The work of the department of Decentralized Energy Conversion (DEU) is focused mainly in the area of combustion and gasification process optimization for decentralized heat and power generation from biogeneous and fossil fuels. In addition, research of flameless combustion of gaseous, solid and liquid fuels is being conducted. Based on our experience in fluidized bed technologies, processes for CCS (Carbon Capture and Storage) are currently being developed and optimized with the aim of commercialization. Several test facilities are available for experimental investigations at the IFK experimental test centre (i.e. lab and pilot scale (dual) fluidized bed reactors, scaled FB cold models, flameless burners, biomass-fired resorption chiller).
Currently the work of the department is focused on:
![von LeJean Hardin and Jamie Payne derivative work: Jarl Arntzen (Diskussion) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons](https://www.ifk.uni-stuttgart.de/forschung/dezentrale-energieumwandlung/_img_/530px-Carbon_sequestration-2009-10-07.svg.png?__scale=w:1000,h:1000,q:100,t:3)
Carbon Capture and Storage
- Calcium Looping (Post-combustion capture) – Separation of CO2 from power plant flue gases with natural limestone
- Chemical Looping (Combustion with pure oxygen) – Combustion of coal using pure oxygen supplied in solid form by regenerable metal oxides
- Oxy-fuel CFB (Combustion with pure oxygen) – Combustion of coal with pure oxygen in a circulating fluidized bed reactor
Gasification
- Sorption Enhanced Gasification (SEG) – Gasification of solid fuels (biomass, coal) for the production of a hydrogen rich product gas
- Air gasification of biomass
- O2-steam gasification of biomass
- Fundamental research on formation and conversion of tars in gasifiers
- Investigations on the reduction of impurities (e.g. tars, H2S) in gasification product gas
Combustion
- Flameless combustion of gaseous, liquid and solid fuels
- Combustion of solid fuels (RDF, biomass, coal) in fluidized beds
Ongoing Projects
Link: https://hyfuelup.eu/
Within the BMWi funded Bio2SNG research project, the CoMBPres gasification is to be further developed and extensively experimentally characterized and validated. The CoMBPres process (Combined Methanation and Biomass Gasification by high Pressure) is an innovative gasification process at elevated pressure, allowing direct thermochemical conversion of biogenic residues into methane, respectively Bio-SNG (SNG: Synthetic Natural Gas). Through a neat in-process utilization of the released methanation enthalpy and integration into the endothermic gasification reaction, conversion efficiencies up to 20% higher than that of state of the art Bio-SNG processes can be achieved.
The research project’s main objective is the experimental validation of hitherto theoretical findings for the CoMBPres gasification at realistic process conditions of up to 400 bar and 900 °C. The experiments will be carried out with a specifically designed test rig for the high pressure water gasification of dry biomass.
The as yet open points towards the way of a first CoMBPres pilot plant are to be addressed by developing, designing, manufacturing, testing and optimizing a specific apparatus for high pressure biomass feeding up to market-readiness, as well as the conception of high temperature product gas heat exchangers.
Contact person: Gebhard Waizmann, Lukas Reiner
Project duration: 36 months
The EU project BackCap, which is funded by the "Research Fund for Coal and Steel", deals with CO2 capture from flue gases using calcium looping.
The focus is on conventional, amortized power plants, which in the future will run as a back-up to the renewable power supply and are to be decarbonized.
The process to be investigated here thus aims at a more flexible CO2 capture, which is to be achieved by means of the sorbent Ca(OH)2. At the IFK, experiments are being carried out on a laboratory scale (TGA) and in the in-house entrained flow reactor.
Contact person: Nico Mader
Project duration: 3 years
Link: https://delegacion.asturias.csic.es/backcap/
Completed Projects
NuCA is a collaborative research project funded by German Federal Ministry for Economic Affair and Energy (BMWi) to investigate the feasibility of the utilization of solid recovered fuel (SRF) through oxy-fuel combustion and sorption enhanced gasification (SEG) processes. The SEG process offers a promising pathway for the production of synthesis gas with high hydrogen content coupled with in-situ removal of CO2. In this process, limestone (CaCO3) is calcined to CaO at high temperatures in combustion reactor by the release of CO2. The gasification process is autothermally operated by circulating hot bed materials which serve as the heat carrier to promote endothermic reactions. At the same time, CaO adsorbs CO2 in the gasifier forming CaCO3. The department of Decentralized Energy Conversion (DEU) will study oxy-SEG process in two types of dual fluidized bed facilities (i.e. scaled-up and pilot scale) with various SRF fuels for flexible synthesis gas production. Within the scope of the project, demonstration of the oxy-SEG process with SRF fuels will be conducted in an industrially relevant environment (200 kW pilot plant). In addition, the integration of SEG process with water electrolysis process will be carried out using process simulation tool in order to achieve a high degree of carbon efficiency within the overall process chain.
Test facilities: DIVA/ELWIRA, MAGNUS
Project duration: 36 Monate
NEWEST-CCUS is an innovative three-year project funded by the ERA-NET Accelerating CCS Technologies (ACT2) initiative to assess the scale of the European market for carbon capture, utilisation and storage (CCUS) technologies in the waste-to-energy (WtE) sector. The innovation focus is on progressing TRL of several promising technologies for WtE sites with a combination of pilot-scale testing and modelling. At the IFK, the research focus will be set on developing the oxy-fuel combustion technology, focusing on developing circulating fluidized bed technology with a potential for higher efficiency with Solid Recovered Fuels when compared with grate fired boilers typically used for WtE combustion.
Project duration: 36 months
The DFG (Deutsche Forschungsgemeinschaft) funded project PyroSEG, aims at investigating reaction mechanisms of Sorption Enhanced Gasification (SEG) of biomass. The results shall be used to enhance reaction models embedded in process models that have already been developed at IFK. Even though gasification in coupled fluidized bed reactors is already industrially available and the function of SEG itself has been demonstrated at TRL 6 (see FLEDGED), some reaction conditions relevant to SEG remain unconsidered in present empirical approaches describing gasification processes. Thus, for the optimization and further development of SEG a deeper understanding of the process is indispensable in this regard. Therefore, within PyroSEG, fundamental studies are performed on relevant reaction pathways and their kinetics. This includes reactions such as primary pyrolysis, char formation, tar reforming on char and active bed materials as well as CO2 removal from the product gas through carbonation of CaO. In addition, hydrodynamic effects in the fluidized bed should be taken into account in the modeling and the experimental investigations.
PyroSEG is conducted as a joint project together with the Department of Thermal Engineering of Tsinghua University (Beijing, China).
Test facility: BAR, experimental setup that has to be developed
Project duration: 3 years
The H2020 CLEANKER project investigated the Calcium Looping technology for CO2 capture from cement plants. The adapted Calcium Looping process uses cement raw meal as sorbent and entrained flow reactors as carbonator (absorber) and calciner (desorber). A demonstration plant treating approx. 1-2 % of the Buzzi Unicem’s cement plant in Vernasca (Italy) will be designed and erected at site. The department of Decentralized Energy Conversion (DEU) will support the demonstration plant design with its expertise in operating pilot plants and will further characterize various raw meal qualities with respect to their suitability as calcium looping sorbent using their mini-pilot entrained flow facility.
Test facility: DIVA
Link: www.cleanker.eu
Project duration: 48 months
FLEDGED is a project funded by the EU Horizon 2020 program, in which a flexible and low cost process for the production of dimethyl ether (DME) from biomass will be developed and demonstrated under industrially relevant conditions. The project focuses on the sorption enhanced gasification (SEG) to produce a tailored syngas and on the steam sorption enhanced DME synthesis as the two key processes. The department of Decentralized Energy Conversion (DEU) investigates the SEG process with biomass and biogenic residue feedstocks experimentally at two different dual fluidized bed facilities (laboratory and pilot scale). Within the experimental investigations stationary gasification conditions as well as the modification of the SEG process to flexibly integrate the addition of hydrogen from water electrolysis into the process are considered.
Test facilities: DIVA/ELWIRA, MAGNUS
Link: www.fledged.eu
Project duration: 36 months
Res2CNG addresses conversion of biogenic residues to methane based fuels with the integration of renewable electrolysis hydrogen. The main focus is on optimal and efficient carbon utilization. At IFK, the steam-oxygen fluidized bed gasification of biogenic residues is investigated experimentally. The focus is on characterizing the syngas composition and occurring gas impurities. As to that, a hot gas cleaning system is developed and tested to improve the syngas quality for the following methanation process.
Test facility: ELWIRA
Project duration: 3 years
CEMCAP is a project funded by Horizon 2020 which addresses CO2 capture from cement production. The primary object of CEMCAP is to prepare the ground for large-scale implementation of CO2 capture in the European cement industry. The department of Decentralized Energy Conversion investigates and optimizes the Calcium-Looping (CaL) process for cement plant application. Synergy effects between the Calcium-Looping process and the cement production offer a high potential for improvement. Exemplarily, the deactivated sorbent of the Calcium-Looping process can be re-utilized as feedstock for the clinker production leading to high make up flows of sorbent and therefore to increased CO2 capture performance and energy efficiency.
The department of Firing Systems (KWF) is also participating in the CEMCAP project. It investigates the implementation of oxy-fuel technology in the cement process.
Test facility: MAGNUS
Link: www.sintef.no/projectweb/cemcap
Project duration: 36/42 months
Within the scope of this project, the development of a FLOX®-type burner for liquid fuels is pursued together with the Oel-Waerme-Institut GmbH and e-flox GmbH. Flameless Oxidation (paraphrased by the term FLOX®) is a low emission combustion process without visible flame which is already widely applied for gaseous fuels in industrial applications. A major advantage of this combustion technology is the inherently lower emission of the pollutant nitrogen oxide (NOx) which allows for meeting emission regulations without additional flue gas treatment. The Öl-FLOX-project aims to develop a FLOX®-type burner which can run both on fuel oil and on biogenic liquid fuels in order to open up new fields of application.
Test facility: Boiler with FLOX®-type burner of the BIO-COOL facility
Project duration: 2,5 years
The main objective of the research cooperation DISS between the University of Stuttgart and the University of Heidelberg is to develop and to apply methods of data assimilation. Focusing on thermochemical energy storage systems, experiments and simulations on different levels will be combined. The results enable prognoses on other levels and thus a continuous optimization of simulations and experiments. At IFK particle-scale models to simulate thermochemical high-temperature energy storage systems based on CaO/CaCO3 will be developed. The models include heat and mass transfer inside the particle and describe the local and temporal changes in physical properties of the particle and process parameters. With such an approach, the effects of diverse process steps on the reactivity and properties of the calcium oxide particle can be simulated.
Project duration: 3 years
FlexiCAL is a research project funded by the European Commission’s Research Fund for Coal and Steel (RFCS). The main objective of this research project is based on assessing and improving the flexibility of coal power plants with CO2 capture using the Calcium Looping technology. At IFK, a fluidized bed reactor configuration with the Calcium Looping carbonator operating in a turbulent mode and with material extraction from the bottom is investigated experimentally. This plant concept allows a higher flexibility in respect to plant loads, since flue gas load and sorbent circulation are decoupled. Within the scope of this project, the flexibility potential, operational limits and dynamic plant behavior are investigated.
Contact person: Joseba Moreno
Test facility: MAGNUS
Link: www.flexical.eu
Project duration: 3 years
Production of Bio-CNG (Compressed Natural Gas) from lignin rich biogenic residues is of economical and as well ecological interest but requires a thermo-chemical conversion. The latter is comprised of the gasification of the biomass to syngas (typically at: 700 - 900 °C) and its subsequent methanation (typically at: 300 - 500 °C). The conversion efficiency can be improved significantly by integration of the exothermic methanation and the endothermic steam gasification process. The optimization potential will be analyzed experimentally within the project, which is funded by the Vector Stiftung. A high pressure gasification reactor, tailored for that purpose, will be designed and constructed.
Contact person: Gebhard Waizmann
Project duration: 3 years
Recently, application of flameless combustion technology to solid fossil fuels like pulverised coal has become of interest. The goal of ultra low NOx-emissions shall be achieved by the separation of coal/primary air and combustion air and by the avoidance of temperature peaks in the flame front. Since coal combustion in flameless mode differs from conventional flame mode in terms of near burner aerodynamics, fuel conversion, heat transfer and emission behaviour, experiments are carried out at IFK's pilot scale test rig KSVA. Based on the experimental results FLOX-specific CFD sub-models are developed and integrated in IFK's CFD code AIOLOS. Eventually, a validated scale-up methodology is aimed for. It is used to design full-scale burners for wall fired and tangentially fired utility boilers. In order to bring the technology closer to the utility plant market, a CFD study is carried out delivering technical solutions for utility boilers and an economical assessment of PC-FLOX burners' application to full scale utility boilers.
This project is funded by the RFCS programme of the European Commission. Project management (scientific and technical) is carried out by IFK.
Test facility: KSVA
Link: floxcoal2.eu-projects.de
Project duration: 3 years
In diesem Europäischen Forschungsprojekt steht die Weiterentwicklung des Calcium-Looping Prozesses zur CO2-Abscheidung durch eine neuartige Technik zur Reaktivierung des Sorbens im Vordergrund.
Am IFK wird die Nutzung des verbrauchten Sorbens des Calcium-Looping-Prozesses zur In-situ Entschwefelung in Kraftwerkskesseln mit zirkulierender Wirbelschichtfeuerung untersucht. Dazu werden Verbrennungsversuche mit Steinkohle an der 150-kWth-Pilotanlage durchgeführt.
Test facility: MAGNUS
Project duration: 3 years
To push the change of the futures supply of liquid fuels for traffic and transportation to regenerative energy, as a well as to store energy with a high energy density, in this research network the creation of liquid hydrocarbons out of biomass is investigated. The IFK investigates the gasification of different residual biomasses like straw, wood waste or manure. As gasification process the SER-gasification, the staged steam gasification and the oxygen gasification is investigated. To demonstrate the CO2 separation out of the SER flue gas as a carbon source for Fischer-Tropsch synthesis in a pilot plant scale, the regenerator of the SER process is operated with an oxygen regeneration.
Test facilities: VERONIKA, DIVA/ELWIRA, MAGNUS
Project duration: 3 years
In this joint research project the gasification of dried manure and sewage sludge is investigated. Additionally to the energetic use of solid waste, the recovery of nutrients out of gasification residues is investigated to close the nutrient cycle.
Test facilities: VERONIKA, DIVA/ELWIRA
Project duration: 1 years
Condensable hydrocarbons (tars) are a major problem in the implementation of gasification projects when they fall below the dew point and condense in downstream equipment. This affects the operation of the gasifier. The determination of the tars quality and quantity is therefore essential for gasification processes. The determination of tars was done previously with time-and cost-intensive sampling and subsequent laboratory analysis. The aim of the DEMITAR project is to develop a technique of an online tar measurement device that can be used reliably and easily in gasification power plants and that provides real time tar concentrations to the operator.
Test facilities: MAGNUS, DIVA/ELWIRA, VERONIKA
Project duration: 3 years
The Chemical Looping Combustion (CLC)-process is used for CO2 free power generation from coal combustion. The process consists of two connected fluidized beds and a circulating solid oxygen carrier. In the air reactor the oxygen carrier gets oxidized with air and in the fuel reactor it gets reduced with coal. A flue gas mainly consisting of CO2 exits the fuel reactor. After condensing the steam the CO2 can be purified, compressed and stored. Unlike the oxyfuel process, chemical looping combustion does not require a cryogenic air separation unit and has therefore electric efficiencies similar to that of a traditional power plant. The CLOCK project focuses on the experimental investigation of synthetic and natural oxygen carriers and simulation of chemical looping on the commercial scale.
The research on the natural oxygen carriers at the IFK are carried out on a dual fluidized bed reactor system to optimize the conversion of fuel as well as to define the optimum operating conditions for the CLC- process with coal.
Test facility: DIVA/ELWIRA
Link: www.cooretec.de
Project duration: 3 years
One possibility for CO2 capture in coal fired power plants is the combustion of fuels with pure oxygen. The generated flue gas consists mainly of CO2 which can be purified and compressed for storage. Up to now, this so called oxyfuel-process has only been investigated for pulverized coal (PC) combustion. The goal of this project is the investigation of oxyfuel combustion for circulating fluidized bed (CFB) boilers.. In a CFB it is also possible to increase the maximum O2 concentration in the combustion chamber to a higher level compared to PC and thus increase process efficiency.
Test facility: MAGNUS
Link: www.cooretec.de
Project duration: 3 years
In this research project existing and future bio energy plants (fermentation and gasification) in Baden-Württemberg will be investigated to determine if they are suitable to extend energy storage and to compensate for wind and solar power fluctuations. The research project analyzes the potential and limitations for a flexible use of electricity supply; covering “biomass storage” by using flexible fuel or substrate loading of bio-energy plants, as well as the “gas storage” of biogas or SNG (methanation) in internal or external storages and different strategies for heat utilization. The results indicate a funding model that is to be developed for the flexible operation of bioenergy plants, including necessary storages.
Test facility: MAGNUS
Project duration: 3 years
The research project P&B2G involves the study of a completely integrated flexible energy approach using existing biomass for an increasing contribution of renewable energies. Based on a concept of biomass gasification, water electrolysis and methanation, different options for storing renewable electricity and also their benefits for power grid stability are examined. In the research project P&B2G, optimal plant locations are determined by interfaces between power and gas grids, including the availability of biomass. A further Life Cycle Assessment (LCA) will help determine the complete benefits and ecological advantages for the whole of Baden-Württemberg and Germany’s electricity supply.
Link: www.pb2g.de
Project duration: 3 years
This joint research project aims at optimizing the energetic and material utilization in the generation of gaseous fuels like substitute natural gas (SNG) or hydrogen from biomass. Processes to be investigated consist of the fermentative conversion to biogas and the thermo-chemical conversion by gasification. In addition to wet biomass for anaerobic fermentation, dry materials containing wood cellulose like wood or straw will be used.
Test facilty: VERONIKA
Link: www.b-2-g.de
Project duration: 3 years
This project focuses on the development and validation of advanced modeling and simulation tools required for implementing the Calcium Looping (CaL) process at commercial scale. Development of realistic process and steam cycle models, reactor operation at bench-scale and industrial expertise will lead to producing guidelines for the design and dimensioning of commercial scale CaL systems. A techno-economical study, including also integration at a cement industry plant, will be performed with reference to a medium scale existing plant and a new state of the art large scale plant. The project is funded in part by the RFCS Framework of the European Commission and is administratively and scientifically coordinated by IFK.
Contact persons: Glykeria Duelli (Varela), Marcel Beirow, Theodor Beisheim, Heiko Dieter
Test facilty: DIVA/ELWIRA
Link: cal-mod.eu-projects.de
Project duration: 3 years
The Calcium Looping process is a newly developed technology for the efficient capture of CO2 from power plant flue gases. The CATS project aims at demonstrating this process in a 200 kwth pilot scale facility. Therefore, a pilot scale plant consisting of two dual circulating fluidized bed reactors has been erected at the institute. The findings from the successful demonstration of the calcium looping process will be used for design of a 20 MWth demonstration plant.
Test facilty: MAGNUS
Project duration: 4,5 years
Within the scope of the BIOCOOL project, a facility has been erected which generates heat and cooling energy through the combustion of biomass. This interesting alternative of great economic and ecologic advantages combines and integrates flameless combustion with a resorption chiller. By means of flameless combustion, the calorific value of low grade fuels is utilized to drive a refrigerating machine whose state-of-the-art technology make it capable of generating cooling energy even from waste heat and solar energy.
Test facilty: BIO-COOL
Project duration: 2 years
The overall objective of the research module F1 "flexible fuel" is to assess the potential utilization of different regional biomass fuels from the Swabian Alb in a AER-demonstration plant. In this module, biomass fuels which do not directly compete with food and heat production (e.g. landscaping material, agricultural residues, etc.) are to be investigated regarding the feasibility of gasification under AER conditions.
Test facilty: DIVA/ELWIRA
Link: www.refuelnet.de
Project duration: 3 years
This project aims at the scale-up of one of the most promising concepts for CO2 capture from coal power plants: post-combustion calcium looping systems. The project focuses on the experimental pilot testing and scaling up of the process at scales in the 1 MW range. The 1 MW calcium looping pilot will be built in the Hunosa 50 MWe coal power plant (circulating fluidized bed) of “La Pereda”, using a side stream of flue gases of the commercial plant. The Project is funded in part by the FP7 Framework of the European Commission.
Test facilty: DIVA/ELWIRA
Link: https://cordis.europa.eu/project/rcn/93423_en.html
Project duration: 3 years
Development and implementation of an integrated, procedural approach for treatment and conversion of biomass for the production of gaseous fuels for utilization in fuel cell and gas turbine systems.
Test facilty: VERONIKA
Link: www.dlratunist.de
Project duration: 2,5 years
The project objective is to examine the potential, process chains and technologies for the production of biogenic gases and to classify and compare theses technologies with other processes with respect to the energy supply in Baden-Wuerttemberg. The project therefore especially focuses on practical experiments and investigations within the scope of the research platform Baden-Wuerttemberg, the biogas facility at the "unteren Lindhöfen", the bioliq facility at the Forschungszentrum Karlsruhe and the wood gasification facility under construction in Geislingen-Türkheim.
Test facilty: -
Project duration: 4 years
The project aims to develop a new pulverized coal burner based on the FLOX (FLameless OXidation) technology. Different designs of a bench-scale FLOX burner are to be tested under various operational conditions. Based on bench-scale experimental experience, literature study and basic numerical modeling, a pilot-scale FLOX burner is to be developed. Substantial pilot-scale experimental investigation is to be carried out in order to demonstrate feasibility and NOx reduction potential of the technology. Based on the experimental studies, the benefits over conventional burners are to be determined. Furthermore, using evaluation criteria the impact of FLOX combustion on power plant operation and associated advanced combustion concepts are to be derived.
Test facilty: KSVA
Link: www.kw21.de
Project duration: 3 years
A 200 kWth dual fluidized bed gasification pilot plant (MAGNUS) based on the Sorption Enhanced Reforming (SER) process was designed, constructed, and commissioned in 2010. Week long measurement campaigns were conducted to demonstrate the process on a pilot scale level. The operation of the pilot plant produced a hydrogen-rich gas (> 70 vol.-%) with a high calorific value suitable SNG production or for combustion in a gas motor or gas turbine. Furthermore, a design for a commercial SER-plant was completed based on the results and operating experience obtained from the pilot plant.
Test facilty: MAGNUS
Project duration: 3,5 years
Patents and Patent Applications
Contact
Jörg Maier
Dipl.-Ing.Head of Department Firing Systems (KWF)