Engineering

Publication Search Results

Now showing 1 - 10 of 467
  • (2006) Ho, Minh; Allinson, G; Wiley, Dianne
    Journal Article
    The sequestration of CO2 as a greenhouse mitigation option is becoming an increasingly important priority for industry. Theoretically membrane based CO2 removal systems have the potential to provide a cost effective, low maintenance approach for removing CO2 from gas streams. This study examines the effect of membrane characteristics, operating parameters and system design on sequestration costs for any source-sink combination. The total sequestration cost per tonne of CO2 avoided for separation, transport and storage are compared for the separation of CO2 from a black coalfired power plant in Australia. The results show that the membranes currently available have a total sequestration cost of US$55-61/tonne CO2 avoided. Lower costs for CO2 avoided can be achieved using an MEA amine based absorption separation system. Gas separation membranes would require significant improvements in CO2 permeability and selectivity, together with reductions in the cost of membranes and changes to the process configurations and operating pressures to be competitive against MEA systems for the purposes of geo-sequestration.

  • (2004) Ho, Minh; Wiley, Dianne
    Conference Paper
    The capture and storage of CO2 (CCS) as a greenhouse mitigation option is becoming an increasingly important priority for Australian industry. Membrane based CO2 removal systems can provide a cost effective, low maintenance approach for removing CO2 from gas streams. This study examines the effect of membrane characteristics and operating parameters on CCS costs using economic models developed by UNSW for any source-sink combination. The total sequestration cost per tonne of CO2 avoided for separation, transport and storage are compared for the separation of CO2 from coal fired power plants and natural gas processing. A cost benefit analysis indicates that sequestration of gases of high purities are dominated by compression costs which can be off-set by utilising membranes of higher selectivity coupled with higher permeability to reduce the required transmembrane pressure.

  • (2011) Hanaor, Dorian; Michelazzi, Marco; Chenu, Jeremy; Leonelli, Cristina; Sorrell, Charles
    Journal Article
    Thick anatase films were fabricated on graphite substrates using a method of anodic aqueous electrophoretic-deposition using oxalic acid as a dispersant. Thick films were subsequently fired in air and in nitrogen at a range of temperatures. The morphology and phase composition were assessed and the photocatalytic performance was examined by the inactivation of Escherichia coli in water. It was found that the transformation of anatase to rutile is enhanced by the presence of a graphite substrate through reduction effects. The use of a nitrogen atmosphere allows higher firing temperatures, results in less cracking of the films and yields superior bactericidal performance in comparison with firing in air. The beneficial effects of a nitrogen firing atmosphere on the photocatalytic performance of the material are likely to be a result of the diffusion of nitrogen and carbon into the TiO2 lattice and the consequent creation of new valence band states.



  • (2004) McAvoy, Gregory
    Thesis



  • (2001) Leung, Audrey
    Thesis
    The volatile aroma compounds in the green plant tissue and grain of five Australian rice varieties were studied in detail. Selected volatile aroma compounds, including 2-acetyl-1- pyrroline (AP), observed in three fragrant varieties, YRF 203, YRF 205 and Kyeema and two non-fragrant varieties, Pelde and Langi, were compared. The development of volatile aroma compounds in the rice plant was followed from early tillering to full maturity. The effect of nitrogen fertilisation level on the volatile aroma compound composition was evaluated. Volatile compounds were extracted by the Likens-Nickerson simultaneous distillation-extraction technique. GC-MS, GC-FID and GC-O were used to separate, identify and quantify the volatile aroma compounds in the rice grain and plant extracts. The 127 volatile compounds identified in rice plant tissue and grain included 28 aldehydes, 23 ketones, 20 alcohols, 8 phenolic compounds, 17 heterocyclic compounds, 7 hydrocarbons, 2 sulphur compounds, 5 terpenes, 11 acids and 6 esters. Most of the homologous series of aliphatic aldehydes, ketones and alcohols that were identified in cooked rice were also identified in plant tissue, but in different proportions. AP was the major volatile compound in fragrant rice plant and grain and was probably the major factor that contributed to the difference between fragrant and non-fragrant varieties. Relative levels of AP in rice plant correlated with the relative level of AP in the rice plant of the same variety. Therefore, AP concentration in rice plant tissue can be used as an early indicator of aroma in rice grain. The non-fragrant whole rice contained more pent-l-en-3- one, D-Limonene and hepta-2,4-dienal than fragrant rice, while fragrant rice contained more but-2-enal, hex-2-en-l-ol, pyridine and AP. Milled fragrant rice contained more but- 2-enal, pyridine, AP and pyrrole than non-fragrant rice. The increase in nitrogen fertilisation resulted in an increase of AP in rice plant tissue and grain in fragrant varieties. In addition, the increase in nitrogen fertilisation resulted in an increase in pyridine, hepta-2,4-dienal and 2-methoxyphenol in the mature rice plant and an increase of pentanal, hexanal, pyridine, heptan-2-one, pentan-l-ol, hexan-l-ol, oct-l-en-3- ol and furfural in milled rice. AP concentration was relatively high at the beginning of plant development and then decreased during plant development. Therefore, AP can be detected at the early stages of plant development, without having to wait until grain maturity.