Woody Waste Research Articles

Biochar mitigation potential in Norway estimated by IPCC Tier 1 and Tier 2 methods

Biochar is a recalcitrant carbon-rich solid produced by pyrolysis of organic residues, and its application to soil is considered a promising approach to mitigate climate change, as biochar resists decomposition to readily contributes to soil carbon (C) sequestration. The IPCC provides a basis for future national-scale accounting of the changes in soil C stocks following biochar application to cropland soils. The IPCC Tier 1 approach for biochar is based on fixed emission factors to estimate biochar C sequestration. In contrast, the Tier 2 approach allows countries to use local emission factors and climate data to calculate the contribution of biochar to soil C sequestration. Accurate accounting of biochar C sequestration is essential for ensuring the credibility of C offsetting projects, as well as providing incentives for implementing biochar in C credit schemes, calling for comparative analyses of the different biochar Tier approaches. Here we retrieved biochar samples from local producers and measured their H/Corg to estimate the persistence of biochar in Norwegian croplands post application. Various feedstocks were considered, including forest residues, woody wastes, manure, sludge, and straw. For all biochar samples, the 100-year stable C fraction was calculated at ≥ 0.945, thus exceeding the default Tier 1 value (0.8). Biochar sourced from woody- and forestry residues had a Corg content above the default Tier 1 value (0.77). Based on this and data about national feedstock supplies, we compared the theoretical potential of biochar soil C sequestration to mitigate climate change in Norway, using the IPCC Tier 1 and Tier 2 approaches. Biochar C sequestration in soil was calculated at 0.79 Tg CO2-eq yr−1 and 0.92 to 0.96 Tg CO2-eq yr−1, respectively for the Tier 1 and Tier 2 approaches, thus, underlining that the choice of IPCC Tier approach can have a large impact on the estimated mitigation potential of biochar.

Hydrothermal carbonization of woody waste: Changes in the physicochemical properties and the structural evolution mechanisms of hydrochar during this process

The Chinese medicine residue (CMR) is composed of wet woody waste, including licorice and ephedra, so using hydrothermal carbonization (HTC) to recover renewable energy from the CMR is a suitable treatment method. An in-depth analysis of the physicochemical properties and structural evolution mechanism of hydrochars is helpful in fundamentally promoting the energy utilization of traditional Chinese medicine waste residue. Therefore, this study analyzed the physicochemical properties and morphological structure of hydrochar produced under varying HTC conditions using multiple testing methods. The evolution of the hydrochar's structural characteristics can be categorized into three stages: component decomposition, structural rearrangement, and carbonization. During the component decomposition and carbonization stages, numerous nanoscale micropores form within the hydrochar. These micropores' specific surface area and pore volume can reach up to 113.420 m2/g and 0.01913 cm3/g, respectively. The highest fractal dimension values for D1 and D2 are 2.6354 and 2.5565, while the maximum values for the microcrystalline stacking height (Lc) and the average number of crystalline layers (Nave) are 0.3354 and 1.9968, respectively. Consequently, the hydrochar produced during these stages exhibits a rougher pore surface and a more complex structure, making it more suitable for adsorbing heavy metals from soil and sequestering CO2. During the structural rearrangement stage, the hydrochar exhibits higher contents of fixed carbon (FC), MgO, P2O5, and a higher C/N atomic ratio, with maximum values of 38.51%, 0.99%, 1.12%, and 28.49, respectively. Thus, the hydrochar produced during this stage is more suitable for soil remediation and nutrient recovery.

Impact of the blending of kaolin on particulate matter (PM) emissions in a biomass field-scale 250 kW grate boiler

The aim of the study was to investigate the impact of adding kaolin on the partitioning of chemical elements in the particulate matter (PM) when virgin and waste woody biomass fuels were fired in a 250 kW grate boiler. A comprehensive analysis of the chemical compositions of the PM has been conducted, including alkali and non-volatile species, size-fractionated mass concentrations and micromorphology images. The results showed that the PM emission levels were significantly decreased by approximately 70–76 % and 60–66 % after the addition of kaolin to virgin wood (VW) and grade A recycled wood (RW), respectively, which inhibited the partitioning of the alkali species into fine and ultrafine PM. On the other hand, the concentration of the non-volatile elements, SiO2 and Al2O3, significantly increased in the PM emissions after the addition of kaolin due to the adhesion and aggregation of particulates between airborne kaolin and the fine and ultrafine PM. Moreover, the addition of the kaolin at 1.55 wt% showed comparable effects with that at 2.5 wt% on the chemical composition of PM emission. Furthermore, the SEM morphology suggested that KCl salts were diminished after the addition of the kaolin. These findings demonstrate the practicality of adding kaolin to mitigate PM emissions and their impacts in actual biomass combustion scenarios.

Структурные особенности коренных сосняков северной и средней тайги при пирогенных воздействиях

The study of indigenous pine forests of evolutionary formation as endangered virgin forests is the basic for fundamental research into the processes of formation of sustainable forest communities. The aim of the study presented in the article is a comparative assessment of the structures of tree fractions of phytocenoses according to the parameters of the age series of stands and the successional position, dynamic indicators of woody waste, the influence of the pyrogenic factor, and the presence of rot damage to the stands. Age structures, numerical and linear parameters of pyrogenic factors, their impact on the infestation of trees with rot, volumetric indicators of wood waste and characteristics of natural regeneration, the mass of wood xylolysis products during its decomposition by wood-destroying fungi have been studied in pine biogeocenoses with various dynamic characteristics in the taiga zone of European Russia. Pine biogeocenoses under these conditions have structures of different ages, altered by fires of different types. Using the example of an indigenous pine forest in the Pechora-Ilychskiy Nature Reserve (middle taiga), the influence of pyrogenic effects on the formation of various types of rot and damage to trunks is shown. The volumes of woody waste are distributed according to the stages of decomposition in pine forests with different structural and dynamic characteristics; pine undergrowth – according to height gradations. An example is given of calculating the mass of wood components deposited in the stands and released during the decomposition of woody waste by wood-destroying fungi for the biogeocenosis of the Pechora-Ilychskiy Nature Reserve. The majority of indigenous pine forests in the northern territories have been affected by fires of varying intensity and types, sometimes several times during a development cycle. Pyrogenic effects have a significant on changes in the age structures of pine forests, damage to their trunks, the general infestation of forest stands by wood-destroying fungi of the biotrophic complex, the volumes of woody waste, and the formation of natural regeneration structures.

Combustion Efficiency of Various Forms of Solid Biofuels in Terms of Changes in the Method of Fuel Feeding into the Combustion Chamber

This study analyzes the combustion of pellets and briquettes made of plant biomass in low-power heating devices powered periodically with fuel being placed on the grate, as well as after modification using an automatic fuel feeding system in the gutter burner. The use of herbaceous biomass in the form of pellets in low-power heating devices with automatic fuel feeding and combustion in a gutter burner is not widely promoted and popular. Therefore, this study used four types of herbaceous waste biomass (wheat straw, rye straw, oat straw and hay) and one type of woody waste biomass (birch sawdust) for testing. The basic chemical characteristics were determined for the raw materials. After appropriate preparation, the selected starting materials were subjected to briquetting and pelleting processes. Selected physical properties were also determined for the obtained biofuels. Biofuels made from birch sawdust had the lowest heat value (16.34 MJ·kg−1), although biofuels made from wheat, rye and hay straw had a slightly lower calorific value, respectively: 16.29; 16.28 and 16.26 MJ·kg−1. However, the calorific value of oat straw biofuels was only 15.47 MJ kg−1. Moreover, the ash content for herbaceous biomass was 2–4 times higher than for woody biomass. Similar differences between herbaceous and woody biomass were also observed for the nitrogen and sulfur content. To burn the prepared biofuels, a domestic grate-fired biomass boiler was used, periodically fed with portions of fuel in the form of pellets or briquettes (type A tests), which was then modified with a gutter burner enabling the automatic feeding of fuel in the form of pellets (type B tests). During the combustion tests with simultaneous timing, the concentration of CO2, CO, NO and SO2 in the exhaust gases was examined and the temperature of the supplied air and exhaust gases was measured. The stack loss (qA), combustion efficiency index (CEI) and toxicity index (TI) were also calculated. The research shows that the use of automatic fuel feeding stabilizes the combustion process. The combustion process is balanced between herbaceous and woody biomass biofuels. Disparities in CO2, CO and Tgas emissions are decreasing. However, during type B tests, an increase in NO emissions is observed. At the same time, the research conducted indicates that the combustion of herbaceous biomass pellets with their automatic feeding into the combustion chamber is characterized by an increase in combustion efficiency, indicating that when the combustion process is automated, they are a good replacement for wood biofuels—both pellets and briquettes.

Co-liquefaction of α-cellulose and phycocyanin: A preliminary study

Hydrothermal liquefaction (HTL) is an efficient technology for converting biomass to platform compounds. It has great potential for reducing the dependence on fossil fuels. The HTL of waste biomass has been extensively studied in recent years due to both its environmental and economic benefits. However, most woody waste contains a large amount of cellulose, and it is difficult to be sufficiently decomposed to valuable chemicals. Phycocyanin, a key component of algae, is easily degraded under high-temperature liquefaction conditions. In this work, focusing on bio-oil generation properties, the co-liquefaction characteristics and synergistic mechanisms of α-cellulose and phycocyanin were explored. The findings revealed a maximum bio-oil yield of 33.1 wt% under the optimal conditions (300 °C for 40 min), with a notable positive synergistic effect of 13.5 wt%. Chemical composition analysis indicated distinct compositional differences between the bio-oils derived from individual and dual feedstock. The amounts of pyridine and pyrimidine compounds increased due to the enhanced co-liquefaction. The results also highlighted the influence of temperature on the degree of conversion and product distribution. Finally, preliminary chemical reaction pathway was elucidated, underscoring the potential of integrating microalgae and woody biomass for enhanced bio-oil production.

Biochar from co-pyrolysis of biological sludge and woody waste followed by chemical and thermal activation: end-of-waste procedure for sludge management and biochar sorption efficiency for anionic and cationic dyes

Nine biochars were produced by co-pyrolysis of sawdust and biological sludge following the “design of experiment” approach. Two kinds of sludge (both deriving from the treatment of mixed industrial-municipal wastewater) and two types of woody waste were selected as categorical predicting variables, while contact time, pyrolysis temperature, and sludge percentage were used as quantitative variables. Biochars were analysed for their product characteristics and environmental compatibility based on the European Standards (EN 12915–1:2009) for materials intended for water treatment (i.e. ash content, water leachable polycyclic aromatic hydrocarbons (PAHs) and elements), as well as for specific surface area (SSA), using them as response variables of a multivariate partial least square multiple regression, whose results provided interesting insights on the relationships between pyrolysis conditions and biochar characteristics. Biochars produced with sludge and/or providing the highest SSA values (258–370 m2 g−1) were selected to undergo a sustainable chemical treatment using a by-product of the gasification of woody biomass, complying in all cases with European Standards and achieving therefore the end-of-waste status for sewage sludge. The biochar deriving from the highest percentage of sludge (30% by weight) and with the highest SSA (390 m2 g−1) was thermally activated achieving SSA of 460 m2 g−1 and then tested for the sorption of direct yellow 50 and methylene blue in ultrapure water and real wastewater, compared to a commercial activated carbon (AC). The biochar showed Langmuir sorption maxima (Qm) 2–9 times lower than AC, thus highlighting promising sorption performances. Qm for methylene blue in wastewater (28 mg‧g−1) was confirmed by column breakthrough experiments.

An Overview of Microwave Assisted Pyrolysis for Waste Management, with Some Thoughts about Processing Industrial Hemp and Other Woody Wastes

The generation of waste is significantly influenced by the increase in population and industrialization, thereby compelling the increased demand for waste management and resource recovery. This paper investigates the potential opportunities presented by the utilization of microwave-assisted pyrolysis for processing plastic and organic waste materials, with a particular focus on industrial hemp leaves, hurds, and root materials, and other feedstocks. Drawing from a range of published studies, it is suggested that microwave-assisted pyrolysis has the potential to achieve energy neutrality or even energy generation, if all byproducts are used. Depending on factors such as recoverable volumes and the associated recovery costs of commercially significant chemicals like vinegars and bio-oils, the microwave-assisted pyrolysis of industrial hemp leaves, hurds, and root materials may prove to provide high return of the yield and profits. Additionally, this paper explores the production of other valuable byproducts such as syngas and biochar from alternative feedstocks, particularly when data related to hemp processing is not readily available.

Lignin-derived carbon quantum dot/PVA films for totally blocking UV and high-energy blue light

Excessive exposure to UV and high-energy blue light (HEBL) can cause fatal eye and skin injuries. As a result, it is crucial to protect our bodies from UV and HEBL radiation. To achieve complete blocking of UV and HEBL, we developed a lignin-derived carbon quantum dot (L-CQD)/polyvinyl alcohol (PVA) film. L-CQD was synthesized from lignin, a waste woody biomass, and then blended with a PVA matrix to create a flexible L-CQD/PVA film. Thanks to simultaneous UV and HEBL absorption characteristics and bright color of L-CQD, the PVA film with 0.375 wt% L-CQD demonstrated outstanding blocking efficiency: 100 % in UV-C, UV-B, and UV-A, and at least 99.9 % in HEBL. It also exhibited a 44 % increase in lightness and a 12 % enhancement in transparency compared to lignin/PVA film. The film's ability to block UV and HEBL was further demonstrated by reducing >40 % UV-induced ROS formation in both cancerous and normal cell lines (Hs 294T, HeLa, CCD-986sk, and L929), as well as by blocking blue laser diode (LD) and LED. Since the L-CQD/PVA film is simple to produce, environmentally friendly, flexible, and thermally stable, it is suitable for use as a protective coating against sunlight and harmful emissions from IT devices.

Estimation of Forest Residual Biomass for Bioelectricity Utilization towards Carbon Neutrality Based on Sentinel-2A Multi-Temporal Images: A Case Study of Aizu Region of Fukushima, Japan

Forest biomass is expected to remain a key part of the national energy portfolio mix, yet residual forest biomass is currently underused. This study aimed to estimate the potential availability of waste woody biomass in the Aizu region and its energy potential for local bioelectricity generation as a sustainable strategy. The results showed that the available quantity of forest residual biomass for energy production was 191,065 tons, with an average of 1.385 t/ha in 2018, of which 72% (146,976 tons) was from logging residue for commercial purposes, and 28% (44,089 tons) was from thinning operations for forest management purposes. Forests within the biomass–collection radius of a local woody power plant can provide 45,925 tons of residual biomass, supplying bioelectricity at 1.6 times the plant’s capacity, which could avoid the amount of 65,246 tons of CO2 emission per year by replacing coal-fired power generation. The results highlight the bioelectricity potential and carbon-neutral capacity of residual biomass. This encourages government initiatives or policy inclinations to sustainably boost the production of bioenergy derived from residual biomass.

Effects of combined application of biochar and sludge compost on seeds germination of oil sunflower (Helianthus annuus L.) and water retention capacity in two different soils

Biochar (BC) and sludge compost (SC) have attracted extensive attention because of their multiple benefits in improving soil quality and functionality. However, the effects of combined application of BC and SC on plant growth and soil properties in different soils are unclear. In this study, a woody waste derived BC and a sludge compost from a commercial factory were applied into an agricultural soil and a salt-affected soil collected from the Yellow River Delta to investigate their effects on the germination of oil sunflower seeds (Helianthus annuus L.) and water retention capacity in the two soils using pot experiments. The results showed that the combined application of BC and SC increased the germination potential of oil sunflower seedlings in the farmland soil and salt-affected soil by 2.00–11.00 times and 0.50–5.00 times, respectively. This is because the BC and SC can collaboratively improve soil physical and chemical properties and increased nutrient availability. Additionally, BC and SC increased the maximum water holding capacity (WHC) of two soils by 3.72–18.80%. These results will provide theoretical basis and technical support for the development of biochar technology to remediate degraded and agricultural soil, thus to ensure the sustainable development of agriculture.

A concise review of technologies for converting forest biomass to bioenergy

The use of biomass is vital in reducing the negative effects of rising fossil fuel consumption. Given its quantity and diversity, forest biomass has garnered a lot of interest among the many kinds of biomass. This study evaluates the various strategies for transforming woody waste into usable biofuels. Carbon dioxide emissions from traditional energy generation systems could be mitigated through the direct utilization of forest biomass. Low energy conversion rates, as well as soot emissions and residues, are some of the problems that come up when directly using forest biomass. The sustainability of direct energy generation from forest biomass is also seriously threatened by the lack of constant access to biomass. Co-combustion with coal and pelletizing biomass is two solutions proposed for this issue. Co-combustion of forest biomass with coal has the potential to lower the process's emissions of carbon monoxide, nitrogen oxides, and sulfides. This article reviews and discusses the biochemical and thermochemical mechanisms that can transform forest biomass into a variety of liquid and gaseous biofuels. Future research using cutting-edge sustainability assessment tools like life cycle assessment, exergy, etc. should investigate the sustainability of forest biomass conversion processes to bioenergy further.

Effect of wood gasification biochar on soil physicochemical properties and enzyme activities, and on crop yield in a wheat-production system with sub-alkaline soil

Biochar may have beneficial effects on soil depending on its properties and pedoclimatic conditions. Highly sloping soils are prone to erosion and organic matter depletion, and biochar can be useful to restore soil fertility and quality, and crop yields. To test the effect of wood gasification biochar (WGB), we conducted a field experiment applying 0 and 60 Mg ha−1 of WGB only (no fertilizer) to a sub-alkaline and fine-textured soil under Mediterranean climate conditions. The effect of WGB on the soil physicochemical properties and on 12 enzyme activities involved in the C, N, P, and S cycles was monitored during a wheat-growing season along with its effect on grain yield. The results show that WGB was rather recalcitrant, and the application of a high dose of it had no effect on most of the soil physicochemical properties, enzyme activities and wheat grain yield. Since enzyme activities involved in the C cycle were similar in WGB-treated and not-treated soils, WGB failed to stimulate organic matter mineralization during the monitored period, with no contribution to N and P supply. Since WGB can contribute to soil C stock with no detrimental effects on wheat yield, wood gasification can allow recycling waste woody materials of urban origin to produce energy and return biochar back to agricultural soils. We suggest that future studies on WGB focus on the effect of its aging in soil on soil physicochemical and biochemical properties, and on crop performances.

Co-firing of coal and woody biomass under conditions of reburning technology with natural gas

It is a continuous imperative to establish the most efficient process of conversion of primary energy from fuel through combustion, which also has the least possible harmful effect on the environment. In this time of expressed demands for decarbonisation, it also means the affirmation of the use of renewable fuels and the indispensable application of appropriate primary measures in the combustion furnace. At the same time, the efficiency of the combustion process depends on several factors, from the type and properties of the fuel to the ambient and technological settings for the process. In this regard, with the aim of determining the static characteristics of combustion, experimental laboratory research was carried out on the combustion of mixtures of brown coal with low heating value and a high ash content with waste woody biomass and different process conditions: temperature, staged combustion air supply (air staging) and in conditions of application of a third or additional fuel (natural gas, reburning technology). Applied experimental methods included the analysis of the combustion process on the basis of input (reactants) - output (products), including the analysis of the composition of flue gases, i.e. the determination of the emission of the key components of flue gases CO2, CO, NOx and SO2, as well as the analysis of the composition of slag, ash and deposits ash, i.e. assessment and evaluation of the behaviour of ash from fuel in that process. Based on the obtained research results, this paper shows the significant positive effects of the application of primary measures in the furnace - compared to conventional combustion: air staging - reduction of net CO2 emissions during co-firing with biomass and reduction of NOx emissions by up to 30%; reburning technology - additional reduction of CO2 and NOx emissions in proportion to the share of natural gas, e.g. at a combustion process temperature of 1350 °C and at a 10% energy share of natural gas during the co-firing of a mixture of brown coal and waste woody biomass, compared to the emission without the use of natural gas, a reduction of NOx emissions by 185 mg/mn3 or by almost 30% was recorded. It was concluded, at the same time, the application of these primary measures in the furnace does not negatively affect the behaviour of ash from the fuel in the given settings of the combustion process.

Experimental and numerical investigation on a solar-driven torrefaction reactor using woody waste (Ashe Juniper)

In this work, designs a novel solar-driven thermochemical conversion reactor to torrefy biomass waste (Ashe Juniper) for further pyrolysis applications. The effect of torrefaction temperature and residence time on the properties of biomass waste was investigated and results showed that torrefaction temperature dominates the properties of product compared to the effect of residence time. The highest energy yield (over 90%) was obtained at 210 ℃ while the highest energy densification (∼1.51) was achieved at 360 ℃. In addition, a two-step kinetic numerical model was used to analyze and predict the experimental process (kinetic rates) and results (C, H, and O contents) based on the experimental results. The analysis results showed that the predicted results are in good agreement with the practical results after torrefaction, indicating the feasibility of this numerical model for torrefaction and pyrolysis applications. The carbon footprint analysis showed that reduction effect of 1.3 ∼ 1.6 tCO2/ton-AJ can be obtained by torrefaction of Ashe Juniper. Finally, the prospects for future industrial applications of solar-driven torrefaction reactors discussed as one of affordable and clean energy.

Primjenom otpadne drvne biomase i Miscanthusa do održivog sektora termoenergetike u vremenu energetske tranzicije / Sustainable Energy Sector Using Waste Woody Biomass and Miscanthus in the Energy Transition

The thermal energy sector is very important at this time of global energy transition. From the aspect of stable energy independence, this is especially important in countries whose energy system is based on fossil fuels, especially coal. This is why decarbonisation of the energy sector is necessary, with a partial and gradual substitution of coal with renewable fuels. However, the use of these fuels is not always possible in existing plants. This refers to the establishment of energy, economic and environmentally acceptable proportion of the co-firing of these fuels, i.e. a mixture of coal and renewable fuels. The success of the establishment of this process is a function of several variables, the dominant of which are the aggregate properties of the fuel, basic and their mixtures, including the ash properties of those fuels. With the motive of contributing to a more successful implementation of the energy transition in the thermal energy sector, and with the aim of obtaining new scientific knowledge about the characteristics of the combustion of lignite and brown coal with different renewable fuels, laboratory research was carried out. In particular, different mixtures of lignite and brown coal, waste woody biomass and Miscanthus as a fast-growing energy crop were subjected to co-firing with variable process conditions. In addition to changing the composition of fuel mixtures, the test regimes included a significant change in process temperature (1250-1450 °C) and the primary measure of staged air supply to the furnace. In these combustion conditions, the emission of undesirable and harmful components into the environment, the efficiency of combustion, and the tendency of the ash from the fuel mixture to possible soiling of the heating surfaces in the furnace were evaluated - an analysis of the characteristics of the ash samples from the reaction zone and samples of the slag and ash to the furnace. Here, in both cases of co-firing, lignite and brown coal with different types of biomass, it was shown that in real conditions it is possible to establish a sustainable primary energy conversion process from fuel with a low unburnt carbon content in the slag (unburnt carbon content, UBC<1%) as well as low CO emission, below 350 mg/mn 3. At the same time, the NOx emission is below 320 mg/mn 3 during the co-firing of lignite mixtures at 1250 °C, and in the case of brown coal mixtures below 740 mg/mn 3 at 1450 °C. In both cases, the net CO2 emission decreases in proportion to the proportion of biomass in the mixture, while the SO2 emission is still high, at a level of up to 2500 mg/mn 3 for lignite mixtures and up to 6400 mg/mn 3 for brown coal mixtures. None of the treated types of biomass, up to the level of applicable content in the mixture with lignite and brown coal, does not worsen the progress of the process from the aspect of possible slagging/fouling heating surfaces in the boiler.

A Study on Applicability of Wood Flour Spacers Made from Woody Waste

Recently, the importance of wastepaper recycling has been emphasized and accordingly, several studies have been conducted to improve the quality of the Korean old corrugated container. A representative example is the application of wood flour-based organic fillers as the spacer. Therefore, if domestic woody waste, which is most commonly used as power plant fuels, can be applied to produce organic fillers, it is expected to become a new economic resource. In this study, we evaluated whether it is possible to manufacture wood flour from woody waste and use it as a spacer for papermaking. This study confirmed that if the wood flour made from woody waste is applied as the spacer for papermaking, the drying load can be reduced by the hydrophobic properties of lignin and securing bulk. In addition, from the analysis of the behavior of wood flour in the paper structure, the shape of the wood flour was found to bend after compression. Moreover, the wood flour was shown to adhere more flatly to the fibers or was located in-between, which minimized the interferences between fibers and stably increased the volume and the strength loss simultaneously. Based on the IR spectral analysis of the handsheets with wood powder being applied, it was confirmed that the intensity of the peaks weakened for the hydroxyl groups, such as OH bending and OH in-plane bending. Therefore, it can be concluded that the application of wood flour manufactured from unused forest resources can effectively increase the associated drying efficiency without chemical heterogeneity.

Effect of Ammoniated Fiber Explosion Combined with H2O2 Pretreatment on the Hydrogen Production Capacity of Herbaceous and Woody Waste.

An appropriate pretreatment process is an important part of the preparation of biomass energy from agricultural and forestry waste. Compared to physical and chemical pretreatments alone, the combined ammoniated fiber explosion (AFEX) + hydrogen peroxide (H2O2) pretreatment process can significantly improve the lignin degradation rate and saccharification efficiency, thus improving the hydrogen production capacity during medium-temperature dark fermentation. This study showed that the combined pretreatment increased the saccharification efficiency of herbaceous, hardwood, and softwood biomass by 58.7, 39.5, and 20.6% and the corresponding gas production reached 145.49, 80.75, and 57.52 mL/g, respectively. In addition, X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy showed that AFEX + H2O2 disrupted the structure of the feedstock and was more favorable for lignin removal. Soluble metabolites indicated that AFEX + H2O2 pretreatment enhanced the butyrate metabolic pathway of the substrate and biohydrogen generation and increased the levels of extracellular polymers and microbial community structure.

A review of converting woody biomass waste into useful and eco-friendly road materials

Abstract Because of abundant reserves and renewable and environmentally friendly properties, the utilization of woody biomass waste in road engineering can alleviate the shortage of fossil fuels and carbon emissions so as to mitigate global climate change and achieve sustainable development of road engineering. This paper synthesizes the state of the art about the strategies of applying five kinds of resources derived from waste woody biomass, including biochar, bio-oil, lignin, wood ash and nanocellulose to road construction. Based on the characteristics analysis of the five materials, it can be concluded that biochar can comprehensively improve the road performance of asphalt and its mixtures, and has the potential of runoff purification; bio-oil can soften asphalt and improve its low-temperature performance, but has negative effects on high-temperature performance; lignin increases the asphalt ageing resistance and can be used as a regenerant, and will improve the overall performance of asphalt mixtures if combined with other modifiers; wood ash can increase subgrade bearing capacity and bring significant environmental benefits; nanocellulose improves the strength of cement mortar, but there is a lack of research on its effects on performance of pavement materials and the interaction mechanism; the lifecycle environmental and economic assessment of woody biomass-modified road materials is not comprehensive. Moreover, prospects were also summarized to show the opportunities for future study, such as the establishment of a database for biomass. This review provides useful insights for the utilization of woody biomass as road materials to achieve waste management and sustainable development. Highlights • Reveal the characteristics of five kinds of materials derived from woody biomass wastes for use as road materials. • The effects of biochar, bio-oil, lignin, wood ash and nanocellulose on road material performance are summarized. • The use of woody biomass such as biochar and bio-oil in road materials contributes to reducing carbon emissions. • Existing problems and future research prospects about the woody biomass waste used in the road structure are put forward.

Investigating the Valorisation of Refused Derived Fuel for Energetic Uses Through Its Co-Gasification with Woody Wastes

The present study aimed to investigate the valorization of Refused Derived Fuel (RDF) produced from solid waste management units for energetic uses, through its co-gasification with agricultural or forest wastes and carbon dioxide agents. Experiments were conducted using a fixed bed reactor and a thermal analysis system. The thermal behavior, the reactivity, the conversion, and the cold gas efficiency up to 950°C were evaluated based on the structural characteristics and inherent minerals of