Exergy analysis of energy-intensive production processes: advancing towards a sustainable chemical industry

Exergy analysis is becoming a very powerful strategy to evaluate the real efficiency of a process. Its application in the chemical industry is still at an early stage but many interesting remarks can be obtained from the recent research in the most energy intensive processes of the chemical industry: the production of chemicals, the cement industry, the paper industry and, the iron and steel industry. The present review analyzes the opportunities and challenges in those sectors by considering exergy analyses as the first required step (although not sufficient) to advance towards a more sustainable chemical industry. Social, environmental and economic factors play a role in the critical evaluation of a process and exergy could be considered as the property that joins together those three cores of sustainability

Identification of the influence of blast-furnance working parameters upon the supply and net calorific value of blast furnance gas

The application of theoretical empirical mathematical model the of blast furnace and energy characteristics of a Cowper stove to identify the influence of working parameters upon the supply and net calorific value of blast furnace-gas has been discussed. Results of exemplary calculations have also been presented

Thermodynamic optimisation and computational analysis of irreversibilities in a small-scale wood-fired circulating fluidised bed adiabatic combustor

An analysis of irreversibilities generated due to combustion in an adiabatic combustor burning wood was conducted. This was done for a reactant mixture varying from a rich to a lean mixture. A non-adiabatic non-premixed combustion model of a numerical code was used to simulate the combustion process where the solid fuel was modelled by using the ultimate analysis data. The entropy generation rates due to the combustion and frictional pressure drop processes were computed to eventually arrive at the irreversibilities generated. It was found that the entropy generation rate due to frictional pressure drop was negligible when compared to that due to combustion. It was also found that a minimum in irreversibilities generated was achieved when the AireFuel mass ratio was 4.9, which corresponds to an equivalence ratio of 1.64, which are lower than the respective AireFuel mass ratio and equivalence ratio for complete combustion with theoretical amount of air of 8.02 and 1.National Research Foundation (NRF), University of Pretoria and the Council for Scientific and Industrial Research (CSIR)http://www.elsevier.com/locate/energyhb201