POSTER:SEPARATION OF NANOPARTICLES FROM NANOPARTICLE ENHANCED PHASE CHANGE MATERIALS

Conference Name: ASME
Location: Denver , CO
Date: 11/2011

List of Authors:

Md Haroon Sheikh, Dr.M.A.R.Sharif

Abstract

NEPCM is a ‘nano enchanced phase change material ‘used for energy (heat) storage application. The phase change material used here are higher order alkanes and in our analysis alkane called “Dodecane” is being used. Nanoparticles are being used to improve the heat transfer coefficient of dodecane to make it suitable for heat energy storage application. As this application requires storing and giving away heat energy as per the requirement, dodecane undergoes phase change. Hence the mixture is known as NEPCM. As everything has got a limited life span, after substantial number of application cycles (approx 5000) NEPCM starts losing its ability to perform efficiently. At this point it is required to replace it with freshly prepared NEPCM. However the used NEPCM cannot be disposed off directly to atmosphere due to presence of nanoparticles which impose health hazard for humans and to the wildlife. Our project deals with establishing the efficient and cost effective methods of removing and exclaiming the nanoparticles from the used NEPCM. With stated motive after attempting several methods currently we could succeed in establishing two methods: 1. Direct distillation of NEPCM using a conventional distillation unit. 2. High speed centrifugation. The results obtained by method #1 were examined using Xray diffraction method and its confirmed that it removes all nanoparticles .With method #2 we could sediment some of the nanoparticles from the NEPCM using high speed (15000rpm) centrifuge. Next step would be to carry out distillation under vacuum which is expected to save about 30% of energy than conventional distillation unit. Also other methods are being explored such as: nanofiltration, spay drying etc. To reclaim and reuse the separated nanoparticles being the secondary objective, its being practiced to stay away from the methods which demands addition of chemicals (toxic, expensive) which may impair the purity of nanoparticles and would make the process uneconomical.