modelled plantations would increase by about 1.57 times and 4.24 times respectively. The reasons why smallholder grower are not responding to these apparent higher present values and policies that would promote long rotation age plantations are discussed.

The silicon industry is an energy-intensive industry with high energy operating costs and is currently facing new challenges to improve sustainability and become more competitive. Petroleum coke, coal, and charcoal are typically utilized as carbonaceous reductants for silicon production, and the mixture of different carbonaceous materials plays a very important role in the specific power consumption and the exergy efficiency of the process. Of these materials, in particular, charcoal preparation requires large amounts of wood, and continued and extensive deforestation contributes to ecological damage. Thus, it is urgent to study carbonaceous reductants that can be alternatives to charcoal or to find strategies that do not require the application of charcoal in the silicon production process. Exergy efficiency was used as an overall indicator to evaluate the effect of different carbon materials on the process of silicon production in this study. An exergetic efficiency of 0.39 was obtained for silicon produced with a mixture of woodchips and no charcoal. The overall exergy efficiency and the silicon yield exergy indicator results indicated that the addition of woodchips to a mixture of carbonaceous materials improved the performance of the silicon furnace, even if the fixed carbon contribution was lower. There was no change in exergetic efficiency (0.33) for the mixture of petroleum coke and coal as carbonaceous materials with or without charcoal and woodchips. Therefore, a mixture of petroleum coke and coal without charcoal can be used as carbonaceous reductants while maintaining the exergetic efficiency of the process of silicon production.

Forestry thinning logs, a low-value by-product of the forestry industry, present an opportunity for bioenergy production. It can be converted into solid, liquid, and gaseous fuels via different conversion techniques. Comparative life cycle assessment and life cycle costing (LCC) analysis were conducted to evaluate six options: woodchip gasification for power generation; wood pellets gasification in combined heat and power plant; wood pellet combustion for domestic water and space heating; pyrolysis for power generation; pyrolysis with bio-oil upgrading to transportation fuels; and ethanol production for transportation fuel mix. The functional unit used in this study was the treatment of 1 Mg of biomass. Global warming; acidification; eutrophication; fossil depletion, human toxicity; and land use impact categories were considered. The LCC also included greenhouse gas (GHG) emissions costs. The effects of uncertainties in the system on the overall performance of the scenarios were also evaluated. The results showed that all options except for ethanol production are GHG emission negative. Woodchips gasification performed best in all environmental impact categories and had the lowest LCC ($177.6/Mg). Biomass drying consumed more than 50% of the energy requirement for all options except for production of liquid transportation fuels via upgrading of pyrolytic oil, in which case the fuel upgrading process was the most energy intensive. In terms of energy return, all options, except electricity production through pyrolysis, offered positive return. The results highlight the importance of using biomass with least possible processing in order to maximise environmental and energy return and minimise LCC.

The objective of this study is to perform a comparative estimation of the life cycle environmental performance of biochar from woodchip pyrolysis, and woodchip combined heat and power production. The wood processing industry draws up over 14% of the whole industrial sector turnover, making the wood industry one of the most valuable players in the Latvian economy. Woodchips are valuable logging residues integrated in the energy sector. The environmental performance is analyzed through the Life Cycle Assessment (LCA). LCA is performed according to the methodology described in the ISO 14040:2006 standards using the SimaPro 8.1.0.60 software and the Ecoinvent 3.1. database.

Woodchip is widely used as fuel in dedicated biomass and, even in some conventional energy generation plants. However, there are concerns about atmospheric air pollution from flue gases emitted during wood biomass combustion, particularly oxides of nitrogen (NOx) and particulates

Woodchip bioreactors (WBRs) are increasingly being applied to remove nitrate from runoff. In this study, replicate columns with aged woodchips were subjected to a range of measured flow rates and influent nitrate concentrations with an artificial stormwater matrix. Dissolved oxygen (DO), nitrate, and dissolved organic carbon (DOC) were measured along the length of the columns. A multispecies reactive transport model with Michaelis-Menten kinetics was developed to explain the concentration profiles of DO, nitrate, and DOC. Four additional models were developed based on simplifying assumptions, and all five models were tested for their ability to predict nitrate concentrations in the experimental columns. Global sensitivity analysis and constrained optimization determined the set of parameters that minimized the root-mean-squared error (RMSE) between the model and the experimental data. A k-fold validation test revealed no statistical difference in RMSE for predicting nitrate concentrations between a zero-order model and the other multispecies reactive transport models tested. Additionally, the multispecies reactive transport models demonstrated no significant differences in predicting DO and DOC concentrations. These results suggest that denitrification in an aged woodchip bioreactor at constant temperature can effectively be modeled using zero-order kinetics when nitrate concentrations are2 mg-N L

The environmental legislation and strict enforcement of environmental regulations are the tools effectively used for developing the market of materials for environmental protection technologies. Sustain ability criteria shift environmental engineering systems to more sustainable-material-based technologies. For carbon-based medium materials in biofiltration, this trend results in attempts to use biochar for biofiltration purposes. The paper presents the analysis of biochar properties based on the main criteria for biofiltration medium integrating the environmental quality properties of biochar, following the European Biochar Certificate guidelines. Three types of biochar produced from feedstock of highly popular and abundant types of waste are analysed. A multi component approach was applied to summarize the results. The lignocellulosic type of biochar was found to be more competitive for use as a biofiltration medium than the types of biochar with high ash or lignin content. (C) 2016 Elsevier Ltd. All rights reserved.

The possibility of using construction and demolition (C&D) waste wood as a bulking material in biosolids composting was investigated. Potential contaminants in C&D waste wood include arsenic (As), chromium (Cr), and copper (Cu) from treated wood, and lead (Pb) from paints. Untreated and treated woodchips from C&D wood were mixed with biosolids, composted using an aerated static pile process, and cured. There were no significant differences between untreated and treated woodchips with respect to composting process, time to stability, or product quality. Composting parameters monitored included moisture content, pH, electrical conductivity, organic matter degradation, fecal coliform levels, and stability by respirometry. Finished compost quality was evaluated in terms of potential toxic elements (PTE) levels. PTE values in treated woodchips (26 ± 35, 29 ± 41, 56 ± 46, and 5 ± 5 µg·g−1 for As, Cr, Cu, and Pb, respectively) were higher and more variable than those in the untreated woodchips (3 ± 3, 17...

Woodchip is preferred to other biomass forms because it offers benefits in terms of load density and uniform sizes. Until now, many studies have been focused on woodchip: comminution wood productivity, the environmental impact of chipping operations, woodchip transportation, woodchip storage techniques, but few have been done on woodchip loading. The goal of this work was to evaluate the working time, productivity and work quality for four types pf loader used in woodchip loading. Front loaders and knuckle-boom loader were tested. The highest productivity was observed for a mechanical shovel equipped with a high dump bucket (303 m3 h-1) when handling woodchips to be stored in piles near a wall, while the lowest working rate was achieved by a wheeled loader with a clamshell bucket (176 m3 h-1) in the same work conditions. Frontal loaders storing woodchip in a pile near a wall showed a 12% increase in productivity. Independently of the pile position, the agricultural telescopic loader showed good performance (about 240 m3 h-1). All loaders achieved a good work quality, with the amount of ground losses always lower than 2 m3 (2% of load). From this study it is found that agricultural telescopic loaders equipped with a hinged bucket are the right machine for woodchip loading.

Transportation and storage are two mainly critical operations of biomass supply chain because the transport must be performed using specific trucks, while in storage large areas are required. The goal of this work is to evaluate if the woodchip stored in pressed bales wrapped with waterproof sheets, as well as being a viable solution to reduce the storage area, is also a valid storage technique. The study was carried out in northwest Italy whereby pressed bales made of woodchip produced by two different tree species (poplar and black locust) were stored by two different methods (covered and uncovered). During the whole storage period the internal temperature values of bales were similar to air temperature values in all storage systems. Furthermore, no significant variations were obtained from two tree species tested between initial and final values of moisture contents (55% for poplar and 44% for black locust) and LHV (7.92 MJ kg− 1 for black locust and 7.04 MJ kg− 1 for poplar). This storage method, although it does not allow an adequate woodchip drying, could be considered an acceptable alternative to other storage techniques because it does not show losses in terms of energy and dry matter for a period of two years.

The high amount of energy consumed during the processing of biomass inflates the production cost of bio-fuels and bio-products. This study was therefore carried out to evaluate the influence of drying and grinding sequence on biomass energy consumption and properties (specific grinding energy requirement, specific drying energy requirement, particle size distribution, bulk density, tap density, aspect ratio, and flow index of grinds). Among the six drying-grinding sequences (12-S, 30-S, 50-S, 30-L-12-S, 50-L-12-S, and 50-L-30-S), sequence 50–S had the lowest geometric mean diameter and sequence 30–S had the highest geometric mean diameter. Drying-grinding sequence significantly affected the bulk density and tap density of grinds. The bulk density of grinds varied from 267.1 kg/m3 (sequence 12-S) to 98.0 kg/m3 (sequence 50-S) while the tap density ranged from 342.6 kg/m3 (sequence 12-S) to 153.7 kg/m3 (sequence 50-S). This variation in the densities followed the changes the particle morphology and aspect ratio distribution. A trade-off was noted between specific grinding energy requirement and specific drying energy requirement. The grinding of samples at higher moisture content consumed higher grinding energy than the grinding of samples at lower moisture content. Moisture loss during grinding however increased as the moisture content of woodchips increased, hence resulted in lower drying energy requirements. The least specific drying energy consumption was (1581 kJ/kg d.b.) for sequence 50-S and the highest specific drying energy consumption was (3933 kJ/kg d.b.) for sequence 12-S.

The effect of airflow rate, biomass moisture content, particle size, and compactness on the surface properties of biochar produced in a top-lit updraft gasifier was investigated. Pine woodchips were studied as the feedstock. The carbonization airflow rates from 8 to 20 L/min were found to produce basic biochars (pH &gt, 7.0) that contained basic functional groups. No acid functional groups were presented when the airflow increased. The surface charge of biochar at varying airflow rates showed that the cation exchange capacity increased with airflow. The increase in biomass moisture content from 10 to 14% caused decrease in the pH from 12 to 7.43, but the smallest or largest particle sizes resulted in low pH, therefore, the carboxylic functional groups increased. Similarly, the biomass compactness exhibited a negative correlation with the pH that reduced with increasing compactness level. Thus, the carboxylic acid functional groups of biochar increased from 0 to 0.016 mmol g&minus, 1, and the basic functional group decreased from 0.115 to 0.073 mmol g&minus, 1 when biomass compactness force increased from 0 to 3 kg. BET (Brunauer-Emmett-Teller) surface area of biochar was greater at higher airflow and smaller particle size, lower moisture content, and less compactness of the biomass.

Increased fish pond production is associated with the generation of various waste including fish pond sediments. Fish pond sediments could be a valuable source of nutrients for growing plants, however they require further processing in order to be applied to soil. Composting is considered one of the methods for processing fish pond sediments. The aim of this work was to investigate the potential of organic fish pond sediments to be managed through laboratory composting with selected waste materials and evaluate the fertilizing potential of the obtained compost. The scope included: (1) analysis of organic fish pond sediments, (2) laboratory composting of organic fish pond sediments with wheat straw and green grass, (3) analysis of the obtained composts, (4) preparation of growing media with selected additives, (5) analysis of the properties of the prepared growing media and (6) analysis of the effect of the investigated growing media on the growth ofPhaseolus vulgaris L.in pot experiments. The addition of cardboard waste and woodchips derived biochar to the obtained compost improved significantly the growth of the roots ofCardamine L. Also, the content of carbon and nitrogen in the compost mixtures increased. The addition of M1 (compost from organic fish pond sediments and 1% of biochar) to the soil had a significant impact on the growth of white beans.Graphic Abstract

This work aimed to study the changes in the physicochemical properties of biochars induced by post-pyrolyzed particle size processing. Twelve distinct physicochemical attributes of four different particle sized biochars,derived from three different feedstocks, including rice husk, tea wastes and woodchips; were investigated. Amongst all of the investigated characteristics water repellency (η2 = 0.99) and mean pore diameter (η2 = 0.95)were the characteristics most affected by feedstock type and particle size, respectively. The interaction effect between biochar type and particle size was extremely significant (P < 0.001) for surface area and mean porediameter. While feedstock mainly controlled biochar characteristics, most characteristics were also particle size dependent, where size dependency was more influential on physical than chemical properties. For most properties a significant interaction effect between biochar type and particle size was also detected. Refereed/Peer-reviewed

Pyrolysis conditions in charcoal production affect yields, properties, and further use of charcoal. Reactivity is a critical property when using charcoal as an alternative to fossil coal and coke, as fuel or reductant, in different industrial processes. This work aimed to obtain a holistic understanding of the effects of pyrolysis conditions on the reactivity of charcoal. Notably, this study focuses on the complex effects that appear when producing charcoal from large biomass particles in comparison with the literature on pulverized biomass. Charcoals were produced from woodchips under a variety of pyrolysis conditions (heating rate, temperature, reaction gas, type of biomass, and bio-oil embedding). Gasification reactivity of produced charcoal was determined through a thermogravimetric analysis at an isothermal condition of 850 °C and 20% of CO₂. The charcoals were characterized for the elemental composition, specific surface area, pore volume and distribution, Raman spectroscopy, and inductively coupled plasma optical emission spectrometry. The analysis results were used to elucidate the relationship between the pyrolysis conditions and the reactivity. Heating rate and temperature were the most influential pyrolysis parameters affecting charcoal reactivity, followed by reaction gas and bio-oil embedding. The effects of these pyrolysis conditions on charcoal reactivity could primarily be explained by the difference in meso- and macropore volume, and the size and structure order of aromatic clusters. The lower reactivity of slow pyrolysis charcoals also coincided with its lower catalytic inorganic content. The reactivity difference between spruce and birch charcoals appears to be mainly caused by the difference in catalytically active inorganic elements. Contrary to pyrolysis of pulverized biomass, low heating rate produced higher specific surface area compared with high heating rate. Furthermore, the porous structure and the reactivity of charcoal produced from woodchips were influenced when the secondary char formation was promoted, which cannot be observed in pyrolysis of pulverized biomass.

The valorization of residual biomass plays today a decisive role in the concept of &ldquo, circular economy&rdquo, according to which each waste material must be reused to its maximum extent. The collection and energy valorization at the local level of biomass from forest management practices and wildfire prevention cutting can be settled in protected areas to contribute to local decarbonization, by removing power generation from fossil fuels. Despite the evident advantages of bioenergy systems, several problems still hinder their diffusion, such as the need to assure their reliability by extending the operating range with materials of different origin. The Italian project &ldquo, INNOVARE&mdash, Innovative plants for distributed poly-generation by residual biomass&rdquo, funded by the Italian Ministry of Economic Development (MISE), has the main scope of improving micro-cogeneration technologies fueled by biomass. A micro-combined heat and power (mCHP) unit was chosen as a case study to discuss pros and cons of biomass-powered cogeneration within a national park, especially due to its flexibility of use. The availability of local biomasses (woodchips, olive milling residuals) was established by studying the agro-industrial production and by identifying forest areas to be properly managed through an approach using a satellite location system based on the microwave technology. A detailed synergic numerical and experimental characterization of the selected cogeneration system was performed in order to identify its main inefficiencies. Improvements of its operation were optimized by acting on the engine control strategy and by also adding a post-treatment system on the engine exhaust gas line. Overall, the electrical output was increased by up to 6% using the correct spark timing, and pollutant emissions were reduced well below the limits allowed by legislation by working with a lean mixture and by adopting an oxidizing catalyst. Finally, the global efficiency of the system increased from 45.8% to 63.2%. The right blending of different biomasses led to an important improvement of the reliability of the entire plant despite using an agrifood residual, such as olive pomace. It was demonstrated that the use of this biomass is feasible if its maximum mass percentage in a wood matrix mixture does not exceed 25%. The project was concluded with a real operation demonstration within a national park in Southern Italy by replacing a diesel genset with the analyzed and improved biomass-powered plant and by proving a decisive improvement of air quality in the real environment during exercise.