Fabrication and thermal conductivity improvement of novel composite adsorbents adding with nanoparticles

Abstract

Thermal conductivity is one of key parameters of adsorbents, which will affect the overall system performance of adsorption chiller. To improve adsorbent's thermal conductivity is always one of research focuses in chemisorption field. A new chemical composite adsorbent is fabricated by adding carbon coated metal(Aluminum and Nickel) nanoparticles with three different addition amounts into the mixture of chloride salts and natural expanded graphite aiming to improve the thermal conductivity. The preparation processes and its thermal conductivity of this novel composite adsorbent are reported and summarized. Experimental results indicate that the nanoparticles are homogenously dispersed in the composite adsorbent by applying the reported preparation processes. The thermal conductivity of the composite adsorbent can averagely enlarge by 20% when the weight ratio of the added nanoparticles is 10 wt%. Moreover, carbon coated aluminum nanoparticles exhibit more effective enlargement in thermal conductivity than nickel nanoparticles. As for the composite adsorbent of CaCl 2-NEG, there is a big reinforcement from 30% to 50% for Al@C nanoparticles, however only 10% in maximum caused by Ni@C nanoparticles. The proposed research provides a methodology to design and prepare thermal conductive chemical composite adsorbent.

Exploration of ammonia resorption cycle for power generation by using novel composite sorbent

“…Mechanical and thermal stability could be ensured during the testing process. Mass ratio between SrCl2 and ENG is selected as 80% whereas mass ratio between ENG and Ni@C is adopted as 20:1 [38]. Only plate samples are tested for optimal heat transfer direction i.e.…”

Investigation on innovative thermal conductive composite strontium chloride for ammonia sorption refrigeration

“…The thermochemical sorption reaction process of SrCl2 with ammonia can be expressed as the equations 1-2. The development of the novel composite SrCl2 can be referred to the reference [22]. ENG is expanded by the optimal expanding process, i.e.…”

“…whereas the ratio between ENG and Ni@C is adopted as 20:1 [22]. Since the anisotropic characteristic of consolidated ENG matrix have already been studied [24], both plate samples…”

“…Compared with CNT, nanoparticles such as Carbon coated Nickel (Ni@C) with core-shell structure manifests the potentials for the improvement of the sorption kinetics. One remarkable fact is that carbon coating is able to protect the external conditions for the metal core, and the metal core may take promoting effects on the composites while maintaining its desirable thermal properties [20][21][22]. The granular shape in nanometer size tends to be easier to occupy the porous structure of the composite sorbent with ENG.…”

Investigation on novel modular sorption thermal cell with improved energy charging and discharging performance

“…Expanded natural graphite (ENG) have proved to be conducive to heat transfer performance with limited improvement for mass transfer. Recently nanoparticles such as carbon coated metal have attempted to be an additive for composite sorbent, which is expected to have a desirable heat and mass transfer performance [21].…”