Production of almond shell containing particleboards and determination of their thermal conductivities

Abstract

Almond kernel, with a continuously increasing consumption, and is also important for our country, is a valuable agricultural product. Its production yields the hard shell as a by-product. The shell and the kernel have approximately the same weight. However, the shell is usually burned, or occasionally ground for use in the cosmetic industry or filters. Almond shell is a porous, hard, lignocellulosic, and a renewable resource. Particleboard industry is considered for sustainable, higher value-added, and environmentally lower-impact use of this resource. For this purpose, a detailed literature review was conducted, and the reviewed studies were compiled and summarized. The literature review reveals numerous studies on the re-evaluation of shells of hard-shell nuts as materials for various industrial sectors. However, studies on almond shells are limited in number. After the literature review and conceptualization stages, particleboards with different densities and almond shell contents were produced using almond shell particles. The thermal conductivities of the boards were determined experimentally. The thermal conductivity value increases with the increase in board density. The almond shell content, however, exhibits different effects depending on the board densities. The smallest thermal conductivity value obtained in the study was 0.07 W/m∙K, while the highest value was found to be 0.19 W/m∙K. Although the study was conducted with a constant temperature difference, the thermal conductivity value increases with increasing temperature values.