Papers by Henning Schramm
2001 European Control Conference (ECC)
A new concept for the control of moving bed chromatographic processes is developed. In a first st... more A new concept for the control of moving bed chromatographic processes is developed. In a first step focus is on the true moving bed process. A fairly simple method is developed for the control of this process with standard PI controllers. This method makes direct use of the underlying spatio-temporal pattern formation phenomena - also termed as nonlinear wave propagation (Marquardt [12], Kienle [4]). According to the well known `Triangle Theory' of Storti et al. [17] the chromatographic unit is working under optimal operating conditions, i.e. with minimal solvent consumption and maximal feed throughput. Finally the application of this method to the simulated moving bed process is discussed.
Die Erfindung betrifft eine Einrichtung (1) zur Abscheidung von CO2 aus einem Abgasstrom (11) ein... more Die Erfindung betrifft eine Einrichtung (1) zur Abscheidung von CO2 aus einem Abgasstrom (11) einer Verbrennungsvorrichtung (10), welche neben einer einen Absorber (21) und einen Desorber (22) aufweisenden CO2-Abscheidungsvorrichtung (20) einen Speicher (30) zur Bevorratung eines Warmetransferfluids (35) aufweist, wobei der Speicher (30) und der Desorber (22) warmetechnisch uber ein Leitungssystem (40) miteinander gekoppelt sind, und wobei der Speicher (30) mit einer elektrisch betriebenen Heizvorrichtung (50) thermisch gekoppelt ist, die eine thermische Konditionierung des Warmetransferfluids (35) in dem Speicher (30) ermoglicht.
L'invention concerne un dispositif (1, 71) de traitement d'un combustible gazeux, en part... more L'invention concerne un dispositif (1, 71) de traitement d'un combustible gazeux, en particulier de traitement de gaz naturel, comprenant un etage d'absorption (3) qui sert a separer le sulfure d'hydrogene et le dioxyde de carbone d'avec le combustible gazeux au moyen d'un fluide de lavage (17) ; un desorbeur (5), installe en aval de l'etage d'absorption (3) du point de vue fluidodynamique, qui sert a separer le sulfure d'hydrogene d'avec le fluide de lavage (17) ; un etage de conversion (7), en liaison fluidodynamique avec le desorbeur (5), qui sert a produire du dioxyde de soufre en tant que fraction d'un courant d'effluent gazeux a partir du sulfure d'hydrogene separe ; ainsi qu'un etage de preparation (9, 73), en liaison fluidodynamique avec l'etage de conversion (7), qui sert a separer le dioxyde de soufre d'avec le courant d'effluent gazeux au moyen d'un fluide de lavage (17). Selon l'invention, on uti...
... state solutions but also for the continuation of stable and unstable periodic solutions in on... more ... state solutions but also for the continuation of stable and unstable periodic solutions in one ... Due to the utilization of sparse matrix techniques and standard numerical routines like Harwell [9 ... example, the coding of the Jacobians' patterns required by the sparse matrix numerics of ...
Computer Aided Chemical Engineering, 2011
ABSTRACT
Energy Procedia, 2011
Processes for carbon capture and storage have the drawback of high energy demand. In this work th... more Processes for carbon capture and storage have the drawback of high energy demand. In this work the application of CO 2 capture by anti-sublimation is analyzed. The process was simulated using Aspen Plus. Process description is accomplished by phase equilibria models which are able to reproduce the vapor-liquid and vapor-solid equilibria. Different process configurations are proposed. Total electric energy demand was defined as the evaluation criteria and the most suitable configuration was selected within technical limits. Further performance enhancement was achieved by improving the compression cooling cycles. An economic evaluation was performed for the low temperature process and the results were compared to a chemical absorption process with monoethanolamine. CO 2 capture by anti-sublimation showed a better performance concerning the energy demand but with a reduced economic benefit due to higher equipment cost.
Journal of Chromatography A, 2003
In this contribution, simple methods are presented for controlling a simulated moving bed (SMB) c... more In this contribution, simple methods are presented for controlling a simulated moving bed (SMB) chromatographic process with standard PI (proportional integral) controllers. The first method represents a simple and model-free inferential control scheme which was motivated from common distillation column control. The SMB unit is equipped with UV detectors. The UV signals in the four separation zones of the unit are fixed by four corresponding PI controllers calculating the ratio of liquid and solid flow in the respective separation zone. In order to be able to adjust the product purity a second, model-based control scheme is proposed. It makes use of the nonlinear wave propagation phenomena in the apparatus. The controlled chromatographic unit is automatically working with minimum solvent consumption and maximum feed throughput--without any numerical optimization calculations. This control algorithm can therefore also be applied for fast optimization of SMB processes.
Journal of Chromatography A, 2003
The improvement of the simulated moving bed (SMB) process based on the introduction of a cyclic m... more The improvement of the simulated moving bed (SMB) process based on the introduction of a cyclic modulation of the feed concentration is described. It is demonstrated that such a feed concentration gradient during the shifting cycle can improve the performance significantly. The productivity and the product concentrations can be increased while simultaneously the solvent consumption can be decreased compared to the conventional SMB process with constant feed parameters.
Industrial & Engineering Chemistry Research, 2010
Capture and sequestration of CO 2 from power plant flue gas have become an important issue in the... more Capture and sequestration of CO 2 from power plant flue gas have become an important issue in the discussion about global warming. Different concepts of capture are being pursued. The advantage of postcombustion processes, such as processes based on absorption and stripping, is the possibility of retrofitting a state-ofthe-art power plant with a capture plant under reasonable effort. Capturing CO 2 by using an absorption/ stripping process requires energy in the form of electricity and steam both supplied by the power plant. The capture process thereby reduces the overall efficiency of the power plant by up to 13%pts (percentage points). Apart from the development of new solvents, alternative and novel configurations of the process can lower the energy requirements. Three alternative configurations are economically and technically evaluated and compared to a baseline process represented by a standard absorption/stripping process using monoethanolamine (MEA) as a solvent. Savings in cost of CO 2-avoided of 2-5% were attained. Regarding the total power required, savings of 4-7% were obtained. The results showed that not the process with the highest energy savings has the lowest cost of CO 2-avoided, but that the influence of rising investment costs of more complex configurations cannot be ignored. For a comprehensive analysis of different configurations it is essential to perform both an economic evaluation and a technical study.
Chemie Ingenieur Technik, 2001
Two different control strategies for Moving Bed chromatographic processes are developed and appli... more Two different control strategies for Moving Bed chromatographic processes are developed and applied to True as well as Simulated Moving Bed processes. The first method represents an inferential control scheme with simple PI controllers. No mathematical model is required. Good control performance is obtained for processes with constant feed compositions and fluctuating flow rates. For processes with fluctuating feed composition and flow rates, a second, model based control scheme is proposed. It is based on nonlinear wave theoryand guarantees minimal solvent consumption and maximal feed throughput for any desired product purity without long winded optimization calculations
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Papers by Henning Schramm