Browsing by Person "Kruse, Andrea"

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A unified appraisal framework for the assessment of biorefinery technologies : an approach and first steps to application
(2016) Suwelack, Kay; Kruse, Andrea
As part of the desired bio-economy, biomass will find a wide industrial application in the future, re-placing fossil resources and reducing the need of their import from insecure third countries. However, such an increased industrial application of biomass holds its own problems e.g. like an intensifying competition between food and fuel (and so an increasing competition for arable land) and sometimes other serious social problems, such as the so-called Tortilla-Crisis in Mexico in 2007. Therefore, (political) decision making within a bio-economy has not only to account for economic and ecologic aspects, but also for societal ones in the fields of human rights and justice. Moreover, the three aspects of sustainability (economics, environment, and societal aspects) are to be aligned and balanced within those decisions. A standardized assessment methodology for biorefinery technologies, acknowledging all these aspects, has not been presented in literature so far. However, the need for such a standardized assessment framework was already discussed and demanded in the literature. In the present work, a basic architecture for such an assessment methodology as well as a standardized procedure for the selection of biorefinery technologies is presented (Section 2). The methodology includes thoroughly executed technology analysis by Technology Design Assessments (data level). It concerns explicit values and ethics by the use of the triple bottom line approach of sustainability on the impact level. On the decision making level a tailor-made multi-criteria decision making method (Multi-criteria Based Benchmarking) is proposed and Advanced Radar Plots are used for transparent and easy visual comparison of different policy options. The appraisal framework proposed goes beyond the literature on bioenergy appraisal frameworks and can be used as a baseline for future research. Furthermore, first steps towards the implementation of the proposed methodology are undertaken. In this context, hydrothermal carbonization is used as an example as a promising technology in a new developing bio-economy. Based on data from lab experiments, model equations are derived using a severity approach for proper mass balancing (Section 3 and 4). With these equations the product yields of hydrothermal carbonization (of biogas digestate and wheat straw) as well as the degree of carbonization of the hydrochar produced are quantified as functions of different process parameters using a severity approach. In contrast to other studies, a logarithmic dependence on process severity was applied. Process severity itself was calculated from temperature, retention time and catalyst concentration. By these models basing on few selected reaction conditions, a wide range of process conditions can be covered and the yields for the solid, liquid, and gaseous product phase can be predicted. The equations form the necessary data input for the basic Technology Design Assessment of HTC defined within the proposed standardized appraisal framework.
Challenges of green production of 2,5‐furandicarboxylic acid from bio‐derived 5‐hydroxymethylfurfural: Overcoming deactivation by concomitant amino acids
(2022) Neukum, Dominik; Baumgarten, Lorena; Wüst, Dominik; Sarma, Bidyut Bikash; Saraçi, Erisa; Kruse, Andrea; Grunwaldt, Jan‐Dierk
The oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA) is highly attractive as FDCA is considered as substitute for the petrochemically derived terephthalic acid. There are only few reports on the direct use of unrefined HMF solutions from biomass resources and the influence of remaining constituents on the catalytic processes. In this work, the oxidation of HMF in a solution as obtained from hydrolysis and dehydration of saccharides in chicory roots was investigated without intermediate purification steps. The amount of base added to the solution was critical to increase the FDCA yield. Catalyst deactivation occurred and was attributed to poisoning by amino acids from the bio‐source. A strong influence of amino acids on the catalytic activity was found for all supported Au, Pt, Pd, and Ru catalysts. A supported AuPd(2 : 1)/C alloy catalyst exhibited both superior catalytic activity and higher stability against deactivation by the critical amino acids.
Continuous synthesis of 5‐hydroxymethylfurfural from biomass in on‐farm biorefinery
(2022) Świątek, Katarzyna; Olszewski, Maciej P.; Kruse, Andrea
5‐hydroxymethylfurfural (HMF) is the object of extensive research in recent times. The challenge in the industrial production of HMF is the choice of cheap, hexose feedstock. This study compares continuous HMF synthesis from hexoses—fructose and glucose, and biomass—Miscanthus × giganteus and chicory roots. The experiments were conducted in technical‐scale biorefinery (TRL 6/7). In the first stage, optimal conditions for the production of HMF from hexoses were selected using sulfuric acid as a catalyst in an aqueous medium. The following conditions were chosen for fructose: temperature of 200°C, the reaction time of 18 min, and pH = 2, and for glucose: 210°C, 18 min, and pH = 3. Under these conditions, the HMF yield was 56.5 mol% (39.6 wt.%) from fructose and 18.1 mol% (12.6 wt.%) from glucose. From the biomass, the HMF yields were 36.7 and 16.2 wt.% for miscanthus and chicory roots, respectively. Some results from the conversion of biomass solutions are unexpected and show a need for further investigations. This work has demonstrated the capacity to produce HMF from biomass as part of an environmentally friendly process in a biorefinery. Further research in this field and process optimization will be a step forward in the sustainable production of bioplastics.
Evaluation of the char formation during the hydrothermal treatment of wooden balls
(2023) Pfersich, Jens; Arauzo, Pablo J.; Modugno, Pierpaolo; Titirici, Maria‐Magdalene; Kruse, Andrea
With wooden balls, a visualization of the hydrothermal carbonization to show the progress of the conversion to char is presented. In the present study, the balls represent the particles of biomass to investigate the differences in conversion outside and inside of biomass particles, during hydrothermal carbonization. A special focus is on hydrochar and pyrochar formation. The wooden balls are treated in subcritical water at 220 °C for holding times between 0 and 960 min. Even after 960 min, hydrolysis of the original biomass is incomplete as cellulose and hemicellulose are linked by lignin, inhibiting the reaction with water. Moreover, two different pathways of char production can be observed. Inside of the wooden ball pyrochar is formed as any water got that deep in, on the surface hydrochar is fixed, originated from the surrounding liquid. On the ground of the HTC reactor, a thin, brittle precipitate of likely hydrochar or humins can be found either from the precipitation of loosely attached compounds on the surface of the biomass or direct precipitation from the liquid.
Processing miscanthus to high‐value chemicals: A techno‐economic analysis based on process simulation
(2022) Götz, Markus; Rudi, Andreas; Heck, Raphael; Schultmann, Frank; Kruse, Andrea
Thermochemical biorefineries for the production of chemicals and materials can play an important role in the bioeconomy. However, their economic viability is often questioned under the premise of the economy of scale. This paper presents a regional, modular biorefinery concept for the production of the platform chemicals hydroxymethylfurfural (HMF), furfural and phenols from the lignocellulosic perennial miscanthus, which can be cultivated on marginal and degraded areas. The paper focuses on the question of the minimum selling price of HMF and the optimal plant size for this purpose, using the region of Baden‐Württemberg, Germany, as an example. Based on small pilot plant results, a scalable process simulation was created via AspenPlus. This allows different scenarios and process combinations of this multi‐output biorefinery concept to be compared with each other. Using this, a minimum sales price for the main product HMF is calculated using methods of dynamic investment cost calculation according to the net present value method. Based on this, the plant capacity was scaled. The scenarios and sensitivity analyses show that, with an accuracy of ±15%, regional biorefineries could already offer platform chemicals at prices of 2.21–2.90 EUR/kg HMF at the current stage of development. This corresponds to three to four times the price of today's comparative fossil base chemicals and is thus a competitive option from the authors’ point of view. The local biomass and the heat prices were identified as the main influencing factors. As a result, the selection of the location will have a decisive influence on the economic viability of such concepts in the case of further development and optimization of the process in first demonstration plants.
A proposal for evaluating the economic viability of biorefineries against petrochemical benchmarks
(2024) Götz, Markus; Kruse, Andrea
Usually costs of bio‐based products are compared to those of their fossil counterparts, most often made from crude oil. This paper adds new insights into this kind of comparison and provides approaches as to how future innovations in biorefineries and bio‐based chemicals can be compared to commercial fossil alternatives. The shift to alternative carbon sources will lead to higher costs in the short term. However, expected changes in the crude oil market and regulatory effects will cause rising costs of fossil chemicals in the near future. This work also provides strategies for implementing increased prices.