Evonik (Germany)

Bio-based carboxylic acids are key platform chemicals for a circular economy, offering sustainable alternatives to fossil-derived products. Yet, high substrate and processing costs, along with narrow profit margins, restrict industrial-scale bioproduction. In situ product removal (ISPR) holds the potential to increase productivity and yield in fermentations by circumventing product inhibition. Thus, it presents a promising process intensification measure to bridge the commercial gap between bio-based and petrochemical platform chemicals. One effective method for product recovery is reactive extraction with trioctylamine. In the present study, this method was applied to itaconic acid (ITA) fermentations with Ustilago cynodontis. First, the successful operation of dispersion-based apparatuses for reactive extraction was proven using small-scale mixer-settlers, with 1-octanol and the biocompatible 2-octanone as diluents. We then developed an improved feeding profile, lowering byproduct formation by 72%. Subsequently, we demonstrated the feasibility of ISPR using a perfusion bioreactor with an external membrane coupled to reactive extraction and back-extraction. After 233h of fermentation, the total amount of ITA produced was increased by 26%, and productivity was 21% higher compared to extended-batch fermentations. However, the yield was only slightly improved by 5%. Ultimately, we identified product toxicity far below the maximum titer of 80g as a key bottleneck in ISPR fermentations with U.cynodontis. The results underscore the potential of ISPR and warrant further investigation in this field.

ABSTRACT Peak group analysis (PGA), an MCR algorithm, has proven to be very successful in extracting pure component spectra and concentration profiles from IR and Raman spectral data when investigating carbonylation reactions with transition metal catalysts. In this field of study, mixture spectra typically exhibit high spectral selectivity, meaning certain peaks belong exclusively to a single chemical species. Under this condition, PGA can extract the associated pure component spectrum from the mixture spectra, and there is no factor ambiguity in these profiles. Here, we present a short mathematical proof of this remarkable PGA property.

Abstract Glycolipid biosurfactants such as rhamnolipids (RL) and sophorolipids (SL) are manufactured via low energy fermentation and are versatile molecules that can be tailored to fit a wide range of industrial applications. Among many attributes such as small micelle sizes of 1 nm, they display a high level of interfacial activity as well as biodegradability. The biodegradability and the variety of their functionality make them suitable for environmental remediation and oilfield activities ranging from drilling to production. In this study, rhamnolipids have been found to selectively bond with trivalent iron species in the produced water from the Permian basin, in the presence of other divalent cations. RL appears to be much more efficient than conventional or bio-based iron chelating agents, because of its one-of-a-kind umbrella molecular structure and specific complex with iron. Additionally, RL eliminates scale formation in typical produced water containing Ca, Mg and Fe and enhances the performance of commonly used anionic friction reducers (FR) in iron laden produced water, significantly expanding the anionic FR utility in high salinity brines.

In this research article, a novel inverter design was developed to enable higher efficiency and higher power density in dielectric barrier discharge (DBD) plasma reactor for gas conversion. DBD plasma reactors generate nonthermal plasmas that enable electrified chemical production, including syngas synthesis from CO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>, ammonia synthesis, and dry reforming of methane. Achieving high conversion efficiency requires optimization of the specific energy input (SEI) while maintaining overall energy efficiency. Plasma catalysis, however, is highly sensitive to discharge homogeneity, where minor variations in system parameters can significantly alter performance. One of the important aspects of overall performance is the plasma driver and the conventional AC power supplies for DBD applications are bulky, cascaded, cost-inefficient, and typically achieve less than 70% efficiency at rated power. Inaccuracies in SEI estimation further arise when inverter efficiency is neglected. The proposed inverter utilizes transformer secondary leakage parameters to improve performance. The inverter achieves efficiencies above 80%, doubles the power density for a rated output of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1{\,}\mathrm {kW}$</tex-math> </inline-formula>, and reduces inverter cost by approximately 30%. Experimental validation was performed on a coaxial-bed DBD reactor operated at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$160{\,}\mathrm {kHz}$</tex-math> </inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$14{\,}\mathrm {kV}$</tex-math> </inline-formula>, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$350{\,}\mathrm {W}$</tex-math> </inline-formula>, achieving an efficiency of 84%. These results demonstrate the potential of the proposed inverter to enhance DBD plasma processes, while further investigation into discharge characteristics at full rated power are still under investigation.

A robust, simple, and safe anodic treatment of an industrial wastewater is developed containing tetrabutylammonium (TBA) salts. The use of a quasidivided electrolysis cell set‐up proves to be the key to success. Quasidivision enables the generation of oxidizing mediators without the necessity of an expensive and/or fragile membrane as separator. Screening experiments with significantly different current densities between anode and cathode reveal a higher efficiency compared to similar current densities at both electrodes. Furthermore, acidification of the wastewater prior to electrolysis improves the degradation efficiency by prevention of sulfurous electrode coatings (electrofouling). Under optimized conditions, the concentration of TBA cations is diminished to levels (<1 ppm) far below those required by environmental guidelines. 99% of the TBA species are depleted in total with a degradation rate around 1 mmol TBA bromide/100 min with an energy consumption of 2.5 kWh L−1. The developed process is applicable to wastewater with a varying composition.

The growing demand for sustainable surfactants has led to increased interest in biosurfactants such as rhamnolipids. We studied the self-assembly of the biosurfactant di-rhamnolipid ( ) in starting at the cmc up to the Lyotropic Liquid Crystal (LLC) regime. Measuring the phase behaviour at two different pH values, 6.0 ( pH ≈ pKa ) and 8.0 ( pH ≫ pKa ), one sees how the charge of the surfactant influences the properties. At a pH ≈ pKa , behaves similar to nonionic alkyl polyglucoside surfactants, and forms micelles over a large concentration range and a lamellar L α phase at high concentrations. In contrast, at a pH ≫ pKa the surfactant's carboxyl group is deprotonated, leading to ionic behaviour and the formation of globular micelles at low concentrations and a hexagonal H 1 phase at higher concentrations respectively. The transition between the micellar and the H 1 phase occurs over a narrow concentration range, suggesting a sharp structural reorganisation. Our findings highlight the strong influence of the pH on the self-assembly of di-rhamnolipid over a broad concentration range. • Full binary phase diagram of the biosurfactant di-rhamnolipid. • pH-dependent formation of L α and H 1 lyotropic liyquid crystal mesophases. • SANS and SAXS study at high surfactant concentrations.

The effects of Lys and Ile supplementation in a barley-based substrate on growth performance and nutrient deposition in Tenebrio molitor larvae were evaluated. Six trays per treatment containing sixty larvae were assigned to five treatments in two 21-day periods: barley (B); an 85% barley and 15% soybean meal mixture (BS) and B supplemented with synthetic Lys (BL), Ile (BI) or a combination of both (BLI), as potential limiting amino acids (AA) for larval growth. Supplementing AAs was provided in agar cubes twice per week. Larval performance was measured, and larvae were analyzed for nutrient content and AA profile. Final larval weight increased (p = 0.042) in BS and BL compared to B, with intermediate values for BI and BLI. Larval contents (mg/larva) in total AAs and seven key AAs (sum of Lys, Met, Cys, Thr, Trp, Val and Ile) were higher in BS-fed larvae than in BL and BLI, with the lowest values for BI and B (p < 0.001). Barley supplementation with Lys improved larval AA content, although the levels remained lower than those observed with BS. Conversely, Ile supplementation had no apparent effect on overall AA deposition compared to Lys alone, suggesting the presence of additional limiting AAs for optimal larval growth.

A unique multimetalliccatalyst system that allows for the directcarbonylation of aliphatic and aromatic olefins with carbon dioxideand hydrogen has been developed. The employment of palladium and iridiumprecursors, in conjunction with 1,2-bis­(di-tert-butylphosphino­methyl)­benzene(dtbpx) or its derivatives as active ligandsand Zn­(OTf)2 (OTf: trifluoromethane­sulfonate) asan essential acidic additive, has been shown to result in the selectiveformation of aliphatic esters in CO2-based carbonylations,exhibiting unparalleled regioselectivity. Detailed control experimentsand mechanistic investigations suggest an initial Ir-catalyzed formationof alkyl formates from carbon dioxide, followed by Pd-catalyzed alkoxycarbonylationat a low CO concentration. The desired transformation has been observedto occur in several industrially relevant alkene substrates, therebycreating a potential avenue for further research and industrial applications.