The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ha Herbert Zondag - One of the best experts on this subject based on the ideXlab platform.
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prototype thermochemical heat storage with open Reactor System
Applied Energy, 2013Co-Authors: Ha Herbert Zondag, Benjamin Kikkert, Sf Simon Smeding, Robert De Boer, M BakkerAbstract:Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage System has been realized at ECN, applying an open sorption System concept. The packed bed contains 17dm3 of sorption material and is capable of generating 150W of thermal power. An effective energy storage density of approximately 0.5GJ/m3 was obtained.
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prototype thermochemical heat storage with open Reactor System
Applied Energy, 2013Co-Authors: Ha Herbert Zondag, Benjamin Kikkert, Sf Simon Smeding, Robert De Boer, M BakkerAbstract:Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage System has been realized at ECN, applying an open sorption System concept. The packed bed contains 17dm3 of sorption material and is capable of generating 150W of thermal power. An effective energy storage density of approximately 0.5GJ/m3 was obtained.
Hermann Hofbauer - One of the best experts on this subject based on the ideXlab platform.
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the different demands of oxygen carriers on the Reactor System of a clc plant results of oxygen carrier testing in a 120 kwth pilot plant
Applied Energy, 2015Co-Authors: Karl Mayer, Tobias Pröll, Stefan Penthor, Hermann HofbauerAbstract:Abstract Chemical looping combustion is now at a point beyond proof of concept. Lots of different oxygen carriers have been developed using different metal oxides, support materials and production methods. The interchangeability of oxygen carriers in a chemical looping combustion plant is investigated in a 120 kW th pilot. Four different oxygen carriers are tested with focus on Reactor temperature, total solids inventory, specific fuel Reactor inventory, solids circulation rate and air to fuel ratio. The experimental data of this work, the data of previous work with the same pilot plant and thermodynamic data allow the identification of three groups of oxygen carriers according to the demands on the Reactor System for good fuel conversion. Different Reactor configurations and potentially limiting factors for each type of oxygen carrier are identified. Changing oxygen carriers of the same group in an existing chemical looping plant seems to be possible without big changes of the Reactor configuration.
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comparison of the performance behaviour of silica sand and olivine in a dual fluidised bed Reactor System for steam gasification of biomass at pilot plant scale
Chemical Engineering Journal, 2011Co-Authors: Stefan Koppatz, Christoph Pfeifer, Hermann HofbauerAbstract:The behaviour of olivine compared to silica sand as bed material was investigated in a dual fluidised bed Reactor System (DFB) for steam gasification of biomass. This study presents fundamental experimental data on the impact of olivine on the product gas and distribution of condensable hydrocarbons (tars) effected by the catalytic properties of olivine. The results obtained with olivine are compared to silica sand, which is taken as a reference as it is considered to be inert. The experimental device is a pilot plant of 100 kW fuel input and the design is comparable to large scale applications. Pressure and temperature profiles of the Reactor System are presented to illustrate the System performance. A clear shift was found for the product gas composition (H2: 5 percentage points in volume, CO and CO2: up to 10 percentage points in volume) using silica sand and olivine as bed material. Olivine is identified as increasing the product gas yield and the H2 yield by promoting the CO-shift reaction. It was found that olivine reduced the GC/MS detectable tar content by approx. 35% and the content of gravimetrically detected tars by approx. 60% in the product gas. The changes in tar yield (related to the fuel input) were found to be decreased by about 30% and 57% for GC/MS and grav. detectable tars, respectively. Classifications for condensable hydrocarbons proposed in literature are used to lump the detected tar species into appropriate groups. Thus, the behaviour and shifting of the tar with respect to the classification is identified. In particular, naphthalene was found to contribute notably to the GC/MS tar complex at quantities of 40–45 wt.% (olivine) and 31–33 wt.% (silica sand). In contrast to silica sand, olivine has a decomposition effect on the higher hydrocarbons.
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design of a chemical looping combustor using a dual circulating fluidized bed dcfb Reactor System
Chemical Engineering & Technology, 2009Co-Authors: Philipp Kolbitsch, Tobias Pröll, Johannes Bolharnordenkampf, Hermann HofbauerAbstract:A dual circulating fluidized bed (DCFB) Reactor System for chemical looping combustion is proposed. The Reactor is designed to operate with a Ni-based oxygen carrier and is fueled with either natural gas or designed mixtures of CH4, CO, H2, and higher hydrocarbons at 120-kW fuel power. The main design parameters are determined and the DCFB System, which promises large scale applicability, is introduced. The DCFB Reactor System features effective control of the solid circulation rate via the primary fast fluidized bed (air Reactor) without changing the fluidization regime in the secondary Reactor (fuel Reactor). Therefore, the secondary Reactor can be optimized on fuel conversion without affecting the global solid circulation rates. The air Reactor design can focus on the transportation of the solids to the fuel Reactor. Besides a short introduction of the auxiliary units of the Reactor System, a pressure profile of the pilot rig in hot operation is presented.
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modeling of a 120 kw chemical looping combustion Reactor System using a ni based oxygen carrier
Chemical Engineering Science, 2009Co-Authors: Philipp Kolbitsch, Tobias Pröll, Hermann HofbauerAbstract:A modeling tool for the investigation of chemical looping combustion (CLC) in a dual circulating fluidized bed (DCFB) Reactor System is introduced. CLC is a novel combustion process with inherent CO2CO2 separation, consisting of two fluidized bed Reactors, an air Reactor (AR) and a fuel Reactor (FR). A solid oxygen carrier (OC) that circulates between the Reactors, transports the necessary oxygen for the combustion. In the DCFB concept both AR and FR are designed as circulating fluidized beds (CFBs). Each CFB is modeled using a very simple structure in which the reacting gas is only in contact with a defined fraction of the well mixed solids. The solids distribution along the height axis is defined by a void fraction profile. Different parameters that characterize the gas–solids contact are merged into only one parameter: the fraction of solids exposed to the gas passing in plug flow (φs,coreφs,core). Using this model, the performance of the 120 kW DCFB chemical looping combustor at Vienna University of Technology is investigated. This pilot rig is designed for a Ni-based OC and natural gas as fuel. The influence of the Reactor temperatures, solids circulation rate, air/fuel ratio and fuel power are determined. Furthermore, it is shown that with the applied kinetics data, the OC is only fully oxidized in the AR when the AR solids inventory is much larger than the FR solids inventory or when both Reactors are very large. To compare different Reactor Systems, the effect of the solids distribution between AR and FR is studied and both gas and solids conversions are reported.
M Bakker - One of the best experts on this subject based on the ideXlab platform.
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prototype thermochemical heat storage with open Reactor System
Applied Energy, 2013Co-Authors: Ha Herbert Zondag, Benjamin Kikkert, Sf Simon Smeding, Robert De Boer, M BakkerAbstract:Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage System has been realized at ECN, applying an open sorption System concept. The packed bed contains 17dm3 of sorption material and is capable of generating 150W of thermal power. An effective energy storage density of approximately 0.5GJ/m3 was obtained.
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prototype thermochemical heat storage with open Reactor System
Applied Energy, 2013Co-Authors: Ha Herbert Zondag, Benjamin Kikkert, Sf Simon Smeding, Robert De Boer, M BakkerAbstract:Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage System has been realized at ECN, applying an open sorption System concept. The packed bed contains 17dm3 of sorption material and is capable of generating 150W of thermal power. An effective energy storage density of approximately 0.5GJ/m3 was obtained.
Parimal Pal - One of the best experts on this subject based on the ideXlab platform.
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fermentative production of gluconic acid in membrane integrated hybrid Reactor System analysis of process intensification
Chemical Engineering and Processing, 2017Co-Authors: Parimal Pal, Ramesh Kumar, Jayato Nayak, Subhamay BanerjeeAbstract:Abstract Gluconic acid was produced through microbial conversion of hydrolyzed sugarcane juice by Gluconobacter oxydans in a multi-stage membrane-integrated hybrid Reactor System. Provision of continuous production, withdrawal of product, separation and recycle of cells, separation and recycle of unconverted sugars to the fermentation unit in the System, resulted in high concentration (44.7 g/L), yield (0.94 g/g), productivity (6.5 g/L/h) and purity (∼97%) of the product in a very simple, eco-friendly, modular and compact membrane-based process. The product could be further concentrated up to 540 g/L using an additional nanofiltration step. Integration of downstream membrane separation with conventional fermenter culminated in a highly intensified green process. This work focuses on analysis of process intensification and eco-friendliness factors like space intensification, energy intensification, capacity flexibility, economic gain, E-factor and atom efficiency to assess business sustainability of the membrane-based process.
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fermentative production of glutamic acid from renewable carbon source process intensification through membrane integrated hybrid bio Reactor System
Chemical Engineering and Processing, 2015Co-Authors: Parimal Pal, Vikrama Chakravorty Dekonda, Ramesh KumarAbstract:Abstract A three-stage membrane-integrated hybrid Reactor System was developed and experimentally investigated for direct production of l (+) glutamic acid from a cheap and renewal carbon source. This manufacturing scheme is a continuous one with selective production of glutamic acid by fermentation of sugar cane juice using Corynebacterium glutamicum. Integration of specially designed membrane modules with traditional fermenter culminated in development of a hybrid process with high process intensification that permitted fermentation under high cell density with recycle of separated cells and unconverted sugars. The modular design ensured high yield (0.95 g/g), productivity (8.3 g/l/h), concentration (175 g/L) and purity (∼97%) in a very simple, environmentally benign, compact and flexible plant configuration reflecting all the major characteristics of high process intensification. Process intensification measured and analysed in terms of space intensification, application flexibility, capacity flexibility, energy saving and cost advantage parameters indicate development of an economically viable green process.
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modelling and simulation of continuous l lactic acid production from sugarcane juice in membrane integrated hybrid Reactor System
Biochemical Engineering Journal, 2013Co-Authors: Pinaki Dey, Parimal PalAbstract:Abstract Modelling and simulation was done for a two-stage membrane-integrated hybrid Reactor System for continuous production of L (+) lactic acid under non-neutralizing conditions. The model captures microbial conversion of sugar cane juice to lactic acid under substrate–product inhibitions with downstream purification by nanofiltration. All the major phenomena and the governing parameters like fluid flow, feed dilution, substrate–product inhibitions, Donnan and steric effects during micro and nanofiltration for cell recycle, product separation and purification have been reflected in the modelling. The model describes a green, integrated continuous process of direct lactic acid production starting with a cheap, renewable carbon source. The highest lactic acid concentration achieved after the final stage of nanofiltration was 66.97 g/L at 13 kg/cm 2 operating pressure when the overall productivity reached 12.40 g/(L h). The developed model could successfully predict production, purification and transport of lactic acid through two stage membrane modules. Performance of the model was very good as indicated in the high overall correlation coefficient ( R 2 > 0.980) and the low relative error ( RE
Makoto Shoda - One of the best experts on this subject based on the ideXlab platform.
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Solid state fermentation of lipopeptide antibiotic iturin A by using a novel solid state fermentation Reactor System.
Journal of environmental sciences (China), 2009Co-Authors: Takashi Ano, Guang Yuan Jin, Shinji Mizumoto, Mohammad Shahedur Rahman, Kasumasa Okuno, Makoto ShodaAbstract:A new solid state fermentation Reactor (SSFR) for solid substrate was used for the production of lipopeptide antibiotic iturin A using Bacillus subtilis RB14-CS. Solid state fermentation (SSF) is the technique of cultivation of microorganisms on solid and moist substrates in the absence of free water. SSF has shown much promise in the development of several bioprocesses and products because of their several advantages like absence of free water that allows simplified downstream processing and low cost. SSFR allows agitation of the SSF culture with improved temperature control and air supply. Interestingly, when okara, the widely available waste product from the tofu industries, was used as the solid substrate for the SSFR, no iturin A production was observed. However, without agitation, production of iturin A was observed in the SSFR but the production level remained low. The low production of iturin A was found to be due to the heat generation and excess temperature rise inside the Reactor System during the fermentation process. Maintaining the temperature within a range of 25-30°C, production of iturin A was significantly improved in the SSFR. This was comparable to the laboratory scale production, and signifies the potential application of the SSFR for SSF.
