Optimization of Steam Distillation of Essential Oil of Eucalyptus tereticornis by Response Surface Methodology

This paper deals with optimization of yield of Eucalyptus tereticornis oil in steam distillation using response surface methodology (RSM). The factors considered were mass of solute/solvent ratio (A), extraction time (B) and steam rate (C). These parameters were varied at two levels. Conditions of optimum oil yield predicted were 105 min of extraction time and 0.032 kg/h steam rate. These factors gave an optimum oil yield of 2.05 %. Significant model terms were time, steam rate, and the interactions between them. Analysis of variance (ANOVA) indicates that the model was significant as evidenced from R2 of 0.9844 and the model F-value of 49.13. The oil yield predicted by the model was closed to the experimentally determined values (1.85 % and 1.87 % respectively); hence the model can be used for prediction of oil yield in essential oil extraction from E. tereticornis leaf via steam distillation method.Keywords: RSM, Eucalyptus tereticornis, steam distillation, Box-Bohnke

Experimental study of the heat transfer performance of PCMs within metal finned containers

Latent heat thermal energy storages (LHTES) are particularly attractive methods owing to these factors: meet the time shift between energy supply and demand; provide a high energy storage capacity; store and release heat at a relatively constant temperature; provide constant comfort thermal environment without temperature swings when it is applied for space heating or cooling. Nevertheless, the efficiency of using the LHTES techniques is heavily affected by the low thermal conductivities of phase change materials (PCMs). This characteristic of PCMs prolongs the charging and discharging cycle and barriers the widely practical application of LHTES. Hence, researchers generated a lot of related technologies, such as metal fines, carbon fibres, metal honeycomb structure, etc, to overcome this issue and aimed to achieve reasonable thermal conductivities. The objective of this paper is to study the heat performance of two kinds of PCMs within three different types of metal finned structures (straight fins, honeycomb and square finned structure) at the volume ratios of 1.8, 2.7, and 3.6 %, respectively. Two organic PCMs, paraffin wax RT 25 (phase transform at 25 °C) and RT 42 (phase transform at 42 °C) are employed as the heat storage media. The characteristics of them with the thermal conductivity enhancers (TCEs) during the melting and solidification process were investigated experimentally. The results indicate that the heat transfer improvements during the melting process are more efficiency than the solidification process for all of the three structures and both PCMs. To be specific, for paraffin RT 25, the heat transfer efficiencies were increased by 25, 33, and 37 %, in the finned, honeycomb and square cell structured container during the melting process, and increased by 8, 12, and 17.1 %, respectively for the solidification processes. The similar effect happened for paraffin RT 42, the heat transfer efficiencies were increased by 28, 33, and 40 % during melting process, and increased by 17, 28, and 35 %, respectively during freezing process. The performance of the TCEs on the RT 42 is slightly better than that of RT 25, especially during the solidification process due to its higher heat transfer rate between the PCM and TECs induced by a relative higher melting temperature. Meanwhile, the efficiencies of the volume ratios of the TECs were examined. The results show that straight fins have the best efficiency compared to others

Adoption of Green Building Technologies in Ghana

This chapter aims at fostering a crystal-clear understanding of how to promote GBTs adoption in Ghana, a developing country in West Africa. To this end, the primary drivers for GBTs adoption have been discussed, with a focus on Ghana. Similarly, this chapter has analyzed the key barriers hampering the widespread adoption of GBTs in Ghana. Finally, strategies that can be used to overcome the current barriers in the industry and promote the GBTs adoption are presented. The value of this research lies in the fact that this research can help policy makers, practitioners, and advocates promote the GBTs adoption. The key strategies they could adopt for promoting the GBTs adoption include—more publicity through media; GBTs-related educational and training programs for key stakeholders; availability of institutional framework for effective GBTs implementation; a strengthened GBTs R&D; and financial and further market-based incentives.No Full Tex