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Mitigation of global warming, energy security and industrial competitiveness urge the energy-intensive pulp and paper industry (PPI) to transform energy use practices. This study investigates how the PPI has responded to the need for the energy transition in the 2000s. Finland and Sweden as forerunners of energy-efficient operation and decarbonization of the PPI are used as target countries. Understanding of changes in energy consumption is complemented using decomposition analysis (Logarithmic Mean Divisia Index Method) and the energy efficiency index approach. Analysis of companies’ investments in energy technologies is used for explaining changes in energy production. Evidence of significant development towards the more sustainable operation of the PPI was found. Energy consumption per produced unit has decreased, i.e., energy efficiency has improved. Fossil fuels have been partially replaced with bio-based alternatives. Thus, the CO2 intensity has decreased substantially. The generation of renewable electricity has increased in both countries. Examples of Finland and Sweden indicate that the PPI has great potential to contribute to CO2 emission reduction worldwide in the future as energy efficiency can be further improved, and the share of fossil fuels can be decreased increasing the use of biofuels and self-generated green electricity at least in kraft pulp mills.

The utilization of paper on a commercial scale is increasing day by day throughout the world that produces million of tons of paper waste yearly and burdened for landfills. The present study focuses on the exploitation of waste papers (office paper, newspaper and tissue paper) as a cheapest alternative source of energy to extract fermentable sugar by applying chemical and enzymatic pretreatments. The quantification of released sugar was analyzed by spectrophotometer and high performance liquid chromatography refractive index (HPLC-RI) detector. Cellulose (12 FPU/g) and β-glucosidase (12 FPU/g) was found to be effective for the extraction of fermentable sugar from paper waste. The contents of cellulose (C6H10O5)n, hemicellulose (C5H10O5)n and lignin (C9H10O2,C10H12O3,C11H14O4) found in office paper were 40%, 32.5%, 22.5%, in newspaper 46.5%, 30.5% 22.5%, and in tissue paper 62%, 22%, 15.5%, respectively. The percentages of sugar contents assessed in this study were 62% in tissue paper and 46.5% in newspaper and 40% in office papers. Among the three substrates, tissue paper (23.4 mg/mL) released a significant amount of glucose (C6H6O12), whereas newspaper (20.8 mg/mL) and office paper (19.6 mg/mL) released less amount of sugar. This research of acid pre-treatment and enzymatic hydrolysis was an efficient method to improve glucose conversion from lignocellulosic waste. Furthermore, this approach can be proved the first step towards the sustainable production of bioethanol from wastepaper-extracted sugar.

Paper and pulp mills generate substantial quantities of cellulose-rich sludge materials that are disposed in landfills at a large scale. For sustainability purposes, sludge materials can be bioprocessed to produce renewable fuels and useful chemicals. The enzymatic hydrolysis of cellulose is the process bottleneck that affects the conversion economics directly by using zero-cost raw materials. In order to study and optimize the process, the characteristics of the sludge raw materials should be first evaluated. In this work, sludge samples were obtained from paper mills located at different locations in Wisconsin and Minnesota. Part of the sludge samples was washed (de-ashed) with hydrochloric acid while the other part remained unwashed. The samples were subjected to multiple spectroscopic analyses techniques to evaluate the morphological properties of cellulose fibers and to estimate the total structural carbohydrate content. The results showed that the de-ashing process changed some fiber characteristics and cellulose crystallinity structure in all sludge samples. Sludge sample A (obtained from Kraft pulp and recycled paper mill region) showed a high percentage of fiber, with crystalline cellulose, compared to the other two sludge samples suggesting that sludge A is a valuable source to make value-added products. Aspen Plus mass and energy calculations performed in view of the ‘zero’ cost and the reliable supply of sludge raw materials producing 2 mol H2/mol glucose. Moreover, the results showed that extracting crystalline cellulose from these sludge samples is more profitable than crystalline cellulose made from the other lignocellulosic feedstocks. The results reported here showed that the utilization of these sludge materials would be an economically attractive and promising alternative for the production of hydrogen.

By way of broadening the use of diverse sustainable bioethanol feedstocks, the potentials of Paper mulberry fruit juice (PMFJ), as a non-food, sugar-based substrate, were evaluated for fuel ethanol production. The suitability of PMFJ was proven, as maximum ethanol concentration (56.4 g/L) and yield (0.39 g/g) were achieved within half a day of the start of fermentation, corresponding to very high ethanol productivity of 4.7 g/L/hr. The established potentials were further optimally maximized through the response surface methodology (RSM). At the optimal temperature of 30 °C, yeast concentration of 0.55 g/L, and pH of 5, ethanol concentration, productivity, and yield obtained were 73.69 g/L, 4.61 g/L/hr, and 0.48 g/g, respectively. Under these ideal conditions, diverse metal salts were afterward screened for their effects on PMFJ fermentation. Based on a two-level fractional factorial design, nutrient addition had no positive impact on ethanol production. Thus, under the optimal process conditions, and without any external nutrient supplementation, bioethanol from PMFJ compared favorably with typical sugar-based energy crops, highlighting its resourcefulness as a high-value biomass resource for fuel ethanol production. Graphical Abstract

Paper waste is a raw material for a lot of products with different added value. The engineering, economic and environmental aspects of paper waste recycling are analysed for production of composite material, cellulose nanofibers and nanocrystals, bricks with paper components, porous carbon, film of biopolymer, enzymatic sugar and bioenergy: bioethanol, hydrogen and biofuel. Through multicriteria analysis, it was possible to determine the most feasible paper waste recycling product in case of four product groups: egg packaging boxes, cardboard, reused paper, cellulose nanomaterials (nanofibers and nanocrystals). The production of cellulose nanofibres and cellulose nanocrystals has an advantage over egg packaging and cardboard production as well as reusable paper.

Paper sludge is a solid waste by-product abundantly produced in the paper industry and contains fine minerals and lignocellulosic biomass. In this contribution, the ex-situ catalytic fast pyrolysis of paper sludge with a high mineral content of ca. 71 wt% is reported for the first time and demonstrated in a pilot-scale unit (feeding rate of 11.3 kg h−1) using a granular Na2CO3/γ-Al2O3 catalyst (loading of 650 g) to produce a high-grade bio-oil at a fast pyrolysis temperature of 475 ± 5 °C (pre-screened using a pyroprobe) and a catalytic upgrading temperature of 500 °C. Besides, > 99 wt% minerals in the paper sludge could be recovered, including paper fillers such as CaCO3 (major) and talc. The bio-oil obtained at a carbon yield of 21 C.% has a low oxygen content of 3.2 wt%, a low total acidity number of 5.2 mg KOH g−1, low H2O content of 0.7 wt%, and a high higher heating value of 40.9 MJ kg−1. It consists of value-added bio-based chemicals such as paraffins, olefins, and low molecular weight aromatics. The results demonstrate that the use of paper sludge to recover minerals and to obtain fuels and chemicals using ex-situ catalytic pyrolysis is technically feasible at a pilot plant scale, which will be of importance for the development of future bio-based economy.

Waste-to-energy or value-added products have been increasingly considered in many pulp and paper mills (PPMs) worldwide. However, developing appropriate conversion technologies is a major challenge in transforming PPMs wastes into biofuels or value-added biomaterials. In the present study, a long-term (320 d) anaerobic digestion of primary sludge of a thermomechanical pulp mill (TMP) was carried out for the first time in a thermophilic anaerobic membrane bioreactor (ThAnMBR). Effect of organic loading rate (OLR) in the range of 2.5–6.8 kg-COD/m3 d and hydraulic retention times (HRT) of 3–8 d on the process performance was investigated. Under various OLRs, stable biogas productions were obtained, and the best results were achieved with lower OLR (2.5 kg-COD/m3 d) and higher HRT (8 d), at biogas yields of 189 L biogas/kg MLSS fed. However, it was found that biogas production and sludge biomass degradation decrease when the organic loading rate increases. The proportion of sludge reduction ranged from 28.9 to 46.7% depending on the applied OLRs. Despite varying OLRs, stable membrane performance was obtained, where the required membrane flux was easily maintained during the reactor operation. In this study, also the properties of digestate and membrane permeates were studied under different operating conditions, and they fluctuated to some extent with OLR. ThAnMBR is a promising new technology for pulp and paper mill primary sludge treatment.

Brazil is currently focused on its energy matrix transition in favor of increasing of the share of renewable energy carriers for both enhanced energy security and mitigation of greenhouse gas emissions. In this context, the country`s pulp and paper industry whose different wastes teams are not generally exploited, could play a critical role. Accordingly, the main objective of this work is to develop a conceptual ‘systemic’ biorefinery framework integrating the treatment of pulp and paper mill wastewater using upflow anaerobic sludge blanket (UASB) reactor with energy recovery through biogas production and its conversion into heat and power in stationary engines and boilers, respectively. Based on the results obtained through the present case study, it was revealed that the adoption of UASB reactors by the paper mill industry could properly addresses the environmental concerns faced while could contribute to the national agenda favoring an increasing share of renewable energies in the country`s energy matrix. The financial analysis showed that the investment required for the implementation of UASB reactors within a biorefinery platform would be minor vs. the investment in the whole mill and would be returned in 6.4 yr with a high return on investment even when operated at half of operational capacity. Moreover, through the developed UASB reactor-based biorefinery, the Brazilian pulp and paper industry as a whole could avoid 1.06 ×105 CO2eq tons, effectively contributing to the decarbonization of the country`s economy.

Aims: The aim of the present study is to produce ethanol from waste paper and spent mushroom using Saccharomyces cerevisiae as enzymes for the fermentation process. Study Design: Waste paper and spent mushroom samples were subjected to fermentation and hydrolysis by Aspergilus niger and Saccharomyces cerevisiae to produce bioethanol. Place and Duration of Study: This study was carried out in the Environmental Microbiology Laboratory, University of Port Harcourt, Nigeria, between May and October 2017. Methodology: Waste paper and spent mushrooms samples were hydrolyzed by Aspergillus niger, and the hydrolysate from each set up subjected to fermentation by Saccharomyces cerevisiae. Ethanol was extracted by fractional distillation, and qualitatively determined by Gas Chromatography with Mass Spectrometry. Results: After 8 days of fermentation, there was decrease in glucose content in waste paper hydrolysate ranging from (0.51-0.1 mg/l), and spent mushroom substrate (0.3-0.07 mg/l). Upon extraction of the bioethanol, the highest yield was recorded for waste paper hydrolysate which after characterization with GC-MS ethanol concentration was 28.01 mg/l, followed by spent mushroom hydrolysate 26.8 mg/l. Conclusion: This study revealed that bioethanol can be obtained from fermentation of waste paper using Saccharomyces cerevisiae and ethanol can be obtained after the paper has been used in growing edible mushroom; if adopted, this could be a way to achieving environmental sustainability.

Ample interest for more efficient utilization of bio-based residues has emerged in the Nordic pulp and paper (P&P) industry, which uses virgin wood as feedstock. Although different bioenergy retrofit technologies for production of liquid, solid, and gaseous bioenergy products have been applied in the existing P&P mills, the number of installations remains small. The lack of profound knowledge of existing bioenergy retrofits hinders the replication and market uptake of potential technologies. This review synthesises the existing knowledge of European installations and identifies the key drivers and barriers for implementation to foster the market uptake of potential technologies. The bioenergy retrofits were reviewed in terms of technical maturity, drivers, barriers and market potential. Based on this evaluation, common drivers and barriers towards wider market uptake were outlined from political, economic, social, technical, environmental, and legal perspective. Technologies already commercially applied include anaerobic fermentation of sludge, bark gasification, tall oil diesel and bioethanol production, whereas lignin extraction, biomethanol production, hydrothermal liquefaction and hydrothermal carbonization are being demonstrated or first applications are under construction. The findings of this review show that a stable flow of residues at P&P mills creates a solid base for retrofitting. New innovative bio-based products would allow widening the companies' product portfolios and creating new businesses. Also, European Union's (EU) legislation drives towards advanced biofuels production. Wider uptake of the retrofitting technologies requires overcoming the barriers related to uncertainty of economic feasibility and unestablished markets for new products rather than technical immaturity.

A new process for the production of bioethanol from paper mill sludge (PMS) is described in this work. PMS biomass feedstock was processed via the simultaneous saccharification and fermentation (SSF) with and without accelerants. The enzymatic hydrolysis and fermentation were first evaluated, and the energy demand was 2.2 MJ/L of produced ethanol. When the enzymatic hydrolysis and fermentation were combined, the energy demand was reduced to 1.0 MJ/L ethanol, the sugars production increased, and the overall capital cost of the process decreased. The sugar yield was improved by adding accelerant and selecting the optimal fiber recovery method. The accelerant improved the enzymatic hydrolysis via a pathing/bridging mechanism. The SSF with the chemical fiber recovery method coupled with accelerant addition would be the best process configuration. Upon this combination, the glucose profile was enhanced from 9.8 g/L to 17.0 g/L. The sludge fiber conversion by SSF was improved by selecting an efficient fiber recovery method combined with the accelerant addition. SSF in chemical fiber recovery with accelerant addition was the best process by a 10% improvement of ethanol yield. The proposed process configuration offers a lower cost and sustainable process and contributes to the circular economy of zero waste discharges.

This study presents 5-hydroxymethylfurfural removal from waste hand paper hydrolysate using activated carbon adsorption. In this context, the effects of adsorbent dosage, initial 5-hydroxymethylfurfural concentration, temperature, and agitation speed on 5-hydroxymethylfurfural adsorption were investigated. Moreover, isotherm and kinetic evaluations were performed using Langmuir, Freundlich, and Temkin models. The experimental data were correlated with zero, first, pseudo-first, and Weber–Morris intraparticle diffusion models. The toxicity of 5-hydroxymethylfurfural was determined using the resazurin reduction assay, and the EC50 of 5-hydroxymethylfurfural in the hydrolysate was found as 192 mg/L. Most convenient 5-hydroxymethylfurfural adsorption was obtained at 5 g/L AC dosage, 40 °C and 150 rpm agitation speed. The highest 5-hydroxymethylfurfural removal efficiency was 92% at 7 g/L AC dosage. The adsorption data fitted best with the Langmuir isotherm model with a maximum uptake capacity of 70.92 mg/g (R2: 0.96). The zero-order reaction kinetic model was the most suitable one among the others inspected. It was determined that intraparticle diffusion was not the rate-limiting step. This study showed that waste hand paper hydrolysate can effectively be detoxified by activated carbon adsorption. © 2019, Islamic Azad University (IAU).

Black liquor (spent cooking liquor) is one of the major byproducts of pulp and paper manufacturing. Black liquor contains 10–50% lignin, which is the main organic matter found within that liquor. Different types of black liquors are obtained as per the type of feedstock, pulping process and cooking method adopted by industries. In recent years, industries have been required to accommodate newer varieties of feedstock such as non-wood and recycled fibers during the delignification process, which can save plenty of trees and hence reduce their carbon footprint. Therefore, the newer black liquors being generated differ in their physical characteristics, chemical composition, and energy content from that of traditional processes.Currently, black liquor is seen as a platform for the production of many renewable materials for industrial applications that can be environmentally friendly with the potential to be used substitute for fuel and commercial materials. However, most of the published review articles focus on the kraft spent liquor and its derived kraft lignin that is obtained from kraft pulping process at the pulp and paper as a source of bio-fuel and biomaterials. Meanwhile, several other black liquors such as soda, and neutral sulfite spent (NSSC) liquor and their derived lignin are not highlighted as sources of biofuel and biomaterials. Therefore, this review highlights all the types of black liquors including soda, and neutral sulfite spent (NSSC) liquor in terms of their sources, physical and chemical characterization, purification processes, and the potential applications of black liquor and its derived lignin.

International audience; The hemp plant Cannabis sativa Linn, referring to industrial hemp, is a high-yielding annual industrial crop grown providing fibers from hemp stalk and oil from hemp seeds. Although hemp is a niche crop, hemp production is currently undergoing a renaissance. More than 30 countries grow hemp, with China being the largest hemp producing and exporting country. Europe and Canada are also important actors in the global hemp market. Traditionally, hemp as a fiber plant has been used for the production of apparels, fabrics, papers, cordages and building materials. The hurds, as waste by-product of fiber production, were used for bedding of animals, the seeds for human nutrition, e.g., as flour, and the oil for a wide range of purposes, from cooking to cosmetics. Hemp has also been an important crop throughout human history for medicine. Other more recent applications include materials for insulation and furniture, automotive composites for interior applications and motor vehicle parts, bioplastics, jewelry and fashion sectors, animal feed, animal bedding, and energy and fuel production. Foods containing hemp seed and oil are currently marketed worldwide for both animal and human nutrition. They also find applications in beverages and in neutraceutical products. Hemp oil is also used for cosmetics and personal care items, paints, printing inks, detergents and solvents. It is estimated that the global market for hemp consists of more than 25,000 products. Currently, the construction and insulation sector, paper and textile industries, and food and nutrition domains are the main markets while the cosmetics and automotive sector are growing markets. Innovative applications, e.g., in the medical and therapeutic domains, cosmeceuticals, phytoremediation, acoustic domain, wastewater treatment, biofuels, biopesticides and biotechnology, open new challenges. Hemp is also the object of numerous fundamental studies. This review presents and discusses the traditional and new uses of industrial hemp.

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 VSadded) 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.

Background: In spite of the continuous efforts and investments in the last decades, lignocellulosic ethanol is still not economically competitive with fossil fuels. Optimization is still required in different parts of the process. Namely, the cost effective usage of enzymes has been pursued by different strategies, one of them being recycling. Results: Cellulase recycling was analyzed on Recycled Paper Sludge (RPS) conversion into bioethanol under intensified conditions. Different cocktails were studied regarding thermostability, hydrolysis efficiency, distribution in the multiphasic system and recovery from solid. Celluclast showed inferior stability at higher temperatures (45-55 ºC), nevertheless its performance at moderate temperatures (40ºC) was slightly superior to other cocktails (ACCELLERASE®1500 and Cellic®CTec2). Celluclast distribution in the solid-liquid medium was also more favorable, enabling to recover 88 % of final activity at the end of the process. A Central Composite Design studied the influence of solids concentration and enzyme dosage on RPS conversion by Celluclast. Solids concentration showed a significant positive effect on glucose production, no major limitations being found from utilizing high amounts of solids under the studied conditions. Increasing enzyme loading from 20 to 30 FPU/ gcellulose had no significant effect on sugars production, suggesting that 22 % solids and 20 FPU/gcellulose are the best operational conditions towards an intensified process. Applying these, a system of multiple rounds of hydrolysis with enzyme recycling was implemented, allowing to maintain steady levels of enzyme activity with only 50 % of enzyme on each recycling stage. Additionally, interesting levels of solid conversion (70-81 %) were also achieved, leading to considerable improvements on glucose and ethanol production comparatively with the reports available so far (3.4 and 3.8 fold, respectively). Conclusions: Enzyme recycling viability depends on enzyme distribution between the solid and liquid phases at the end of hydrolysis, as well as enzymes thermostability. Both are critical features to be observed for a judicious choice of enzyme cocktail. This work demonstrates that enzyme recycling in intensified biomass degradation can be achieved through simple means. The process is possibly much more effective at larger scale, hence novel enzyme formulations favoring this possibility should be developed for industrial usage., This work had the fnancial support of the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the MultiBiorefnery project (POCI-01-0145-FEDER-016403). Furthermore, FCT equally supported the Ph.D. grant to DG (SFRH/BD/88623/2012)., info:eu-repo/semantics/publishedVersion

The present work establishes the cost-effective and miniature microfluidic self-pumping paper based enzymatic biofuel cell (P-EBFC). The developed Y-shaped P-EBFC consists of buckeye composite multiwall carbon nanotube (MWCNT) buckypaper (BP) based bio-anode and bio-cathode that were immobilized with electro-biocatalytic enzymes glucose oxidase (GOx) and laccase, respectively. The electrocatalytic activity of enzymes on electrode surface is confirmed using cyclic voltammetry (CV) technique. Such immobilized bio-anode and bio-cathode show exquisite electrocatalytic activity towards glucose and O2, respectively. Most appealingly, P-EBFC can directly harvest energy from widely available beverages containing glucose such as Mountain Dew, Pepsi, 7up and fresh watermelon juice. This could provide potential application of P-EBFC as a portable power device.

Sustainable power generation for portable electronic devices is of high interest due to increasing energy demands. Miniaturized biofuel cells are well-reported for this purpose where ubiquitous fluids, like glucose or lactate, can be leveraged. However, such biofuel cells need enzymes to complete the catalysis, leading to many prevalent issues like the longevity of enzymes, complicated immobilization, additional mediators etc. Therefore, non-enzymatic glucose biofuel cells (NEGBFCs) are gaining interest due to their cost-effectiveness, high repeatability and excellent stability. However, based on our best knowledge such glucose biofuel cells are not reported in microfluidic environment, and therefore their potential is not exploited. Realization of the functionality of such NEGBFCs in a microscale is crucial to replace them with their enzymatic counterparts. In this work, for the first time, a microfluidic non-enzymatic glucose biofuel cell (μNEGBFC) is developed on a paper-based platform using metallic catalysts. The catalysts for electrocatalytic energy generation is fabricated using electrodeposition method and their detailed physicochemical characterizations are done. The μNEGBFC is capable of producing a power density of 12.5 μW/cm2 with a stable potential of 410 mV. This green power output can be used to operate low-power micro-devices and lab-on-chip sensors in a more continual and viable manner.

As a kind of industrial hazardous solid waste, paper mill sludge (PMS) was hard to treated by conventional process because of its high moisture, high organic content and and high environmental risk. The hydrothermal liquefaction (HTL) shows excellent potential for the conversion to a wide variety of organic matter with high water contents including various kinds sludge into fuels or value-added chemicals. In this paper, the liquefaction potential for PMS under different reaction temperatures were investigated, and the products were classified into several main components based on the results of GC-MS. The results showed that the highest yield of bio-oil was 44 % (wt/wt dry PMS without ash) at 340 °C with simply compound composition. And the bio-oil product has above 26 % long chain hydrocarbon and 22 % cycloketones. It has potential for conversion to biomass platform compounds. It can be used as bio-fuel for heat recovery of alkali recovery system of paper mill. So, adjusting different reaction temperatures of HTL, the properties of products can meet the different requirements for platform chemical and/or bio-oil fuel.

This study used the subcritical hydrothermal liquefaction technique (SHLT) in the co- liquefaction of process rejects at a wastepaper-based paper mill (PRWPM) and waste soybean oil (WSO) for the production of biofuels and bio-char material. PRWPM emits complicated waste composed of cellulose, hemicellulose, lignin, and plastic from sealing film. The waste is produced from the recycled paper process of a mill plant located in central Taiwan. The source of WSO is the rejected organic waste from a cooking oil factory located in north Taiwan. PRWPM and WSO are suitable for use as fuels, but due to their high oxygen content, their use as commercial liquid fuels is not frequent, thus making deoxygenation and hydrogenation necessary. The temperature and pressure of SHLT were set at 523–643 K and 40–250 bar, respectively. The experimental conditions included solvent ratios of oil–water, temperature, reaction time, and ratios of solvent to PRWPM. The analysis results contained approximated components, heating values, elements, surface features, simulated distillations, product compositions, and recovery yields. The HHV of the product occurred at an oil–water ratio of 75:25, with a value of 38.04 MJ kg−1. At an oil–water ratio of 25:75, the liquid oil-phase product of SHTL has the highest heating value 42.02 MJ kg−1. Higher WSO content implies a lower heating value of the oil-phase product. The simulated distillation result of the oil-phase product with higher content of alcohol and alkanes obtained at the oil–water ratio of 25:75 is better than the other ratios. Here, the carbon number of the oil product is between C8–C36. The product conversion rate rises with an increase of the WSO ratio. It is proved that blending soybean oil with water can significantly enhance the quality of liquefied oil and the conversion rate of PRWPM. Therefore, the solid and liquid biomass wastes co-liquefaction to produce gas and liquid biofuels under SHLT are quite feasible.

Wastewater containing kraft lignin (KL) discharged from pulp and paper industries could cause serious environmental contamination. Appropriate effluent treatment is required to reduce the pollution. Investigations on anaerobic bacteria capable of degrading KL are beneficial to both lignin removal and biofuel regeneration from the effluent. In this paper, an anaerobic strain capable of degrading KL was isolated from the sludge of a pulp and paper mill and identified as Dysgonomonas sp. WJDL-Y1 by 16S rRNA analysis. Optimum conditions for KL degradation by strain WJDL-Y1 were obtained at initial pH of 6.8, C:N ratio of 6 and temperature of 33°C, based on statistical analyses by response surface methodology. For a 1.2 g/l KL solution, a COD removal rate of 20.7% concomitant with biomass increase of 17.6% was achieved after 4 days of incubation under the optimum conditions. After the treatment by strain WJDL-Y1, KL was modified and degraded.

Due to the health and environment impacts of fossil fuels utilization, biofuels have been investigated as a potential alternative renewable source of energy. Bioethanol is currently the most produced biofuel, mainly of first generation, resulting in food-fuel competition. Second generation bioethanol is produced from lignocellulosic biomass, but a costly and difficult pretreatment is required. The pulp and paper industry has the biggest income of biomass for non-food-chain production, and, simultaneously generates a high amount of residues. According to the circular economy model, these residues, rich in monosaccharides, or even in polysaccharides besides lignin, can be utilized as a proper feedstock for second generation bioethanol production. Biorefineries can be integrated in the existing pulp and paper industrial plants by exploiting the high level of technology and also the infrastructures and logistics that are required to fractionate and handle woody biomass. This would contribute to the diversification of products and the increase of profitability of pulp and paper industry with additional environmental benefits. This work reviews the literature supporting the feasibility of producing ethanol from Kraft pulp, spent sulfite liquor, and pulp and paper sludge, presenting and discussing the practical attempt of biorefineries implementation in pulp and paper mills for bioethanol production.

A novel paper‐based biofuel cell with a series/parallel array structure has been fabricated, in which the cell voltage and output power can easily be adjusted as required by printing. The output of the fabricated 4‐series/4‐parallel biofuel cell reached 0.97±0.02 mW at 1.4 V, which is the highest output power reported to date for a paper‐based biofuel cell. This work contributes to the development of flexible, wearable energy storage device.

Worldwide pulp and paper industry is recognized as a serious threat due to the discharge of various toxic contents present in its effluent to the surrounding environment. To combat this challenge, the role of oleaginous yeast to utilize the pulp and paper industry effluent for the integrated toxic contents removal and sustainable biodiesel production were undertaken. Oleaginous yeast Rhodosporidium kratochvilovae HIMPA1 was used as a model organism for its unique ability to utilize pulp and paper industry effluent as a culture medium and accumulate high quantity of triacylglycerol or neutral lipids as large size lipid droplets of 4.56 ± 0.24 μm within its cellular compartment. The maximum cell dry weight (13.87 g/L) with total lipid yield of 8.56 g/L was obtained after 144 h of cultivation. Data showed significant reduction in effluent toxic components i.e. color, 89%; lignin, 94.27%; phenol, 99.60%; biochemical oxygen demand, 77.36%; total dissolved solids, 84.59%; and chemical oxygen demand, 94.22%. Fatty acid methyl esters profile revealed high quantity of long chain monounsaturated fatty acids (45.43%) and polyunsaturated fatty acids (15.91%) that improves biodiesel quality under low temperature condition in terms of low cold filter plugging point along with good oxidative stability and cetane number as per American Society for Testing and Materials D6751-02 and European Committee for Standardization - EN14214 guidelines.

Humanity is facing some major global threats, namely lack of environmental sustainability, the energy crisis associated with the unsustainable reliance on fossil fuels, and water scarcity, which will be exacerbated with the rapid growth of urban areas. Researchers have drawn their attention to microalgae, photosynthetic microorganisms known for their environmental applications, such as wastewater remediation and lipids accumulation, to produce third-generation biofuels to solve some of these major issues. Considering this dual role, this study evaluated the potential of the microalga Chlorella vulgaris on nutrient removal from a paper industry effluent and bioenergy production. Firstly, experiments were performed to assess the potential of this microalga to: (i) successfully grow in different concentrations of a paper industry effluent (20% to 100%), and (ii) treat the industrial effluent, reducing phosphorus concentrations to values below the accepted legal limits. Then, a techno-economic assessment was performed to study the viability of a C. vulgaris biorefinery targeting the remediation of a paper industry effluent and bioenergy production. The results have shown that C. vulgaris was able to successfully grow and treat the paper industry effluent. Under these conditions, average biomass productivities determined for this microalga ranged between 15.5 &plusmn, 0.5 and 26 &plusmn, 1 mg dry weight (DW) L&minus, 1 d&minus, 1, with maximum biomass concentrations reaching values between 337 &plusmn, 9 and 495 &plusmn, 25 mg DW L&minus, 1. Moreover, final phosphorus concentrations ranged between 0.12 &plusmn, 0.01 and 0.5 &plusmn, 0.3 mg P L&minus, 1, values below the legal limits imposed by the Portuguese Environment Agency on the paper industry. Regarding the proposal of a microalgal biorefinery for the bioremediation of paper industry effluents with bioenergy production, the techno-economic study demonstrated that six of the seven studied scenarios resulted in an economically-viable infrastructure. The highest net present value (15.4 million euros) and lowest discounted payback period (13 years) were determined for Scenario 3, which assumed a photosynthetic efficiency of 3%, a lipids extraction efficiency of 75%, and an anaerobic digestion efficiency of 45%. Therefore, it was possible to conclude that besides being economically viable, the proposed biorefinery presents several environmental benefits: (i) the remediation of an industrial effluent, (ii) CO2 uptake for microalgal growth, which contributes to a reduction in greenhouse gases emissions, (iii) production of clean and renewable energy, (iv) soil regeneration, and (v) promotion of a circular economy.

The aim of the project “More Fuels from Organic Residues” (MOTOR) is to produce advanced biofuels for the transport sectors where electrification or gaseous biofuels will not generate the reduction of their carbon footprint in the short term. In MOTOR, wet lignocellulosic waste streams that do not compete with the food/feed market are used as a feedstock for a smart fermentation process. In the present study, the utilization of paper sludge as substrate for fermentation for production of fuel precursors and subsequent catalytic conversion to fuels at laboratory scale is described. The steps of the process were assessed experimentally, and based on the data generated, a conceptual process is being developed to explore the economic and sustainability aspects of the new value chain for biofuel.. Results show that solubilization of sugars from paper sludge using existing enzyme cocktails is very limited and needs improvement. On the other hand, the catalytic production of fuel from the fermentation products shows promising results in terms of type of products., Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 24-27

In order to make 2nd-generation biofuels more competitive, high solid-matter content has to be reached. To progress towards this target, the mechanism for destructuring lignocellulose fibres in semidilute conditions has to be well understood, as this configuration shows the basic mechanism which limits transfers and efficiency. This study aims to delve deeply into the biophysical and transfer limitations occurring during enzymatic hydrolysis. A specific experimental set-up associating in-situ and ex-situ physical (rheometry, chord length analysis) and biochemical analysis was used to expand the knowledge of hydrolysis of extruded softwood paper pulp over 24 h under different substrate concentrations (1%–3%) and enzyme doses (Accellerase 1500, 5 and 25 FPU/g cellulose). Non-Newtonian behaviour associated with pronounced yield stress stand as the major factors limiting process efficiency. A critical time was deduced from viscosity evolution, and the existence of a unique, dimensionless viscosity-time curve was established, suggesting similar mechanisms for fibre degradation. In addition, chord length distribution allowed for the description of population evolution and was discussed in the light of in-situ viscosity and hydrolysis yield. Physical (viscosity, particle size) and biochemical (substrate) kinetics were modelled (second-order) and coefficients identified. A chronology of the encountered phenomenological limitations demonstrates the necessity of optimising bioprocesses by considering physical parameters. A reference feed rate is proposed in order to reach high solid loading under fed-batch strategy.

The economics of Recycled Paper Sludge conversion into ethanol was here assessed with emphasis on integrating a cellulase recycling system. Without cellulases recycling this process presented positive economic outputs (payback period of 7.85 years; 10.90 Million US$ of accumulated NPV) despite the modest ethanol titers. Recycling both free and solid-bound enzymes allowed considerable savings of enzyme but also an increase on annual costs (0.88 %), resulting on a superior economic output: payback period decreased to 7.25 years; accumulated NPV increased to 14.44 Million US$. Recycling exclusively the liquid fraction enabled a clear costs reduction, however, also total ethanol decreased, attenuating the abovementioned benefits. Targeting higher ethanol concentrations, superior solids consistencies were also evaluated. Despite a costs reduction, total ethanol decreased due to a higher ethanol retention on the solid. A sensitivity analysis further revealed that the cost of enzymes and ultrafiltration membrane may be critical on enzyme recycling economic feasibility., This work had the financial support of the Portuguese Foundation for Science and Technology, Portugal (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the MultiBiorefinery project (POCI-01-0145-FEDER-016403). Furthermore, FCT equally supported the PhD grant to DG (SFRH/BD/88623/2012)., info:eu-repo/semantics/publishedVersion

Cellulase has by vast applications in the biofuel, pulp and paper, detergent and textile industries. The three components of the enzyme complex (endoglucanase, exoglucanase and β-glucosidase) can effectively depolymerize the cellulose chains in lignocellulosic substrate. Solid-state fermentation (SSF) by fungi is a preferable production route for cellulase because of its low cost, among other advantages. This work describes the cellulase production by Aspergillus niger NRRL3 grown on SSF. SSF was carried out on soybean hulls and waste paper as supports. The effect of the support on cellulase production was assessed under a completely randomized factorial design. The support-time interaction was significant for all the variables studied. Both materials were characterized in terms of water absorption index and critical humidity point. Samples of culture were analyzed with scanning electron microscopy (SEM) to study spores and fungal growth. Maximum endoglucanase activity was found at 96 h using soybean hulls as support (5914.29 U L−1), being four times higher than that obtained using waste paper at the same fermentation time. The exoglucanase activity in soybean hulls was maximal at 96 h (4551.19 U L−1), being 9.6 times higher than that obtained in waste paper at the same time. The maximum β-glucosidase activity in soybean hulls (984.01 U L−1) was reached at 96 h, being 1.7 times greater than that obtained in waste paper. Besides, the use of soybean hulls provided high volumetric productivities at shorter times, which may decrease production costs considering a scaled process. Fil: Boggione, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; Argentina Fil: Allasia, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina Fil: Bassani, Georgina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; Argentina Fil: Farruggia, Beatriz Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Procesos Biotecnológicos y Químicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Procesos Biotecnológicos y Químicos Rosario; Argentina

A biofuel cell that can generate electricity using only water is expected to be used as a new energy harvester for an emergency power supply. A new 4-series/4-parallel structured paper-substrate biofuel cell was prepared using a fuel supply paper preloaded with glucose and phosphate buffer salts. When a power generation test was conducted by supplying water to the fuel-preloaded paper, the paper-based biofuel cell produced an output approximately 90% (0.84 mW) of that obtained by supplying a phosphate buffer containing glucose as the electrolyte. The open-circuit voltage was 2.1 V, and an LED could be powered by simply supplying water to the cell without using a booster circuit.

Paper mill sludge (PMS) solids are predominantly comprised of cellulosic fibers and fillers rejected during the pulping or paper making process. Most sludges are dewatered and discharged into landfills or land spread at a cost to the mill; creating large economic and environmental burdens. This lignocellulosic residual stream can be used as a source of sugars for microbial fermentation to renewable chemicals. The aim of this study was to determine the possibility of converting mill sludge to sugars and then fermentation to either isoprene or ethanol. Chemical analysis indicated that the cellulosic fiber composition between 28 to 68% and hemicellulose content ranged from 8.4 to 10.7%. Calcium carbonate concentration in the sludge ranged from 0.4 to 34%. Sludge samples were enzyme hydrolyzed to convert cellulose fibers to glucose, percent conversion ranged from 10.5 to 98%. Calcium carbonate present with the sludge resulted in low hydrolysis rates; washing of sludge with hydrochloric acid to neutralize the calcium carbonate, increased hydrolysis rates by 50 to 88%. The production of isoprene “very low” (190 to 470 nmol) because the isoprene yields were little. Using an industrial yeast strain for fermentation of the sludge sugars obtained from all sludge samples, the maximum conversion efficiency was achieved with productivity ranging from 0.18 to 1.64 g L−1 h−1. Our data demonstrates that PMS can be converted into sugars that can be fermented to renewable chemicals for industry.

In accordance with global estimations, approx. 15 million tons of residues are yearly generated from paper and pulp industry, which are traditionally used as biofuels or just disposed in landfills. However, residues composition and laws in force urge producers to search for new waste management strategies. From another point of view, the construction industry uses more than 33% of total natural resources, worldwide which has led several governments to limit the use of natural raw materials for building. In particular, fired brick industry produces yearly approx. 1600 billion bricks which represents millions of tons of natural resources consumption. Therefore, the goal is to contribute to reduce the amount of used clay. Thus, this paper explores the mineral and technological properties of brick made by using different percentages of paper pulp residues and fired at 900 °C. Results indicate that by increasing the replacement ratio, blend requires larger amounts of water which leads to a proportional increasing of shrinkage during drying. In spite of mineral transformations are not influenced by paper pulp residue, the porosity is linearly increased which leads to reduce compressive strength and thermal conductivity up to 30% for 20% of replacement ratio, in both cases. Thus, it is concluded that series made by replacing up to 10% show compressive strength above 5 MPa, water absorption beyond 20% and toxicity indexes meet the mandatory requirements.

For making biomass fuel i.e. for making alternative fuel for coal or other conventional sources of energy it is important to find certain parameters. Calorific value is the most important property of a fuel whereas moisture content, ash content also significantly affects the performance of fuel. Here, the work focuses on making a biomass fuel with the combination of three materials i.e. sugarcane bagasse, sawdust and paper waste. These raw materials are selected on the basis of their calorific value, ash content, moisture content, easy availability and its cost. In sugar mills, major by product is sugarcane bagasse and therefore we used 50-60% of sugarcane bagasse for making fuel, paper waste is easily available and also its property is that it increases the calorific value if it is used 10-20% and if it is further increased then calorific value starts decreasing, sawdust is used 20-40% . Its calorific value is also high. MINITAB SOFTWARE is used for the design of experiment. Moisture content is determined with the help of DIGITAL MOISTURE ANALYZER. Ash content is determined by using ELECTRIC COIL HEATER and MUFFLE FURNACE. Calorific value is calculated by using MODIFIED DULONG FORMULA. From tests it is obtained that moisture content is between 8%-12%, ash content is in the range of 4%-8% and calorific value is between 2800 Kcal/kg – 3000 Kcal/kg. Now this fuel is compared with coal. The main point of view for making this bio fuel is that it can be efficiently used for co generation with coal which results in less consumption of conventional fuels which will have large no. of benefits like first and foremost is that coal is conventional and non renewable source of energy so its consumption will be reduced, pollution will be less, emissions of GHG like SOX, NOX, CO2 will be reduced, cost of plant is reduced, ash content is the main drawback of thermal plants, handling of ash is very big problem of thermal power plants and if 50% use of coal is reduced then ash is reduced and last raw materials will be used efficiently.

A paper-based, origami, glucose/O2, biofuel cell (PBFC) was constructed as an array of two individual cells by screen-printing. The fabricated PBFC, which modulated output voltage by paper folding, exhibited almost 1 V of open-circuit voltage without any booster circuit. The maximum output power density of the PBFC was 180 µW cm−2. This PBFC concept is highly applicable to the development of high-power, low-cost, and flexible energy-harvesting devices.

Fatty acid methyl ester (FAME) from spent vegetable oils requires pre and or post-transesterification treatment to meet International norms for biodiesel. The present study assessed the potential of waste printing paper (WPP) as post-transesterification treatment for adsorption of metals from FAME obtained from Nigerian neat and spent vegetable oils (NSpVOs). The WPP adsorbent was prepared according to Moyib et al. (2017). The adsorption experiments for the removal of single metal ions were carried out using 10 mL FAME samples, 1.0 g WPP at a constant 25 o C, pH 6 for 60 min. At the end of the contact time, alkali metals in FAMEs were estimated according to EN 14108 and EN 14109 for Na and K, respectively and alkaline and heavy metals followed AOAC (2005). The results revealed WPP was able to reduce the metal content in the FAME to acceptable limit level and also, enhanced biofuel properties such as acid value (AV) and Conradson carbon (CC) but with loss of minute FAME. Cluster analysis distinguished FAMEs after and before WPP adsorption treatment. Part I and II of this study show feasibility for diversifying Nigerian spent vegetable oils as non-food option for production of biodiesel and achieve low carbon footprint. Also, WPP as locally available and cheap adsorbent showed good potential as post-transesterification treatment of FAME to desirable quality.

Pulp and paper industry primary sludge being largely composed of lignocellulosic fibres, it could be used as carbon source by bacteria having cellulolytic capability. The aim of this study was to evaluate the use of cellulose contained in this type of sludge for Clostridium thermocellum to produce ethanol, hydrogen and cellulases. In an ATCC 1191 medium containing 5 kg m−3 dry primary sludge from recycled paper mill, batch culture reached stationary phase after 2 days. All of the available cellulose was hydrolysed after 60 h of incubation, with a final pH of 5.83. Metabolites produced after 60 h of fermentation were acetate (8.50 mol m−3), ethanol (11.30 mol m−3), lactate (8.75 mol m−3), formate (0.27 mol m−3), hydrogen (11.20 mol m−3) and carbon dioxide (18.41 mol m−3). Cellulase activity was detected in the supernatant after 36 h, with a maximal activity of 0.25 U cm−3 at 72 h. Pulp and paper primary sludge appeared to be a readily usable substrate for C. thermocellum at this concentration, yielding both potential biofuels (hydrogen and ethanol) as well as active cellulases.

This paper presents a MILP (Mixed Integer Linear Programming) model for a continuous packed-bed biomass dryer. The model minimizes total drying costs, including both capital and operational costs, of the dryer. Heated air, which flows through a biomass bed and perforated conveyor, is used as drying gas by the dryer. We define the dryer size with the help of an experimentally-measured characteristic drying curve. The MILP model is tested in a case study where the dryer is assumed to have been installed at a Scandinavian pulp and paper mill. There are three different heat sources available for the heating of drying air: warm water at 60 °C, warm water at 80 °C and backpressure steam at the pressure of 0.4 MPa. The results indicate that, in practice, the use of only low-temperature warm water flows for heating of drying air is the most economic method when their prices are low (below 1 € MWh-1 in the case study). Warm water flows are usually waste heat from pulp and paper mills and their prices are low compared to the price of back-pressure steam (typically from 10 to 15 € MWh-1). The use of steam for drying may be reasonable if the price of warm water is for some reason clearly higher than the price of a typical waste-heat stream. The MILP model presented in this work can be used for minimizing drying costs of any material (not only biomass) dried in a continuous packed-bed dryer if the characteristic drying curve of the material is available.

The aim of this research it is to show how the biogas anaerobic digestion from treatment of recycled pulp and paper wastewater industry (RPPW) can be a renewable energy. Furthermore, a kinetic study of hydrolyzed COD and productions of methane from UASB digester treating RPPW for the continuous test is established. This will allow to reduce the organic matter deposited in landfills and CO2 emissions and to find viable solutions to minimize the environmental impact of RPPW. This study analyses the biogas products and energy recovery processes from a thermic and electric point of view from the theoretical equations. Thus, this study evaluated the performance of mesophilic methanogenic up-flow sludge blanket reactors (UASB) operating continuously in single-stage (UASB I). The maximum methane yields were 250.9 mLCH4/gCOD removed for UASB I, corresponding to 82.7% of the maximum theoretical energy 6.336 kJ/gCOD removed, Methanogenic potential were 4 137 928 m3CH4/year and electrical energy potential were 510 703 MWh/year. The kinetic study allowed us a hydrolysis rate kh = 0.04 indicates a correct simulation for the UASB digester treatment system for RPPW with an R = 99.668%.

Paper mill sludge (PMS) is a residual biomass that is generated at paper mills in large quantities. Currently, PMS is commonly disposed in landfills, which causes environmental issues through chemical leaching and greenhouse gas production. In this research, we are exploring the potential of fast pyrolysis process for converting PMS into useful bio-oil and biochar products. We demonstrate that by subjecting PMS to a combination of acid hydrolysis and torrefaction pre-treatment processes it is possible to alter the physicochemical properties and composition of the feedstock material. Fast pyrolysis of pretreated PMS produced bio-oil with significantly higher selectivity to levoglucosenone and significantly reduced the amount of ketone, aldehyde, and organic acid components. Pretreatment of PMS with combined 4% mass fraction phosphoric acid hydrolysis and 220 °C torrefaction processed prior to fast pyrolysis resulted in a 17 times increase of relative selectivity towards levoglucosenone in bio-oil product along with a reduction of acids, ketones, and aldehydes combined from 21 % to 11 %. Biochar, produced in higher yield, has characteristics that potentially make the solid byproduct ideal for soil amendment agent or sorbent material. This work reveals a promising process system to convert PMS waste into useful bio-based products. More in-depth research is required to gather more data information for assessing the economic and sustainability aspects of the process.

Currently one of the world’s primary energy sources, fossil fuels are also causing an increase in environmental pollution. Besides pollution, these fossil fuels are also diminishing in quantities which increase the need for alternative fuels. This rising need lead to the development of alternative renewable energy resources. A diverse range of sources are available that can be efficiently utilized to produce biofuels, in this research we utilize Tectona grandis (teak wood), Pterocarpus marsupium (malabar kino)and paper as biomass sources to produce bioethanol using Saccharomycescerevisiae fermentation. These biomasses were said to be lignocellulosic substrates rich in cellulose, hemicellulose and lignin. Simultaneous saccharification and fermentation (SSF) are used to in the conversion of substrate to ethanol in which the polysaccharides in the biomass are converted into simple sugars by hydrolysis. After which Saccharomyces cerevisiae used these basic sugars for the development of ethanol by fermentation. A bioethanol yield of 14.1%, 10.81% and 7.5% was obtained from Tectona grandis ,Pterocarpus marsupium and paper respectively, which was analyzed using dichromate titrimetric method. Thebioethanol yield from Tectona grandis is predominantly when compared with other biomasses.

This paper introduces a novel enzymatic fuel cell design that employs cellulose paper-based quasi-2D microfluidic system to supply biofuel to the enzymatic layer. The state of the art nanoarchitectural design, employing carbon nanotube-based papers for the bioelectrodes, allows a single cell to maintain 400 mV for 16 days of continuous operation in glucose solution and reach 1 mA of current output. Stacks of cells connected in series show successful performance using glucose in Gatorade® resulting in stack-cell potential of 1.8 V, employed to power a digital clock for 36 h, continuously. These designs open the possibility for obtaining enzymatic fuel cells that can run small portable devices on easily available ubiquitous liquids while addressing environmental concerns that are prevalent in traditional fuel cells. Keywords: Enzyme, Bioelectrodes, Enzymatic biofuel cells, Microfluidic system, Capillary driven flow, Bucky paper