Increased deployment of solar PV enables the transition to decarbonized energy systems, capable of tempering the dire consequences of global warming. Even though backsheets are very important regarding lifetime energy yield of the PV module, the environmental impacts of their production, use and end-of-life (EoL) processing are largely neglected. As part of a recently finalized Dutch national project EXTENSIBLE (Energy yield assessment of neXT gENeration and SustaInaBLE backsheets) the environmental impacts for 7 different polymeric backsheets have been evaluated via a life cycle assessment (LCA). The selected backsheets include 3 traditional polyethylene terephthalate (PET) - based backsheets with a fluorine containing outer layer (two white pigmented and one fully transparent). The other 4 backsheets are novel high-performance polyolefin (PO) -based backsheets, manufactured by Endurans Solar , also including one transparent version. From results of the LCA it is concluded that in comparison with PET-based backsheets and fluoropolymer containing backsheets, PO-based backsheets perform best in terms of energy yield, reliability and environmental impacts. The production of fluoropolymer- and PET-based backsheets cause substantial environmental impacts, especially regarding climate change and ozone depletion. This conclusion is corroborated by recent literature data. Regarding the EoL phase, it was shown from a theoretical assessment that pyrolysis of the spent backsheets potentially leads to much lower GWP when compared to incineration, especially for the PO-based backsheets. Incineration of the shredded and solid backsheet material causes direct emissions of CO with a limited heat recovery potential only. Deploying pyrolysis for spent PO-based backsheets significantly improves their life-time GWP per kWh produced. Pyrolysis offers the possibility to recover a large part of the polyolefin as an usable pyrolysis oil that might serve as feedstock for chemicals or as transportable liquid fuel for the generation of process heat in recovery boilers, thereby avoiding the use of new fossil resources. EoL pyrolysis (or incineration) of fluoropolymer-based backsheets is problematic due to the presence of fluorinated hydrocarbons, leading to corrosive and/or toxic products.

Analytical pyrolysis (Py-GC/MS) on mg-scale of Norway spruce (Picea abies)-derived kraft lignin, ethanosolv lignin, and dried lignin-rich soda-anthraquinone (AQ) black liquors was studied at 500 °C to compare the valorization potential of these materials, focusing on the type and yield of condensable pyrolysis products. Of particular interest was the relatively selective formation of guaiacol (2-methoxyphenol) from the dried soda-AQ black liquors in contrast to the formation of complex phenolic product mixtures from the pyrolysis of the kraft and ethanosolv lignins. It was shown that this finding could be attributed to differences in composition and structure as was assessed by various NMR and 2D-GC/FID analyses. From a comparison between the analytical pyrolysis results and the results of Norway spruce-derived pyrolysis oils that were produced in earlier research with a state-of-the-art kg-scale bubbling fluidized bed pyrolysis reactor, it was concluded that analytical pyrolysis is suitable to predict the pyrolysis behavior of lignin also on a larger scale. However, it was found that the prediction of reliable product yields for larger-scale pyrolysis from the semi-quantitative analytical pyrolysis yield results was less accurate, mainly due to differences in process conditions, such as heating rate and hot-vapor-residence times leading to secondary degradation reaction of the individual monomers.

Fast pyrolysis is an efficient technology to convert lignocellulosic biomass to a liquid product. However, the high contents of oxygenated compounds and water hinder the direct utilization of pyrolysis oils. Here, we report an upgrading concept to obtain liquid products with improved product properties and enriched in valuable low molecular weight chemicals and particularly alkylphenols. It entails two steps, viz. i) pyrolysis with in-situ staged condensation at multiple kg scale followed by ii) a catalytic hydrotreatment of selected fractions using a Ru/C catalyst. Of all pyrolysis oil fractions after staged condensation, the product collected in a condenser equipped with an electrostatic precipitator (ESP) at 120 degrees C was identified as the most attractive for hydrotreatment when considering product yields and composition. The best hydrotreatment results (Ru/C, 350 degrees C, 100 bar H-2, 4 h) were achieved using beechwood and walnut shells as feedstock, resulting in a high oil yield (about 64 wt% based on pyrolysis oil fraction intake) with a higher heating value of about 37 MJ/kg and enriched in alkylphenols (about 16 wt%). Overall, it was shown that the type of biomass (beech sawdust, walnut granulates, and pine/spruce sawdust) has a limited impact on liquid and alkylphenols yields which implies feedstock flexibility of this integrated concept.

Lignin is an abundant and heterogeneous waste byproduct of the cellulosic industry, which has the potential of being transformed into valuable biochemicals via microbial fermentation. In this study, we applied a fast-pyrolysis process using softwood lignin resulting in a two-phase bio-oil containing monomeric and oligomeric aromatics without syringol. We demonstrated that an additional hydrodeoxygenation step within the process leads to an enhanced thermochemical conversion of guaiacol into catechol and phenol. After steam bath distillation, Pseudomonas putida KT2440-BN6 achieved a percent yield of cis, cis-muconic acid of up to 95 mol% from catechol derived from the aqueous phase. We next established a downstream process for purifying cis, cis-muconic acid (39.9 g/L) produced in a 42.5 L fermenter using glucose and benzoate as carbon substrates. On the basis of the obtained values for each unit operation of the empirical processes, we next performed a limited life cycle and cost analysis of an integrated biotechnological and chemical process for producing adipic acid and then compared it with the conventional petrochemical route. The simulated scenarios estimate that by attaining a mixture of catechol, phenol, cresol, and guaiacol (1:0.34:0.18:0, mol ratio), a titer of 62.5 (g/L) cis, cis-muconic acid in the bioreactor, and a controlled cooling of pyrolysis gases to concentrate monomeric aromatics in the aqueous phase, the bio-based route results in a reduction of CO2 -eq emission by 58% and energy demand by 23% with a contribution margin for the aqueous phase of up to 88.05 euro/ton. We conclude that the bio-based production of adipic acid from softwood lignins brings environmental benefits over the petrochemical procedure and is cost-effective at an industrial scale. Further research is essential to achieve the proposed cis, cis-muconic acid yield from true lignin-derived aromatics using whole-cell biocatalysts.

AbstractDas Vergrößern des Recyclingstroms erfordert einen neuen Ansatz, der über das Schmelzen und Umformen hinausgeht. Es gibt einige Techniken des chemischen Recyclings mit dem Potential, bestehende Recyclingmöglichkeiten zu ergänzen. In diesem Aufsatz sind die Methoden des chemischen Recyclings dargestellt und anhand einer Ökobilanz bewertet, ergänzt durch eine Aufzählung von Prozessen und Firmen in diesem Bereich. Wir zeigen, dass bestimmte Techniken besonders für spezifische Müllströme geeignet sind und dass nur eine Kombination aus den vorhandenen Methoden geeignet ist, das Kunststoffmüllproblem zu lösen. Aktuelle Forschung sollte realistischeren und weniger reinen Mischströmen größere Aufmerksamkeit widmen, während Trenn‐ und Sortierprozesse z. B. durch effektivere Regularien verbessert werden müssen. Dieser Aufsatz soll zur Entwicklung von Verfahren inspirieren, mit denen hochwertige Produkte hergestellt werden können, die die Kreislaufwirtschaft antreiben, indem sie nötige Wirtschaftsanreize und Erleichterungen für die Umwelt bieten.

Increasing the stream of recycled plastic necessitates an approach beyond the traditional recycling via melting and re-extrusion. Various chemical recycling processes have great potential to enhance recycling rates. In this Review, a summary of the various chemical recycling routes and assessment via life-cycle analysis is complemented by an extensive list of processes developed by companies active in chemical recycling. We show that each of the currently available processes is applicable for specific plastic waste streams. Thus, only a combination of different technologies can address the plastic waste problem. Research should focus on more realistic, more contaminated and mixed waste streams, while collection and sorting infrastructure will need to be improved, that is, by stricter regulation. This Review aims to inspire both science and innovation for the production of higher value and quality products from plastic recycling suitable for reuse or valorization to create the necessary economic and environmental push for a circular economy.

The last decades, investigators have been striving to find alternatives to materials and products from fossil sources in response to the need to get independent from petroleum. So far, the most attractive renewable source has been found to be biomass and especially wood that is easily accessible and offers a wide range of building blocks with diverse chemistries and structures that can then be used to build materials for the modern world. In this study, wood from Aspen, Pine and Birch as well as a mixture of Spruce and Pine was subjected to torrefaction and the fraction of the condensables with a dew point above 140 degrees C was used for the partial replacement of phenol (up to 40% wt) in the synthesis of resol phenol-formaldehyde resins suitable to be used as adhesives in the manufacturing of plywood panels. The condensables and the resins were subjected to typical lab analysis and thermal study with TGA and DSC while the plywood panels were tested and evaluated according to the European standards used by the relative industry. It was found that the studied torrefaction condensables may be successfully used in this application while the one from pine was the best performed overall.

In het E3 BioFRAME project wordt het gebruik van de producten van organosolv fractionering van biomassa onderzocht voor vier product toepassingen (autobanden, asfalt, brandstoffen en verpakkingen). Hiervoor zijn succesvolle bench-schaal experimenten gedaan voor de fractionering van plantgewassen tarwestro, beuk- en dennenhout. Opschaalde producties zijn gedaan bij Fraunhofer CBP in Leuna waarbij op kilogram schaal fracties van lignine en cellulose zijn geproduceerd met behulp van aceton organosolv fractionering. Resultaten voor bandentoepassingen laten zien dat lignine niet goed gedispergeerd wordt in de rubber-polymeer matrix door sterke lignine-lignine interactie en door een te grote deeltjesgrootte. Voor asfalttoepassingen werd gevonden dat het meng/smeltgedrag en de dispersie van lignine in bitumen slecht zijn. Desondanks werd gevonden dat het bijmengen van kleine hoeveelheden lignine in asfalt de sterkte van het asfalt niet significant verlaagde. Voor brandstoftoepassingen werd gevonden dat nog slechts beperkte hoeveelheden lignine in brandstoffen kunnen worden opgelost, onvoldoende om economisch haalbaar te zijn. Er is met een lignine/biobrandstof wel een succesvolle motortest uitgevoerd. Voor cellulosetoepassingen in PaperFoam verpakkingsmaterialen werd gevonden dat de verpakkingen onvoldoende sterkte hadden, en dat de diverse mechanische en chemische methoden om dit te verbeteren onvoldoende effectief of niet kosteneffectief waren. Ten slotte is het economisch perspectief voor toepassingen van lignine en cellulose geschetst. De hoogste potentiele waarde voor lignine werd gevonden in autobandentoepassing met, echter deze toepassing heeft een beperkt marktvolume. Ook voor cellulose in verpakkingsmaterialen werd een goede waarde maar een nog beperkt marktvolume gevonden.

The ex-situ catalytic pyrolysis of sugarcane bagasse with various HZSM-5 (23, 50, and 80) catalysts was studied in a tandem micro reactor-GC/MS at 400 degrees C, 450 degrees C, 500 degrees C and 550 degrees C with a catalyst to biomass (C/B) ratios ranging from 2 to 23. The yields of benzene, toluene and xylenes (BTX) were significantly affected by pyrolysis temperature and C/B ratio. The highest BTX yield of 22% was obtained for the HZSM-5 (23) catalyst at C/B ratio of 12.5 and a temperature of 475 degrees C. Finally, an experimental design was performed to determine the optimal process conditions for BTX yields.

Five technical lignins (three organosolv, Kraft and soda lignin) were depolymerised to produce monomeric biobased aromatics, particularly alkylphenols, by a new two-stage thermochemical approach consisting of dedicated pyrolysis followed by catalytic hydrodeoxygenation (HDO) of the resulting pyrolysis oils. Pyrolysis yielded a mixture of guaiacols, catechols and, optionally, syringols in addition to alkylphenols. HDO with heterogeneous catalysts (Ru/C, CoMo/alumina, phosphided NiMO/C) effectively directed the product mixture towards alkylphenols by, among others, demethoxylation. Up to 15wt% monomeric aromatics of which 11wt% alkylphenols was obtained (on the lignin intake) with limited solid formation (<3wt% on lignin oil intake). For comparison, solid Kraft lignin was also directly hydrotreated for simultaneous depolymerisation and deoxygenation resulting in two times more alkylphenols. However, the alkylphenols concentration in the product oil is higher for the two-stage approach. Future research should compare direct hydrotreatment and the two-stage approach in more detail by techno-economic assessments.

Pyrolysis is a thermochemical conversion option that can play an important role in hybrid biorefinery concepts because it offers a flexible way to convert biomass and/or biomass residues into (a precursor for) value-added chemicals and products that enhance the profitability of the biorefinery. To determine the added value of the utilization of side streams other than their use as fuel for power, pyrolysis development, application research, and detailed technoeconomic and socioeconomic analyses are required and should guide research efforts. The pyrolysis of biomass into a physicochemically complex liquid product is the first step in the process of obtaining useful materials such as chemicals or drop-in biofuels. Separation/purification/upgrading of pyrolysis oil into biofuels and/or individual chemicals is challenging and poses a broad area of research that may require the development of a whole new type of chemistry, specifically devoted to the physicochemical characteristics of biomass pyrolysis oils.

Biomass Power for the World: Transformations to Effective Use Edited by Wim van Swaaij, Sascha Kersten, and Wolfgang Palz Copyright a#169; 2015 Pan Stanford Publishing Pte. Ltd. ISBN 978-981-4613-88-0 (Hardcover), 978-981-4669-24-5 (Paperback), 978-981-4613-89-7 (eBook) www.panstanford.com

Non-purified lignins resulting from ethanol-based organosolv fractionation of wheat straw were characterized for the presence of impurities (carbohydrates and ash), functional groups (hydroxyl, carboxyl and methoxyl), phenyl-propanoid structural moieties, molar mass distribution and thermal behavior. In accordance with its herbaceous nature, the syringyl/guaiacyl-ratio of the wheat straw lignins was substantially lower than of Alcell lignin. In addition, the content of p-hydroxyphenyl and carboxyl groups is substantially higher for the wheat straw lignins. The non-purified organosolv lignins had a high purity with 0.4–5.2% carbohydrate impurities, both originating from lignin to carbohydrate complexes and residual organosolv liquor. The use of H2SO4 in the organosolv process improved the lignin yield, but at low acid doses increased the carbohydrate impurities. For applications where a low amount of carbohydrates is important, lignin from a high-temperature autocatalytic organosolv process was found to be preferred. The highest content of total hydroxyl groups was determined when lignins were produced using 30 mM H2SO4 as catalyst or 50% w/w aqueous ethanol as solvent for the organosolv process. Aliphatic hydroxyl groups, the most predominant type of hydroxyl groups present originating for a substantial part from residual carbohydrates, were found to decrease with reaction time and ethanol proportion of the organosolv solvent. The correlations between organosolv process conditions and lignin characteristics determined can facilitate the use of organosolv lignins in value-added applications such as in polymers and resins and as a feedstock for bio-based aromatics.

To assess the potential of acetic and formic acid organosolv fractionation of wheat straw as basis of an integral biorefinery concept, detailed knowledge on yield, composition and purity of the obtained streams is needed. Therefore, the process was performed, all fractions extensively characterized and the mass balance studied. Cellulose pulp yield was 48% of straw dry matter, while it was 21% and 27% for the lignin and hemicellulose-rich fractions. Composition analysis showed that 67% of wheat straw xylan and 96% of lignin were solubilized during the process, resulting in cellulose pulp of 63% purity, containing 93% of wheat straw cellulose. The isolated lignin fraction contained 84% of initial lignin and had a purity of 78%. A good part of wheat straw xylan (58%) ended up in the hemicellulose-rich fraction, half of it as monomeric xylose, together with proteins (44%), minerals (69%) and noticeable amounts of acids used during processing.

Bio‐based industries (pulp and paper and biorefineries) produce > 50 Mt/yr of lignin that results from fractionation of lignocellulosic biomass. Lignin is world's second biopolymer and a major potential source for production of performance materials and aromatic chemicals. Lignin valorization is a key‐issue for enhanced profitability of sustainable bio‐based industries. Despite a myriad of potential applications for lignin and decades of research, its heterogeneity and recalcitrance still preclude commercial value‐added applications. Most lignin is utilized for heat and power. Unconventional solutions are needed to better exploit lignin's potential. Organosolv lignins are especially suitable as feedstock for high‐value chemicals. At ECN , a lignin biorefinery approach ( LIBRA ) has been developed, involving a dedicated lignin pyrolysis protocol that is robust, continuous, and capable of processing different lignins. Typical product yields are 20% gas, 35% char, and 45% oil. The oil contains approximately 45% oligomeric phenolic substances, 23% monomeric phenols, and 33% water. The future perspective is scale‐up of the process to produce larger lignin pyrolysis oil samples for separation, purification, and industrial application tests. Presently, small lignin pyrolysis oil samples are investigated as feedstock for extracting high‐value chemicals, as a substitute for phenol in several applications, and as a feedstock for hydrotreating. The biochar is tested as growth enhancer and as substitute for carbon‐black in rubber. Regarding the large lignin side streams from (future) bio‐based industries, the LIBRA pyrolysis technology has ample potential to increase the profitability of lignocellulosic biorefineries provided that for both the liquid product and the solid char value‐added applications are developed. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd

The effects of thermochemical treatments (aquathermolysis, pyrolysis, and combinations thereof) on the lignocellulosic structure and composition of wheat straw were studied with 13C and 1H solid state NMR spectroscopy and proton T1ρ relaxation measurements. Results show that aquathermolysis removes hemicellulose, acetyl groups, and ash minerals. As a result, the susceptibility of lignocellulose to pyrolysis is reduced most likely due to the removal of catalytically active salts, although recondensation of lignin during aquathermolysis treatment can also play a role. In contrast to pyrolysis of wheat straw, pyrolysis of aquathermolysed wheat straw leaves traces of cellulose in the char as well as more intense lignin methoxy peaks. Finally, it was found that both pyrolysis chars contain aliphatic chains, which were attributed to the presence of cutin or cutin-like materials, a macromolecule that covers the aerial surface of plants, not soluble in water and seemingly stable under the pyrolysis conditions applied.

Wheat straw was fractionated using a three-step biorefining approach: (1) aqueous pretreatment for hemicellulose prehydrolysis into sugars, (2) organosolv delignification, and (3) enzymatic cellulose hydrolysis into glucose. Prehydrolysis was applied to avoid degradation of hemicellulose sugars during organosolv delignification. Maximum xylose yield obtained was 67% or 0.17 kg/kg straw (prehydrolysis: 175 °C, 30 min, 20 mM H2SO4) compared to 4% in case of organosolv without prehydrolysis (organosolv: 200 °C, 60 min, 60% w/w aqueous ethanol). Prehydrolysis was found to reduce the lignin yield by organosolv delignification due to the formation of ‘pseudo-lignin’ and lignin recondensation during prehydrolysis. This reduction could partly be compensated by increasing the temperature of the organosolv delignification step. Prehydrolysis substantially improved the enzymatic cellulose digestibility from 49% after organosolv without prehydrolysis to 80% (20 FPU/g substrate). Increasing the organosolv delignification temperature to 220 °C resulted in a maximum enzymatic glucose yield of 93% or 0.36 kg/kg straw.