Author
Joachim Werther
Other affiliations: Nagoya University, University of Hamburg, Tsinghua University
Bio: Joachim Werther is an academic researcher from Hamburg University of Technology. The author has contributed to research in topics: Fluidized bed & Fluidized bed combustion. The author has an hindex of 41, co-authored 210 publications receiving 6833 citations. Previous affiliations of Joachim Werther include Nagoya University & University of Hamburg.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, various issues related to the combustion of agricultural residues are discussed, such as densification, combustion mechanisms, problems of low melting point of ash such as agglomeration and fouling, emissions and co-combustion.
1,057 citations
TL;DR: In this article, a review of the current and future issues related to the combustion of sewage sludge is presented, and a number of technologies for thermal processing of sludge are discussed in three groups, i.e., mono-combustion, cocombustions and alternative processes.
1,026 citations
TL;DR: In this paper, an overview is given on available measuring techniques for industrial routine measurements, mainly temperature and pressure drop measurements, and also some advanced techniques which are either still under development or which are particularly intended for academic investigations of basic fluidization phenomena.
238 citations
TL;DR: Experiments of sewage sludge gasification were performed in a circulating fluidized bed of pilot plant scale (15m height, 01m id) for the examination of the influence of the air ratio, gasification temperature, feeding height and fluidization velocity several screening tests were conducted to understand better the results from the screening experiments, axial profiles of the gas composition were measured.
Abstract: Experiments of sewage sludge gasification were performed in a circulating fluidized bed of pilot plant scale (15 m height, 01 m id) For the examination of the influence of the air ratio, gasification temperature, feeding height and fluidization velocity several screening tests were conducted To understand better the results from the screening experiments, axial profiles of the gas composition were measured As the most influencing factor for the heating value of the gasification gas the air ratio was found Additionally, a low feeding height is recommended for good gas quality While feeding into the lower dense zone of a circulating fluidized bed (CFB), mixing of the fuel particles is better With low feeding ports, high velocities are attainable and therefore high fuel throughput can be achieved In a second step a model of the CFB gasifier was developed The fluid dynamics of a CFB were included as well as the complete reaction network of gasification With the measured axial profiles of gas composition during pyrolysis, and gasification with air and a CO2/N2-mixture kinetic rate expressions for sewage sludge gasification under fluidized-bed conditions were determined which may now be used for reactor scale-up calculations
214 citations
TL;DR: In this article, the authors investigated co-combustion of sewage sludge together with coal or wood in two circulating fluidized bed (CFB) plants, a laboratory scale plant and a pilot scale 12MWth CFB boiler, in both of which the gas residence times are comparable to those in commercial plant.
208 citations
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TL;DR: In this article, the authors extensively review the principles of anaerobic digestion, the process parameters and their interaction, the design methods, the biogas utilisation, the possible problems and potential pro-active cures, and the recent developments to reduce the impact of the problems.
2,616 citations
TL;DR: The literature treating mechanisms of catalyst deactivation is reviewed in this paper, which can be classified into six distinct types: (i) poisoning, (ii) fouling, (iii) thermal degradation, (iv) vapor compound formation accompanied by transport, (v) vapor solid and/or solid solid reactions, and (vi) attrition/crushing.
Abstract: The literature treating mechanisms of catalyst deactivation is reviewed. Intrinsic mechanisms of catalyst deactivation are many; nevertheless, they can be classified into six distinct types: (i) poisoning, (ii) fouling, (iii) thermal degradation, (iv) vapor compound formation accompanied by transport, (v) vapor-solid and/or solid-solid reactions, and (vi) attrition/crushing. As (i), (iv), and (v) are chemical in nature and (ii) and (v) are mechanical, the causes of deactivation are basically three-fold: chemical, mechanical and thermal. Each of these six mechanisms is defined and its features are illustrated by data and examples from the literature. The status of knowledge and needs for further work are also summarized for each type of deactivation mechanism. The development during the past two decades of more sophisticated surface spectroscopies and powerful computer technologies provides opportunities for obtaining substantially better understanding of deactivation mechanisms and building this understanding into comprehensive mathematical models that will enable more effective design and optimization of processes involving deactivating catalysts. © 2001 Elsevier Science B.V. All rights reserved.
2,526 citations
1,990 citations
TL;DR: An extended overview of the chemical composition of biomass was conducted in this article, where reference peer-reviewed data for chemical composition was used to describe the biomass system, including traditional and complete proximate, ultimate and ash analyses.
1,792 citations
TL;DR: In this article, the state of the art in modeling chemical and physical processes of wood and biomass pyrolysis is reported, and the main achievements of numerical simulations are discussed.
1,495 citations