Continuous fluid solids processes, such as fluidized coking of hydrocarbons, are used in many industrial processes. For example, heavy hydrocarbons are sometimes treated by a coking process to thermally crack and separate the hydrocarbon into lighter, more desirable components. Some of these coking processes are done using a continuous fluid coking process. In these processes, it is often desirable to obtain samples of the fluid solids to determine how the process is operating, to optimize variables in the process such as heat, to diagnosis of problems with a process, etc. However, obtaining such a sample is usually not just a straightforward process of obtaining some of the fluid solids.
For example, in a fluid coking process for hydrocarbons, typically a reactor or coker containing fluidized hot coke particles is used to treat an incoming feed of hydrocarbon. The hydrocarbon introduced into the coker is thermally cracked by the heat provided by the hot coke and more desirable components of the hydrocarbon are separated out. Typically, the coker is operated at a temperature of about 530° C. Coke particles formed during the process are generally coated with residual hydrocarbons and are therefore removed from the coker to a heater or burner where the coke particles are heated to remove this hydrocarbon coating. A portion of the coke particles heated in the burner are then recirculated back to the coker.
The coke that is heated in the burner is typically heated to 550° C. or more before it is transported back to the reactor vessel (coker). The heated coke is then passed back into the reactor where, with the addition of steam, a bed of fluidized coke is formed in the reactor. In operation, a feed, such as a heavy hydrocarbon like bitumen, is introduced into the reactor and placed in contact with the bed of fluidized coke. The heat from the heated coke causes some of the feed to be vaporized, while some of it is deposited on the coke particles and undergoes thermal cracking. This material on the coke particles cracks and vaporizes leaving a residue on the coke particles that dries to form coke. The coke particles used in the process will eventually form a number of layers like an onion, as hydrocarbon forms on the coke particles and forms more and more layers of coke.
During the fluid coking process, it is often desirable to obtain a sample of coke to determine the operating conditions in the reactor, burner, etc. However, the sample of the coke will typically be at an elevated temperature (i.e., greater than 500° C.) and will usually contain hydrocarbon. However, by withdrawing some of the hot coke into a sample container and letting it cool naturally, this can result in the coke sample to continue with the thermal cracking of any hydrocarbon present in the sample. This can result in the obtained sample having much different characteristics by the time it is tested than the sample that was originally collected.