Is the slurry in a slurry bed the \"boss\"?

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The slurry in the hydrotreatment of residue in a slurry bed process is truly the ‘boss’ – it’s prone to anger and difficult to deal with! To understand this \"sir\" properly, let’s start with the term \"slurry\". Slurry means \"paste\" + water; as a noun, it refers to a viscous liquid, and as a verb it has the same meaning as \"paste\". This characteristic is particularly prominent in the hydrogenation of slurry-bed residue oil. Starting with the term “elderly man”: the slurry bed inside the reactor serves as the environment in which the catalysts are suspended, and it is responsible for the gradual removal of asphaltenes. In the absence of hydrogen, these substances tend to settle and aggregate, and at high temperatures they condense at the bottom of the reactor, forming a \"second liquid phase\" (commonly referred to as sludge or paste). Therefore, restoring hydrogen supply as soon as possible is essential in case of an accident; otherwise, the consequences can be severe and difficult to control. It’s best to regularly remove the sludge from the bottom of the reactor on a regular basis. As for the \"second stage,\" at high temperatures the slurry is subjected to primary high-temperature flashing; the hydrogen-saturated slurry phase increases the likelihood of asphalt nuclei aggregating, making it more difficult to handle. This requires short residence times, high flow rates, rapid washing, quick cooling, and swift pressure reduction – otherwise the components will really stick together. Finally, there is the \"Third Master\", whose nickname is \"Oil Dregs\". It undergoes self-polymerization and deposition-coking as a result of pressure reduction to remove dissolved hydrogen, along with dehydration and condensation driven by its own metallic catalytic effect. At low temperatures, it tends to dry out and become rigid, turning into semi-coke and losing its fluidity permanently; therefore, it requires heating oil at 220°C to maintain proper conditions, while also ensuring continuous circulation in the storage tank and thorough mixing without any dead zones. The three gentlemen each have different temperaments; if not served well, they stop doing their tasks properly and even cause trouble inside the pipes and equipment. Therefore, when those pipes and equipment are taken out of use, they must be cleaned with oil right away, thoroughly and completely.