A high-temperature and high-pressure cell for in situ visualization of reaction processes by neutron imaging

Jun Abe; Yoshihiro Matsumoto; Tsukasa Miyazaki; Takashi Noma

doi:10.1063/5.0159685

A high-temperature and high-pressure cell for in situ visualization of reaction processes by neutron imaging

Rev Sci Instrum. 2023 Aug 1;94(8):083904. doi: 10.1063/5.0159685.

Authors

Jun Abe¹, Yoshihiro Matsumoto¹, Tsukasa Miyazaki¹, Takashi Noma¹

Affiliation

¹ Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai, Ibaraki 319-1106, Japan.

PMID: 38065167
DOI: 10.1063/5.0159685

Abstract

This study developed a high-temperature and high-pressure (HTHP) cell for in situ neutron imaging of hydrothermal reactions. The cell's maximum temperature and pressure were 500 °C and 50 MPa, respectively, and its vessel for observing reactions comprised SUS316 stainless steel. Neutron transmission images were obtained to observe the behavior of sub- and supercritical water and the decomposition of two plastics (polypropylene and polyethylene) at HTHP. The images showed that water's density and phase changed with temperature and pressure, affecting neutron transmission (and thus image brightness). The plastics began to melt and change shape at 150-200 °C, and they decomposed at 500 °C and 20 MPa. This study provides a basis for future research using the HTHP cell to examine various reactions such as the decomposition of biomass samples, the reforming of heavy oil, and the synthesis of nano-materials using sub- and supercritical water.