Journal Papers

Articles in journals and conferences

2024

  • Müller J., Elhaus N., Treiber P., Karl J., Hofer M. (2024): GreenLNG – CO2 neutrale Methansubstitute aus Wind, PV und Biomasse. gwf Gas + Energie, 05398_2024_06_01.
  • Elhaus, N., Volkmann, M., Kolb, S., Schindhelm, L., Herkendell, K., & Karl, J. (2024). Techno-economic evaluation of anaerobic digestion and biological methanation in Power-to-Methane-Systems. Energy Conversion and Management, 315, 118787. https://doi.org/10.1016/j.enconman.2024.118787
  • Miederer, J., Kolb, S., Karl, J. (2024): Efficient Scheduling of Methanation on Wastewater Treatment Plants, In: 10th International Conference on Renewable Energy Gas Technology: 15th/16th May, 2024, Lund, Sweden. Lund, Sweden: Renewable Energy Technology International AB. 146 S. ISBN: 978-91-981149-9-7

Articles in journals and conferences of former years:

  • Torrigino, F.; Nagel, M.; Peng, Z.; Hartmann, M.; Herkendell, K. Sustainably Sourced Mesoporous Carbon Molecular Sieves as Immobilization Matrices for Enzymatic Biofuel Cell Applications. Catalysts 2023, 13, 1415. DOI: https://doi.org/10.3390/catal13111415
  • Elhaus, N., Kolb, S., Müller, J., Goldbrunner, M., Karl, J., & Herkendell, K. (2023). Environmental assessment of anaerobic digestion and biological methanation in power-to-methane systems. Journal of Cleaner Production, 429, 139509. DOI: https://doi.org/10.1016/j.jclepro.2023.139509
  • Böhm, L.; Kolb, S.; Plankenbühler, T.; Miederer, J.; Markthaler, S.; Karl, J. Short-Term Natural Gas andCarbon Price Forecasting Using Artificial Neural Networks. Energies, 2023, 16, 6643. DOI: https://doi.org/10.3390/en16186643
  • Matino, I.; Dettori, S.; Conde, A. S.; Colla, V.; Petrucciani, A.; Zaccara, A.; Iannino, V.; Mocci, C.; Hauser, A.; Kolb, S.; Karl, J.; Haag, S.; Bampaou, M.; Panopoulos, K.; Heracleous, E.; Kienberger, N.; Rechberger, K.; Rog, L.; Rompalski, P. Hydrogen intensified synthesis processes to valorise process off-gases in integrated steelworks. Matériaux & Techniques, 2023, 111(2), 204. DOI: https://doi.org/10.1051/mattech/2023025
  • Hauser, A.; Feldner, A.; Treiber, P.; Grimm, F.; Karl, J.: Utilization of Synthetic Steel Gases in an Additively Manufactured Reactor for Catalytic Methanation. Sustainability, 2023, 15(9), 7652. DOI: https://doi.org/10.3390/su15097652
  • Li, Y.; Grimm, F.; Karl, J.: The conversion of naphthalene on SOFC anodes and its impact on the cell performance. In: Fuel, Vol. 343, 1 July 2023, 127928. DOI: https://doi.org/10.1016/j.fuel.2023.127928
  • Lukas, J.; Kolb, S.; Heinbuch, J.; Willig, L.; Plankenbühler, T.; Müller, D.; Karl, J.: Image-based biomass characterization: Comparison of conventional image processing and a deep learning approach. In: Fuel, Vol. 341, 1 June 2023, 127705. DOI: https://doi.org/10.1016/j.fuel.2023.127705
  • Plankenbühler, T.; Müller, D.; Karl, J.: An adaptive and flexible biomass power plant control system based on on-line fuel image analysis. In: Thermal Science and Engineering Progress, Vol. 40, 1 May 2023, 101765. DOI: https://doi.org/10.1016/j.tsep.2023.101765
  • Li, Y.; Grimm, F.; Karl, J.: Numerical and experimental analysis of the effects of tar components on single planar SOFC under high fuel utilization. In: Electrochimica Acta, Vol. 449, 1 May 2023, 142234. DOI: https://doi.org/10.1016/j.electacta.2023.142234

  • Hauser, A.; Neubert, M.; Feldner, A.; Horn, A.; Grimm, F.; Karl, J. Design and Implementation of an Additively Manufactured Reactor Concept for the Catalytic Methanation. Appl. Sci. 2022, 12, 9393.  DOI: https://doi.org/10.3390/app12189393
  • Weitzer, M.; Müller, D.; Karl, J.: Two-phase expansion processes in heat pump – ORC systems (Carnot batteries) with volumetric machines for enhanced off-design efficiency. In: Renewable Energy, Vol. 199, pp. 720-732, November 2022, DOI: https://doi.org/10.1016/j.renene.2022.08.143
  • Kolb,S.; Müller, J.; Luna-Jaspe, N.; Karl, J.: Renewable hydrogen imports for the German energy transition – A comparative life cycle assessment. In: Journal of cleaner Production, 31 July 2022, 133289, DOI: https://doi.org/10.1016/j.jclepro.2022.133289
  • Bampaou, M.; Panopoulos, K.; Seferlis, P.; Sasiain, A.; Haag, S.; Wolf-Zoellner, P.; Lehner, M.; Rog, L.; Rompalski, P.; Kolb, S.; Kieberger, N.; Dettori, S.; Matino, I.; Colla, V. Economic Evaluation of Renewable Hydrogen Integration into Steelworks for the Production of Methanol and Methane. In: Energies, Vol. 15, 4650, DOI: https://doi.org/10.3390/en15134650 
  • Hauser, A., Wolf-Zoellner, P., Haag, S., Dettori, S., Tang, X., Mighani, M., Matino, I., Mocci, C., Colla, V., Kolb, S., Bampaou, M., Panopoulos, K., Kieberger, N., Rechberger, K., Karl, J.: Valorizing Steelworks Gases by Coupling Novel Methane and Methnaol Synthesis Reactors with an Economic Hybrid Model Predictive Controller. Metals 2022, 12(6), 1023, DOI: https://doi.org/10.3390/met12061023
  • Heracleous, E., Koidi, V., Lappas, A., Hauser, A., Haag, S.: Valorization of steel-work off-gases: Influence of impurities on the performance of Cu-based methanol synthesis catalyst. Chemical Engineering Journal 2022, 444, 15 September 2022, 136571, DOI: https://doi.org/10.1016/j.cej.2022.136571
  • Dettori, S., Matino, I. Iannino, V., Colla, V., Hauser, A., Wolf-Zoellner, P. Haag, S.: Optimizing methane and methanol production from integrated steelworks process off-gases through economic hybrid model predictive control. IFAC-PapersOnLine 2022, 55(2), 66-71, 05 May 2022, DOI: https://doi.org/10.1016/j.ifacol.2022.04.171
  • Markthaler, S.; Plankenbühler, T.; Miederer, J.; Kolb, S.; Herkendell, K.; Karl, J.: Combined Two-Model CFD Simulation of Trickle Bed Reactors with Head-Sump Extension: Case Study on Hydrodynamics and Biological Methanation. In: Industrial & Engineering Chemistry Research, Vol. 61, Issue 11, 4134–4152, DOI: https://doi.org/10.1021/acs.iecr.1c04262
  • Schneider, T.; Moffitt, J.; Volz, N.; Müller, D.; Karl, J.: Long-term effects of ilmenite on a micro-scale bubbling fluidized bed combined heat an power pilot plant for oxygen carrier aided combustion of wood. In: Applied Energy, Vol. 314, 118953, 15 May 2022. DOI: https://doi.org/10.1016/j.apenergy.2022.118953
  • Schneider, T.; Müler, D.; Karl, J.: Effect of Natural Ilmenit on the Solid Biomass Conversion of Inhomogeneous Fuels in Small-Scale Bubbling Fluidized Beds. In: Energies 2022, 15, 2747. DOI: https://doi.org/10.3390/en15082747
  • Leimbach, S.; Lukas, J.; Kolb, S.; Yang, L.; Plankenbühler, T.; Sega, M.; Harting, J.; Karl, J.: Early Detection of Agglomeration in Fluidized Beds by Means of Frequency Analysis of Pressure Fluctuations. In: Energy & Fuels (2022), 14.04.2022. DOI: https://doi.org/10.1021/acs.energyfuels.1c04356
  • Weitzer M.; Müller, D.; Steger, D.; Charalampidis, A.; Karellas, S.; Karl, J.: Organic flash cycles in Rankine-based Carnot batteries with large storage temperature spreads. In: Energy Conversion and Management, Vol. 255, 115323, 01.03.2022. DOI: https://doi.org/10.1016/j.enconman.2022.115323
  • Yang, L.; Sega, M.; Leimbach, S.; Kolb, S.; Karl, J.; Harting, J.: Capillary Interactions, Aggregate Formation and the Rheology of Particle-Laden Flows: A Lattice Boltzmann Study. In: Industrial & Engineering Chemistry Research, Vol. 61, Issue 4, 1863-1870, DOI: https://doi.org/10.1021/acs.iecr.1c03909

 

  • Matino, I., Dettori, S., Zaccara, A., Petrucciani, A., Iannino, V., Colla, V., Bampaou, M., Panopoulos, K., Rechberger, K., Kolb, S., Hauser, A., Wolf-Zoellner, P., Haag, S., Kieberger, N., Rompalski, P.: Hydrogen role in the valorization of integrated steelworks process off-gases through methane and methanol syntheses. Matériaux & Techniques 2021, 109. DOI: https://doi.org/10.1051/mattech/2022009
  • Weitzer M.; Müller, D.; Karl J.: Advanced Organic Rankine Cycles for thermally integrated Carnot batteries. In: Proceedings of the 6th International Seminar on ORC Power Systems, 2021. DOI: https://doi.org/10.14459/2021mp1633100
  • Li, Y.; Pang, Y.; Tu, H.; Torrigino, F.; Biollaz, S.; Li, Z.; Huang, Y.; Yin, X.; Grimm, F.; Karl, J.: Impact of syngas from biomass gasification on solid oxide fuel cells: A review study for the energy transition. In: Energy Conversion and Management, Vol 250, 114894, 15.12.2021. DOI: https://doi.org/10.1016/j.enconman.2021.114894
  • Schneider, T.; Krumrein, J.; Müller, D.; Karl, J.: Investigation of the Oxygen Supply and Distribution in a Bubbling Fluidized Bed by Using Natural Ilmenite for Oxygen Carrier Aided. In: Energy & Fuels, Vol. 35, Issue 14, 09.07.2021. DOI: https://doi.org/10.1021/acs.energyfuels.1c01178.
  • Kolb, S.; Plankenbühler, T., Hofmann, K.; Bergerson, J.; Karl, J.: Life cycle greenhouse gas emissions of renewable gas technologies: A comparative review. In: Renewable and Sustainable Energy Reviews, Vol. 146, 111147, 07.05.2021. DOI: https://doi.org/10.1016/j.rser.2021.111147

  • Hauser, A.; Weitzer, M.; Gunsch, S.; Neubert, M.; Karl, J.: Dynamic hydrogen-intensified methanation of synthetic by-product gases from steelworks. In: Fuel Processing Technology, Volume 217, 15 June 2021, 106701. DOI: https://doi.org/10.1016/j.fuproc.2020.106701

  • Thema, M.; Weidlich, T.; Kaul, A.; Böllmann, A.; Huber, H.; Bellack, A.; Karl, J.; Sterner, M.: Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor. In: Bioresource Technology, Volume 333, August 2021, 125135. DOI: https://doi.org/10.1016/j.biortech.2021.125135

  • Kalu, A.; Vrzel, J.; Kolb, S.; Karl, J; Marzahn, P.; Pfaffenberger, F.; Ludwig, R.: Considering the Environmental Impacts of BioenergyTechnologies to Support German Energy Transition. In: Energies 2021, 14, 1534. DOI: https://doi.org/10.3390/en14061534
  • Schneider, T.; Ruf, F.; Müller, D.; Karl, J.: Performance of a fluidized bed-fired Stirling engine as micro-scale combined heat and power system on wood pellets. In: Applied Thermal Engineering,

    Volume 189, 5 May 2021, 116712. DOI: https://doi.org/10.1016/j.applthermaleng.2021.116712

  • Eppinger, B.; Steger, D.; Regensburger, C.; Karl, J.; Schlücker, E.; Will, S.: Carnot battery: Simulation and design of a reversible heat pump-organic Rankine cycle pilot plant. In: Applied Energy,

    Volume 288, 15 April 2021, 116650. DOI: https://doi.org/10.1016/j.apenergy.2021.116650

  • Kolb, S.; Plankenbühler, T.; Frank, J.; Dettelbacher, J.; Ludwig, R.; Karl, J.; Dillig, M.: Scenarios for the integration of renewable gases into the German natural gas market – A simulation-based optimisation approach. In: Renewable and Sustainable Energy Reviews, Vol. 139, 110696, 20.01.2021. DOI: https://doi.org/10.1016/j.rser.2020.110696
  • Miederer, J., Kolb, S., Karl, J. (2021): Datengetriebene Modellierung eines Klärwerks mittels Machine Learning-Algorithmen zur Erstellung eines Digitalen Zwillings, In: 4th Doctoral Colloquium Bioenergy: 13th/14th September, 2021. Fortbildungszentrum Technik und Umwelt (FTU), KIT Campus Nord (2021). (Tagungsreader, 22). Leipzig: DBFZ. 296 S. ISBN: 978-3-946629-77-1. [4th Doctoral Colloquium Bioenergy, 13.-14.09.2021, Karlsruhe]. DOI: 10.48480/2ebd-1q24

  • Eppinger, B.; Zigan, L.; Karl, J.; Will, S.: Pumped thermal energy storage with heat pump-ORC-systems: Comparison of latent and sensible thermal storages for various fluids. In: Applied Energy, Vol. 280, 115940, 15.12.2020. DOI:  https://doi.org/10.1016/j.apenergy.2020.115940
  • Kolb, S.; Plankenbühler, T.; Neubert, M.; Karl, J.: Erneuerbare Gase für das Energiesystem der Zukunft. In: Gwf Gas+Energie, Vol. 161(11-12), pp. 58-67, 01.12.2020.
  • Markthaler, S.; Plankenbühler, T.; Weidlich, T.; Neubert, M.; Karl, J.: Numerical simulation of trickle bed reactors for biological methanation. In: Chemical Engineering Science, Vol, 226, 23.11.2020. DOI: https://doi.org/10.1016/j.ces.2020.115847
  • Zuh, J.; Zhu, L.; Guo, D.; Chen, Y.; Wang, X.; Zhu, Y.: Co-pyrolysis of petrochemical sludge and sawdust for syngas production by TG-MS and fixed bed reactor. In: International Journal of Hydrogen Energy, Volume 45, Issue 55, Pages 30232-30243, 06.11.2020. DOI:https://doi.org/10.1016/j.ijhydene.2020.08.092
  • Steger, D.; Regensburger, C.; Eppinger, B.; Will, S.; Karl, J.; Schlücker, E.: Design aspects of a reversible heat pump – Organic rankine cycle pilot plant for energy storage. In: Energy, Vol. 208, 118216, 01.10.2020. DOI:https://doi.org/10.1016/j.energy.2020.118216
  • Kolb, S.; Dillig, M.; Plankenbühler, T.; Karl, J.: The impact of renewables on electricity prices in Germany – An update for the years 2014–2018. In: Renewable and Sustainable Energy Reviews, Vol. 134, 110307, 12.09.2020. DOI: https://doi.org/10.1016/j.rser.2020.110307
  • Schneider, T.; Müller, D.; Karl, J.: A review of thermochemical biomass conversion combined with Stirling engines for small-scale cogeration of heat and power. In: Renewable and Sustainable Energy Reviews, Vol. 134, Issue C, Art Nr. 110288, 10.09.2020 DOI:https://doi.org/10.1016/j.rser.2020.110288
  • Wang, X.; Liu, H.; Wang, Y.; Zhu, Y.: CFD simulation of dynamic heat transfer behaviors in super-long thermosyphons for shallow geothermal application. In: Applied Thermal Engineering, Vol. 174, 115295, 25.06.2020. DOI:https://doi.org/10.1016/j.applthermaleng.2020.115295
  • Plankenbühler, T.; Kolb, S.; Grümer, F.; Müller, D.; Karl, J.: Image-Based Model for Assessment of Wood Chip Quality and Mixture Ratios. In: Processess, Vol. 8 (6), 728, 23.06.2020. DOI:https://doi.org/10.3390/pr8060728
  • Scharrer, D.; Eppinger, B.; Schmitt, P,; Zenk, J.; Bazan, P.; Karl, J.; Will, S.; Bruckner, M.; German, R.: Life Cycle Assessment of a Reversible Heat Pump-Organic Rankine Cycle-Heat Storage System with Geothermal Heat Supply. In: Energies, Vol. 13, Issue 12, Art. Nr. 3253, 23.06.2020. DOI:https://doi.org/10.3390/en13123253
  • Teng, W.; Wang, X.; Zhu, Y.: Experimental investigations on start-up and thermal performance of sodium heat pipe under swing conditions. In: Internation Journal of Heat Mass Transfer, Vol. 152, 119505, Mai 2020. DOI:https://doi.org/10.1016/j.ijheatmasstransfer.2020.119505
  • Müller, D.; Plankenbühler, T.; Karl, J.: A Methodology for Measuring the Heat Release Efficiency in Bubbling Fluidises Bed Combustors. In: Energies, Vol. 13, Issue 10, Art. Nr. 2420, 12.05.2020. DOI:https://doi.org/10.3390/en13102420
  • Grimm, F.; Neubert, M.; Karl, J.; Menzler, N.; Guillion, O.; Selection of cathode materials for forsteride-supported oxide fuel-cells – part II: Electro-catalytic activity. In: Journal of Power Sources, Volume 451, 01.03.2020. DOI: https://doi.org/10.1016/j.jpowsour.2020.227811

  • Neubert, M.; Widzgowski, J.; Rönsch, S.; Treiber, P.; Dillig, M.; Karl, J.: Simulation-Based Evaluation of a Two-Stage Small-Scale Methanation Unit for Decentralized Applications. In: Energy Fuels 2017, 31 (2), pp 2076–2086. http://pubs.acs.org/doi/abs/10.1021/acs.energyfuels.6b02793
  • Staub, S.; Bauer, J.; Müller, D.; Franke, J.; Karl, J.: CO2-Neutral Generation of Heat and Power in Smart Homes by Organic Rankine Cycle Powered Combined Heat and Power Micro Plants. In: AEF (Advanced Engineering Forum) 19 (2016), S. 10-19. 10.4028/www.scientific.net/AEF.19.10
  • Großmann, K.; Treiber, P.; Karl, J.: Steam methane reforming at low S/C ratios for power-to-gas applications. In: International Journal of Hydrogen Energy 41 (2016), Nr. 40, S. 17784-17792. http://dx.doi.org/10.1016/j.ijhydene.2016.08.007
  • Dillig M., Karl J.: The impact of renewables on electricity prices in Germany – An estimation based on historic spot prices in the years 2011–2013. In: Renewable and Sustainable Energy Reviews 57 (2016). http://dx.doi.org/10.1016/j.rser.2015.12.003
  • Hoeftberger, D.; Karl, J.: The Indirectly Heated Carbonate Looping Process for CO2 Capture – A Concept with Heat Pipe Heat Exchanger. In: Journal of Energy Resources Technology 138 (2016), Nr. 4. doi: 10.1115/1.4033302
  • Reschmeier, R.; Karl, J.: Experimental study of wood char gasification kinetics in fluidized beds. In: Biomass & Bioenergy 85 (2016), S. 288-299. http://dx.doi.org/10.1016/j.biombioe.2015.05.029
  • Leimert, J.; Dillig, M.; Karl, J.: Hydrogen inactivation of liquid metal heat pipes. In: International Journal of Heat & Mass Transfer 92 (2016), S. 920-928. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2015.09.058
  • Leimert, J; Karl, J: Nickel membranes for  in-situ hydrogen separation in high-temperature fluidized bed gasification processes. In: International Journey of Hydrogen Energy, Vol. 41, Issue 22, Pages 9355-9366 (2016). http://dx.doi.org/10.1016/j.ijhydene.2016.04.073
  • Leimert, J; Bartolf, A; Karl, J: Hydrogen concentration measurement in high temperature applications using hydrogen permeation. In: International Journey of Hydrogen Energy, Vol. 41, Issue 32, Pages 14360-14367 (2016). http://dx.doi.org/10.1016/j.ijhydene.2016.05.061
  • Leimert, J.; Treiber, P.; Karl, J.: The Heatpipe Reformer with optimized combustor design for enhanced cold gas efficiency. In: Fuel Processing Technology 141 (2016), S. 68-73. http://dx.doi.org/10.1016/j.fuproc.2015.04.026

  • Karl J.: Motives for biomass based bio-SNG production and perspectives of the Heatpipe Reformer technology. Tagungsband – 2nd International Conference on Renewable Energy Gas Technology, Barcelona, 7-8 May 2015, S. 19-22.
  • Dillig M., Karl J.: Deutschland ohne erneuerbare Energien?. In: BWK Das Energie-Fachmagazin 67 (2015), S. 32-36.
  • Koytsoumpa El., Atsonios K., Panopulos KD., Karellas S., Kakaras E., Karl J.: Modelling and assessment of acid gas removal processes in coal-derived SNG production. In: Applied Thermal Engineering 74 (2015), S. 128-135. http://dx.doi.org/10.1016/j.applthermaleng.2014.02.026
  • Gatternig, B; Karl, J: Prediction of ash-induced agglomeration in biomass-fired fluidized beds by an advanced regression-based approach. In: Fuel, Vol. 161, Pages 157-167 (2015). http://dx.doi.org/10.1016/j.fuel.2015.08.040
  • Gatternig B., Karl J.,: Investigations on the mechanisms of ash-induced agglomeration in fluidized bed combustion of biomass. In: Energy & Fuels (2015). DOI: 10.1021/ef502658b
  • Dillig M., Biedermann Th., Karl J.: Thermal contact resistance in solid oxide fuel cell stacks. In: Journal of Power Sources 300 (30.12.2015), S. 69-76. http://dx.doi.org/10.1016/j.jpowsour.2015.09.031
  • Treiber, P.; Leimert, J.; Neubert, M.; Karl, J.: Integrated Syngas Cleaning and CO2 Removal for Medium-scale Coal-to-SNG Plants . Synthesis Gas Chemistry – DGMK Conference, , 07./09.10.2015.
  • Plankenbühler, T.; Karl, J.: Numerische Simulation und experimentelle Untersuchung der Verschlackungsneigung biogener Brennstoffe. VDI-Berichte, , 2015.
  • Leimert, J.; Dillig, M.; Karl, J.: Hydrogen inactivation of liquid metal heat pipes. In: International Journal of Heat and Mass Transfer 92 (01.01.2016), S. 920-928. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2015.09.058
  • Dillig, M.; Meyer, T.; Karl, J.: Integration of Planar Heat Pipes to Solid Oxide Cell Short Stacks. In: Fuel Cells (2015). DOI: 10.1002/fuce.201400198

  • Karl, J: Biomass heat pipe reformer – design and performance of an idirectly heated steam gasifier. In: Biomass Conversion and Biorefinery, Vol. 4, Issue 1, Pages 1-14 (2014). http://dx.doi.org/10.1007/s13399-013-0102-6
  • Müller, D.; Karl, J.: Burnout optimization of staged small-scale fluidized bed combustion systems. 22nd European Biomass Conference, Hamburg, 23.-26. June 2014.
  • Dillig M., Karl J.: Deutschland ohne Erneuerbare Energien?. In: Deutschland ohne Erneuerbare Energien – Lehrstuhl für Energieverfahrenstechnik 1 (2014).
  • Leimert, J.; Karl, J.: Herstellung von Wasserstoff auf Basis der Heatpipe Reformer Technologie. DGMK Tagungsbericht zur Fachbereichstagung “Konversion von Biomassen”, , 12.-14.05.2014, S. 259-267.
  • Plankenbühler, T.; Karl, J.: Influence on fuel fine particles on slagging of commercial size biomass boilers. Conference Proceeding, 22nd European Biomass Conference and Exhibition, Hamburg, 23.-26. June 2014.
  • Dillig, M.; Karl, J.: Operation of SOFC short stacks with integrated planar high temperature heat pipes. Proceedings of 11th European SOFC and SOE Forum 2014, Lucerne (CH), 01. – 04.07.2014.
  • Gatternig, B.; Karl, J.;: The Influence of Particle Size, Fluidization Velocity, and Fuel Type on Ash-Induced Agglomeration in Biomass Combustion. In: Frontiers in Energy Research 2 (19.11.2014), Nr. 51.
  • Dillig, M.; Leimert, J.; Karl, J.: Planar High Temperature Heat Pipes for SOFC/SOEC Stack Applications. In: Fuel Cells 14 (2014), Nr. 3, S. 479–488.
  • Reschmeier, R.; Roveda, D.; Müller, D.; Karl, J.: Pyrolysis kinetics of wood pellets in fluidized beds. In: Journal of Analytical and Applied Pyrolysis (2014), Nr. http://dx.doi.org/10.1016/j.jaap.2014.05.009.

  • Karl J.: Dezentrale Energiesysteme – Neue Technologien im liberalisierten Energiemarkt. In: TK Verlag (2013).
  • Reil, S.; Baumhakl, C.; Karl, J.; Messer, J.; Stork, H.; Beer, S.: Vergleich verschiedener Methoden zur Teeranalytik auf Basis von SPA und nasschemischen Verfahren bei der thermochemischen Biomassevergasung. In: 5. Statustreffen Energetische Biomassenutzung (14.-15.11.2013).
  • Höftberger, D.; Karl, J.: Self-Fluidization in an Indirectly Heated Calciner. In: Chemical Engineering & Technology 36 (2013), Nr. 9, S. 1533-1538.
  • Dillig, M.; Karl, J.: Substitute Natural Gas from Biomass – Decentralised Gasification and Methanation. International Seminar on Biomass, Biogas and Energy Efficiency, Sao Paulo, 03.-05.04.2013.
  • Gatternig, B.; Karl, J.: Development of novel modelling approaches for agglomeration prediction. Conference Proceeding, 21st European Biomass Conference and Exhibition, Copenhagen, 3.-7. June 2013.
  • European Commission: Substitute natural gas from Coal with internal sequestration of CO2. In: Final Report CO2freeSNG, DOI: 10.2777/4460 (2013).
  • Plankenbühler, T.; Karl, J.: Erweiterung des Brennstoffbandes moderner Biomassefeuerungen. 5. Statuskonferenz Energetische Biomassenutzung, Leipzig, 14.-15. November 2013.
  • Müller, D.; Karl, J.: Biomass CHP with Micro-Fluidized-bed combustion. Conference Proceeding, 21st European Biomass Conference and Exhibition, Copenhagen, 3.-7. June 2013.
  • Baumhakl, C.; Karl, J.: Optimized Bio-SNG Production from Thermal Gasification with Hot-gas-cleaning Technologies. Conference Proceedings, 3rd International Conference of Energy Process Engineering, Frankfurt a. Main, 3.-6. June 2013.
  • Baumhakl, C.; Karl, J.: Efficient Bio-SNG Production from Thermal Gasification with Hot-gas-cleaning Technologies. Conference Proceeding, 21st European Biomass Conference and Exhibition, Copenhagen, 3.-7. June 2013.
  • Karl, J.: Liberalisierter Energiemarkt – Neue Technologien und dezentrale Energiesysteme
    bilden die Grundlage für die Energiewende. In: ReCource (2013), Nr. 3, S. 18-23.
  • Karl, J.: Biomass heat pipe reformer—design and performance of an indirectly heated steam gasifier. In: Biomass Conv. Bioref. (2013), Nr. DOI 10.1007/s13399-013-0102-6.
  • Patuzzi, F.; Roveda, D.; Mimmo, T.; Karl, J.; Baratieri, M.: A comparison between on-line and off-line tar analysis methods applied to common reed pyrolysis. In: Fuel (2013), Nr. 111, S. 689-695.
  • Kienberger, T.; Zuber, C.; Novosel, K.; Baumhakl, C.; Karl, J.: Desulfurization and in situ tar reduction within catalytic methanation of biogenous synthesis gas. In: Fuel (2013), Nr. 106, S. 102-112.
  • Reschmeier, R.; Karl, J.: Kinetik der Pyrolyse von Holzwürfeln in Wirbelschichten. In: 26. Deutscher Flammentag, VDI Berichte 2161 (11./12.09.2013), S. 727-731.

  • Höftberger, D.; Karl, J.: Self-Fluidization in an Indirectly Heated Calciner. In: Proceedings of the 2nd International Conference on Chemical Looping (26.-28.09.2012).
  • Karellas, S.; Kapodistrias, S.; Panopoulos, K.; Karl, J.: Investigation of the production of Substitute Natural Gas in Greece from local biomass feedstock by means of the BioHPR. 20th European Biomass Conference and Exhibitions , Milan, Italy, 18 – 22 June 2012.
  • Karellas, S.; Panopoulus, K.D.; Panousis, G.; Rigas, A.; Karl, J.; Karakas, E.: An evaluation of Substitute natural gas production from different coal gasification processes based on modeling. In: Energy 45 (2012), Nr. 1, S. 183-194.
  • Hoeftberger D.; Karl J.: Self-Fluidization in an Indirectly Heated Calciner. Proceedings 2nd International Conference on Chemical Looping, Darmstadt, 26.09.12-28.09.12.
  • Janics A.: Solid Oxide Fuel Cells under Thermal Cycling Conditions. In: Proceedings of 10th European SOFC Forum 2012 (2012), S. A1269 – A1276.
  • Baumhakl C.; Karl J.: Optimierung der dezentralen SNG-Erzeugung durch die Heißgasreinigung von Synthesegas. In: Konferenzbeitrag Energetische Biomassenutzung – Neue Technologien und Konzepte für die Bioenergie der Zukunft (5.11.2012-6.11.2012).
  • Baumhakl C.; Kienberger T.; Karl J.: Substitute Natural Gas (SNG) from Coal and Lignite – Methanation of synthesis gas from allothermal gasification. In: Proceeding of the 37th International Conference on Clean Coal & Fuel Systems (3.6.2012 – 7.6.2012).
  • Roveda D.; Schlattinger R.; Karl J.: Tar online measurement system for biomass gasification based on absorption aspectroscopy. In: In review (2012).
  • Patuzzi F.; Roveda D.; Mimmo T.; Karl J.; Baratieri M.: A comparison between on-line and off-line tar analysis methods applied to common reed pyrolysis. In: In review (2012).
  • Roveda D., Kienberger T., Grigiante M., Karl J. : A Tar Online Measurement System Based on the Absorption Principle. In: Proceedings of the 20th European Biomass Conference & Exhibition (18.06.12 – 22.06.12), S. DOI: http://dx.doi.org/10.5071/20thEUBCE2012-2CO.10.2.
  • Patuzzi F., Roveda D., Mimmo T., Karl J., Baratieri M.: Characterization of the Tar Produced During Pyrolysis of Common Reed: A Comparative Study Between On-Line and Off-Line Measuring Method Approaches. In: Proceedings of the 20th European Biomass Conference & Exhibition (18.06.12 – 22.06.12), S. DOI: http://dx.doi.org/10.5071/20thEUBCE2012-2EO.3.5.
  • Dillig, M.; Karl, J.: Thermal Management of High Temperature Solid Oxide Electrolyser Cell/Fuel Cell Systems. In: Energy Procedia 28 (2011), S. 37-47.

  • Baumhakl C., Karl J., Kienberger T.: Substitute Natural Gas (SNG) aus Kohle – Methanierung von Synthesegas aus der allothermen Kohlevergasung. 25. VDI-Flammentag 2011, Karlsruhe, 14.-15.09.2011.
  • Karellas, S.; Panopoulos, K.; Karl, J.; Kakaras, E.: A modelling evaluation of Synthetic Natural Gas production from coal/lignite steam gasification. ECOS 2011 24th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Novi-Sad, Serbia., July 4-7 2011.
  • Roveda D., Karl J. : On-Line Kinetic Analysis in a Fluidized Bed Reactor. In: Proceedings of the 19th European Biomass Conference & Exhibition (06.06.11 – 10.06.11), S. DOI: http://dx.doi.org/10.5071/19thEUBCE2011-OB8.2.
  • Hauth, M.; Kienberger, T.; Karl, J. : Transient Operation Effects of SOFCs Driven with Tar Loaded Synthesis Gas. In: Solid Oxide Fuel Cells 12, SOFC-XII (2011), S. 2713-2723.
  • Koytsoumpa, E.; Griendl, L.; Karellas, E.; Panopoulos, K.; Nikolopoulos, A.; Karl, J.: Simulations of a fixed bed catalytic reactor for the production of methane from syngas. In: International Smart Energy Networks of Cooperation for Sustainable Development (2011), S. 1515-1526.
  • Griendl, L.; Hohenwarter, U.; Karl, J.: Further Development of a 2.5 MWth Oxyfuel PC Burner. 2nd Proc. Oxyfuel Combustion Conference, Queensland, 2011.
  • Hauth, M.; Lerch, W.; König, K.; Karl, J.: Impact of naphthalene on the performance of SOFCs during operation with synthetic wood gas. In: Journal of Power Sources 196 (01.09.2011), Nr. 17, S. 7144-7151.
  • Baumhakl, C.; Karl, J.; Kienberger, T.: Substitute Natural Gas (SNG) aus Kohle – Methanierung von Synthesegas aus der allothermen Kohlevergasung. Tagungsband zum 25. VDI-Flammentag, Karlsruhe, 2011.
  • Baumhakl, C.; Karellas, S.: Tar analysis from biomass gasification by means of online fluorescence spectroscopy. In: Optics and lasers in engineering (2011), S. DOI: 0.1016/j.optlaseng.2011.02.015.

  • Schuster A., Karl J., Karellas S.: Simulation of an innovative stand-alone solar desalation system using an organic Rankine cycle. In: International Journal of Thermodynamics 10 (24.02.2010), Nr. 4, S. 155-163.
  • Karl, J.; Kienberger, T.; Kröner, M.: Methan aus Holz – die erneuerbare Gaswirtschaft/ Auf dem Holzweg. In: Erneuerbare Energien 20 (2010), S. 170-174.
  • Gatternig, B.; Hohenwarter, U.; Schröttner, H.; Karl, J.: The Influence of Volatile Alkali Species on Coating Formation in Biomass Fired Fluidized beds. 18th European Biomass Conference and Exhibition, Lyon, 2010.
  • Kienberger, T.; Karl, J.: Subsitute Natural Gas (SNG) – Theoretische Grundlagen – Stand der Technik – Forschung am Institut für Wärmetechnik. EnInnov2010; 11.Symposium Energieinnovation, Verlag der TU Graz, 2010, S. 159-159.
  • Kienberger, T.; Karl, J.: Methanierung biogener Synthesegase – Einfluss von Vergasungs-Betriebsparametern auf Gasqualität und Katalysatordeaktivierung. DGMK-Fachbereichstagung “Konversion von Biomassen”, , 2010, S. 93-100.
  • Hauth, M.; Karl, J.: Entwicklungsstand innovativer SOFC Systeme zur dezentralen Energiebereitstellung. EnInnov2010; 11.Symposium Energieinnovation, Verlag der TU Graz, 2010, S. 159-159.
  • Gatternig, B.; Hohenwarter, U.; Karl, J.: Ascheproblematik in biomassegefeuerten Wirbelschichtanlagen. EnInnov2010; 11.Symposium Energieinnovation, Verlag der TU Graz, 2010, S. 159-159.
  • Kienberger, T.; Mair, S.; Karl, J.: Fixed-Bed Methanation of biogeneous SynGas, Ideas for the decentralized approach. From research to industry and markets : proceedings of the 18th European Biomass Conference, , 2010, S. 1840-1847.

  • Karl, J.: Small-Scale Generation of Substitute Natural Gas. ICPS 09 – International Conference on Polygeneration Strategies, Wien, 01.-04.09.2009.
  • Kleinhappl M., Martini S., Roveda D., Titz M., Draxler J., Überall F.: Treatment of wood drying condensates; process approach for recovery of valuable substances. Proceedings 17th European Biomass Conference and Exhibition, Hamburg, 29.06.2009 – 03.07.2010.
  • Hofmann, Ph.; Panopoulos, K.D.; Aravind, P.V.; Siedlecki, M.; Schweiger, A.; Karl, J.; Ouweltjes, J.P.; Kakaras, E.: Operation of solid oxide fuel cell on biomass product gas with tar levels >10 g Nm-3. In: International Journal of Hydrogen Energy 34 (01.11.2009), Nr. 22, S. 9203-9212.
  • Gatternig, B.; Hohenwarter, U.; Schröttner, H.; Karl, J.;: Development of ash induced coatings on bed material particles in biomass fired fluidized bed combustion. Proceedings 17th European Biomass Conference and Exhibition, Hamburg, 29.06.2009 – 03.07.2010.
  • Biollaz, S.M.A.; Hottinger, P.; Pitta, Chr.; Karl, J.: Results from a 1200h test of a tubular SOFC with wood gas. Proceedings 17th European Biomass Conference and Exhibition, Hamburg, 29.06.2009 – 03.07.2009.
  • Kienberger, T.; Karl, J.: Substitute Natural Gas (SNG) from Biomass – Influence of tars on Catylytic Methanization. Proceedings 17th European Biomass Conference and Exhibition, Hamburg, 29.06.2009 – 03.07.2009.
  • Hauth, M.; Frank, N.; Karl, J.: Influence of Tars on the Maximum Hydrogen Utilization in SOFCs with Biogeneous Gases. Proceedings European FUEL CELL FORUM 2009, Lucerne / Switzerland, 2009.
  • Karl, J.; Frank, N.; Karellas, S.; Saule, M.; Hohenwarter, U.: Conversion of Syngas From Biomass in Solid Oxide Fuel Cells. In: Journal of Fuel Cell Science and Technology 6/021005-5 (May 2009).
  • Kienberger, T.; Karl, J.: Tests on methanation with tar and sulphur loaded syngas. Proceedings of the Conference – International conference on polygeneration strategies, Vienna, 2009.
  • Karl, J.; Baumhakl, C.; Kienberger, T.: Substitute Natural Gas aus Kohle. Proceedings – Kraftwerkstechnisches Kolloquium, Dresden, 2009.
  • Griendl, L.; Hohenwarter, U.; Karl, J.: Numerical Simulation of a 3 MWth Oxycoal Burner. 1st Oxyfuel Combustion Conference, Cottbus, 2009.
  • Kienberger, T.; Karl, J.: Methanation with an allothermal Samart lab scale Gasification System. Proceedings – 17th European Biomass Conference and Exhibition, Hamburg, 29.06.2009 – 03.07.2009, S. 966-973.

  • Schweiger, A.; Karl, J.: Thermodynamic Evaluation of the Impact of a Hot Gas Cleaning System for integrated Gasification Systems. 16th European Biomass Conference & Exhibition, Convention and Exhibition Centre, Valencia, Spain, June 2008.
  • Karl, J.: Distributed Generation of Substitute Natural Gas from Biomass. Proceedings Biomass Conference & Exhibition OD6.1, Convention and Exhibition Centre, Valencia, Spain, June 2008.
  • Hofmann, Ph.; Panopoulos, K.D.; Fryda, L.E.; Schweiger, A.; Ouweltjes, J.P.; Karl J.: Integrating biomass gasification with solid oxide fuel cells: Effect of real product gas tars, fluctuations and particulates on Ni-GDC anode. In: International Journal of Hydrogen Energy (January 2008).
  • Karl, J.: KWK mit thermischer Vergasung von Biomass – Stand der Technik und aktuelle Entwicklungen. Tagungsband 14. Internationale Fachtagung “Energetische Nutzung nachwachsender Rohstoffe”, Bergakademie Freiberg, 11./12. Sep 2008.
  • Karl, J.: Innovative Technologien für die Kraft-Wärme-Kopplung. Tagungsband Orientierungsseminar zum 17. OTTI-Symposium Bioenergie, Kloster Banz, 19. -21. November 2008.
  • Karl, J.: Kraft-Wärme-Kopplung: Stand der Technik und Wirtschaftlichkeit. Tagungsband Orientierungsseminar zum 17. OTTI-Symposium Bioenergie, Kloster Banz, 19. -21. November 2008.
  • Karellas, S.; Karl, J.; Kakaras, E.: An innovative biomass gasification process and its coupling with microturbine and fuel cell systems. In: Energy 33 (February 2008), S. 284-291.
  • Fryda, L.; Panopoulos, K.D.; Karl, J.; Kakaras, E.: Exergetic analysis of solid oxide fuel cell and biomass gasification integration with heat pipes. In: Energy 33 (February 2008), Nr. 2, S. 292-299.
  • Karellas, S.; Kakaras, E.; Papadopoulos, T.; Schäfer, C.; Karl, J.: Hydrogen production from allothermal biomass gasification by means of palladium membranes. In: Fuel Processing Technology 89 (2008), S. 582-588.

  • Karl, J.: Einführung in die Technik der thermischen Verwertung von festen Biobrennstoffen. OTTI-Symposium Bioenergie – Orientierungsseminar Technische Grundlagen, Kloster Banz, 22.11.2006.
  • Hofmann, Ph.; Schweiger, A.; Fryda, L.; Panopoulos, K.D.; Hohenwarter, U.; Bentzen, J.D.; Ouweltjes, J.P.; Ahrenfeldt, J.; Henriksen, U.; Kakaras, E.: High temperature electrolyte supported Ni-GDC/YSZ/LSM SOFC operation on two-stage Viking gasifier product gas. In: Journal of Power Sources 173 (May 2007), S. 357-366.
  • Saule, M.; Deschermeier, R.; Frank, N.; Karl, J.: EFC2007-39064Carbon deposition during SOFC operation with biogenous gases. Proceedings of the Second European Fuel Cell Technology and Applications Conference, Rome, December 2007.
  • Frank, N.; Saule, M.; Karellas, S.; Karl, J.: Poster presentation: P1005-180: Degradation of Solid Oxide Fuel Cells with Wood Gases. Lucerne FUEL CELL FORUM 2006 (SOFC), Lucerne, 2007.
  • Schuster, A.; Karl, J.; Karellas, S.: Simulation of an Innovative Stand-Alone Solar Desalination System using an Organic Rankine Cycle. In: International Journal of Thermodynamics 10 (2007), Nr. 4, S. 155-163.
  • Frank, N.; Saule, M.; Karl, J.: Degradation of solid oxide fuel cells with wood. WHEC 16, Lyon, France, June 2007.
  • Schuster, A.; Storch, G.; Karl, J.; Hauer, A.: Innovative Concepts for Combined Heat and Power Production with Biogenous Gases. 20th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems ( ECOS 2007 ), 2, Padova, Italy, 25.-28. June 2007.
  • Karl, J.: Kraft-Wärme-Kopplung: Stand der Technik und Wirtschaftlichkeit. Tagungsband 16. OTTI-Symposium Bioenergie, Kloster Banz, 22./23. November 2007.
  • Karl, J.: Thermische Vergasung in C.A.R.M.E.N.. In: Jahrbuch 2006/2007 “Nachwachsende Rohstoffe – Wirtschaftsfaktor Biomasse 2006/2007” (2007), S. 269-275.
  • Karl, J.; Frank, N.; Saule, M.: Betrieb von SOFC-Brennstoffzellen mit biogenen Synthesegasen – Ergebnisse des EU Projekts Biocellus. Proc. Dechema Dechema-Tagung Biomasse und Brennstoffzellen, Frankfurt, 16.01.2007.
  • Schuster, A.; Brückner, T.; Karl, J.: Abwärmenutzung von Biogasanlagen mit Niedertemperatur Organic Rankine Cycle. 15. Symposium Bioenergie, Kloster Banz, Bad Staffelstein, 23./24. November 2007.
  • Karl, J.: Technische Grundlagen der Kraft-Wärme-Kopplung. OTTI-Profiseminar KWK mit Biomasse, Freising, 21./22. März 2007.
  • Karellas, S.; Karl, J.: Analysis of the product gas from biomass gasification by means of laser spectroscopy. In: Optics and Lasers in Engineering 45 (2007), S. 935-946.
  • Schuster, A.; Karl, J.; Karellas, S.: Simulation of an Innovative Stand-Alone Solar Desalination System Using an Organic Rankine Cycle. In: Int. J. of Thermodynamics ISSN 1301-9724 10 (December 2007), Nr. 4, S. 155-163.

  • Karl, J.: Kraft-Wärme-Kopplung: Stand der Technik und Wirtschaftlichkeit. Tagungsband 16. OTTI-Symposium Bioenergie, Kloster Banz, 23./24. November 2006.
  • Panopoulos, K.D.; Fryda, L.E.; Karl, J.; Poulou, S.; Kakaras, E.: High temperature solid oxide fuel cell integrated with novel allothermal biomass gasification: Part II: Exergy analysis. In: Journal of Power Sources 159 (13.09.2006), Nr. 1, S. 586-594.
  • Panopoulos, K.D.; Fryda, L.E.; Karl, J.; Poulou, S.; Kakaras, E.: High temperature solid oxide fuel cell integrated with novel allothermal biomass gasification: Part I: Modelling and feasibility study. In: Journal of Power Sources 159 (13.09.2006), Nr. 1, S. 570-585.
  • Frank, N.; Saule, M.; Karl, J.: Degradation of Solid Oxide Fuel Cells with Wood. 16th world hydrogen energy conference, Lyon, France, 13.-16. Juni 2006.
  • Karl, J.; Frank, N.; Karellas, S.; Saule, M.; Hohenwarter, U.: Conversion of Syngas from Biomass in Solid Oxide Fuel Cells. The 4th International Conference on FUEL CELL SCIENCE, ENGINEERING and TECHNOLOGY, Proceedings, Irvine CA, 19.-21. Juni 2006.
  • Karl, J.; Schuster, A.: Konzepte für die Kraft-Wärme-Kopplung mit biogenen Gasen. In: Gas-Erdgas GWF, Oldenburg Industrieverlag 12 (2006), S. 712-718.
  • Frank, N.; Saule, M.; Karellas, S.; Karl, J.: Degradation of Solid Oxide Fuel Cells with Wood Gases. 7th European Solid oxide fuel cell Forum, Luzern, Schweiz, 09.-07. Juli 2006.
  • Alonso-Herranz, E.; Karl, J.; Porteanu, H.; Spliethoff, H.: IS-Measurements for the Characterisation of Boilers Heat Exchanger Tubes Surface during Combustion. 10th International Conference on Boiler Technology, Proceedings, Szcyrk, Orle Gniazdo, Polen, 17.-20. September 2006.
  • Saule, M.; Frank, N.; Hofmann, P.; Ouweltjes, J.P.; Schweiger, A.; Karl, J.: Operation of Solid Oxide Fuel Cells with Syngas from Biomass. H2expo, Proceedings of H2expo, Vortrag und Paper, Hamburg, 25.-26. Oktober 2006.
  • Karl, J.; Frank. N.; Karellas, S.; Saule, M.; Hohenwarter, U.: Conversion of Syngas from Biomass in Solid Oxide Fuel Cells. Proc. of ASME Conf. FUELCELL2006, Irvine, CA, 19.-21. June 2006.
  • Schuster, A.; Karellas S.; Karl, J.: Innovative Applications of Organic Rankine Cycles. ECOS 2006, Proceedings of the 19th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, Aghia Pelagia, Kreta, 12.-14. Juli 2006.
  • Alonso-Herranz, E.; Karl, J.; Ottmann, M.; Porteanu, H.; Spliethoff, H.: Measurement of Hight Corrosion in Biomass Combustion Chambers. 7th European Conference on Industrial Furnaces and Boilers, Proceedings, CD-Rom, Porto, 18.-21. April 2006.
  • Karl, J.; Frank, N.; Saule, M.: Betrieb von Hochtemperatur-Brennstoffzellen mit biogenen Synthesegasen. Tagungsband 7. DGMK-Fachtagung “Energie aus Biomasse”, Velen, 2006.
  • Karl, J.: Technische Grundlagen der Kraft-Wärme-Kopplung. OTTI-Profiseminar KWK mit Biomasse, Freising, 22./23. März 2006.

  • Karellas, S.; Karl, J.: Investigation of the influence of the gas quality from the biomass gasification to integrated systems with microturbines and fuel cells. 7th International Conference on Heat Engines and Environmental Protection, Balatonfüred, Hungary, 23.-25. May 2005.
  • Karl, J.; Karellas, S.; Frank, N.; Spliethoff, H.: Highly efficent conversion of Syngas from Biomass gasification in Solid Oxide Fuel Cells. Proceedings of the 14 th European Biomass Conference, Paris, 17.-21. Oktober 2005.
  • Karl, J.: Kraft-Wärme-Kopplung: Stand der Technik und Wirtschaftlichkeit. Tagungsband 14. OTTI-Symposium Bioenergie, Kloster Banz, 24./25. November 2005.
  • Karl, J.: Kraft-Wärme-Kopplung mit fester Biomasse. Tagungsband 13. C.A.R.M.E.N.-Symposium Im Kreislauf der Natur – Naturstoffe für die moderne Gesellschaft, Straubing, 2005.
  • Karl, J.: Stand und Perspektiven thermischer Verfahren. In: M. Faulstich (Hrsg.) “Energie aus Biomasse und Abfall”, Band 1, Förster Verlag, Sulzbach-Rosenberg (2005).
  • Karl, J.; Karellas, S.; Frank, N.; Spliethoff, H.: Highly efficient conversion of Syngas from Biomass gasification in Solid Oxide Fuel Cells. Proc. of the 14th European Biomass Conference, Paris, 17.-21. September 2005.
  • Karl, J.: Regenerativer Strom aus Biomasse. In: TUM-Mitteilungen der Technischen Universität München 1/2005 (2005), S. 58-59.
  • Karl, J.: Biomass Heatpipe Reformer – Messergebnisse und Betriebserfahrungen. Tagungsband GVC-Fachausschussitzung, Bad Herrenalb, 07.03.2005, S. 61-62.
  • Karl, J.: Brennstoffzellensysteme mit integrierter Vergasung von Biomasse. Tagungsband OTTI-Profiseminar Stationäre und portable Brennstoffzellensysteme, Regensburg, 16./17. Februar 2005.
  • Karl, J.: Innovative Konzepte für Kraft-Wärme-Kopplung mit Biomasse. Tagungsband OTTI-Profiseminar KWK mit Biomasse, Garching, 16./17. März 2005, S. 115-129.
  • Karl, J.: Regenerative Gase aus Biomasse – Der Heatpipe Reformer. In: Erneuerbare Energien 1/2005 (2005), S. 66-67.

  • Karl, J.: Thermische Vergasung. In: C.A.R.M.E.N JAHRBUCH 2005 -Nachwachsende Rohstoffe, C.A.R.M.E.N. e.V. (2004).
  • Ottmann, M.; Karl, J.; Hein, D.: Standardisiertes Verfahren zur Bestimmung des thermischen Ascheverhaltens biogener Brennstoffe. Tagungsband zum 13. Symposium “Energie aus Biomasse”, Kloster Banz, 25./26. November 2004, S. 118-123.
  • Karl, J.: Wirbelschichtvergasung – Stand der Technik. Tagung “Biomasse-Vergasung – der Königsweg für eine effiziente Strom- und Kraftstoffbereitstellung?”, FNR-Schriftenreihe “Nachwachsende Rohstoffe”, Landwirtschaftverlag, Münster, 2004, S. 71-83.
  • Karellas, S.; Raindl, M.; Karl, J.;: Online optical analysis of the product gas from the gasification of biomass. 4. Konferenz über Optische Analysenmesstechnik in Industrie und Umwelt, VDI-Berichte 1863, Düsseldorf, 7./8. September 2004.
  • Karl, J.; Karellas, S.: Highly efficient SOFC systems with indirect gasification. Proceedings 6th European Solid Oxide Fuel Cell Forum, Lucerne, 2004, S. 534-545.
  • Karellas, S.; Karl, J.; Metz, Th.; Kuhn, S.: Use of the Raman Spectroscopy for the Analysis of the Product Gas from the Allothermal Biogas Gasification VDI. In: VDI-Berichte 1844, Photonics in Measurement (23./24. Juni 2004).
  • Metz, Th.; Kuhn, St.; Karellas, S.; Stocker, R.; Karl, J.; Hein, D.: Heatpipe Reformer – Experimentelle Ergebnisse. 10. Internationaler Kongress für nachwachsende Rohstoffe und Pflanzentechnologie, Magdeburg, 7./8. Juni 2004.
  • Metz, Th.; Kuhn, St.; Karellas, S.; Stocker, R.; Karl, J.; Hein, D.: Experimental Results of the Biomass Heatpipe Reformer. 2nd World Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection, Rome, Italy, 10.-14. May 2004.
  • Karl, J.: Erzeugung wasserstoffreiche Brenngase mit dem Heatpipe-Reformer. In: Euroheat & Power 33 (2004), Nr. 3, S. 32-36.
  • Karl, J.; Karellas, S.; Kuhn, S.; Metz, T.: Erzeugung von Synthesegas mit dem Biomass Heatpipe Reformer – Betriebserfahrungen und Leistungsgrenzen. Tagungsband 6. DGMK-Fachtagung “Energie aus Biomasse”, Velen, 2004.
  • Karl, J.: Innovative Konzepte für Kraft-Wärme-Kopplung mit Biomasse. Tagungsband OTTI-Profiseminar KWK mit Biomasse, Garching, 24./25. März 2004.

  • Karl, J.: Konzepte für die Kraft-Wärme-Kopplungsanlagen. Tagungsband zum Otti-Kolleg Fachseminar “Kraft-Wärme-Kopplung mit Biobrennstoffen”, Banz, 19.11.2003, S. 69-100.
  • Karl, J.: Decentralised CHP with the Biomass Heatpipe Reformer. In: European Bio-Energy Projects 1999-2002 European Commission, EUR 20808 (2003), S. 66-67.
  • Christ, F.; Goldbrunner, M.; Karl, J.: CFD-Simulation of Condensation Processes in the Presence of Non-Condensable Gases in a High-Temperature Heat Pipe with CFX4.4 Proc.. ASTAR International Workshop on “Advanced Numerical Methods for Multidimensional Simulation of Two-Phase Flow”, GRS Garching, 15./16. September 2003.
  • Karl, J.: Indirect Gasification Solves Tar Problem. In: Hydrogen and Fuel Cell project synopses book, European Commission, EUR 20718 (2003), S. 102-103.
  • Metz, Th.; Kuhn, S.; Karellas, S.; Karl, J.: Heatpipe Reformer Prototyp A – Experimentelle Ergebnisse, Arbeitsgruppentreffen Wasserstoffreiches Vergasungsgas der FEE e.V.. In: ökologische Stoffverwertung Berichte, Henner-Verlag 1/03 (2003).
  • Goldbrunner, M.; Karl, J.; Hein, D.: Concentration and temperature measurements by means of Raman spectroscopy in case of condensation with non-condensable gas. In: Kerntechnik, Hanser Verlag 68 (May 2003), Nr. 3, S. 106-113.
  • Karl, J.; Karellas, S.; Hein, D.: Integration of SOFC fuel cells systems in CHP-Systems with indirect gasification. Tagungsband Grove Fuel Cell Symposium, London, 24.-26. September 2003.
  • Ottmann, M.; Karl, J.; Hein, D.: Entwicklung von Sonden zur “Online-Korrosionsmessung”. 22. Deutscher Flammentag, Verbrennung und Feuerungen, VDI Energietechnik, VDI-Berichte 1750, Cottbus, 9./10. Oktober 2003, S. 393-399.
  • Stocker, R.; Karl, J.; Hein, D.: Bestimmung verbrennungsrelevanter Größen in Flammen mit einem optimierten laseroptischen Messverfahren. 21. Deutscher Flammentag, Verbrennung und Feuerungen, VDI Energietechnik, VDI-Berichte 1750, Cottbus, 9./10. Oktober 2003, S. 343-351.

  • Karl, J.: Kraft-Wärme-Kopplung mit Vergasungsanlagen. Tagungsband zum Otti-Kolleg Fachseminar “Kraft-Wärme-Kopplung mit Biobrennstoffen”, Banz, 20.11.2003, S. 69-100.
  • Karl, J.: Performance characteristics of the Biomass Heatpipe Reformer. Proc. of the 12th European Conf. on Biomass for Energy, Amsterdam, 2002.
  • Karl, J.; Hein, D.: Integration von Brennstoffzellensystemen in KWK-Anlagen mit allothermer Vergasung. Tagungsband Energie Innovativ Nürnberg, VDI-Verlag, Düsseldorf, 2002, S. 337-348.
  • Karl, J.: Dezentrale Verwertung von Biomasse und biogenen Reststoffen. Tagungsband Energie Innovativ Nürnberg, VDI-Verlag, Düsseldorf, 2002, S. 49-61.
  • Karl, J.; Brost, O.; Metz, Th.; Groll, M.; Hein, D.: Decentralized generation of heat and power by means of the Biomass Heatpipe Reformer. Proc. 12 Int. Heat Pipe Conf., Moscow, 2002.

  • Karl, J.: Kraft-Wärme-Kopplung mit Vergasungsanlagen. Tagungsband zum Otti-Kolleg Fachseminar “Kraft-Wärme-Kopplung mit Biobrennstoffen”, Kloster Banz, 21.11.2001, S. 65-95.
  • Schmitz, W.; Karl, J.; Hein, D.: Allothermal fluidized bed gasification – possibilities for the implementation of the heat input in fluidized beds. 1st World Conference on Biomass for Energy and Industry, Sevilla, Spain, June 2000, S. 1566-1569.
  • Stocker, R.; Harlfinger, J.; Karl, J.; Hein, D.: Laseroptische Messungen an Erdgasflammen mit variabler Wärmeabfuhr. 20. Deutscher Flammentag, Essen, VDI-Berichte Nr. 1629, , 2001.
  • Kuhn, St.; Karellas, S.; Karl, J.; Metz, Th.; Hein, D.: Erzeugung wasserstoffreicher Gase aus kohlenstoffhaltigen Einsatzstoffen. In: BayFORREST-Statusbericht (2001).
  • Stocker, R.; Karl, J.; Hein, D.: OH LIF in atmospheric pressure flames excited by a tunable OPO (Type II) laser system. Proceedings of the 3rd Symp. on Flow Visualization and Image Processing, Hawaii, 2001.
  • Karl, J.; Schmitz, W.; Hein, D.: Allothermal Gasification in Fluidized Bed Gasifiers. M. Kwauk, J. Li, W.-Ch. Yang (Ed.) Fluidization X, Proc. of the 10th Eng. Found. Conf on Fluid., New York, 2001.

  • Karl J., Ottmann M., Hein D.: Measuring Water Termperatures by Means of Linear Raman Spectroscopy. In: R.J. Adrian et.al (ED.), Laser Techniuqes Applied to Fluid Mechanics, Springer-Verlag (2000), S. 87-102.
  • Karl, J.: Kraft-Wärme-Kopplung mit Vergasungsanlagen. Tagungsband zum Otti-Kolleg Fachseminar “Kraft-Wärme-Kopplung mit Biobrennstoffen”, Banz, 22.11.2000, S. 56-87.
  • Goldbrunner, M.; Karl, J.; Hein, D.: Spontaneous Condensation in Boundary Layers at Stratified Flow. Eurotherm 3rd ETSC 2000, Heidelberg, Germany, 10.-13. September 2000.
  • Goldbrunner, M.; Karl, J.; Hein, D.: Experimental Investigation of Heat Transfer Phenomena during Direct Contact Condensation in the Presence of Non Condensable Gas by Means of Linear Raman Spectroscopy. 10th Int. Symp. in Laser Techniques Applied to Fluid Mechanics, Lisbon, Portugal, 10.-13. July 2000.
  • Stocker, R.; Karl, J.; Hein, D.: Fluorescence spectroscopic measurements in methane/air and hydrogen/oxygen atmospheric pressure flames in the excitation wavelength range of 303 nm to 240 nm. 10th Int. Symp. in Laser Techniques Applied to Fluid Mechanics, Lisbon, Portugal, 10.-13. July 2000.
  • Schmitz, W.; Karl, J.; Hein, D.: “Kreislaufrechnungen zur Stromerzeugung aus biomassestämmigem Brenngas, Modellierung – Ergebnisse – energetische Bewertung integrierter Prozesse”. Fachtagung “Energetische und stoffliche Nutzung von Abfällen und Biomassen”, DGMK-Tagungsbericht 2000-1, Hamburg, 2000, S. 263-271.
  • Karl, J.; Schmitz, W.; Hein, D.: Allotherme Wirbelschichtvergasung – Möglichkeiten zur Realisierung des Wärmeeintrags in Wirbelschichten. Tagungsband 4. DGMK-Fachtagung “Energetische und stoffliche Nutzung von Abfällen und Biomassen”, Velen, 2000.
  • Karl, J.: Spontaneous condensation in boundary layers. In: Heat and Mass Transfer 36 (2000), S. 37-44.

  • Karl, J.; Hein, D.: Effect Of Spontaneous Condensation On Condensation Heat Transfer In The Presence Of Non Condensable Gases. Proceedings of the 5th ASME/JSME Joint Thermal Engineering Conference, No. AJTE99-6118, San Diego, 1999.

  • Karl, J.; Ottmann, M.; Hein, D.: Measuring Water Temperatures by means of Linear Raman Spectroscopy. Proceedings of the 9th Int. Symp. on Appl. of Laser Techniques to Fluid Mechanics, Lisbon, 1998, S. 23.2.1-23.2.8.
  • Hein, D.; Karl, J.; Ruile, H.: Transport phenomena and heat transfer with direct contact condensation. In: Kerntechnik 63 (1998), Nr. 1-2, S. 51-56.

  • Karl, J.; Weiss, T.: Measurement of Condensation Heat Transfer Coefficients at Stratified Flow Using Linear Raman Spectroscopy. In: Journal of Flow Visualization and Image Processing 4 (1997), S. 231-244.
  • Karl, J.; Hein, D.: Measuring water temperature profiles at stratified flow by means of linear Raman Spectroscopy. Proceedings of the Japanese-German Symposium on Multiphase Flow, Tokyo, 1997.
  • Karl, J.; Weiss, T.: Measurement of Condensation Heat Transfer Coefficients at Stratified Flow Using Linear Raman Spectroscopy. Proceedings of the 1st Symp. on Flow Visualization and Image Processing, Honolulu, 1997, S. 479-484.