TY - JOUR
T1 - Preparation and thermal conductivity enhancement of a paraffin wax-based composite phase change material doped with garlic stem biochar microparticles
AU - Xiong, Teng
AU - Ok, Yong Sik
AU - Dissanayake, Pavani Dulanja
AU - Tsang, Daniel C.W.
AU - Kim, Sumin
AU - Kua, Harn Wei
AU - Shah, Kwok Wei
N1 - Funding Information:
This work was supported by the City Developments Limited (CDL) project R-296-000-174-720 and NUS-AGC Inc. project R-296-000-183-597 . The authors would also like to acknowledge the support provided by the Department of the Built Environment, National University of Singapore .
Publisher Copyright:
© 2022
PY - 2022/6/25
Y1 - 2022/6/25
N2 - The addition of thermally conductive nanomaterials is an effective strategy for increasing the thermal conductivity of phase change materials (PCMs). However, nanomaterials are expensive and may significantly reduce the latent heat capacity of PCMs. In this study, low-cost and eco-friendly biochar microparticles were prepared from garlic stems, a common food waste in Singapore. The thermal properties of paraffin wax (PW) doped with 1, 3, and 5 wt% garlic stem biochar (GSB) microparticles were investigated. The GSB microparticles prepared at 700 °C had three-dimensional porous and two-dimensional flake-like structures, which contributed to the formation of additional heat transfer pathways in the PW. The addition of 5 wt% GSB microparticles enhanced the thermal conductivity of PW by 27.3% and 7.2% in the solid and liquid phases, respectively. The T-history test revealed that the melting and solidification rates of PW improved by 90 and 115 s, respectively. The improved heat transfer performance was mainly ascribed to the high degree of graphitization and the interconnected porous carbon structure of the GSB microparticles. The phase change temperatures of PW were slightly changed upon the addition of GSB microparticles, and the latent heat capacity was only reduced by 6.1%. These results suggest that the GSB microparticles can be used as a potential alternative to other nanoadditives such as metal- and metal oxide-based nanoadditives.
AB - The addition of thermally conductive nanomaterials is an effective strategy for increasing the thermal conductivity of phase change materials (PCMs). However, nanomaterials are expensive and may significantly reduce the latent heat capacity of PCMs. In this study, low-cost and eco-friendly biochar microparticles were prepared from garlic stems, a common food waste in Singapore. The thermal properties of paraffin wax (PW) doped with 1, 3, and 5 wt% garlic stem biochar (GSB) microparticles were investigated. The GSB microparticles prepared at 700 °C had three-dimensional porous and two-dimensional flake-like structures, which contributed to the formation of additional heat transfer pathways in the PW. The addition of 5 wt% GSB microparticles enhanced the thermal conductivity of PW by 27.3% and 7.2% in the solid and liquid phases, respectively. The T-history test revealed that the melting and solidification rates of PW improved by 90 and 115 s, respectively. The improved heat transfer performance was mainly ascribed to the high degree of graphitization and the interconnected porous carbon structure of the GSB microparticles. The phase change temperatures of PW were slightly changed upon the addition of GSB microparticles, and the latent heat capacity was only reduced by 6.1%. These results suggest that the GSB microparticles can be used as a potential alternative to other nanoadditives such as metal- and metal oxide-based nanoadditives.
KW - Food waste management
KW - Garlic stem biochar
KW - Phase change material
KW - Thermal conductivity
KW - Thermal storage
UR - http://www.scopus.com/inward/record.url?scp=85126085253&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2022.154341
DO - 10.1016/j.scitotenv.2022.154341
M3 - Journal article
C2 - 35257765
AN - SCOPUS:85126085253
SN - 0048-9697
VL - 827
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 154341
ER -