Search

The co-pyrolysis of paper mill sludge (PS) and biomass has attracted significant attention due to its potential for simultaneous resource utilization and waste disposal. In this work, the co-pyrolysis of PS with corn stover (CS) was carried out in a fixed bed reactor to investigate the effect of temperature and PS to CS ratio on the product characteristics. A comparison between the experimental and calculated values of product yield and composition was performed to obtain a deeper understanding of the synergistic interactions. The results exhibited a positive synergistic effect on bio-oil production at lower CS proportions with higher temperatures. Higher temperatures and lower CS proportions were favorable for the formation of aromatics (up to 45.03%) in co-pyrolysis, while the synergistic interactions promoted the production of phenols and exhibited an inhibitory effect on aromatics production. The interactions also inhibited H 2 but promoted CO production due to the enhanced decarbonylation of co-pyrolysis intermediates in the presence of PS internal minerals. Additionally, the characterization of biochars indicated an increasing degree of aromaticity with higher temperatures and CS proportions. The synergistic interactions at higher temperatures facilitated the development of pore structures in the biochar, especially micropores. This study provides valuable insights into the relationship between parameters, products, and synergies in the co-pyrolysis of PS and biomass wastes. [Display omitted] • A comprehensive study on the co-pyrolysis of paper sludge and corn stover was conducted. • Lower corn stover ratios with higher temperatures jointly promoted bio-oil yield. • The formation of phenols and CO was synergistically enhanced during co-pyrolysis. • Higher temperatures facilitated the development of micropores in the biochars. [ABSTRACT FROM AUTHOR]

Highlights • Superstructure of integrated biorefinery in pulp and paper industry was developed. • It includes pulping, biochemical production and black liquor utilization sections. • Lignocellulosic biomass extracted from eucalyptus and bagasse are the feedstocks. • Potential of integrated biorefinery process was illustrated in three scenarios. • Integrated succinic acid and lactic acid can improve profitability. Abstract This work aims at developing sustainable processes for pulp and paper industry by integration of the biorefinery concept to an existing pulp and paper process. A systematic methodology employing a superstructure-based process synthesis approach is employed with support from computer-aided tools to determine potential pathways for a long-term sustainable growth objective. A superstructure of the multi-product biorefinery process network for the pulp and paper industry is developed. It is divided into three sub-networks, a chemical pulping section, a biochemical production section and a black liquor utilization section. Superstructure optimization is performed with the objective to maximize profit to determine optimal integrated networks for three scenarios. The obtained results provide useful insights for further development of the optimal networks as sustainable integrated biorefinery combined with pulp and paper mills. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Paper sludge (PS), a by-product of paper mill wastewater treatment, has attracted increasing attention due to the dual nature of resources and pollution. This study focused on investigating the effect of temperature on the product properties and synergies of the co-pyrolysis process involving PS and corn stover (CS) using a fixed bed reactor. The results showed that co-pyrolysis led to an increase in the production of bio-oil, while reducing the formation of char and gases. Notably, the most significant synergistic effect was observed at 600 °C, where the experimental bio-oil yield surpassed the calculated value by 8.9%. At temperatures below 500 °C, ketones, aldehydes, and acids were the predominant products in the co-pyrolysis, which shifted towards phenols and aromatics as the temperature increased. Moreover, a promotion of CO content and an inhibition of CO 2 content with temperature were also observed during co-pyrolysis, suggesting that higher temperatures facilitated synergistic decarbonylation. The co-pyrolysis biochar exhibited a higher abundance of carbonyl and alkyl groups compared to the biochar derived from PS pyrolysis, and the synergistic effect at higher temperatures promoted the development of micropores within the co-pyrolysis biochar. These findings emphasize the temperature-dependent nature of the co-pyrolysis process, offering valuable insights into the potential resource utilization of PS and CS wastes. • Effect of temperature on paper sludge and corn stover co-pyrolysis were studied. • The most significant synergy for enhancing bio-oil production was observed at 600 °C. • Increasing temperature shifted low molecular compounds towards phenols and aromatics. • The synergy at higher temperatures promoted the development of micropores in biochar. [ABSTRACT FROM AUTHOR]

Abstract Studies on the influence of paper mill wastewater, which affects photosynthesis, on reed chlorophyll and biomass can provide a theoretical basis for the ecological restoration of wetland plants. The influence of different concentrations of wastewater (chemical oxygen demands (COD) of 300, 175 and 50 mg•L−1) and different irrigation times (germination, blade-expansion, rapid-growth, heading and maturity stages) on the contents of chlorophyll a , chlorophyll b , total chlorophyll and chlorophyll a /b in reeds were tested in experimental pools that simulated the wetland ecosystem of the Liaoning Shuangtai estuary. The contents of chlorophyll a , chlorophyll b , total chlorophyll and chlorophyll a /b all increased significantly with increasing concentrations of wastewater, and their contents all differed significantly from each other. The contents of chlorophyll a , chlorophyll b and total chlorophyll were maximal when irrigated at the beginning of all growth stages with COD of 300 mg•L−1(C 1 O) at 2.253, 0.458 and 2.711 mg•g−1 fresh weight (FW), respectively, with irrigation at the rapid-growth stage and were minimal in the control plants at 0.142, 0.068 and 0.210 mg•g−1 FW, respectively, with irrigation at maturity. Chlorophyll a /b was maximal at C 1 O at 5.753 with irrigation at germination stage and was minimal in the control plants at 2.113 with irrigation at maturity. Reed biomass was maximal at C 1 O at 3.26 kg, which was 2.76 times higher than the control. Reed biomass was positively correlated with the content of chlorophyll and with COD in the wastewater. Paper mill wastewater generally increased the content of chlorophyll and the net photosynthesis rate and enhanced the growth of reeds. Highlights • Different concentrations of wastewater and different irrigation times on the contents of chlorophyll in reeds were tested. • The contents of chlorophyll increased with increasing concentrations of wastewater, they contents differed from each other. • Reed biomass was positively correlated with chlorophyll content and the level of COD of the wastewater. • Paper mill wastewater increased the content of chlorophyll and the net photosynthesis rate of the reeds. • Paper mill wastewater enhanced the growth of the reeds. [ABSTRACT FROM AUTHOR]

Renewable biomass-based activated carbon fiber paper (ACFP) possesses a three-dimensional network porous structure for high-efficient toxic gas purification. However, intelligently building high catalytic activity biomass-based carbon materials with superior flexibility remains a significant challenge. Herein, a series of paper-based catalysts (MnO 2 /ACFP) with varying MnO 2 loadings were fabricated by combining MnO 2 -loaded ACF and softwood (Pinales) fiber via a wet-papermaking process. The precursor derives from abundant and green biomass, meanwhile, the channels of plant fiber facilitate gas flow and the effective dispersion of active sites. Noteworthy, the introduction of softwood fiber imparts flexibility to the catalyst, enabling it to be folded, wound, and bent without compromising mechanical strength, thus exhibiting excellent processability. Formaldehyde (HCHO) removal in a static system was applied to evaluate their reactivities. Among all, MnO 2 /ACFP-1.7 (12.22 wt% Mn) shows 100 % removal of HCHO in 1 h with a turnover frequency value of 0.01526 min−1, being more than 10 times that of the bulk MnO 2 particles. The underlying mechanism for the enhanced catalytic performance can be ascribed to the synergistic effect of its stronger gas capture ability together with more exposed active sites. This work provides insight into the design of a flexible and environmentally friendly catalyst for the degradation of organic contaminants. [Display omitted] • MnO 2 -loaded ACF and softwood fiber were combined by the wet-papermaking process. • This catalyst exhibits excellent flexibility and good air permeability. • It can be applied as a paper-based catalyst for HCHO oxidation. • This catalyst presents superior catalytic activity and excellent recycle stability. [ABSTRACT FROM AUTHOR]

Abstract The global demand for bio-plastic particularly polyhydroxyalkanoate (PHA) have been increased in the last few decades as a substitute of petrochemical-based plastic. Utilization of waste paper, the primary constituent of municipal solid waste (MSW), as a carbon source for polyhydroxybutyrate (PHB) production is not only an alternative, environmental friendly route of waste management but also helps to valorize the waste. In this study, hydrogen peroxide pretreated waste paper saccharification has been optimized using central composite design (CCD). The maximum hydrolysis (88.18%) occurred at paper loading 5.0 g/L, agitation 242 rpm, working volume 20%, cellulase 49.82 U/g, β-glucosidase 20.9 U/g and hemicellulase 29.5 U/g. PHB synthesis and biomass accumulation by xylose-utilizing Burkholderia sacchari using waste paper hydrolysate were studied using different nitrogen sources and carbon to nitrogen (C/N) ratios. Maximum PHB and dry cell weight (DCW) occurred with ammonium sulfate and a C/N ratio of 20. The highest biomass (3.63 g/L), the maximum PHB accumulation (44.2%) and the maximum reducing sugar utilization (92.1%) were observed after 48 h of cultivation using diluted hydrolysate. The physicochemical properties of the extracted PHB were compatible with the standard PHB. Hence, the waste paper could be exploited as a renewable feedstock for the sustainable production of PHB. Graphical abstract Image 1 Highlights • The maximum enzymatic hydrolysis 88.18% was achieved by response surface method. • PHB produced from waste paper hydrolysate using xylose utilizing B. sacchari. • Maximum PHB and dry cell weight occurred with (NH 4) 2 SO 4 and C/N ratio of 20. • High thermostability of PHB with a maximum degradation rate around ∼ 300 °C. • PHB production using waste paper is cost effective and ecofriendy approach. [ABSTRACT FROM AUTHOR]

• Novel application of sidehill screen to remove ash from paper sludge. • Study of screening parameters yielded high pilot scale performance. • Process simulation of plant scale valorization demonstrated technical feasibility. • Techno-economic analysis yielded financial feasibility for sludge valorization. Paper sludge biomass represents an underutilized feedstock rich in pulped and processed cellulose which is currently a waste stream with significant disposal cost to industry for landfilling services. Effective fractionation of the cellulose from paper sludge presents an opportunity to yield cellulose as feedstock for value-added processes. A novel approach to cellulose fractionation is the sidehill screening system, herein studied at the pilot-plant scale. Composition analysis determined ash removal and carbohydrate retention of both sidehill and high-performance benchtop screening systems. Sidehill screening resulted in greater carbohydrates retention relative to benchtop screening (90% vs 66%) and similar ash removal (95% vs 98%). Techno-economic analysis for production of sugar syrup yielded a minimum selling price of $331/metric ton of sugar syrup including disposal savings, significantly less than a commercial sugar syrup without fractionation. Sensitivity analysis showed that screening conditions played a significant role in economic feasibility for cellulosic yield and downstream processes. [ABSTRACT FROM AUTHOR]

The performance of an amine-based post-combustion CO 2 capture and storage (CCS) process in an existing Kraft pulp mill and an existing pulp and board mill was assessed. The pulp and paper industry is an energy-intensive industry, with significant amounts of CO 2 emitted onsite. The majority of this CO 2 originates from the combustion of biomass, which renders it carbon neutral if the biomass used by the industry is grown and harvested in a sustainable manner. If the CO 2 emissions from the pulp and paper industry were to be captured and permanently stored, then this could make the industry a potential carbon sink. In this evaluation, different configurations of capturing CO 2 from the flue gases of the recovery boiler, the multi-fuel boiler and the lime kiln were assessed. For a stand-alone Kraft pulp mill, the excess steam available is sufficient to cover the demand from the CO 2 capture plant. For an integrated pulp and board mill, there is less excess steam available for the CO 2 capture plant and an auxiliary boiler may be required. The retrofit of a post-combustion CO 2 capture plant into an existing pulp mill increases the steam demand by 1–8 GJ/air dried tonne (adt) pulp, depending on the volume of the flue gas treated. This translates to a reduction in the amount of electricity exported to the grid by 0.1–1.0 MWh/adt pulp for a stand-alone Kraft pulp mill, and by 0.1–0.5 MWh/adt pulp for an integrated pulp and board mill. The total potential for negative CO 2 emissions amounts to just under 2.0 Mt CO 2 /a both for the market pulp mill and for the integrated pulp and board mill. [ABSTRACT FROM AUTHOR]

Developing separation materials for rapidly oil absorption and emulsions separation is urgently needed and remains a great challenge. Here, a biomass-derived banana peel/waste paper (BPWP) hybrid aerogel with hierarchical porous structure has been successfully fabricated via combination of freezing-cast, freeze-drying and pyrolysis approach, for application in oil adsorption and water-in-oil emulsions separation. In this hybrid system, the microsheets that derived from banana peel immobilize were immobilized on surface of the waste paper fibers, forming a hierarchical structure. The resulting BPWP aerogels exhibit a compression strain of 75%, high-hydrophobicity (WCA of 149.3°)/underair superoleophilicity (OCA of 0°), and high porosity, which can absorb of free oils in water with high oil sorption capacity of 35–115 times its own weight. Moreover, these aerogels effectively separate various surfactant-stabilized water-in-oil emulsions driven solely by gravity, with high separation efficiency above 99.6% and higher fluxes of up to 8550 L m −2 h −1 than traditional filtration membranes with pressure driven, even the sizes of emulsified droplets are smaller than the pore size of the BPWP aerogels. More importantly, the BPWP aerogels exhibit a superior antifouling property and regenerability for emulsion separation, which match well with the requirements for treating the real emulsions. Due to the advantages of banana peel/waste paper aerogels in rich source and high oil separation efficiency, the obtained banana peel/waste paper aerogel can be a potential candidate in industrial applications and environmental protection. This work opens up a new avenue for design new hierarchical biomass-derived aerogels for a variety of applications including energy storage, sensors and pressure-sensitive electronics. [ABSTRACT FROM AUTHOR]

Green liquor dregs wastes coming from pulp and paper production are currently disposed in landfills at a huge cost for industry and the environment. In this work, a novel and more sustainable waste management strategy is proposed. Dregs were used for the first time as fine filler in the production of biomass fly ash-based geopolymeric mortars. The influence of the dregs incorporation amount on the fresh (geopolymer kinetics and mortars workability) and hardened-state (mechanical resistance, water absorption and capillary water absorption) properties of the mortars was evaluated. Although dregs incorporation reduce the flow workability (up to 19%), their presence and amount did not significantly alter the geopolymerization kinetics. Additionally dregs-containing mortars exhibited enhanced tensile (up to 71%) and compressive strength (up to 34%), and lower water absorption in comparison with the reference mortar. These results demonstrate the feasibility of using dregs as fine filler in geopolymers production. Moreover the mortars were produced using mainly biomass fly ash waste as aluminosilicate source which further reduces the environmental impact of the pulp and paper industry. [ABSTRACT FROM AUTHOR]

The present study investigates the effect on methane production from waste paper when co-digested with macroalgal biomass. Both feedstocks were previously mechanically pretreated to reduce their particle size. The study was planned according two factors: the feedstock to inoculum (F/I) ratio and the waste paper to macroalgae (WP/MA) ratio. The F/I ratios checked were 0.2, 0.3 and 0.4 and the WP/MA ratios were 0:100, 25:75, 50:50, 75:25 and 100:0. The highest methane yield (386 L kg −1 VS added ) was achieved at an F/I ratio of 0.2 and a WP/MA ratio of 50:50. A biodegradability index of 0.87 obtained in this study indicates complete conversion of feedstock at an optimum C/N ratio of 26. Synergistic effect was found for WP/MA 25:75, 50:50 and 75:25 mixing ratios compared with the substrates mono-digestion. [ABSTRACT FROM AUTHOR]

The synthesis of carbon quantum dots (CQDs) from biomass through a "bottom-up" method has attracted a great deal of interest because of its outstanding environmental and economic advantages. However, the yield of biomass-based CQDs is still low due to the high polymerization of biochar. In this study, we propose a new approach for harvesting high-yield biomass-based CQDs by integrating mechanochemistry and strong chemical oxidation. Ball milling can reduce the particle size and resistance of biochar and increase the contents of C C, while the powerful oxidant HOO- produced by alkaline hydrogen peroxide can break C C to generate biomass-based CQDs. Using this two-step process, the yields of biomass-based CQDs reached 57.75% for blue-green algae, 65.8% for straw, 47.9% for corn protein meal, and 45.35% for Typha angustifolia. Based on the excellent sensitivity and selectivity for Fe3+ of biomass-based CQDs, CQDs paper-based sensors were prepared for expedient and precise detection of Fe3+ in surface water, wastewater treatment plant effluent, and tap water. When the Fe3+ content is between 0 and 60 μM, the R2 of Fe3+ detection by blue-green algae CQDs can reach 0.9956. This work provides a new and reliable method for the large-scale preparation of biomass-based CQDs and expands their environmental applications. [Display omitted] • A method was proposed to improve the yield of biomass-based carbon quantum dot (CQD). • Ball milling can reduce the resistance of biochar and increase the contents of C C. • This scalable method is applicable to other biomass wastes. • The CQDs has excellent sensitivity and selectivity for Fe3+. • The paper-based CQD sensors are applicable in different water bodies. [ABSTRACT FROM AUTHOR]

Hemicellulose materials are arguably the second most abundant renewable component of lignocellulosic biomass after cellulose. They are relatively under-utilized hetero-polysaccharides present in lignocellulosic biomass. In this research an alkaline treatment was optimized for extraction of polymeric hemicellulose from fully bleached hardwood pulp (B-HWP) and partially delignified switchgrass (SWG). The hemicellulose extracted from B-HWP was relatively pure with zero percent lignin and 89.5% xylose content whereas the partially delignified SWG hemicellulose contained about 6-3% lignin and 72–82% xylose, depending on the NaOH concentration during extraction (3–17% NaOH solution). A maximum molecular weight of SWG hemicellulose of 64,300 g/mol was achieved for the 10% NaOH solution extraction, whereas the MW of B-HWP hemicellulose at 10% NaOH solution extraction was lower at 49,200 g/mol. We have demonstrated that the residual lignin in SWG hemicellulose lowered the system T g and this might be utilized as a way to increase the applications of hemicellulose in high value biomaterials. Furthermore, the hemicellulose could be crosslinked with zirconium to develop a water resistant gel for coating or adhesive applications. Our results showed that the loading stress required to break an hemicellulose based adhesive connection between two paper surfaces was 0.89, 2.02, 2.75, 3.46, and 3.11 (MPa) for 2, 4, 6, 8 and 10% AZC samples, indicating that up to about 8% AZC crosslinker in the hemicellulose increases the adhesive behavior of the material. [ABSTRACT FROM AUTHOR]

In the anaerobic digestion of lignocellulosic materials such as waste paper, the accessibility of microorganisms to the fermentable sugars is restricted by their complex structure. A mechanical pretreatment with a Hollander beater was assessed in order to reduce the biomass particle size and to increase the feedstock’ specific surface area available to the microorganisms, and therefore improve the biogas yield. Pretreatment of paper waste for 60 min improves the methane yield by 21%, from a value of 210 ml/gVS corresponding to untreated paper waste to 254 ml/gVS. 30 min pretreatment have no significant effect on the methane yield. A response surface methodology was used to evaluate the effect of the beating time and feedstock/inoculum ratio on the methane yield. An optimum methane yield of 253 ml/gVS was achieved at 55 min of beating pretreatment and a F/I ratio of 0.3. [ABSTRACT FROM AUTHOR]

In this study, waste paper was used as the raw material for hydrogen gas production by dark fermentation at different initial substrate and cell concentrations. Glucose obtained from acid hydrolyzed waste paper was used at six different concentrations between 3.84 and 45.5 gL −1 to determine the effects of sugar concentration on bio-hydrogen production. The highest cumulative hydrogen gas was obtained at 18.9 gL −1 initial sugar concentration. Sugar concentrations above 18.9 gL −1 resulted in product inhibition. Similarly, the initial biomass concentration was varied between 0.25 and 2 gL −1 while sugar concentration was kept constant at 18.58 ± 2.45 gL −1 to determine the effects of initial biomass concentration. The highest cumulative hydrogen gas production was obtained with the initial biomass concentration of 0.5 gL −1 . The highest hydrogen yield (140 ml H 2 g −1 total sugar) was observed at 3.84 gL −1 total sugar concentration. Hydrogen yield decreased with increasing initial sugar concentration due to inhibition by volatile fatty acids (VFAs) produced by dark fermentation and furan derivatives produced from acid hydrolysis of waste paper. [ABSTRACT FROM AUTHOR]

The work describes the combination of granulated biomass fly ash (G BFA) with Fenton process to enhance the removal of adsorbable organic halides (AOX) from pulp bleaching wastewater. At optimal operating conditions, wastewater's chemical and biochemical oxygen demand (COD and BOD 5 , respectively) and colour were also quantified, and operating cost of treatment assessed. For the first time, raw pulp bleaching wastewater was used to granulate BFA, instead of water, reducing the water footprint of the treatment. Five wastewater treatment setups were studied: (i) conventional Fenton process; (ii) G BFA application; (iii) simultaneous application of G BFA and Fenton process; (iv) sequential treatment by G BFA followed by Fenton process; (v) sequential treatment by Fenton process followed by G BFA. The latter yielded the highest AOX removal (60–70%), whilst COD was also reduced (≈15%) and wastewater biodegradability (BOD 5 /COD) was enhanced from 0.075 to a maximum of 0.134. Another positive feature of the proposed solution was that G BFA were successfully recovered and reused without regeneration, yielding similar AOX removal compared with fresh G BFA. The operating cost of removing 1 g of AOX from the pulp bleaching wastewater by the optimal treatment setup (60–70% removal of AOX) was 14–26% lower than the operating cost of conducting Fenton process alone (50% removal of AOX). [Display omitted] • Biomass fly ash was unprecedently granulated with raw pulp bleaching wastewater. • Granulated biomass fly ash (G BFA) was coupled with Fenton process to degrade AOX. • Sequential treatment of Fenton followed by G BFA yielded AOX removals of 60–70%. • COD was reduced (≈15%) and wastewater biodegradability (BOD 5 /COD) was enhanced. • Sequential coupling process was 14–26% cheaper than conventional Fenton process. [ABSTRACT FROM AUTHOR]

Abstract With the rapid development of flexible electronics, new opportunities are opening up for paper-based electrodes. Herein, an integrated paper electrode consisting of homogeneously mixed cellulose fibers, activated carbon (AC), and carbon black is fabricated using cotton stalks as the raw material. Assembled from two such electrodes, the flexible supercapacitor exhibits high energy density, high power density, and outstanding cyclability. Remarkably, the thickness and AC mass loading of the paper electrode can be easily scaled up to commercial levels (610 µm and 9.8 mg cm−2), while still delivering great performances. Moreover, it is demonstrated that the replacement of AC with Ni-Co layered double hydroxide or Fe 2 O 3 can result in paper-based asymmetric supercapacitor with extremely high energy density (331 μW h cm−2 and 10.3 mW h cm−3), substantially outperforming conventional paper-based supercapacitors. The fabrication methodology of integrated paper electrodes in this report manifests great potential, offering a new vision for flexible energy storage. Graphical abstract fx1 Highlights • An integrated paper electrode is fabricated using cotton stalks as the raw material. • The paper is composed of homogeneously mixed cellulose fibers, AC, and CB. • The paper thickness and AC mass loading can be easily scaled up to commercial levels. • The flexible symmetric supercapacitor delivers favorable energy and power densities. • The paper-based asymmetric supercapacitor exhibits extremely high energy density. [ABSTRACT FROM AUTHOR]

Abstract: The pulp and paper industry is placed in a unique position as biomass used as feedstock is now in increasingly high demand from the energy sector. Increased demand for biomass increases pressure on the availability of this resource, which might strengthen the need for recycling of paper. In this study, we calculate the energy use and carbon dioxide emissions for paper production from three pulp types. Increased recycling enables an increase in biomass availability and reduces life-cycle energy use and carbon dioxide emissions. Recovered paper as feedstock leads to lowest energy use (22GJ/t) and CO2 emissions (−1100kgCO2/t) when biomass not used for paper production is assumed to be converted into bio-energy. Large differences exist between paper grades in e.g. electricity and heat use during production, fibre furnish, filler content and recyclability. We found large variation in energy use over the life-cycle of different grades. However, in all paper grades, life-cycle energy use decreases with increased recycling rates and increased use of recovered fibres. The average life-cycle energy use of the paper mix produced in The Netherlands, where the recycling rate is approximately 75%, is about 14GJ/t. This equals CO2 savings of about 1tCO2/t paper if no recycled fibres would be used. [ABSTRACT FROM AUTHOR]

Production of transportation fuels from biorefineries via biomass gasification has been suggested as a way of introducing renewable alternatives in the transportation system with an aim to reduce greenhouse gas emissions to the atmosphere. By co-locating gasification-based processes within heat demanding industries, excess heat from the gasification process can replace fossil or renewable fuels. The objective of this study was to compare the heat integration potential of four different gasification-based biorefinery concepts with a chemical pulp and paper mill. The results showed that the choice of end-product which was either methanol, Fischer-Tropsch crude, synthetic natural gas or electricity, can have significant impact on the heat integration potential with a pulp and paper mill and that the heat saving measures implemented in the mill in connection to integration of a gasification process can increase the biomass resource efficiency by up to 3%-points. Heat saving measures can reduce the necessary biomass input to the biorefinery by 50% if the sizing constraint is to replace the bark boiler with excess heat from the biorefinery. A large integrated gasification process with excess steam utilisation in a condensing turbine was beneficial only if grid electricity is produced at below 30% electrical efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The carbon paper is synthesized by the simple, cheap and large-scale pyrolysis of filter paper and is used as an interlayer for Li–S battery. The as-prepared carbon paper is composed of carbon fiber with porous structure. The specific surface area is 534m2 g−1, and the average pore size is 4.1nm. The porosity of the as-prepared carbon paper lies in favor of the electrolyte permeating through the layer, which allows electrochemical reactions to occur. The prepared carbon paper is used as an interlayer between the cathode and the separator in Li–S battery and can significantly improve the electrochemical performance of the cell with reversible capacity, cycling ability, and rate capability. [Copyright &y& Elsevier]

In the boilers of pulp mills the fuel blends used vary because they are essentially composed of residual forest biomass. Consequently, the physical-chemical properties of the produced ash streams can exhibit high temporal variability, making their proper management and recycling difficult. This study aims to characterize the ash from the incineration of biomass samples used as fuel in order to understand its influence on the properties of the generated ash fluxes. This can anticipate suitable blending procedures that minimize the variability of the ash characteristics. For this purpose, typical biomass samples (eucalyptus bark, treetops and knots, pine treetops, silver wattle, Sydney golden wattle, white poplar, and grey willow) were incinerated (at 550 and 825 °C) and the resulting ashes were characterized. The thermal behavior of the biomass was evaluated by TG/DTA and the generated ash content was determined. The particle size distribution (laser diffraction), morphology (SEM), mineralogy (XRD), and chemical composition (XRF) were other evaluated properties. From the results obtained it is concluded that the ashes cannot be used as raw materials for clinker production. However, they can be used in concrete and mortar formulations, as a cement substitute or as filler. The maximum incorporation amount depends on the type of biomass used, ranging from 54 wt% for pine treetops to 100 wt% for eucalyptus bark. This knowledge is fundamental to understand how to optimize the biomass blends used in industrial combustion systems to obtain ashes with suitable properties to be used as secondary raw materials in building materials formulations. [Display omitted] • Eight types of biomass fuels used in two bubbling fluidized bed boilers were studied. • The ashes generated after biomass incineration at 550 and 825 °C were characterized. • Slagging and fouling are forecast to happen in the combustion systems under study. • The obtained ashes cannot be used as secondary raw material for clinker production. • Maximum ash incorporation in cementitious formulations ranges from 54 to 100 wt%. [ABSTRACT FROM AUTHOR]

Abstract: Carbon capture and storage (CCS) is one of a suite of technology options that might play a significant role in reducing greenhouse gas emissions. However, outside of traditional enhanced oil and gas recovery operations with a well established business model, CCS project deployments are struggling with adoption of a federal or international climate policy driver appearing unlikely for the foreseeable future. As part of a feasibility study for an industrial CCS project at the Boise White Paper mill in Washington State, a business model and CCS system design was developed that provided financial surety for the project developers while recognizing that uncertainty in revenue forecasts for CO2 storage would persist for the foreseeable future. Key to the business model was installation of a new 37MWe biomass-fueled power island at the plant that would replace antiquated boilers and that could still supply the necessary steam to run pulp and paper production operations when capturing CO2 emissions under favorable market conditions for monetizing CO2 storage credits. Under unfavorable market conditions, CO2 capture would be suspended and excess power generated from the plant would reduce external electrical energy purchases required for paper mill operations. The net CO2 reduction for the project versus current operations is 1.0MMT of CO2 per year with the CCS system online, and 139ktons per year with the CCS system offline due to reduced natural gas co-firing. So, both operational modes offered a significant net reduction in CO2 emissions. Based on assumptions regarding electricity and natural gas pricing, and CO2 storage revenue generated through an open market mechanism priced at $15 per metric ton CO2, the payback period for the project capturing 0.5MMT/yr (62% of total CO2 production) was estimated at 6.7 years versus 7.4 years with the CCS system offline. Geologic storage was evaluated in the deep flood basalt formations that dominate the storage capacity in Eastern Washington. Sub-basalt sediments were also examined at the site to provide alternative or supplemental storage capacity in the event that storage in the basalt sequences did not prove technically or economically feasible. [Copyright &y& Elsevier]

Abstract: Rice straw, rice husk and paper sludge are by-products and industrial waste, and are beneficial resources as raw biomass materials used for manufacturing value-added composite products. We investigated the effect on selected mechanical properties of adding rice straw, rice husk and paper sludge to wood composites to replace wood particles for manufacturing green pallets. Results showed that increasing the contents of rice straw and rice husk dramatically decreased the mechanical strength of the composites. This is because the wax and silicate coating of these materials obstructed the strong bonding with UF resin. When 10wt.% of wood particle was replaced with 10wt.% of paper sludge, the wood–paper sludge composites showed similar mechanical properties to those of wood particle. Wood particle can be replaced by 10wt.% of dried paper sludge in accordance with the minimum requirement recommended by standards in green pallet manufacturing. [Copyright &y& Elsevier]

Abstract: The pulp and paper industry both uses and produces large amounts of energy and rising fuel prices bring along significant challenges to the sector. Several strategies can be applied in order to remain competitive e.g. an increase in energy efficiency, a switch in fuel and/or a novel energy conversion technology. In this study, we investigate if improved energy conversion strategies can reduce energy costs, primary energy use and CO2 emissions of paper mills within different European countries (The Netherlands, Poland and Sweden). Our results show that differences in history and availability of resources has led to different conversion strategies in the three countries. We found that a natural gas combined cycle, which is largely implemented in The Netherlands due to long term domestic availability of natural gas, has the lowest primary energy demand. Due to a long history of low electricity prices, CHP has not been common in Sweden. Many Swedish mills use biomass as an energy source and due to low CO2 emissions of the national grid the CO2 emission profile of the Swedish paper industry is very low. Our results imply that future conversion routes for the Swedish paper and board industry are again wood based; in case of increasing electricity prices these would be biomass gasification based CHP solutions. With a reduction of 800kg CO2/ton paper on average, a switch from coal to biomass would reduce CO2 emissions in the Polish pulp and paper industry with approximately 0.6Mton/year. A carbon price of 20–25€/ton would, according to our results, be enough to provoke this switch. Due to the high share of natural gas, the CO2 emission reduction potential of the Dutch paper industry (1.5Mton/year) is even larger than in Poland. Due to high biomass prices and relative low CO2 emission profile of natural gas, a carbon prices of more than 60€/ton CO2 would be needed to provoke a switch in The Netherlands. Provided with few alternatives, the most effective strategy in The Netherlands would be an increase in energy efficiency. [Copyright &y& Elsevier]

Little is known about the effect of seed source and nursery culture on the growth and performance of artificially regenerated paper birch planted in the field. In the summer of 2000, trees were vertically uprooted in Prince George, BC using a tripod and winch device to determine if seed source and nursery culture significantly affected the root strength of 5-year-old paper birch. Trees from a seed source in the Skeena region had the greatest uprooting resistance, and the most root biomass, but the least root strength compared to the other three seed sources tested. The Skeena trees may be exhibiting an adaptive strategy which provides maximum root reinforcement across a wide range of environments. Uprooting resistance was similar for the 415D stocktypes grown at Red Rock and Kalamalka nurseries. However, trees grown in 515A styroblock at Kalamalka had the least uprooting resistance and root biomass of all treatments. In addition, the relationship between uprooting resistance and ground line diameter was different between nurseries. The results of this study suggest that regardless of height and diameter leaving the nursery, seed source root resistance and growth continued to be impacted by nursery culture 5 years after planting. [Copyright &y& Elsevier]

In this paper an approach for analysing the potential for implementation of different technology pathways for the European pulp and paper industry (PPI) is presented. The approach is based on detailed technical research and aggregates the knowledge from previous studies to incorporate the whole European PPI. Thus, the potential for different technology pathways can be estimated on a European level whilst still considering important characteristics of individual mills. The usefulness of the approach was exemplified by applying it to a case study of the potential for introduction of carbon capture and storage (CCS) within the European PPI. The results from the case study show that for the European PPI, CCS has an up-hill road in order to be a viable, large scale alternative for reduction of CO2 emissions. If CCS is to be introduced in large scale within the European PPI, large biomass-based point sources of CO2 emissions need to be included when planning for CCS infrastructure and also the infrastructure needs to be built out for clusters emitting <20 MtCO2/yr. [ABSTRACT FROM AUTHOR]

Abstract: In this study we investigated the feasibility of producing polyhydroxyalkanoate (PHA) by microbial enrichments on paper mill wastewater. The complete process includes (1) paper mill wastewater acidogenic fermentation in a simple batch process, (2) enrichment of a PHA-producing microbial community in a selector operated in sequencing batch mode with feast-famine regime, (3) Cellular PHA content maximization of the enrichment in an accumulator in fed-batch mode. The selective pressure required to establish a PHA-producing microbial enrichment, as derived from our previous research on synthetic medium, was validated using an agro-industrial waste stream in this study. The microbial enrichment obtained could accumulate maximum up to 77% PHA of cell dry weight within 5 h, which is currently the best result obtained on real agro-industrial waste streams, especially in terms of biomass specific efficiency. Biomass in this enrichment included both Plasticicumulans acidivorans, which was the main PHA producer, and a flanking population, which exhibited limited PHA-producing capacity. The fraction of P. acidivorans in the biomass was largely dependent on the fraction of volatile fatty acids in the total soluble COD in the wastewater after acidification. Based on this observation, one simple equation was proposed for predicting the PHA storage capacity of the enrichment. Moreover, some crucial bottlenecks that may impede the successful scaling-up of the process are discussed. [Copyright &y& Elsevier]

[Display omitted] • Filter paper is used as carbon source to prepare highly porous N-doped carbon. • KHCO 3 is chosen as the activator because it is safe and non-corrosive. • Addition of urea at the activation step significantly improves the surface area. • At 0 °C and 20 bar, the carbon shows high CO 2 uptake of 19.65 mmol/g. Herein, we presented the preparation of N-doped porous carbon from lab used filter paper. Filter paper was first carbonized at 500 °C. The obtained carbon was then pyrolyzed with KHCO 3 and urea. Effects of KHCO 3 activation on the carbons' physicochemical properties were thoroughly investigated. The derived carbon materials were also tested for CO 2 adsorption with pressure up to 20 bar. The carbons exhibited very high CO 2 uptake of 19.65 mmol/g at 0 °C and 20 bar. The correlations between adsorption performances and the carbons' physicochemical properties at 1/20 bar were analyzed and discussed. [ABSTRACT FROM AUTHOR]

This study shows a comparative techno-economic analysis of the integration of biomass gasification for generation of producer gas to be used in electricity production and to replace natural gas in the lime kilns of the pulp and paper industry. Three study cases with alternative configurations of the energy system integrating biomass gasification were analysed, including or not the co-generation of electricity and thermal energy, namely: i) Case I, for generation of electricity from residual forest biomass (RFB) in an integrated gasification combined cycle system, ii) Case II, generation of producer gas by RFB gasification for replacement of natural gas in the burners of a lime kiln, and iii) Case III, as an integration of Cases I and II for combined production of electricity and heat. Residual forest biomass from eucalyptus logging activities for feedstock processing for the pulp and paper industry was considered as fuel for direct (air) gasification in bubbling fluidized bed. The analysis made is supported on review reports, namely, the evaluation of the existing literature on investment projects in biomass power plants, and on experimental investigation for determining the composition of the producer gas from gasification of the selected feedstock. An economic model was developed that combines the net present value, internal rate of return and payback period. The main results of the energy system analysis show that the net electricity generation is between 72 and 83 GWh/year, while the production of CaO in the lime kiln supported by combustion of producer gas, is 82.12 kt/year, and a global energy efficiency between 21.70 and 34.17 % is achieved for the analysed configurations of the energy system. The results of the economic analysis show a positive NPV, an IRR greater than the discount rate and a PBP less than the useful life of the plant. The sensitivity analysis shows quite favorable investment projections given the low probability that the NPV will reach negative values and compromise the economic viability of the project. • The technical-economic viability of the forest biomass residues gasification is addressed. • Integration of IGCC concepts in the pulp and paper industry is reviewed. • The opportunities and drawbacks of IGCC in the pulp and paper industry are discussed. • Replacement of natural gas for producer gas for electricity generation and lime production is analysed. • A Monte Carlo sensitivity analysis is performed. [ABSTRACT FROM AUTHOR]

Aim of this research was to treat the organics enriched Paper and Pulp Industry (PPI) effluents using multi-metal tolerant predominant indigenous bacterial species. In addition, assessing the potential of treated bacterial biomass as a single cell protein (SCP). The multi-metal tolerant Streptomyces tuirus OS1 was enumerated from the Paper and Pulp Industry (PPI) effluents was identified through standard molecular characterization. S. tuirus OS1 proficiently ameliorated organic contaminants in PPI effluent in the in study at 35 °C, 45 °C, and 25 °C. Fortunately, the S. tuirus OS1 considerably increased the dissolved oxygen level in treated PPI effluent in 30 days of bioremediation process. Interestingly, at 35 °C of bioremediation process the S. tuirus OS1 demonstrated increased dried biomass (7.1 g L−1) with the total crude protein (SCP) as 5.3 g L−1 (78.79%) in 30 days of bioremediation process. These findings suggest that S. tuirus OS1 is capable of reducing organic pollutants in PPI effluents and producing biomass with enriched protein content. [Display omitted] • Novel report about the bioremediation efficiency of S. tuirus OS1 on PPI effluent. • Physicochemical properties of PPI effluent beyond the permissible limits. • S. tuirus OS1 possess fine multi-metal tolerant and degradation potential. • S. tuirus OS1 actively reduced the most of the physicochemical properties at 35 °C. • The dried biomass of S. tuirus OS1 contained 78.79% of total protein as SCP. [ABSTRACT FROM AUTHOR]

Highlights: [•] Paper grade pulp was upgraded to dissolving pulp by two stages of treatment. [•] EG-rich industrial cellulase was used for enzymatic treatment. [•] α-Cellulose content and viscosity can be adjusted by alkali peroxide treatment. [•] Reducing sugar in spent liquor can be recovered to generate value-added products. [Copyright &y& Elsevier]

For treating pulp and paper (P&P) industry wastewaters, the high-loaded/nutrient-limited moving bed biofilm reactor (MBBR) is frequently followed by an activated sludge, in the Biofilm-Activated Sludge (BAS) configuration. Evidences show that the MBBR performance relies on a complex surface-volume relation, affecting the biosolids dynamics. That subject was addressed in parallel lab-scale MBBRs, with carrier filling degrees of 15% and 45%, fed with P&P wastewater. The removal of chemical oxygen demand (COD) and utilization of nutrients were evaluated for varying hydraulic retention times (HRT, 1.6–4.9 h), and availabilities of nitrogen and phosphorous. Nutrients excess and 4.9 h HRT led to soluble COD removal close to 50% (totality of the biodegradable portion) in both reactors, but only 32% was achieved at 1.6 h HRT and 45% filling degree. Restrained wastewater-biosolids contact time rather than overload justified that, as the maximum capacity (Kincannon–Stover model, 30.6 kg sCOD/(m3 d)) was substantially higher than the apparent removal rates (≤ 14.1 kg sCOD/(m3 d)). The performance at 4.9 h HRT was matched at 3.2 h HRT with threefold filling ratio, which compensated the lower contact time. Higher HRT was also responsible for i) improving nutrients usage (up to 1.72 times higher sCOD/P and 1.47 sCOD/N); ii) superior suspended solids content, corresponding up to 30% of total biomass at 4.9 h, against 8.6% at 1.6 h; and iii) up to 2.45 times greater planktonic maximum specific activity. Nutrients restriction boosted the sCOD/nutrient consumption ratio up to 2.65 times for the limited nutrient and 1.70 for the abundant one, with minimal sCOD:N:P (100:0.70:0.14) at limited N and 4.9 h HRT. ga1 • 1-year study of various MBBR organic, N and P loads for treating P&P wastewater. • Limitation of either N or P boosts the usage efficiency of both in COD removal. • Minimal nutrients dosing was achieved at higher HRT and limited N availability. • Threefold carrier filling ratio allows 33% volume saving while keeping performance. • Suspended biomass was shown to better use restricted nutrients than the biofilm. [ABSTRACT FROM AUTHOR]

Abstract: The effect of waste paper on biogas yield produced by co-digesting fixed amount of cow dung and water hyacinth in five digesters A–E was studied at room temperature. Waste paper was observed to improve biogas yield in digesters B–E with digester A acting as the control. However, as the amount of waste paper increased the biogas yield was observed to decrease. Kinetic model based on first order kinetic was derived to estimate the maximum, ultimate, biogas yield and also the ultimate methane yield from these biomass mixtures. The maximum biogas yield estimated using this model for digesters B–E were 0.282, 0.262, 0.233, and 0.217 lg−1 VS fed with goodness of fit (R 2) of 0.995, 0.99, 0.889, and 0.925 respectively, which were obtained by fitting the experimental biogas yield (yt ) against (exp(kt)−1)/exp(kt). The ultimate biogas and methane yield at very low batch solid load were extrapolated to be 0.34 and 0.204 lg−1 VS fed respectively. In essence, the addition of waste paper in the co-digestion of cow dung and water hyacinth can be a feasible means of improving biogas yield and also alternative means of recycling waste paper. Furthermore, the kinetic model developed can compliment other models used in anaerobic digestion of agricultural and solid waste. [Copyright &y& Elsevier]

An incubation study was conducted under laboratory conditions to compare the effects of soil amendment of combined paper mill sludge (PS) and decomposed cow manure (DCM) on selected microbial indicators. A lateritic soil (Typic Haplustalf) was amended with 0 (control), 20 or 80tha−1 (wet weight) of PS or DCM. The amended soils were then adjusted to 60% water holding capacity (WHC) or submerged conditions, and incubated at 27°C in dark for up to 120days (d). The microbial biomass C (MBC), the basal soil respiration and the enzyme activities of the β-glucosidase, acid phosphatase and sulphatase were analyzed at day 15, 30, 45, 60 and 120. Compared to the unamended soil (control), the MBC, the basal soil respiration and the enzyme activities increased with the rate of PS and DCM. At similar rate, the DCM treatment increased significantly the MBC, the soil respiration and the enzyme activities compared to the PS treatment. Also, the water regimes affected the microbial activities. At 60% WHC, the MBC and soil respiration increased during the first 30d and decreased thereafter. The enzyme activities showed similar trends, where they increased for the first 60d, and decreased thereafter. In contrast, under submerged condition, the MBC and enzymes activities declined during 120d, whereas the soil respiration increased. Compared to the control, the used of PS and DCM had no negative impact of the soil microbial parameters, even at the highest application rate. Long-term field experiments are required to confirm these laboratory results. [Copyright &y& Elsevier]

• Handy paper-like purifier with striking multifunctional water decontamination properties. • High loading of functional components onto bacterial cellulose via chemical bonds. • Superior adsorption capacities towards metal ions and organic dyes, and disinfection efficiency. • Simultaneous removal of multiple species from polluted water, and superior reusability. Contaminated water contains various types of pollutants, the removal of which requires two or more technologies. It is imperative but challenging to develop water purifier for simultaneous removal of multiple pollutants for the sake of easy operation, low cost, and etc. Previously reported multifunctional purifiers are normally nanoparticles which require caution during use. Here, we describe a design of paper-like multifunctional purifier, which has biomass-based structure by grafting polyethylenimine derived quaternary ammonium compounds onto three-dimensional bacterial cellulose substrate. Compared to similar materials reported previously, our product exhibited strikingly higher adsorption capacities towards various metal ions including Pb2+, Cu2+, and Cr6+, anionic organic dyes including congo red, methyl orange and methyl red, and excellent disinfection efficiency towards both Gram-negative and Gram-positive bacteria. Remarkably, this purifier also demonstrated effective removal of the three contaminative species simultaneously from both simulated and local polluted water. With more virtues of superior reusability and extreme handy convenience, we hope our molecular design could inspire further efforts on the rational construction of multifunctional water purifier with easy operation. We reckon our material to have strong potential for the possible use in water treatment, especially in regions that are short of environmental infrastructures. [ABSTRACT FROM AUTHOR]

The biorefinery design has attracted interest from the industry and scientific community due to its main role in a future transition to a sustainable bioeconomy. This paper provides a critical review of the integration of biorefinery concepts in the pulp and paper industry, focusing on gasification-based biorefineries, including technological and commercial drivers and barriers, and biorefinery general opportunities and challenges. The pulp and paper industry is commonly recognized as highly suitable to integrate biorefinery concepts. For this purpose, various integrable biorefinery designs composed of distinct conversion processes are proposed in the literature. However, key technologies and biorefinery concepts must firstly be improved and proven at a market level to increase stakeholders confidence. Gasification can be a driving force for this integration and efficient replacement of natural gas by producer gas in burners is the first and most immediate step. Nonetheless, drawbacks associated with the contaminants present in the producer gas (e.g., tars) must be addressed. Research rarely focus on this first step and is more centered on sophisticated gasification applications (e.g., methanol synthesis), without considering associated technological and commercial barriers. Furthermore, supporting policies are generally required to make the integration of biomass gasification technologies in the pulp and paper industry profitable and to avoid the interruption of operation of fully functioning large-scale gasification plants. • Integration of biorefinery concepts in the pulp and paper industry is reviewed. • Gasification-based biorefineries opportunities and drawbacks are discussed. • Producer gas has large potential by representing a middle platform compound. • Efficient replacement of natural gas by producer gas is a driving force. • Government policies and improvement of key technologies are main factors. [ABSTRACT FROM AUTHOR]

Abstract: The Scandinavian mechanical pulp and paper industry has been facing great challenges during the past decades, mainly because of declining demand for newsprint, and higher prices on raw material and energy. One way of increasing profitability is to produce more value-added products besides the production of pulp and paper. In this study, integration potentials of three possible future biomass gasification-based energy mills with an existing thermo-mechanical pulp (TMP) mill, co-located with a sawmill, have been evaluated. The product gas was utilized for electricity production in a gas turbine, for production of methanol or for production of Fischer–Tropsch (FT) liquids. Integration of the energy mills showed good potential as the TMP mill constitutes a heat sink for which the excess heat from the energy mills can be utilized all year round. However, since there is little excess heat from the TMP mill at the required level to be utilized for biomass drying, for example, heat integration is typically one way. It has also been shown that integration of biomass gasification with a TMP mill results in larger CO2 emissions reduction than stand-alone operation. Still, compared to co-firing biomass in a coal power plant, the energy mills all have lower potentials for CO2 emissions reduction. [Copyright &y& Elsevier]

Abstract: In life cycle assessment (LCA) of paper products, it is common to either assume that the carbon impacts of forestry are neutral (i.e. no net emissions) or to credit harvested wood products as a carbon store. When comparing virgin and recycled materials, this means that forest carbon flows are either shown as nil or a net sequestration credit. However, harvested wood products typically account for less than half of the carbon stored in a forest, with additional stores in below ground biomass, deadwood, litter and soils. Each of these stores may be affected by changes in demand for virgin pulp and paper. In this study the countries likely to provide pulp displaced by moving to recyclate, or used when switching from recyclate were identified for both the UK and China (the largest export market for UK-derived recyclate). Changes in forest carbon stores in each country were then assessed and attributed to the extraction of a unit of timber in each country where demand for pulp and paper was identified as a driver for change. The analysis shows that when switching from virgin to recycled content within the UK and China, no additional biogenic CO2 emissions are avoided with the exception of Canadian pulp, where the data suggests that forests are being degraded, with associated carbon losses. When switching from recycled to virgin content, net biogenic CO2 emissions are seen from most relevant countries. In the example of newsprint, this is equivalent to 2–23 tonnes CO2 per tonne of newsprint. The exceptions to this are Chile and Russia, where demand for virgin fibre does not appear to be associated with deforestation. Despite limitations, the research highlights that biogenic carbon is a significant issue which may dominate the outcome of LCAs assessing the climate change impact of switching between virgin and recycled pulp. [Copyright &y& Elsevier]

Abstract: Purple nutsedge (Cyperus rotundus L.) is a serious weed capable of piercing polyethylene (PE) plastic mulch used in horticulture. A biodegradable plastic, PE and four different papers were tested for 2 years in fields highly-infested with C. rotundus in Zaragoza (Spain). All four papers were able to withstand all weed species. C. rotundus plants penetrated the biodegradable plastic mulch most, possibly because this material had least resistance to slow perforation. Differences in weed biomass between mulching materials were lower because of small size and weight of C. rotundus. Therefore all mulching treatments had a similar impact on weed biomass reduction 63 days after transplanting; biodegradable plastic had most biomass and papers the least, the differences being significant some years, only. Tomato yield was very similar for all mulching treatments and significantly higher than in the non-mulched plots. No effect of treatment was observed on fruit quality parameters. Commercial paper used as mulch without special additives can satisfactory control C. rotundus in processing tomato provided that climate is appropriate to maintain the paper dry during most of the time. Also the crop needs to cover the soil fast enough before the buried part of the mulch degrades allowing wind to lift and tear the mulch. [Copyright &y& Elsevier]

Abstract: This paper presents the application of a comprehensive approach to the design of small scale sustainable distributed generation systems with special focus on energy recovery from paper production process sludge. The methodology integrates a detailed fluid-dynamic analysis tool with preliminary experimental analysis on a laboratory scale to guide the design of a prototype bubbling fluidized bed gasifier in the 85kW power range fitting with small and medium size paper production industries. Preliminary tests show stable operation even for this rather small power scale, and deviation from chemical equilibrium concentration in agreement with literature available data. Energy content in the sludge may be recovered along with a significant reduction of residual volume and mass. The concept may then be used to increase the overall sustainability of paper production. [Copyright &y& Elsevier]

Abstract: The purpose of this work is to demonstrate how α-methylstyrene (AMS) can replace styrene in preparing styrene–butadiene (SB) type latexes and to compare the properties of the paper coating of the prepared α-methylstyrene–butadiene emulsion with the commercial styrene–butadiene latex reference sample. A lot of work is nowadays being conducted on different biorefinery concepts replacing fossil oil with biomass based raw materials due to the expected rise of the fossil oil cost. Aromatics can in principle be produced from renewable raw materials, such as lignin, sugars and terpenes for example. The potential methods include thermochemical conversions, catalytic fast pyrolysis, metabolic engineering, catalytic aromatisation and dehydrogenation among others. Terpenes, such as α-limonene and pinene, are possible sources of aromatics, and they can indeed be catalytically converted to p-cymene. Industrial hydrodealkylation and disproportionation processes developed by major petrochemical companies can further convert p-cymene to BTX aromatics or simultaneously dehydrogenate the alkyl chain of p-cymene to styrenic monomers such as α-methylstyrene. Based on the measured paper properties for uncalendered and calendered coated samples, AMS proved to be adequate to replace the oil based styrene in commercial reference SB latexes. Even though the emulsion polymerisation for the α-methylstyrene–butadiene latex was not optimised, almost all tested properties were at least equally good as in the commercial reference sample. α-Methylstyrene containing coating colours had slightly higher viscosity than the other coating colours. Coating colours containing α-methylstyrene seems to have an improved water retention compared to the commercial reference styrene–butadiene latex coating colour and the laboratory prepared styrene–butadiene coating colour. The paper coated with the commercial reference latex containing coating colour was less porous than the other coated papers. Despite of that, both dry and wet surface strength were at least equally good as in the case of the commercial reference latex. The results are promising when thinking of the future development of the bio-based latexes. [Copyright &y& Elsevier]

Recently, microwave absorbing materials have been widely used with the development of electromagnetic wave technology such as 5G communication. It is urgent to develop low-cost electromagnetic wave absorbing materials to meet the increasing civil market demand. Herein, we report a novel and simple strategy to synthesize lightweight silicon carbide microwave absorber by calcining tissue and glass microspheres at high temperature. The results show that higher synthesis temperature can improve the crystallinity of SiC, generate more whiskers and reduce the impurity content. This in turn increases the dielectric loss of the material. The products synthesized at 1600 °C have excellent microwave absorption properties. At the thickness of 1.3 mm, it achieves a reflection loss of −32.5 dB and an effective absorption bandwidth of 4.1 GHz. This study broadens the way for the potential reuse of waste paper and glass, and provides a useful reference for the preparation of low-cost microwave absorbing materials. [ABSTRACT FROM AUTHOR]

Land restoration at a former landfill site, Bidston Moss, NW England, has involved heavy applications of paper mill sludge (PMS), a byproduct of paper recycling. The development of earthworm communities at the site has been assisted by earthworm inoculation. Initially low numbers of epigeic species were present, but as the restoration has progressed since 1996 a substantial number, biomass and diversity of earthworms has become established, including a variety of ecological types. In some areas there is substantial surface casting. Cast colour indicates selective consumption of PMS, and δ13C ratios suggest that PMS is a major nutrient source for earthworms. Although concentrations of copper in the PMS are higher than those typical for soils, concentrations in earthworm tissue are relatively low. Low availability of copper will reflect the high content of organic matter and clay, and relatively high pH, of the PMS. [ABSTRACT FROM AUTHOR]

Among the various waste-to-energy conversion methods, gasification is a technically feasible option for municipal solid waste valorization, meeting current emission limits and reducing landfill disposal burden. This work investigates the potential of paper rich (⁓ 76 % wt.) commercial refuse-derived fuel (RDF) having high ash content (⁓ 17 % wt.) for gasification and co-gasification in downdraft gasifier. The ash formed from RDF, with higher proportion of alkaline earth metals (Ca and Mg) and lower proportion of alkali metals (Na and K), can effectively avoid agglomeration and clinker formation during gasification. The producer gas obtained from RDF gasification reports a maximum lower heating value of 4.34 MJ/Nm3at an equivalence ratio of 0.34 with corresponding cold gas efficiency of 59.24%.Co-gasification of RDF with biomass was examined as a strategy to reduce overall ash content of the mixture, using sawdust. Co-gasification has exhibited a synergy between RDF and sawdust when the RDF fraction in feedstock is at the higher side. A maximum lower heating value of 4.65 MJ/Nm3 was obtained during the co-gasification and the tar yield reduced from 13.6 g/Nm3to 8.8 g/Nm3 when RDF in the feed increased from 25% to 75% (w/w). • Investigates potential of paper-rich RDF for gasification and co-gasification. • Absence of agglomeration and clinker formation during gasification and co-gasification. • Producer gas with LHV and CGE of 4.34 MJ/Nm3 and 59.24%, respectively from RDF gasification. • RDF has exhibited synergy with biomass at higher RDF fraction during co-gasification. • Reduction in tar content with increase in RDF fraction during co-gasification. [ABSTRACT FROM AUTHOR]

Abstract: Supercritical water gasification (SCWG) is a method by which biomass can be converted into a hydrogen-rich gas product. Wet industrial waste streams, which contain both organic and inorganic material, are well suited for treatment by SCWG. In this study, the gasification of two streams of biomass resulting from the pulp and paper industry, black liquor and paper sludge, has been investigated. The purpose is to convert these to useful products, both gaseous and solids, which can be used either in the papermaking process or in external applications. Simple compounds, such as glucose, have been fully gasified in SCWG, but gasification of more complex compounds, such as biomass and waste, have not reached as high conversions. The investigated paper sludge was not easily gasified. Improving gasification results with catalysts is an option and the use of alkali salts for this purpose was studied. The relationship between alkali concentration, temperature, and gasification yields was studied with the addition of KOH, K2CO3, NaOH and black liquor to the paper sludge. Addition of black liquor to the paper sludge resulted in similarly enhancing effects as when the alkali salts were added, which made it possible to raise the dry matter content and gasification yield without expensive additives. [Copyright &y& Elsevier]

This work reports an innovative simulation method for effectively utilizing paper-mill sludge based on the co-gasification approach for energy-enriched renewable fuel production. An Aspen plus-based co-gasification model was developed to simulate and examine the synergetic effects of biomass and paper-mill sludge co-gasification. Initially, the model was validated using experimental data from the reported literature and found good agreement regarding gasification and co-gasification approaches. Sensitivity analysis of biomass gasification revealed that the maximum H 2 content of 29.6% and CO (36.0%), LHV (7.8 MJ/Nm3), 72.2% (CCE) was obtained at optimal (850 °C: temperature; 1 bar: pressure; 0.2: ER) conditions. Further, the H 2 proportion enhanced, and CO declined to 38.8 and 30.7% at the same operating conditions, respectively, with a co-gasification ratio of 50% compared to 0% (H 2 : 29.6% and CO: 36.0%). However, with increasing the co-gasification ratio beyond 20%, the CO content started to follow upward trends; at the same CGR, the H 2 , LHV, and CCE observed were 36.0%, 7.76 MJ/Nm3, and 65.2%, respectively. Hence, the developed co-gasification model can provide vital information for large-scale gasifier design, operating decisions, and optimization using different biomass blends. • Biomass and PMS utilization to produce renewable fuel. • Co-gasification parametric effects evaluation on product yield. • Increasing the proportion of PMS in feedstock mixture increases H 2 content. • 20% PMS co-gasification provided consistency with reported literature. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hydrophobic building material was produced as an alternative to natural wood. • Heat transfer coefficient reduced with various combinations. • A material with high compressive strength was obtained. • The material environmentally friendly is produced from biomass waste. This study aimed to produce a construction composite material that is environmentally friendly, easily accessible, inexpensive and renewable and provides thermal and water insulation. Waste papers, hazelnut shells, pinecones and sheep wool were used at the production stage. The filling rates of the materials were optimized using the RSM. A hydrophobic surface-active substance was used to reduce water absorbability, microbial activity and mold formation. It was observed that these specimens' contact angles were 84° to 146°, thermal conductivity were 0.0511 to 0.0861 W/mK and densities were 0.678 to 0.99 g/cm3. As a result of the compressive and flexural strength tests, it was found that the compressive strength of the specimens was very high, the highest compressive strength was found as 32.8093 N/mm2 in the specimen N25, and the highest flexure strength was found as 6.352 N/mm2 in the specimen N20. A completely environment-friendly, biodegradable and low-cost material was produced out of biomass wastes. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of combining CO2 capture and storage with alternative systems for biomass-based combined heat and power production (CHP) in Kraft pulp and paper mills. We compare heat, power, and CO2 balances of systems with alternative configurations of the CHP and CO2-capture systems. Because the captured CO2 comes from renewable biomass, the studied systems yield negative CO2 emissions. It is shown that pulp mills and integrated pulp and paper mills have the potential to become net exporters of biomass-based electricity while at the same time removing CO2 from the atmosphere on a net basis. The study shows that that the overall best CO2 abatement is achieved when CO2 capture is carried out within a biomass integrated gasifier with combined cycle where the syngas undergoes a CO-shift reaction. This configuration combines efficient energy conversion with a high CO2 capture efficiency. Furthermore, cost curves are constructed, which show how the cost of CO2 capture and storage in pulp and paper mills depends on system configuration and the CO2 transportation distance. [Copyright &y& Elsevier]

Abstract: Densified biomass pellets using waste wood sawdust (S) as main materials and wrapping paper fiber (P) as “solid bridge”, named as P/S-BPs, was prepared by a hydraulic press powder pelletizer under room temperature and pressure lower than10MPa. The effects of the addition of P to S and the compressed pressure on the density, resiliency (R), abrasion resistance (AR), impact resistance index (IRI)) and the combustion behavior of the P/S-BPs were investigated. The results showed that the addition of P to S greatly reduced the negative effects of resiliencies on the densities and mechanical properties of P/S-BPs during storage. For example, P/S-BPs compressed at 6MPa in a P/S mass ratio of 1–3 showed the smooth surface and low resiliency of 10% with a high relaxed density of 1.08kgm−3. This is due to the strengthened interlocking bonds through fabricating “solid bridge” and increasing attracting force by adding P to resist the disruptive force created by elastic recovery even under low pressure. Combustion results showed that the addition of P decreased the soot index (SI) due to the lower devolatilization rate and burnout rate, and increased the HHV per unit volume because of its high relaxed density. Thus, compression of waste P and S in a P/S mass ratio of 1–3 at room temperature under 6MPa is a cost-effective process to produce densified sustainable bio-fuel from waste S and P as well as dispose them. [Copyright &y& Elsevier]

Abstract: This aim of this study was to optimize the conditions for efficient saccharification of paper sludge (PS) considering PS cellulose concentration, buffer capacity, and cellulase activity from Acremonium cellulolyticus. PS is a cellulosic biomass, the residue of paper making industry, composed of 24.5% cellulose, 10.5% clay, and 65% water. Clay present in PS did not show any inhibitory effect on the saccharification process but influenced the buffer pH. Maleate buffer in the pH range 5.2–5.6 was suitable for the saccharification of PS cellulose. The maximum reducing sugar concentration that could be obtained from 75.6 kg m−3 of PS cellulose was predicted to be 37.8 kg m−3. This was experimentally confirmed to be 38.4 kg m−3 under the optimal saccharification conditions at pH 5.2 (1.06 kmol m−3 Maleate buffer) using Cellulase 20,000 FPU m−3. Almost 100% saccharification yield (SY) was obtained at a low PS cellulose concentration of 15 kg m−3, but this value decreased when the cellulose content increased. When PS was hydrolyzed with commercial cellulase GC220, the SY and glucose content were 54% and 60% of SY, respectively. The corresponding values with Cellulosin T2 were 63% and 75% of SY, respectively. A. cellulolyticus yielded SY and glucose content values almost 10% higher than those obtained with other cellulases. [Copyright &y& Elsevier]