Stages of destruction and elastic compression of granular nanoporous carbon medium at high pressures

TL;DR

This study investigates the high-pressure behavior of granular nanoporous carbon, identifying eight stages of volume change, including destruction and elastic compression, with implications for improving nuclear plant air filters.

Contribution

It provides a detailed analysis of the pressure-dependent stages of volume change in nanoporous carbon, highlighting elastic and destructive phases at nanoscales.

Findings

Eight stages of volume change identified

Linear dependence on double log plot for each stage

Elastic compression observed without structural disintegration

Abstract

The granular nanoporous carbon medium, made of the cylindrical coal granules of the adsorbent of SKT 3, at an influence by the high pressures from 1MPa to 3GPa has been researched. The eight consecutive stages of the materials specific volume change, which is characterized by a certain dependence of the volume change on the pressure change, have been registered. It is shown that there is a linear dependence on the double log log plot of the materials specific volume change on the pressure for an every stage of considered process. The two stages are clearly distinguished such as a stage of materials mechanical destruction, and a stage of elastic compression of material without the disintegration of structure at a nanscale. The hysteresis dependence of the materials specific volume change on the pressure change at the pressure decrease is observed. The small disperse coal dust particles jettisoning between the high pressure cell and the base plate was observed, resulting in the elastic stress reduction in relation to the small disperse coal dust particles volume. The obtained research data can be used to improve the designs of air filters for the radioactive chemical elements absorption at the NPP with the aims to protect the environment.