Combustion behaviour of some biodesulphurized coals assessed by TGA/DTA

Thermal analysis, i.e. TGA/DTA is used to study the changes in the combustion behaviour of microbially treated coals. In view of their high sulphur content and industrial significance three samples are under consideration, i.e. one lignite and two subbituminous from different region in Bulgaria. The differences in burning profiles can be related to structural changes resulted from biological treatments. The overall biological treatment generates these changes probably due to the oxidation process. Concerning organic sulphur biodesulphurization there is no change in any drastic mannerof the thermal characteristic parameters. In general, applied biotreatments provoke a complex influence on combustion coal behaviour. From one side a better ignition performance, a minor decrease in higher heating value and diminishing peak temperature of maximum weight loss rate for all biotreated samples are observed. From other side some decrease in the combustibility indicated by an increase in the combustion time and the end of combustion temperature are obvious. Also well determined decrease of self-heating temperature after biotreatments evolves high risk of spontaneous unmanageable coal combustion

Combustion behaviour of some biodesulphurized coals assessed by TGA/DTA

Thermal analysis, i.e. TGA/DTA is used to study the changes in the combustion behaviour of microbially treated coals. In view of their high sulphur content and industrial significance three samples are under consideration, i.e. one lignite and two subbituminous from different region in Bulgaria. The differences in burning profiles can be related to structural changes resulted from biological treatments. The overall biological treatment generates these changes probably due to the oxidation process. Concerning organic sulphur biodesulphurization there is no change in any drastic mannerof the thermal characteristic parameters. In general, applied biotreatments provoke a complex influence on combustion coal behaviour. From one side a better ignition performance, a minor decrease in higher heating value and diminishing peak temperature of maximum weight loss rate for all biotreated samples are observed. From other side some decrease in the combustibility indicated by an increase in the combustion time and the end of combustion temperature are obvious. Also well determined decrease of self-heating temperature after biotreatments evolves high risk of spontaneous unmanageable coal combustion

Biodesulphurized subbituminous coal by different fungi and bacteria studied by reductive pyrolysis. Part 1: Initial coal

One of the perspective methods for clean solid fuels production is biodesulphurization. In order to increase the effect of this approach it is necessary to apply the advantages of more informative analytical techniques. Atmospheric pressure temperature programming reduction (AP-TPR) coupled with different detection systems gave us ground to attain more satisfactory explanation of the effects of biodesulphurization on the treated solid products. Subbituminous high sulphur coal from ‘‘Pirin” basin (Bulgaria) was selected as a high sulphur containing sample. Different types of microorganisms were chosen and maximal desulphurization of 26% was registered. Biodesulphurization treatments were performed with three types of fungi: ‘‘Trametes Versicolor” – ATCC No. 200801, ‘‘Phanerochaeta Chrysosporium” – ME446, Pleurotus Sajor-Caju and one Mixed Culture of bacteria – ATCC No. 39327. A high degree of inorganic sulphur removal (79%) with Mixed Culture of bacteria and consecutive reduction by 13% for organic sulphur (Sorg) decrease with ‘‘Phanerochaeta Chrysosporium” and ‘‘Trametes Versicolor” were achieved. To follow the Sorg changes a set of different detection systems i.e. AP-TPR coupled ‘‘on-line” with mass spectrometry (AP-TPR/MS), on-line with potentiometry (AP-TPR/pot) and by the ‘‘off-line” AP-TPR/GC/MS analysis was used. The need of applying different atmospheres in pyrolysis experiments was proved and their effects were discussed. In order to reach more precise total sulphur balance, oxygen bomb combustion followed by ion chromatography was used

Reductive Pyrolysis Study of Biodesulfurized Subbituminous Coal

Biodesulfurization is one of the perspective methods for production of friendly fuels. Reductive pyrolysis in mode of atmospheric pressure temperature programmed reduction (AP-TPR) combined with varied detection systems gave us possibility to obtain more s a t isfactory explanation of biodesulfurization effects. AP-TPR coupled “on-line” and “off-line” with potentiometry, massspectrometry and GC/MS analysis with inner sulfur standards for quantification were applied. Subbituminous coal from “Pirin” basin, Bulgaria was treated by three different types of microorganisms with maximal desulfurization effect for total (26%) and organic sulfur (13%). Namely, two types white rot fungi – “Trametes Versicolor , “Phanerochaeta Chrysosporium” and one mixed bacterial culture were used. Improved sulfur balance determination was registered

Reductive Pyrolysis Study of Biodesulfurized Subbituminous Coal

Biodesulfurization is one of the perspective methods for production of friendly fuels. Reductive pyrolysis in mode of atmospheric pressure temperature programmed reduction (AP-TPR) combined with varied detection systems gave us possibility to obtain more s a t isfactory explanation of biodesulfurization effects. AP-TPR coupled “on-line” and “off-line” with potentiometry, massspectrometry and GC/MS analysis with inner sulfur standards for quantification were applied. Subbituminous coal from “Pirin” basin, Bulgaria was treated by three different types of microorganisms with maximal desulfurization effect for total (26%) and organic sulfur (13%). Namely, two types white rot fungi – “Trametes Versicolor , “Phanerochaeta Chrysosporium” and one mixed bacterial culture were used. Improved sulfur balance determination was registered

Biodesulphurized subbituminous coal by different fungi and bacteria studied by reductive pyrolysis

One of the perspective methods for clean solid fuels production is biodesulphurization. In order to increase the effect of this approach it is necessary to apply the advantages of more informative analytical techniques. Atmospheric pressure temperature programming reduction (AP-TPR) coupled with different detection systems gave us ground to attain more satisfactory explanation of the effects of biodesulphurization on the treated solid products. Subbituminous high sulphur coal from “Pirin” basin (Bulgaria) was selected as a high sulphur containing sample. Three different types of microorganisms were chosen and maximal desulphurization of 26% was registered. The following biodesulphurization treatments were performed: three types of fungi – “Trametes Versicolor” – ATCC №200801, “Phanerochaeta Chrysosporium” – ME446, Pleurotus Sajor-Caju and Mixed Culture of bacteria – ATCC №39327. A high degree of inorganic sulphur removal (79%) was established and consecutive reduction by ~ 13% for organic sulphur (Sorg) was achieved. To follow the Sorg changes a set of different detection systems i.e. AP-TPR coupled “on-line” with mass-spectrometry (AP-TPR/MS), on-line with potentiometry (AP-TPR/pot) and by the “off-line” AP-TPR/GC/MS analysis was used. In order to reach more precise sulphur balance, oxygen bomb combustion followed by ion chromatography was used

Harm avoidance is related to mismatch negativity (MMN) amplitude in healthy subjects

Event-related potential (ERP) studies evidenced that some personality dimensions induced different controlled cognitive attitudes towards the processing of information. However, few data are available on the possible relationships between personality and automatic attention or early sensory processing. In the present study the relationships between the mismatch negativity (MMN) and personality described by the Cloninger model of personality were investigated. Subjects were 32 healthy volunteers. The MMN was recorded with frequent stimuli tones of 1470 Hz, 70 dB and 40 ms duration, and target (20%) tones of 1470 Hz, 70 dB, 80 ms duration. The subjects completed a French version of the 226-item self-questionnaire TCI within the day following psychophysiological recording. The results showed that the HA dimension was negatively correlated with the MMN amplitude. The association was more present among women than men. No significant relationship existed between the other dimensions of personality and either the MMN amplitude or latency. These findings suggest that the MMN is related to the behavioral inhibition system (BIS), a fact which is consistent with clinical studies conducted on schizophrenia and anxiety disorders. In conclusion, this study suggests that personality dimensions induce different automatic attitudes towards the processing of information. (C) 2002 Published by Elsevier Science Ltd