scholarly journals Total energy analysis of nuclear and fossil fueled power plants

1971 ◽  
Author(s):  
W. D. Franklin ◽  
M. Mutsakis ◽  
R. G. Ort
Author(s):  
Sérgio Peres ◽  
Alex Green

The catalytic indirectly heated gasification of bagasse was investigated in this study. The quality of the gaseous fuel was assessed using the total energy analysis of the gas, in which both heat content and total yields of the gas produced from the gasification of bagasse are analyzed at temperatures ranging from 700 to 1000°C. Untreated bagasse gasification was used as a baseline for the investigation of the effect of catalysts on the gasification process. The total energy analysis showed a significant improvement of gas quality due to increase of temperature and due to the use of alumina-zinc based catalysts at temperatures below 900°C. The presence of these catalysts in the gasification process affected the quality of the gases formed, mainly by increasing the hydrogen production, reduction of the gas dilution by carbon dioxide and a slightly higher production of carbon monoxide. Above 900°C, temperature dominates the gasification reaction mechanisms causing the catalysts to have little or no significant effect. Thermal cracking of tar is of major importance on the gasification process, as the tar yields reduce from 42.1 to 24.7% of the bagasse original weight with the increase of the gasifier temperature from 700 to 1000°C. However, the solid residue reduced only from 16 to 13.3%. Hence, the increase in the gaseous yields at high temperature appeared to be due to the gasification of tar with some contribution from secondary reactions involving char. The result was the production of a medium heat content gaseous fuel.


1997 ◽  
Vol 25 (1) ◽  
pp. 13-31 ◽  
Author(s):  
William R. Dunbar ◽  
Noam Lior

The teaching of power cycles in courses of thermodynamics or thermal engineering was traditionally based on first-law analysis. Second-law analysis was typically taught later, and not integrated with it. This approach leaves the student ignorant of the effect of operating parameters and cycle modifications on the accompanying exergy (availability) magnitudes and component irreversibilities, which are necessary for evaluating the potential for further system improvements. It also leaves many of the students with an ambiguous understanding of the exergy concept and its use. Consonant with the gradual changes in this educational approach, which increasingly attempt to integrate first- and second-law analysis, this paper recommends a strategy which integrates exergy analysis into the introduction and teaching of energy systems, demonstrated and made didactically appealing by an examination of the historical evolution of power plants, emphasizing the objectives for improvements, accomplishments, constraints, and consequently the remaining opportunities. Important conclusions from exergy analysis, not obtainable from the conventional energy analysis, were emphasized. It was found that this approach evoked the intellectual curiosity of students and increased their interest in the course.


1981 ◽  
Vol 1 (2) ◽  
pp. 238-254 ◽  
Author(s):  
Nicholas Tsoulfanidis

2019 ◽  
Vol 2 (1) ◽  
pp. 25-30
Author(s):  
Carrin Aprinada ◽  
Irvan S. Kartawiria ◽  
Evita H. Legowo

Molasses is mostly used as feedstock for the bioethanol production in Indonesia. Bioethanol industries has the potential to be more developed if the mandate of blending gasoline with 5% bioethanol is implemented. However, some previous studies abroad have shown that mostly the net energy for producing bioethanol is negative. The main purpose of this research is to analyze the net energy requirement if a bioethanol conversion plant from scenario of a bioethanol producer in East Java. Bioethanol conversion processes inside the plant are pre-fermentation, fermentation, evaporation, distillation and dehydration. Method which was used in this research are modelling and calculation made on monthly basis for plant capacity of 30,000 KL/ year ethanol of 99.5% purity. The result shows that the total energy required to produce 1 L of ethanol is 4.55 MJ. The energy content of 1 L ethanol is 23.46 MJ. The largest energy requirement is for evaporation process (62%) followed by distillation process (33%). Thus, the net energy requirement for bioethanol production process is positive.


1975 ◽  
Vol 26 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Charles T. Rombough ◽  
Billy V. Koen

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