Sundaravadivelnathan Ponnusamy

Life cycle assessment of biodiesel production from algal bio-crude oils extracted under subcritical water conditions

A life cycle assessment study is performed for the energy requirements and greenhouse gas emissions in an algal biodiesel production system. Subcritical water (SCW) extraction was applied for extracting bio-crude oil from algae, and conventional transesterification method was used for converting the algal oil to biodiesel. 58MJ of energy is required to produce 1kg of biodiesel without any co-products management, of which 36% was spent on cultivation and 56% on lipid extraction. SCW extraction with thermal energy recovery reduces the energy consumption by 3-5 folds when compared to the traditional solvent extraction. It is estimated that 1kg of algal biodiesel fixes about 0.6kg of CO2. An optimized case considering the energy credits from co-products could further reduce the total energy demand. The energy demand for producing 1kg of biodiesel in the optimized case is 28.23MJ.

Evaluation of Novel Modified Activated Alumina as Adsorbent for Arsenic Removal

In this research work, the feasibility of using novel activated alumina (AA) and modified AA adsorbents for arsenic (As) removal from drinking water was evaluated. A sol-gel derived activated alumina adsorbent was prepared. Equilibrium adsorption studies were conducted to evaluate the As removal efficiency of synthesized and modified adsorbents. Results on As adsorption using Solgel AA and modified Solgel AA adsorbents demonstrated that ZnO nanoparticle-modified AA (Nanogel AA) provided better adsorption performance. The high As adsorption capacity of Nanogel AA is attributed to the enhanced pore textural and surface properties as well as to the pH independency of the adsorbent. The Freundlich adsorption isotherm fitted well with the adsorption of arsenic over modified AA.