Bio-based Chemicals Research Articles

Highly active and scalable SO3H functionalized carbon catalyst synthesized from bagasse for transformation of bio-based platform chemicals into fuel precursors and its in-depth characterization studies

Scalable synthesis of SO3H functionalized carbon from sugar industry waste (bagasse) and detailed structural characterization and activity were reported. The incorporation of SO3H functionality groups on the carbon surface and the growth of the aromatic carbon framework was supported by FT-IR and 13C CP-MAS NMR analysis. The hydrothermally synthesized carbon exhibited total acidity of 5 mmol/g and uniform distribution of sulphur on the surface of carbon. The synthesized catalyst was found to be efficient for the acetalization, alkylation and alcoholysis reactions and exhibits excellent stability during the reactions. Various bio-derived carbonyl compounds were demonstrated by the solvent-free acetalization of bio-derived glycerol gives 50–100% conversion and 52–98% selectivity towards solketal derivatives at room temperature. The synthesized catalyst's reactivity was better than the commercially used Brønsted/Lewis acids. Furthermore, the SO3H functionalized carbon was also used for alcoholysis followed by ring-opening of furfuryl alcohol, giving 67–98% selectivity towards alkyl levulinates with complete conversion of furfuryl alcohol. The mechanistic pathway suggests that the alcoholysis reaction goes through three different intermediates (2-alkoxymethylfuran, 4,5,5-trialkoxypentan-2-one, and 5-hydroxy-4,5-dialkoxypentan-2-one) to produce the alkyl levulinates. Additionally, the catalyst was tested for solvent-free condensation of 2-methylfuran with various carbonyl compounds to selectively produce an excellent yield of fuel precursors (for C12-C15 hydrocarbons) at 60 °C. The catalyst was reused up to four cycles with 14% loss in the conversion of furfural for acetalization of glycerol, and negligible losses in the alkylation of 2-methylfuran were observed.

A synergistic hydrothermal-deep eutectic solvents (DES) pretreatment for acquiring xylooligosaccharides and lignin nanoparticles from Eucommia ulmoides wood

To achieve an effective deconstruction for preparation of xylooligosaccharides (XOS) and lignin nanoparticles (LNPs) from Eucommia ulmoides, a synergistic pretreatment was successfully developed. Herein, the hemicelluloses were preferentially dissociated in acetic acid-catalyzed hydrothermal pretreatment (HTP) for preparation of XOS, and the hydrothermally-pretreated substrate was then subjected to deep eutectic solvents (DES) delignification for fabrication of LNPs. Results showed that the optimal yield (33.88% based on xylan) of XOS is obtained under the given HTP condition (170 °C, 0.5 h). NMR characterization showed that the linkages of lignin were mainly composed of β-O-4, β-β, β-5, etc. Besides, GPC analysis showed that the molecular weight of DES lignin fractions was lower (1130–1200 g/mol) than those of corresponding parent lignin fractions (8500–9620 g/mol). Further TEM characterization indicated that the optimal LNPs fraction has a narrow size distribution and the corresponding size is ranged from 60 to 110 nm. In short, the synergistic pretreatment could be used as a green and cost-effective approach for the development of bio-based chemicals and biomaterials from Eucommia ulmoides biomass.

Co-production of hydrogen and acetaldehyde from ethanol over a highly dispersed Cu catalyst

Ethanol is one of the most promising bio-based renewable platform chemicals. Catalytic upgrading of ethanol into valuable products is of great importance, and co-production of hydrogen and acetaldehyde via the dehydrogenation of ethanol is an effective way for its high atomic utilization. In this work, unsaturated Cu sites (Cu1.4/ZnxMg4.6-xAl2O7.6) with plenty interface of between Cu and support, strong metal-support interaction were synthesized via the controlled calcination and reduction of hydrotalcite-like Cu1.4ZnxMg4.6-xAl2(OH)16CO3 and used in the dehydrogenation of ethanol. Characterization results disclosed that the dispersion of Cu and surface area of Cu1.4/Zn3.2Mg1.4Al2O7.6 reached 77.8% and 167.5 m2/g, respectively. This catalyst exhibited excellent activity for the dehydrogenation of ethanol to acetaldehyde, and the detected selectivity of acetaldehyde and H2 was higher than 98.5% at 280 °C, 0.1 MPa and WHSV = 11.8 h−1. The calculated space–time yield of acetaldehyde reached 7.0 g-acetaldehyde/g-cat/h. At the same time, Cu1.4/Zn3.2Mg1.4Al2O7.6 could maintain its activity within 50 h on stream.

Complete Genome Sequences of Five Isolated Pseudomonas Strains that Catabolize Pentose Sugars and Aromatic Compounds Obtained from Lignocellulosic Biomass.

ABSTRACTWe report on complete genome sequences of five Pseudomonas soil isolates that are capable of metabolizing pentose sugars and aromatic monomers. These complete genome sequence data provide insight into possible alternative hosts for the production of biofuels and bio-based chemicals from lignocellulosic feedstock.

Economic and environmental performance of non-cellulosic fermentable carbohydrates production for biofuels and chemicals

Fermentable carbohydrates (FC) are a major cost component and a major environmental burden in the production of biofuels and bio-based commodity chemicals; consequently, the cost of FC determines the economic feasibility and environmental performance of biofuels and bio-based commodity chemicals. Producing FC with conventional technology and without the additional processing steps of food-grade sugar can result in a low-cost industrial-grade fermentable sugar that is competitive with that of raw sugar. This study assesses the minimum selling prices (MSP) and the life cycle environmental impacts of FC produced from energycane, sweet sorghum, sugar beet, and corn all of which are grown in the US. The study also assesses FC produced from sugarcane grown in Brazil, which is used as a gauging reference of a low-cost FC source. The MSP was determined by calculating the prices of FC that will result in a net present value (NPV) of 0 with a discount rate that is better than that of a low-risk investment. Environmental performance was assessed by accounting for the life cycle emissions of greenhouse gas, use of fossil energy, and eutrophication potential. The MSP of FC produced from the evaluated feedstocks varies from $0.30 kg−1 for FC produced from sugarcane to $0.50 kg−1 for FC produced from sugar beet or sweet sorghum. The study shows that in the US, FC from energycane has a similar MSP of $0.40 kg−1 to that of FC from corn at $0.38 kg−1, but FC from energycane has lower environmental impacts than FC from corn. The potential for economic feasibility exists in the US for FC from energycane, and with similar environmental impacts to sugarcane and lower environmental impacts than corn. Opportunities for a lower MSP of $0.32 kg−1 exist by using sweet sorghum as a supplementary feedstock with energycane to increase the utilization of the processing plant and reduce the capital cost per unit mass of FC. Producing FC in the US from energycane and supplementing it with sweet sorghum results in an MSP that is lower than raw sugar, which varied from $0.20 kg−1 to $0.63 kg−1 and averaged $0.35 kg−1 from years 2005 through 2019. This shows that the US has access to a low-cost source of FC with lower environmental impacts than corn and with a price that is not subjected to external factors like the fluctuating price of raw sugar.

Ni-Cu/Al2O3 from Layered Double Hydroxides Hydrogenates Furfural to Alcohols

The hydrogenation of furfural is an important process in the synthesis of bio-based chemicals. Copper-based catalysts favor the hydrogenation of furfural to alcohols. Catalytic activity and stability were higher at a Ni-to-Cu atomic ratio of 1:1 and 1.5:0.5 compared to 0.5:1.5. Here, we prepared Ni-Cu/Al2O3 hydrogenation catalysts derived from layered double hydroxides (LDHs). Catalysts calcined at 673 K and reduced at 773 K with nominal Ni/Cu atomic ratios y/x = 1.5/0.5, 1/1 and 0.5/1.5 were characterized by XRD, FESEM-EDX, H2-TPR, XPS, FAA and BET. Their activity was tested at 463 K and in a 0.05 g g−1 furfural solution in ethanol, and the space velocity in a packed-bed reactor (PBR) was 2.85 gFF gcat−1 h−1. In a slurry reactor (SSR) at 5 MPa H2 and a contact time of 4 h, conversion was complete, while it varied from 91 to 99% in the PBR. Tetrahydrofurfuryl alcohol (TFA) was the main product in the SSR, with a selectivity of 32%, 63% and 56% for Ni0.5Cu1.5Al1, Ni1Cu1Al1 and Ni1.5Cu0.5Al1, respectively. The main product in the atmospheric PBR was furfuryl alcohol (FA), with a selectivity of 57% (Ni0.5Cu1.5Al1), 61% (Ni1Cu1Al1) and 58% (Ni1.5Cu0.5Al1). Other products included furan, methylfuran, 1-butanol and 1,2-pentanediol. Ethyl tetrahydrofurfuryl ether and difurfuryl ether were also formed via the nucleophilic addition of furfural with ethanol and furfuryl alcohol.

Catalytic Conversion of Glucose into 5-hydroxymethyl furfural over Spent Dry Batteries as Catalysts

Biomass is a popular renewable carbon source because it has a lot of potential as a substitute for scarce fossil fuels and has been used to make essential compounds like 5-hydroxymethylfurfural (HMF). One of the main components of biomass, glucose, has been extensively studied as a precursor for the production of HMF. Several efforts have been made to find efficient and repeatable procedures for the synthesis of HMF, a chemical platform used in the manufacturing of fuels and other high-value compounds. Sulfonated graphite (SG) was produced from spent dry batteries and utilized as a catalyst to convert glucose to 5-hydroxymethylfurfural (HMF). Temperature, reaction time, and catalyst loading were the variables studied. When dimethyl sulfoxide was utilized as the solvent at 180°C after 3 hours of reaction time, the greatest HMF yield, glucose conversion, and selectivity were attained, with 56.53 %, 97.5 %, and 57.979 %, respectively. This study demonstrates how to manufacture sulfonated graphite with increased catalytic activity for converting glucose to key biobased platform chemicals in a long-term sustainable manner.

Efficient Synthesis of Biobased Furoic Acid from Corncob via Chemoenzymatic Approach

Valorization of lignocellulosic materials into value-added biobased chemicals is attracting increasing attention in the sustainable chemical industry. As an important building block, furoic acid has been commonly utilized to manufacture polymers, flavors, perfumes, bactericides, fungicides, etc. It is generally produced through the selective oxidation of furfural. In this study, we provide the results of the conversion of biomass-based xylose to furoic acid in a chemoenzymatic cascade reaction with the use of a heterogeneous chemocatalyst and a dehydrogenase biocatalyst. For this purpose, NaOH-treated waste shrimp shell was used as a biobased carrier to prepare high activity and thermostability of biobased solid acid catalysts (Sn-DAT-SS) for the dehydration of corncob-valorized xylose into furfural at 170 °C in 30 min. Subsequently, xylose-derived furfural and its derivative furfuryl alcohol were wholly oxidized into furoic acid with whole cells of E. coli HMFOMUT at 30 °C and pH 7.0. The productivity of furoic acid was 0.35 g furoic acid/(g xylan in corncob). This established chemoenzymatic process could be utilized to efficiently valorize biomass into value-added furoic acid.

Waste-Derived Fuels and Renewable Chemicals for Bioeconomy Promotion: A Sustainable Approach.

Bio-based fuels and chemicals through the biorefinery approach has gained significant interest as an alternative platform for the petroleum-derived processes as these biobased processes are noticed to have positive environmental and societal impacts. Decades of research was involved in understanding the diversity of microorganisms in different habitats that could synthesize various secondary metabolites that have functional potential as fuels, chemicals, nutraceuticals, food ingredients, and many more. Later, due to the substrate-related process economics, the diverse low-value, high-carbon feedstocks like lignocellulosic biomass, industrial byproducts, and waste streams were investigated to have greater potential. Among them, municipal solid wastes can be used as the source of substrates for the production of commercially viable gaseous and liquid fuels, as well as short-chain fattyacids and carboxylic acids. In this work, technologies and processes demanding the production of value-added products were explained in detail to understand and inculcate the value of municipal solid wastes and the economy, and it can provide to the biorefinery aspect.

Evaluating the bioenergy potential of cupuassu shell through pyrolysis kinetics, thermodynamic parameters of activation, and evolved gas analysis with TG/FTIR technique

This research aimed to investigate the physicochemical properties and the pyrolysis performance of cupuassu shell (Theobroma grandiflorum) under a thermogravimetric scale. The pyrolysis experiments were carried out using a pure nitrogen atmosphere and at five heating rates (5, 10, 20, 30, and 40 K min−1). The pyrolysis kinetic triplet was calculated from the DTG thermograms using the isoconversional methods of Friedman, Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink combined with the compensation effect and master plots methods. TGA analyses revealed that cupuassu shell pyrolysis follows a devolatilization process of two steps: (1) represented by the two-dimensional diffusion-reaction model (D2), with average activation energies within 102.9–107.5 kJ mol−1, and (2) represented by the fourth-order reaction model (F4) with average activation energies within 176.7–243.0 kJ mol−1. Still, the pre-exponential factor value for the first kinetic stage (1.64×108 min−1) was lower than that of the second kinetic stage (3.19×1010 min−1). As verified, the kinetic triplets efficiently derived the global kinetic expression of cupuassu shell pyrolysis, reproducing reliable data on conversion rates. The evaluation of thermodynamic parameters of activation showed that cupuassu shell is viable biomass for pyrolysis applications, with values of ΔH≠ > 0, ΔG≠ > 0, and ΔS≠ < 0. The TGA-FTIR analysis showed that the evolved pyrolysis products were dominated by alcohols, aldehydes, ketones, organic acids, and aromatic/aliphatic hydrocarbons, supporting the utility of cupuassu shell as a potential source for bio-based chemicals production. In summary, the insights of this study validate the cupuassu shell as a prospective feedstock for producing bioenergy and bio-based chemicals, also bringing useful information for engineering purposes in the design or simulation of large-scale pyrolysis reactors.

Developing Multi-Copy Chromosomal Integration Strategies for Heterologous Biosynthesis of Caffeic Acid in Saccharomyces cerevisiae.

Caffeic acid, a plant-sourced phenolic compound, has a variety of biological activities, such as antioxidant and antimicrobial properties. The caffeic acid biosynthetic pathway was initially constructed in S. cerevisiae, using codon-optimized TAL (coTAL, encoding tyrosine ammonia lyase) from Rhodobacter capsulatus, coC3H (encoding p-coumaric acid 3-hydroxylase) and coCPR1 (encoding cytochrome P450 reductase 1) from Arabidopsis thaliana in 2 μ multi-copy plasmids to produce caffeic acid from glucose. Then, integrated expression of coTAL via delta integration with the POT1 gene (encoding triose phosphate isomerase) as selection marker and episomal expression of coC3H, coCPR1 using the episomal plasmid pLC-c3 were combined, and caffeic acid production was proved to be improved. Next, the delta and rDNA multi-copy integration methods were applied to integrate the genes coC3H and coCPR1 into the chromosome of high p-coumaric acid yielding strain QT3-20. The strain D9 constructed via delta integration outperformed the other strains, leading to 50-fold increased caffeic acid production in optimized rich media compared with the initial construct. The intercomparison between three alternative multi-copy strategies for de novo synthesis of caffeic acid in S. cerevisiae suggested that delta-integration was effective in improving caffeic acid productivity, providing a promising strategy for the production of valuable bio-based chemicals in recombinant S. cerevisiae.

Investigation into Lewis and Brønsted acid interactions between metal chloride and aqueous choline chloride-oxalic acid for enhanced furfural production from lignocellulosic biomass

Furfural has been identified as a valuable biobased platform chemical that can be further converted into bioenergy and biochemicals. Furfural is derived from lignocellulosic biomass and can also be regarded as a sustainable alternative to petrochemical products. Herein, the performance of trivalent metal chlorides (FeCl3, AlCl3) and tetravalent metal chlorides (SnCl4, TeCl4) as Lewis acidic cocatalysts was investigated in an aqueous choline chloride-oxalic acid (16.4 wt% H2O) deep eutectic solvent (DES) system for producing furfural from oil palm fronds (OPFs). The metal chlorides with greater electrical field gradients were stronger Lewis acids that enhanced both furfural production and degradation reactions. The main degradation product in this reaction system was humin, and this result was confirmed by FTIR analysis. By subjecting OPFs to an aqueous DES reaction (120 °C, 45 min) with SnCl4 (2.50 wt%), a furfural yield of 59.4% was obtained; without incorporated metal chlorides, the furfural yield was 46.1%. Characterization studies showed synergistic Lewis and Brønsted acid interactions between metal chlorides and DES components. Overall, the residual OPFs showed high glucan content, which led to the production of glucose (71.4%) as a byproduct via enzymatic hydrolysis. Additionally, the aqueous DES system was recycled and reused for several additional runs. The proposed aqueous DES system presents a promising biorefinery approach for the conversion of OPFs to biochemicals.

Near-Infrared Spectroscopy can Predict Anatomical Abundance in Corn Stover

Feedstock heterogeneity is a key challenge impacting the deconstruction and conversion of herbaceous lignocellulosic biomass to biobased fuels, chemicals, and materials. Upstream processing to homogenize biomass feedstock streams into their anatomical components via air classification allows for a more tailored approach to subsequent mechanical and chemical processing. Here, we show that differing corn stover anatomical tissues respond differently to pretreatment and enzymatic hydrolysis and therefore, a one-size-fits-all approach to chemical processing biomass is inappropriate. To inform on-line downstream processing, a robust and high-throughput analytical technique is needed to quantitatively characterize the separated biomass. Predictive correlation of near-infrared spectra to biomass chemical composition is such a technique. Here, we demonstrate the capability of models developed using an “off-the-shelf,” industrially relevant spectrometer with limited spectral range to make strong predictions of both cell wall chemical composition and the relative abundance of anatomical components of the corn stover, the latter for the first time ever. Gaussian process regression (GPR) yields stronger correlations (average R2v = 88% for chemical composition and 95% for anatomical relative abundance) than the more commonly used partial least squares (PLS) regression (average R2v = 84% for chemical composition and 92% for anatomical relative abundance). In nearly all cases, both GPR and PLS outperform models generated using neural networks. These results highlight the potential for coupling NIRS with predictive models based on GPR due to the potential to yield more robust correlations.

Thermochemical Conversion of Untreated and Pretreated Biomass for Efficient Production of Levoglucosenone and 5-Chloromethylfurfural in the Presence of an Acid Catalyst

Levoglucosenone (LGO) and 5-chloromethyl furfural (5-CMF) are two bio-based platform chemicals with applications in medicines, green solvents, fuels, and the polymer industry. This study demonstrates the one-step thermochemical conversion of raw and pretreated (delignified) biomass to highly-valuable two platform chemicals in a fluidized bed reactor. Hydrochloric acid gas is utilized to convert biomass thermochemically. The addition of hydrochloric acid gas facilitates the formation of LGO and CMF. Acid gas reacts with biomass to form 5-CMF, which acts as a catalyst to increase the concentration of LGO in the resulting bio-oil. The presence of higher cellulose content in delignified biomass significantly boosts the synthesis of both platform chemicals (LGO and CMF). GC-MS analysis was used to determine the chemical composition of bio-oil produced from thermal and thermochemical conversion of biomass. At 350 °C, the maximum concentration of LGO (27.70 mg/mL of bio-oil) was achieved, whereas at 400 °C, the highest concentration of CMF (19.24 mg/mL of bio-oil) was obtained from hardwood-delignified biomass. The findings suggest that 350 °C is the optimal temperature for producing LGO and 400 °C is optimal for producing CMF from delignified biomass. The secondary cracking process is accelerated by temperatures over 400 °C, resulting in a low concentration of the target platform chemicals. This work reveals the simultaneous generation of LGO and CMF, two high-value commercially relevant biobased compounds.

Practical genetic control strategies for industrial bioprocesses.

Optimization of metabolism to maximize production of bio-based chemicals must consistently balance cellular resources for biocatalyst growth and desired compound synthesis. This mini-review discusses synthetic biology strategies for dynamically controlling expression of genes to enable dual-phase fermentations in which growth and production are separated into dedicated phases. Emphasis is placed on practical examples which can be reliably scaled to commercial production with the current state of technology. Recent case studies are presented, and recommendations are provided for environmental signals and genetic control circuits.

Forecast for US Federal and International Regulatory Policy: Biobased Chemistry and Biotechnology, 2022

Forecast for US Federal and International Regulatory Policy: Biobased Chemistry and Biotechnology, 2022

Physical and Chemical Properties of Acacia mangium Lignin Isolated from Pulp Mill Byproduct for Potential Application in Wood Composites.

The efficient isolation process and understanding of lignin properties are essential to determine key features and insights for more effective lignin valorization as a renewable feedstock for the production of bio-based chemicals including wood adhesives. This study successfully used dilute acid precipitation to recover lignin from black liquor (BL) through a single-step and ethanol-fractionated-step, with a lignin recovery of ~35% and ~16%, respectively. The physical characteristics of lignin, i.e., its morphological structure, were evaluated by scanning electron microscopy (SEM). The chemical properties of the isolated lignin were characterized using comprehensive analytical techniques such as chemical composition, solubility test, morphological structure, Fourier-transform infrared spectroscopy (FTIR), 1H and 13C Nuclear Magnetic Resonance (NMR), elucidation structure by pyrolysis-gas chromatography-mass spectroscopy (Py-GCMS), and gel permeation chromatography (GPC). The fingerprint analysis by FTIR detected the unique peaks corresponding to lignin, such as C=C and C-O in aromatic rings, but no significant differences in the fingerprint result between both lignin. The 1H and 13C NMR showed unique signals related to functional groups in lignin molecules such as methoxy, aromatic protons, aldehyde, and carboxylic acid. The lower insoluble acid content of lignin derived from fractionated-step (69.94%) than single-step (77.45%) correlated to lignin yield, total phenolic content, solubility, thermal stability, and molecular distribution. It contradicted the syringyl/guaiacyl (S/G) units’ ratio where ethanol fractionation slightly increased syringyl unit content, increasing the S/G ratio. Hence, the fractionation step affected more rupture and pores on the lignin morphological surface than the ethanol-fractionated step. The interrelationships between these chemical and physicochemical as well as different isolation methods were investigated. The results obtained could enhance the wider industrial application of lignin in manufacturing wood-based composites with improved properties and lower environmental impact.

An efficient strategy to degrade lignin by a novel endophytic fungus Chaetomium globosum combined with ultrasound

Green biological pretreatment of lignocellulose is the critical step in the degradation of biomass in the sustainable economy for biofuels and bio-based chemicals. In the present study, a novel laccase-producing endophytic fungus Chaetomium globosum was screened out from the flower of Hibiscus manihot L. in combination with ultrasound to improve the degradation of lignin in larch sawdust. Under the optimized conditions with the material to liquid ratio 1:20, temperature 30 °C, time 4 days, pH 7, the ultrasonic power 200 W, time 20 min, the degradation rate of lignin reached 34.29%, which increased 1.5-fold and 2-fold higher than that of fungus and ultrasonic treatment correspondingly. In addition, SEM and FTIR analysis showed that the combined treatment changed the surface morphology and chemical structure, and found that mycelium colonized in the interior of sawdust. Analysis of three types of lignin contents showed that the contents of p-Hydroxyphenyl and Guaiacyl increased from 0.46 to 0.70 mg/g and from 9.31 to 11.87 mg/g, while the contents of Syringyl propane did not change significantly, the results indicated that laccase from Chaetomium globosum might have special selectivity. After docking the three lignin monomers and laccase molecules, it was found that the hydroxyl group of Coniferyl alcohol was formed by the active groups of GLU-460 and SER-113 amino acids. The hydrogen bond distances were 1.8 Å and 2.2 Å, which were far smaller than the traditional hydrogen bond of 3.5 Å, this indicated that the compound binds strongly to the protein. The benzene ring of Sinapyl alcohol contained two methoxy groups increasing the molecular volume and hydrophobicity, which reduced laccase's ability to oxidize phenols. In general, as indicated by the results of this study, the novel endophytic fungus Chaetomium globosum from Hibiscus manihot L. has great potential to selectively degrade lignin in larch sawdust.

Production of Bioenergy and Bio-Based Chemicals from Cucumber Peel Waste Via Pyrolysis

Production of Bioenergy and Bio-Based Chemicals from Cucumber Peel Waste Via Pyrolysis

The bioeconomy needs economic, ecological and social sustainability

&lt;abstract&gt; &lt;p&gt;The economic concept of the circular bioeconomy addresses not only the sectors of the traditional bioeconomy but also, in particular, the sectors of bio-based chemicals and energies as well as waste management. This concept is basically based on closing material cycles, in particular, but not only, that of carbon. Managing these material cycles is costly, which is why economic sustainability and, in the current transition phase, competitiveness with fossil-based value chains remain a constant challenge. Because of the large material turnover of the mentioned industries, in the interest of environmental sustainability the circular bioeconomy has to respect the limits of natural resources. With the raw material shift from fossil to renewable resources, regional economic structures and jobs will change and, in addition, circularity requires a change in consumption behavior. Both are challenges that need to be addressed in the interest of social acceptance and sustainability. The article focuses on the economic, but addresses also the ecological and social aspects, discusses options for achieving a comprehensively sustainable circular bioeconomy, and identifies research needs necessary for the further development of the bioeconomy.&lt;/p&gt; &lt;/abstract&gt;