Universiti Teknologi Petronas

About: Universiti Teknologi Petronas is a education organization based out in Ipoh, Malaysia. It is known for research contribution in the topics: Adsorption & Ionic liquid. The organization has 6127 authors who have published 11284 publications receiving 119400 citations.

Co-cultivation of activated sludge and microalgae for the simultaneous enhancements of nitrogen-rich wastewater bioremediation and lipid production

Abstract: The symbiotic relationships between activated sludge and microalgae were explored for bio-remediating nitrogen-rich wastewater and producing lipid-based biofuel simultaneously. Various inoculation ratios of activated sludge to microalgae (AS:MA) biomasses were employed to unveil the mechanism of NH4+-N removal in relation to lipid production from algal-bacterial biomass. The presence of nitrifiers in converting NH4+-N into oxidized nitrogen (NO2−-N and NO3−-N) had greatly enhanced the total nitrogen removal in the co-cultivation bioreactors as compared with the individual culture of either activated sludge or microalgae. Accordingly, achieving near complete nitrogen removal (97–98%) when the bioreactors were inoculated with AS:MA ratios of 1:0.75 and beyond. The kinetic growths of co-cultivated activated sludge and microalgae biomasses were also investigated using Verhulst model; demonstrating a significant increase of specific biomass growth rate with increasing of initial microalgae inoculation ratio. The AS:MA ratio of 1:0.75 was considered optimum for the symbiotic algal-bacterial interactions, attaining the highest lipid yield of 130 mg/L and flocculation efficiency of 42% which would aid the biomass harvesting process.

Ethanol dry reforming for syngas production over Ce-promoted Ni/Al2O3 catalyst

Abstract: Ce-promoted and unpromoted 10%Ni/Al 2 O 3 catalysts were prepared by co-impregnation method and evaluated for ethanol dry reforming in a quartz fixed-bed reactor at different CO 2 :C 2 H 5 OH ratios of 2.5:1–1:2.5 and temperature of 923–973 K under atmospheric pressure. Thermogravimetric studies indicated that both catalysts were completely calcined and subsequently reduced to metallic Ni 0 phase. The addition of Ce promoter facilitated the reduction process and decreased reduction temperature by about 315 K. Stronger metal–support interaction was observed with Ce addition. NiO and NiAl 2 O 4 phases were formed on catalyst surface during calcination for both catalysts whilst CeO 2 form was identified on promoted catalyst. Significant enhancement of ethanol conversion up to 75.2% with reaction temperature was observed and catalytic activity appeared to be stable with time-on-stream at beyond 5–7 h for both promoted and unpromoted catalysts. C 2 H 5 OH and CO 2 conversions increased with growing CO 2 partial pressure whilst the optimal C 2 H 5 OH partial pressure was obtained at about 30–40 kPa for both catalysts. C 2 H 5 OH conversion was always greater than that of CO 2 indicating the co-existence of side reactions, namely; ethanol decomposition and dehydrogenation during ethanol dry reforming reaction. Ce-addition improved both C 2 H 5 OH and CO 2 conversions irrespective of reactant partial pressure. Although both carbon nanofilament and graphitic carbon were detected on the surface of spent catalysts by SEM, TEM and Raman measurements, the proportion of carbon nanofilament was dominant and the percentage of amorphous carbon was increased with Ce promoter.