2002 Volume 81 Issue 1 Pages 38-48
Solid particles, accumulated or deposited in the reactors, hot-highpressure separator (HHPS) and downstream transfer lines of the letdown valve (LDV) were observed after long continuous operation of a 150t/d Pilot Plant of Coal Liquefaction at Kashima.
During the operation, two types of solid particles were produced, i.e., particles with cores, and particles without cores. The average size of the former particles was 10-200μm, while that of the latter particles was 1-80μm. The size of the core, included in the larger particles, was as equivalent in size to that of the smaller particles without cores. The cores, as well as the particles without cores, were largely composed of SiO2, with lesser amounts of FeS and CaCO3. These materials were probably formed from coal minerals and catalyst.
It is to note that the particles of 10-100μm in the reactors were missed after a long operation. These results suggested that the fine particles are produced in the reac-tor, flow out from the reactor before their size reach to 10-100μm, or increase their size above 100μm to be accumulated or deposited within the reactor. The mineral particles found in the HHPS and downstream transfer lines of LDV were basically same to those found in the reactor, those of high gravity being deposited on the wall together with heavy oil to be coagulated solid.