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Søren Kiil - One of the best experts on this subject based on the ideXlab platform.

  • Multi-scale experiments and simulation tools for optimisation of wet flue gas Desulphurisation plants
    2011
    Co-Authors: Søren Kiil, Brian Brun Hansen
    Abstract:

    In the Combustion and Harmful Emission Control (CHEC) group at the Technical University of Denmark, research in flue gas Desulphurisation technologies, in particular wet flue gas Desulphurisation, has been one of many important activities. One aim of research into flue gas Desulphurisation has been to obtain a quantitative understanding of the chemistry and mass transport phenomena taking place in the industrial plants and use of that information in optimisation procedures. The quantitative approach requires experimental facilities at both laboratory and pilot-scale and a continuous development of detailed mathematical models describing the processes. Currently, the influence of oxyfuel combustion on the wet FGD plant performance is also of high priority.

  • Simulation studies of the influence of HCl absorption on the performance of a wet flue gas Desulphurisation pilot plant
    Chemical Engineering Science, 2002
    Co-Authors: Søren Kiil, Helle G. Nygaard, Jan Erik Johnsson
    Abstract:

    Abstract The mathematical model of Kiil et al. (Ind. Eng. Chem. Res. 37 (1998) 2792) for a wet flue gas Desulphurisation (FGD) pilot plant was extended to include the simultaneous absorption of HCl. In contrast to earlier models for wet FGD plants, the inclusion of population balance equations for the limestone particles enabled a quantitative description of the influence of HCl absorption on essential process parameters such as the degree of Desulphurisation and the residual limestone level of the gypsum produced. Simulations showed that the presence of 100 ppmv HCl in the flue gas reduced the degree of Desulphurisation from 85 to 84% and increased the residual limestone level of the gypsum from 2.1 to 2.4 wt %. It was found that these undesired effects from HCl absorption could be counteracted by adding adipic acid to the slurry in a concentration of about 1 mM . The influence of holding tank pH and the inlet flue gas concentration of SO2 on the degree of Desulphurisation and the residual limestone level was found to be almost the same irrespective of HCl was present ( 100 ppmv ) in the flue gas or not. The results presented are of importance in the analysis of the performance of wet FGD plants installed at power plants firing coals of varying Cl contents.

Jan Erik Johnsson - One of the best experts on this subject based on the ideXlab platform.

  • Simulation studies of the influence of HCl absorption on the performance of a wet flue gas Desulphurisation pilot plant
    Chemical Engineering Science, 2002
    Co-Authors: Søren Kiil, Helle G. Nygaard, Jan Erik Johnsson
    Abstract:

    Abstract The mathematical model of Kiil et al. (Ind. Eng. Chem. Res. 37 (1998) 2792) for a wet flue gas Desulphurisation (FGD) pilot plant was extended to include the simultaneous absorption of HCl. In contrast to earlier models for wet FGD plants, the inclusion of population balance equations for the limestone particles enabled a quantitative description of the influence of HCl absorption on essential process parameters such as the degree of Desulphurisation and the residual limestone level of the gypsum produced. Simulations showed that the presence of 100 ppmv HCl in the flue gas reduced the degree of Desulphurisation from 85 to 84% and increased the residual limestone level of the gypsum from 2.1 to 2.4 wt %. It was found that these undesired effects from HCl absorption could be counteracted by adding adipic acid to the slurry in a concentration of about 1 mM . The influence of holding tank pH and the inlet flue gas concentration of SO2 on the degree of Desulphurisation and the residual limestone level was found to be almost the same irrespective of HCl was present ( 100 ppmv ) in the flue gas or not. The results presented are of importance in the analysis of the performance of wet FGD plants installed at power plants firing coals of varying Cl contents.

Inamul Haque - One of the best experts on this subject based on the ideXlab platform.

  • Oxidation of high sulphur coal.9 3. Desulphurisation of organic sulphur by peroxyacetic acid (produced in situ) in presence of metal ions
    Fuel Processing Technology, 2005
    Co-Authors: Dipu Borah, Mrinal K. Baruah, Inamul Haque
    Abstract:

    Abstract A chemical oxidative Desulphurisation method for coal organic sulphur has been presented using peroxyacetic acid produced in situ as an oxidant. Sulphur is removed to the extent 6.92–10.02 wt.% at 1–4 h while at 24 h, it increases to 13.41 wt.%. To understand the influence of metal ions on Desulphurisation, each of six metal ions of variable valence states (Cu+, Ni2+, Co2+, Sn2+, Pd2+ and Sb3+) was externally added. Lowest sulphur loss with Ni2+ ion (2.26–9.46 wt.% at 1–4 h and 11.01 wt.% at 24 h) while highest Desulphurisation with Pd2+ ion (23.15–32.32 wt.% at 1–4 h and 32.75 wt.% at 24 h) are observed. Application of the pseudo-first order kinetics shows rate constants for all the systems in the range (0.70–6.78)×10−5 s−1. The activation energy and frequency factor for these systems fall in the range (8.46–12.66) kJ/mol and (1.15–2.64)×10−3 s−1, respectively. Low frequency factor represents an associated type of Desulphurisation reaction involving intermediate activated complexes. The sulphur loss reaction is non-spontaneous in nature and proceeds with the absorption of heat. Occurrence of the reaction is due to the increase in randomness which is governed by the decomposition of activated complex to products and is influenced by the characteristic property of a metal ion. Study of model sulphur compounds (methionine and dibenzothiophene) reveals that the Desulphurisation reaction under the experimental conditions is primarily due to aliphatic sulphur compounds. The method described here is simple with low-cost and easily available chemical, and therefore, has considerable technological interest.

  • Oxidation of high sulphur coal. Part 2. Desulphurisation of organic sulphur by hydrogen peroxide in presence of metal ions
    Fuel, 2001
    Co-Authors: Dipu Borah, Mrinal K. Baruah, Inamul Haque
    Abstract:

    Abstract This paper describes a simple oxidative method of Desulphurisation of coal organic sulphur carried out by using hydrogen peroxide as an oxidant. Desulphurisation achieved up to the extent of 3.70–6.25 wt% in 1–4 h whereas at 24 h, it increases to 9.24 wt%. When metal ions are externally added to the system containing coal and hydrogen peroxide, Desulphurisation is reduced considerably in the presence of Ni 2+ ion while the presence of Cu + , Co 2+ , Sn 2+ , Pd 2+ and Sb 3+ ions enhance the rate of Desulphurisation in 1–4 h. At 24 h, except Cu + and Sn 2+ ions, the presence of other metal ions increases the magnitude of Desulphurisation. Highest Desulphurisation is obtained in a short time period with Pd 2+ ion (28.14 wt%) whereas it is 31.12 wt% in the presence of Sb 3+ ion at 24 h. The Desulphurisation reaction follows pseudo-first order kinetics in all the systems and the rate constants fall in the range of (1.02–8.68)×10 −5  s −1 implying a slow, steady process which is supported by the exceptionally low frequency factor. The activation energy for Desulphurisation in the systems falls in the range of 8.74–13.67 kJ mol −1 . The positive value of Gibbs free energy of activation represents a non-spontaneous reaction. The reaction proceeds with the absorption of heat (endothermic) as revealed by the positive value of enthalpy of activation. Sufficiently low positive values of entropy of activation and frequency factors attribute an associated reaction and proceed through the initial formation of activated complexes. Model study reveals that the process is effective with aliphatic sulphur compounds. The non-spontaneous nature of the reaction is largely due to the resistance offered by the macro-aromatic sulphur compounds. Pragmatic Desulphurisation has been achieved in the process developed here and is therefore of considerable technological interest.

M Fdzpolanco - One of the best experts on this subject based on the ideXlab platform.

  • microaerobic Desulphurisation unit a new biological system for the removal of h2s from biogas
    Bioresource Technology, 2013
    Co-Authors: I Ramos, Rebeca Perez, M Fdzpolanco
    Abstract:

    Abstract A new biotechnology for the removal of H2S from biogas was devised. The Desulphurisation conditions present in microaerobic digesters were reproduced inside an external chamber called a microaerobic Desulphurisation unit (MDU). A 10 L-unit was inoculated with 1 L of digested sludge in order to treat the biogas produced in a pilot digester. During the 128 d of research under such conditions, the average removal efficiency was 94%. The MDU proved to be robust against fluctuations in biogas residence time (57–107 min), inlet H2S concentration (0.17–0.39% v/v), O2/H2S supplied ratio (17.3–1.4 v/v), and temperature (20–35 °C). Microbiological analysis confirmed the presence of at least three genera of sulphide-oxidising bacteria. Approximately 60% of all the H2S oxidised was recovered from the bottom of the system in the form of large solid S0 sheets with 98% w/w of purity. Therefore, this system could become a cost-effective alternative to the conventional biotechniques for biogas Desulphurisation.

Dipu Borah - One of the best experts on this subject based on the ideXlab platform.

  • Oxidation of high sulphur coal.9 3. Desulphurisation of organic sulphur by peroxyacetic acid (produced in situ) in presence of metal ions
    Fuel Processing Technology, 2005
    Co-Authors: Dipu Borah, Mrinal K. Baruah, Inamul Haque
    Abstract:

    Abstract A chemical oxidative Desulphurisation method for coal organic sulphur has been presented using peroxyacetic acid produced in situ as an oxidant. Sulphur is removed to the extent 6.92–10.02 wt.% at 1–4 h while at 24 h, it increases to 13.41 wt.%. To understand the influence of metal ions on Desulphurisation, each of six metal ions of variable valence states (Cu+, Ni2+, Co2+, Sn2+, Pd2+ and Sb3+) was externally added. Lowest sulphur loss with Ni2+ ion (2.26–9.46 wt.% at 1–4 h and 11.01 wt.% at 24 h) while highest Desulphurisation with Pd2+ ion (23.15–32.32 wt.% at 1–4 h and 32.75 wt.% at 24 h) are observed. Application of the pseudo-first order kinetics shows rate constants for all the systems in the range (0.70–6.78)×10−5 s−1. The activation energy and frequency factor for these systems fall in the range (8.46–12.66) kJ/mol and (1.15–2.64)×10−3 s−1, respectively. Low frequency factor represents an associated type of Desulphurisation reaction involving intermediate activated complexes. The sulphur loss reaction is non-spontaneous in nature and proceeds with the absorption of heat. Occurrence of the reaction is due to the increase in randomness which is governed by the decomposition of activated complex to products and is influenced by the characteristic property of a metal ion. Study of model sulphur compounds (methionine and dibenzothiophene) reveals that the Desulphurisation reaction under the experimental conditions is primarily due to aliphatic sulphur compounds. The method described here is simple with low-cost and easily available chemical, and therefore, has considerable technological interest.

  • Oxidation of high sulphur coal. Part 2. Desulphurisation of organic sulphur by hydrogen peroxide in presence of metal ions
    Fuel, 2001
    Co-Authors: Dipu Borah, Mrinal K. Baruah, Inamul Haque
    Abstract:

    Abstract This paper describes a simple oxidative method of Desulphurisation of coal organic sulphur carried out by using hydrogen peroxide as an oxidant. Desulphurisation achieved up to the extent of 3.70–6.25 wt% in 1–4 h whereas at 24 h, it increases to 9.24 wt%. When metal ions are externally added to the system containing coal and hydrogen peroxide, Desulphurisation is reduced considerably in the presence of Ni 2+ ion while the presence of Cu + , Co 2+ , Sn 2+ , Pd 2+ and Sb 3+ ions enhance the rate of Desulphurisation in 1–4 h. At 24 h, except Cu + and Sn 2+ ions, the presence of other metal ions increases the magnitude of Desulphurisation. Highest Desulphurisation is obtained in a short time period with Pd 2+ ion (28.14 wt%) whereas it is 31.12 wt% in the presence of Sb 3+ ion at 24 h. The Desulphurisation reaction follows pseudo-first order kinetics in all the systems and the rate constants fall in the range of (1.02–8.68)×10 −5  s −1 implying a slow, steady process which is supported by the exceptionally low frequency factor. The activation energy for Desulphurisation in the systems falls in the range of 8.74–13.67 kJ mol −1 . The positive value of Gibbs free energy of activation represents a non-spontaneous reaction. The reaction proceeds with the absorption of heat (endothermic) as revealed by the positive value of enthalpy of activation. Sufficiently low positive values of entropy of activation and frequency factors attribute an associated reaction and proceed through the initial formation of activated complexes. Model study reveals that the process is effective with aliphatic sulphur compounds. The non-spontaneous nature of the reaction is largely due to the resistance offered by the macro-aromatic sulphur compounds. Pragmatic Desulphurisation has been achieved in the process developed here and is therefore of considerable technological interest.