Bio-based Chemicals Research Articles

Clinoptilolite—An Efficient Carrier for Catalytically Active Nano Oxide Particles

Many efforts have been devoted to produce green materials and technology to prevent and minimize the adverse effects on the environment and human health caused primarily by population growth and industrial progress. Over the past years, the use of zeolites has attracted considerable attention as both an economically and environmentally friendly option. Zeolites are crystalline, hydrated aluminosilicates with an open-framework structure. Unique structural features make them very useful ion-changers, adsorbents and catalysts. The catalytic use of zeolites has expanded from traditional use in the petrochemical industry and refineries to use in the catalytic degradation of various environmental pollutants and the synthesis of fine chemicals. In recent times, progress on the use of zeolites has been achieved in biomass conversion to fuels and valuable industrial bio-based chemicals. This review highlights the recent advances in the catalytic application of clinoptilolite (CLI), the most abundant and explored natural zeolite. The main goal of the review is to give the current state of CLI applications and insights into CLI catalytic performance, which opens possibilities for a variety of applications.

Controlling the Activity and Selectivity of HZSM-5 Catalysts in the Conversion of Biomass-Derived Oxygenates Using Hierarchical Structures: The Effect of Crystalline Size and Intracrystalline Pore Dimensions on Olefins Selectivity and Catalyst Deactivation

The conversion of biomass-derived oxygenates over zeolite catalysts constitutes a challenge for the efficient production of bio-based chemicals and fuels due to difficulty in controlling the selectivity and high coke formation of such reactions. This is partly attributed to the microstructure of zeolite catalyst which affects the conversion and selectivity of products derived from biomass-derived oxygenates. In this study, the conversion and deactivation characteristics of three different model oxygenates found in biomass bio-oil (namely, acetol, furfural and guaiacol) over ZSM-5 zeolites of varying acidity, pore and crystal size prepared with bottom-up and top-down approaches were evaluated using a fixed bed microreactor at atmospheric pressure and a space velocity of 5 h−1 at a temperature range of 450–650 °C. Analysis of the experimental results indicates that the optimum temperature for such conversions is in the vicinity of 600 °C allowing for complete conversion of the compounds and high resistance to coking. The mechanisms of those conversions are discussed based on the obtained results. In general, crystal size and mesoporosity induce easier access to active sites improving mass transfer but also alter the location type, and strength of acid sites allowing for higher yields of primary and intermediate products such as olefins.

Catalytic conversion of levulinic acid or furfural alcohol into ethyl levulinate using a sulfonic acid-functionalized coffee biochar

A series of sulfonic acid functionalized coffee biochar (SFCB-x) with high acid density and strength were prepared by using sulfuric acid as the sulfating agent. The obtained catalysts could be directly used for esterification of levulinic acid (LA) and alcoholysis of furfural alcohol (FA) affording ethyl levulinate (EL). Further activity tests and characterization confirmed the linear correlation between the catalytic activity and -SO3H density of the catalyst, SFCB-4 holds the highest -SO3H density and thus exhibits the highest catalytic activity towards the production of EL. Under mild conditions, about 97.6% and 81.7% yield of EL could be obtained for LA esterification and alcoholysis of FA, respectively. The catalyst also shows high stability during consecutive catalytic recycles. Furthermore, hot filtration testing suggested that the leaching of the active species was not observed during catalytic recycles, which could be attributed to the covalently linked -SO3H groups on SFCB-4 skeleton. The rational design and construction of SFCB-4 will drive the development of solid acid catalyst derived from natural biomass for the production of bio-based chemicals.

Holistic Approach to Process Design and Scale-Up for Itaconic Acid Production from Crude Substrates

Bio-based bulk chemicals such as carboxylic acids continue to struggle to compete with their fossil counterparts on an economic basis. One possibility to improve the economic feasibility is the use of crude substrates in biorefineries. However, impurities in these substrates pose challenges in fermentation and purification, requiring interdisciplinary research. This work demonstrates a holistic approach to biorefinery process development, using itaconic acid production on thick juice based on sugar beets with Ustilago sp. as an example. A conceptual process design with data from artificially prepared solutions and literature data from fermentation on glucose guides the simultaneous development of the upstream and downstream processes up to a 100 L scale. Techno-economic analysis reveals substrate consumption as the main constituent of production costs and therefore, the product yield is the driver of process economics. Aligning pH-adjusting agents in the fermentation and the downstream process is a central lever for product recovery. Experiments show that fermentation can be transferred from glucose to thick juice by changing the feeding profile. In downstream processing, an additional decolorization step is necessary to remove impurities accompanying the crude substrate. Moreover, we observe an increased use of pH-adjusting agents compared to process simulations.

Plasma-assisted hydrodeoxygenation of bio-oils

Amid the backdrop of ever-escalating energy demand, dwindling energy resources, and fossil fuels-led climate conundrums, the staggering amount of clean and renewable energy supply to feed the energy-hungry civilization is the need of the day. On this frontier, biofuels turn out to be the greener energy substitutes and the use of plasma in sustainable bioeconomy has garnered huge attention recently. Although there are several review articles on plasma-driven biomass valorization and plasma-free hydrodeoxygenation (HDO) of bio-oils, none of the previous reviews on plasma-assisted HDO has been reported yet. This, in turn, highlights the novelty of this approach presenting efficient and sustainable avenues to produce high-quality biofuel. To bridge this significant literature gap regarding the integration of two processes, this review sheds light on growing trends in plasma technology, succinctly highlights the synergistic benefits of plasma-assisted HDO, and summarizes its recent progress for the upgradation of bio-oils into bio-based chemicals and value-added bioproducts together with in-depth critical analysis and comparison between both non-catalytic and catalytic plasma-assisted HDO of bio-oils. Despite being a cutting-edge solution in the upscaling of bio-oils, a limited amount of work has so far been conducted employing this integrated approach that nevertheless provides new insights for further advancements.

Efficient synthesis of furfural from waste biomasses by sulfonated crab shell-based solid acid in a sustainable approach

As one of key biobased chemicals, furfural can be manufactured from the hydrothermal transformation of hemicelluloses in biomass, which is widely utilized in manufacturing furans, plastics, polymers, rubbers, resins, synthetic fibers, medicine, biofuels and other additives. In this work, one eco-friendly and sustainable approach for transforming waste lignocellulosic biomass to furfural was established in one-pot reaction manner. Crab shells (CRSs), which are derived from discarded seafood bio-waste, are known as one kind of naturally renewable and abundant bioresource. Using the pretreated CRS as support, a biobased heterogeneous chemocatalyst Sn-CFCRS was successfully prepared by carbonization followed by sulfonation, which was utilized to transform waste lignocellulosic biomass into furfural. The structure and morphology of the as-prepared chemocatalyst was examined and the acidity was measured. Deep eutectic solvent choline chloride:malic acid (DES ChCl:MA) (pKa=3.46) was chosen to assist Sn-CFCRS for catalysis of biomass. The catalytic performances were evaluated by one-pot transformation of various biomasses to furfural. Sn-CFCRS (2.4 wt%) transformed 75 g/L corncob into 117.1 mM furfural (65.6% yield) at 180 °C after 10 min in ChCl:MA−water (1:9, v/v) containing 50 mM CaCl2. This established sustainable process shows high potential application for valorization of biomass into furfural by utilizing biobased chemocatalyst in a benign reaction medium.

Microbial production of trans-aconitic acid

Trans-aconitic acid (TAA) is a promising bio-based chemical with the structure of unsaturated tricarboxylic acid, and also has the potential to be a non-toxic nematicide as a potent inhibitor of aconitase. However, TAA has not been commercialized because the traditional production processes of plant extraction and chemical synthesis cannot achieve large-scale production at a low cost. The availability of TAA is a serious obstacle to its widespread application. In this study, we developed an efficient microbial synthesis and fermentation production process for TAA. An engineered Aspergillus terreus strain producing cis-aconitic acid and TAA was constructed by blocking itaconic acid biosynthesis in the industrial itaconic acid-producing strain. Through heterologous expression of exogenous aconitate isomerase, we further designed a more efficient cell factory to specifically produce TAA. Subsequently, the fermentation process was developed and scaled up step-by-step, achieving a TAA titer of 60 g L−1 at the demonstration scale of a 20 m3 fermenter. Finally, the field evaluation of the produced TAA for control of the root-knot nematodes was performed in a field trial, effectively reducing the damage of the root-knot nematode. Our work provides a commercially viable solution for the green manufacturing of TAA, which will significantly facilitate biopesticide development and promote its widespread application as a bio-based chemical.

Optimizing Strategies for Bio-Based Ethanol Production Using Genome-Scale Metabolic Modeling of the Hyperthermophilic Archaeon, Pyrococcus furiosus.

A genome-scale metabolic model, encompassing a total of 623 genes, 727 reactions, and 865 metabolites, was developed for Pyrococcus furiosus, an archaeon that grows optimally at 100°C by carbohydrate and peptide fermentation. The model uses subsystem-based genome annotation, along with extensive manual curation of 237 gene-reaction associations including those involved in central carbon metabolism, amino acid metabolism, and energy metabolism. The redox and energy balance of P. furiosus was investigated through random sampling of flux distributions in the model during growth on disaccharides. The core energy balance of the model was shown to depend on high acetate production and the coupling of a sodium-dependent ATP synthase and membrane-bound hydrogenase, which generates a sodium gradient in a ferredoxin-dependent manner, aligning with existing understanding of P. furiosus metabolism. The model was utilized to inform genetic engineering designs that favor the production of ethanol over acetate by implementing an NADPH and CO-dependent energy economy. The P. furiosus model is a powerful tool for understanding the relationship between generation of end products and redox/energy balance at a systems-level that will aid in the design of optimal engineering strategies for production of bio-based chemicals and fuels. IMPORTANCE The bio-based production of organic chemicals provides a sustainable alternative to fossil-based production in the face of today's climate challenges. In this work, we present a genome-scale metabolic reconstruction of Pyrococcus furiosus, a well-established platform organism that has been engineered to produce a variety of chemicals and fuels. The metabolic model was used to design optimal engineering strategies to produce ethanol. The redox and energy balance of P. furiosus was examined in detail, which provided useful insights that will guide future engineering designs.

MgFe2O4Nanoparticle/Peracetic Acid Hybrids for Catalytic Oxidative Depolymerization of Lignin

Lignin is a promising feedstock for renewable fuels and chemicals due to its aromatic skeleton and natural abundance. Lignin can be converted to diverse aromatic monomers as well as dicarboxylic acids depending on the applied conversion technologies. Despite its great potential, its native and processing-induced heterogeneity and complexity limit the conversion efficiency and product selectivity. In this study, magnesium ferrite (MgFe2O4) nanoparticle–peracetic acid (PAA) has been investigated as an efficient catalyst–oxidant incorporation for catalytic oxidative depolymerization of lignin under mild conditions. Typically, the increase in processing severity can enhance the lignin conversion while it results in the further decomposition of aromatic compounds to dicarboxylic acids. However, in this study, the incorporation of MgFe2O4 nanoparticles and PAA not only enhanced the total product yield but also improved the selectivity of aromatic monomers. The oxidative depolymerization system using the catalyst–oxidant combination resulted in 46 wt % of total oil product with a 61% selectivity of aromatic monomers under mild temperature (90 °C). In addition, this combination catalyst showed relatively good cycling stability based on the total product yield after recycling five times via magnetic separation. Overall, MgFe2O4 nanoparticles play an important role as a co-catalyst with a PAA oxidant in the oxidative conversion of lignin with an enhanced conversion efficiency and recyclability, and it will facilitate the valorization of lignin in future bio-based fuels and chemicals.

A specific H2/CO2 consumption molar ratio of 3 as a signature for the chain elongation of carboxylates from brewer's spent grain acidogenesis.

Brewer's spent grain (BSG) is an undervalorized organic feedstock residue composed of fermentable macromolecules, such as proteins, starch, and residual soluble carbohydrates. It also contains at least 50% (as dry weight) of lignocellulose. Methane-arrested anaerobic digestion is one of the promising microbial technologies to valorize such complex organic feedstock into value-added metabolic intermediates, such as ethanol, H2, and short-chain carboxylates (SCC). Under specific fermentation conditions, these intermediates can be microbially transformed into medium-chain carboxylates through a chain elongation pathway. Medium-chain carboxylates are of great interest as they can be used as bio-based pesticides, food additives, or components of drug formulations. They can also be easily upgraded by classical organic chemistry into bio-based fuels and chemicals. This study investigates the production potential of medium-chain carboxylates driven by a mixed microbial culture in the presence of BSG as an organic substrate. Because the conversion of complex organic feedstock to medium-chain carboxylates is limited by the electron donor content, we assessed the supplementation of H2 in the headspace to improve the chain elongation yield and increase the production of medium-chain carboxylates. The supply of CO2 as a carbon source was tested as well. The additions of H2 alone, CO2 alone, and both H2 and CO2 were compared. The exogenous supply of H2 alone allowed CO2 produced during acidogenesis to be consumed and nearly doubled the medium-chain carboxylate production yield. The exogenous supply of CO2 alone inhibited the whole fermentation. The supplementation of both H2 and CO2 allowed a second elongation phase when the organic feedstock was exhausted, which increased the medium-chain carboxylate production by 285% compared to the N2 reference condition. Carbon- and electron-equivalent balances, and the stoichiometric ratio of 3 observed for the consumed H2/CO2, suggest an H2- and CO2-driven second elongation phase, converting SCC to medium-chain carboxylates without an organic electron donor. The thermodynamic assessment confirmed the feasibility of such elongation.

Biosynthesis of diisooctyl 2,5-furandicarboxylate by Candida antarctica lipase B (CALB) immobilized on a macroporous epoxy resin.

Diisooctyl 2,5-furandicarboxylate (DEF), an ester derivative of 2,5-furandicarboxylic acid (FDCA, a bio-based platform chemical), resembles the physical and chemical properties of phthalates. Due to its excellent biodegradability, DEF is considered a safer alternative to the hazardous phthalate plasticizers. Although FDCA esters are currently mainly produced by chemical synthesis, the enzymatic synthesis of DEF is a green, promising alternative. The current study investigated the biosynthesis of DEF by Candida antarctica lipase B (CALB) immobilized on macroporous resins. Out of five macroporous resins (NKA-9, LX-1000EP, LX-1000HA, XAD-7HP, and XAD-8) evaluated, the LX-1000EP epoxy resin was identified as the best carrier for CALB, and the XAD-7HP weakly polar resin was identified as the second best. The optimal immobilization conditions were as follows: CALB (500μL) and LX-1000EP (0.1g) were incubated in phosphate butter (20mM, pH 6.0) for 10h at 35°C. The resulting immobilized CALB (EP-CALB) showed an activity of 639U/g in the hydrolysis of p-nitrophenyl acetate, with an immobilization efficiency of 87.8% and an activity recovery rate of 56.4%. Using 0.02g EP-CALB as the catalyst in 10mL toluene, and the molar ratio of 2,5-dimethyl furanediformate (1mmol/mL) and isooctyl alcohol (4mmol/mL) that was 1:4, a DEF conversion rate of 91.3% was achieved after a 24-h incubation at 50°C. EP-CALB had similar thermal stability and organic solvent tolerance compared to Novozym 435, and both were superior to CALB immobilized on the XAD-7HP resin. EP-CALB also exhibited excellent operational stability, with a conversion rate of 52.6% after 10 repeated uses. EP-CALB could be a promising alternative to Novozym 435 in the biomanufacturing of green and safe plasticizers such as DEF.

Adaptive Laboratory Evolution of Bacillus subtilis 168 for Efficient Production of Surfactin Using NH4Cl as a Nitrogen Source

Bacillus subtilis strain 168 is commonly used as a host to produce recombinant proteins and as a chassis for bio-based chemicals production. However, its preferred nitrogen source is organic nitrogen, which greatly increases production costs. In this study, adaptive laboratory evolution (ALE) was used to improve B. subtilis 168 growth using NH4Cl as the sole nitrogen source. The cell density (OD600) of a mutant strain LJ-3 was 208.7% higher than that of the original strain. We also optimized the metal ions in the medium and this resulted in a further increase in growth rate by 151.3%. Reintroduction of the sfp+ gene into strain LJ-3 led to the LJ-31 clone, which restored LJ-3’s ability to synthesize surfactin. The fermentation system was optimized (C/N, aeration, pH) in a 5 L bioreactor. Dry cell weight of 7.4 g/L and surfactin concentration of 4.1 g/L were achieved using the optimized mineral salt medium after 22 h of batch fermentation with a YP/S value of 0.082 g/g and a YP/X of 0.55 g/g. HPLC analysis identified the surfactin isoforms produced by strain LJ-31 in the synthetic medium as C13-surfactin 13.3%, C14-surfactin 44.02%, and C15-surfactin 32.79%. Hence, the variant LJ-3 isolated by ALE is a promising engineering chassis for efficient and cost-effective production of a variety of metabolites.

Screening of New Industrially Important Bacterial Strains for 1,3-Propanediol, 2,3-Butanediol and Ethanol Production through Biodiesel-Derived Glycerol Fermentations.

A study on the ability of new microbial strains to assimilate biodiesel-derived glycerol at low purity (75% w/w) and produce extra-cellular platform chemical compounds of major interest was carried out. After screening several bacterial strains under different fermentation conditions (e.g., pH, O2 availability, glycerol purity), three of the screened strains stood out for their high potential to produce valued-added products such as 2,3-butanediol (BDO), 1,3-propanediol (PDO) and ethanol (EtOH). The results indicate that under aerobic conditions, Klebsiella oxytoca ACA-DC 1581 produced BDO in high yield (YBDO/Gly = 0.46 g/g, corresponding to 94% of the maximum theoretical yield; Ymt) and titer, while under anaerobic conditions, Citrobacter freundii NRRL-B 2645 and Enterobacter ludwigii FMCC-204 produced PDO (YPDO/Gly = 0.56 g/g, 93% of Ymt) and EtOH (YEtOH/Gly = 0.44 g/g, 88% of Ymt), respectively. In the case of C. freundii, the regulation of pH proved to be mandatory, due to lactic acid production and a subsequent drop of pH that resulted in fermentation ceasing. In the fed-batch culture of K. oxytoca, the BDO maximum titer reached almost 70 g/L, the YBDO/Gly and the mean productivity value (PrBDO) were 0.47 g/g and 0.4 g/L/h, respectively, while no optimization was imposed. The final BDO production obtained by this wild strain (K. oxytoca) is among the highest in the international literature, although the bioprocess requires optimization in terms of productivity and total cost. In addition, for the first time in the literature, a strain from the species Hafnia alvei (viz., Hafnia alvei ACA-DC 1196) was reported as a potential BDO producer. The strains as well as the methodology proposed in this study can contribute to the development of a biorefinery that complements the manufacture of biofuels with high-value biobased chemicals.

Integrated Biphasic Electrochemical Oxidation of Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

Production of biobased platform chemicals and polymers via electrochemical routes enables the direct utilization of electrical energy from renewable sources. To date, the integration of electrochemical conversions in process chains remains largely unexplored, and the reactions are often studied using synthetic solutions. This work demonstrates the biphasic electro-oxidation of hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) and couples the electrochemical oxidation with the biphasic dehydration of fructose to HMF. The integrated approach eradicates the intermediate HMF purification as the HMF-rich organic product phase is fed directly into the electrochemical flow-cell reactor. Here, HMF is extracted into the aqueous phase and oxidized to FDCA on a Ni(OH)2/NiOOH catalyst in a 0.1 M KOH solution at pH 13. The FDCA then remains in the aqueous phase, enabling direct recirculation of the HMF-containing organic phase. We demonstrate a FDCA yield of close to 80% with a feed from HMF synthesis. Further, we analyze the influence of the phase ratio (organic to aqueous) and current density for biphasic electrochemical oxidation. By adjusting the gap width, we were able to decrease the average cell voltage from 7 V down to 3 V at a current density of 30 mA cm–1. This work presents a promising integrated process for the synthesis of green platform chemicals and provides insight into biphasic solutions in electrochemical conversions.

Fractionation of Oil Palm Fiber Using Green Solvent for Lignin Separation

Oil palm processing produces more than 70-wt% of its lignocellulosic content as by-product, the bulk of which is empty fruit bunches (EFB). EFB contains cellulose, hemicellulose, and lignin which makes it a potential source of bio-based chemicals. This research explores the utilization of ethanol as a potentially green, sustainable, and low-cost organic solvent (organosolv) for EFB fractionation. Organosolv processes target extraction of lignin (delignification). Conventional delignification use an acid hydrolysis process with lignin yields of approximately 18-wt%. In this study the EFB was treated in 2 stages, (1) soaking EFB for 1 hour followed by (2) delignification using ethanol as the organic solvent under variable process conditions. Temperature (140°C, 170°C), liquid-to-solid ratio (L/S-w/w) (6:1, 15:1), and wt%-ethanol (20-wt%, 50-wt%) were varied while residence time was constant at 30 minutes (experiments were run in duplicate). Data analysis using 2k Factorial Design Method showed the significant variables were temperature, L/S-ratio, wt%-ethanol, interaction of L/S ratio and temperature, temperature and %wt-ethanol interaction, and L/S-ratio and %wt-ethanol. The optimum operating conditions (170°C, 15:1, 20wt%-ethanol) produced a lignin yield of up to 31%wt. This preliminary study shows ethanol in an organosolv process is a potential delignification option.

Efficient production of acetoin from lactate by engineered Escherichia coli whole-cell biocatalyst.

Acetoin, an important and high-value added bio-based platform chemical, has been widely applied in fields of foods, cosmetics, chemical synthesis, and agriculture. Lactate is a significant intermediate short-chain carboxylate in the anaerobic breakdown of carbohydrates that comprise ~ 18% and ~ 70% in municipal wastewaters and some food processing wastewaters, respectively. In this work, a series of engineered Escherichia coli strains were constructed for efficient production of acetoin from cheaper and abundant lactate through heterogenous co-expression of fusion protein (α-acetolactate synthetase and α-acetolactate decarboxylase), lactate dehydrogenase and NADH oxidase, and blocking acetate synthesis pathways. After optimization of whole-cell bioconversion conditions, the engineered strain BL-11 produced 251.97 mM (22.20 g/L) acetoin with a yield of 0.434 mol/mol in shake flasks. Moreover, a titer of 648.97mM (57.18 g/L) acetoin was obtained in 30 h with a yield of 0.484 mol/mol lactic acid in a 1-L bioreactor. To the best of our knowledge, this is the first report on the production of acetoin from renewable lactate through whole-cell bioconversion with both high titer and yield, which demonstrates the economy and efficiency of acetoin production from lactate. Key Points • The lactate dehydrogenases from different organisms were expressed, purified, and assayed. • It is the first time that acetoin was produced from lactate by whole-cell biocatalysis. • The highest titer of 57.18 g/L acetoin was obtained with high theoretical yield in a 1-L bioreactor.

Pyrolysis of LignoBoost lignin in ZnCl2-KCl-NaCl molten salt media: Insights into process-pyrolysis oil yield and composition relations

Depolymerization of lignin by pyrolysis has been identified as a viable route to produce renewable fuels and biobased platform chemicals. Herein we report the pyrolysis of LignoBoost lignin in a molten salt consisting of ZnCl2-KCl-NaCl (60:20:20 mol ratio) in a g-scale reactor set-up with a focus on the liquid phase yields and composition. The effects of relevant process parameters such as temperature (250–450 °C), reaction time (10–50 min), and N2 flow rate (10–30 mL min−1) on the product yields were elucidated using design of experiments. The highest bio-oil yield was 47.1 wt% (450 °C, 10 min) and the yield of organics in the bio-oil at this condition was 24 wt% (on lignin intake), the remainder being water. The latter is considerably higher than found for an experiment at similar conditions without salt (16 wt%). Temperature and reaction time were shown to have the largest effects on bio-oil yield. Prolonged reaction times resulted in higher amounts of gas phase components (H2, CO2) and water, and a reduced amount of solid products. Statistical analyses and validation experiments showed that the experimental product yields are in good agreement with the predicted values from the model. The properties and molecular composition of the liquid products were determined using various analytical techniques and reveal that the presence of a molten salt during pyrolysis has a positive influence on the composition of the liquid phase like a higher level of depolymerization and higher selectivity to aromatic and phenolic monomers compared to thermal pyrolysis.

Exploring economy-wide sustainable conditions for EU bio-chemical activities

The EU's Green Deal sets out a vision for a clean, competitive, climate neutral circular economy. As a part-solution for decarbonising its industrial base and improving its strategic autonomy, the role of bio-based substitutes is envisaged. Focusing on EU chemicals, the MAGNET simulation model is employed to quantify the impacts from EU bio-based chemical, pharmaceutical and plastic output increases over a thirty-year time horizon to 2050. To support this transformation, a fiscally-neutral tax funded investment scheme is modelled. Results show EU bioeconomy (rural) employment and growth improvements, although bio-feedstock market tensions impact negatively on EU food security, whilst ‘leakage’ effects cause net global increases in greenhouse gases and land use. Further experiments explore (i) sustainable tax schemes on food-based feedstock to mitigate said tensions and (ii) green-investment driven input-saving productivity gains in EU bio-based chemicals. Employing metrics for the five bioeconomy strategy objectives, the former generates environmental, food and (bio-)energy security improvements, relieves land market tensions, but falls short of a win-win/win-neutral outcome. Similarly, for four EU bioeconomy objectives, the latter produces outcomes that are largely on a par, or even better than the baseline. Finally, a stylised combination of both is found to generate the most optimal outcomes.

Physicochemical properties, pyrolysis kinetics, thermodynamic parameters of activation, and evolved volatiles of mango seed waste as a bioenergy feedstock: A potential exploration

An investigation was conducted to elucidate the bioenergy potential of mango seed waste through pyrolysis kinetics, thermodynamics parameters of activation, and analysis of evolved volatiles. Experiments were performed in a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The pyrolysis behavior was assumed to be the sum of four independent parallel reactions corresponding to the devolatilization of extractives, hemicellulose, cellulose, and lignin. The four applied isoconversional methods could determine the average activation energies in the ranges of 113.7 − 120.3, 150.0 − 159.9, 190.0 − 201.1, and 172.6 − 184.8 kJ mol−1 for the decomposition of these components, respectively. The pre-exponential factors obtained by Kissinger's method fell between 3.7 × 1011 and 2.6 × 1015 min−1, with A > 109 min−1, indicating that only simple chemistry reactions occurred. The master plot method assigned F-type reaction models to the devolatilization of pseudo-extractives, pseudo-hemicellulose, and pseudo-lignin. Yet, an A-type model matched well with the devolatilization of pseudo-cellulose. From the verification step of the overall kinetic expression, it was found that the simulated pyrolysis progress profiles match with an excellent agreement with the experimental data with a minimum quality of fit of 92.9%. Thermodynamic parameters of activation were determined within the range of 109.3 − 183.3 kJ mol−1 for ΔH≠, 141.7 − 191.2 kJ mol−1 for ΔG≠, and (−71.3)−3.1 J mol−1K − 1 for ΔS≠. TGA–FTIR analysis indicated that most volatile species, comprising propanoic acid, methanol, acetaldehyde, dimethyl ether, and ethanol, are released below 650 K. The results of this study are important for using mango seed waste as a low-priced material for pyrolysis, with the potential of producing bioenergy and bio-based chemicals. This approach aligns with the valorization principle of utilizing lignocellulosic residues.

Bio-Based Chemicals from Dedicated or Waste Biomasses: Life Cycle Assessment for Evaluating the Impacts on Land

Green chemistry and engineering encourage the usage of renewable sources, in replacement fossil fuels. The sector of bio-based products is one of the most predominant examples of such replacements in different fields. However, the impact of biomasses usage is far from being negligible or net zero. A life cycle perspective is required in order to assess all the different environmental impacts related to biomass exploitation and usage, in particular when dedicated sources are used. This study points out the importance of including the results of a Life Cycle Assessment (LCA) early in the design of new bio-based products, to identify the stage of the value chain with the greatest hotspots and set proper eco-design strategies. At the same time, the use of the LCA results may support purchasing activities through comparing products with different burdens. In this manuscript, a focus on land compartment is carried out, given its relevance to the cultivation phase. Five analysis methods are selected for further description. Three are classified as multi-impact approach methodologies (ReCiPe 2016, IMPACT World + and EF 3.0) since they are able to translate mass and energy balances into several impact categories at the same time, not only those on land comparts which are also included. In addition, the LANCA® model and the True pricing method for agri-food products are discussed, underlining the importance of their usage when a detailed review of the impact on soil is necessary (e.g., during an environmental impact assessment). They are compared in this paper, underlining the main differences and potential fields of application.