Design of slurry bed reactor processes in heavy lifting as if it were refining technology
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This post was last edited by zhuheqing on 2024-7-11 at 10:27. The slurry-bed residue hydrogenation tubular reactor is designed as a circulating reactor; its characteristics of high liquid holdup, high mixing, homogeneous catalysis, and high gas flow rate result in a large height-to-diameter ratio (7–10) for the reactor as well as few internal components. In this reactor, the gas acts as the continuous phase while the liquid is the dispersed phase. The gas residence time is related to the gas flow rate and the reactor height; high mixing leads to no precise value for the liquid residence time, and this is generally considered an idealized assumption. The volume of the slurry bed reactor is proportional to the amount of feed liquid phase it contains, inversely proportional to the reaction kinetics constant r (which is related to the reaction activation energy and reaction order, and indicates the number of moles of reactants converted per unit time per unit volume of the reactor), and proportional to the degree of lightening of the residue oil (0.9–0.94). The square of the diameter of the slurry bed reactor is proportional to the gas feed rate, and inversely proportional to the gas flow velocity (0.02–0.03 m/s). The above design is based on the diameter and height of the fixed-type reactor; if, under unchanged conditions regarding the properties of the raw materials and operating conditions, the processing capacity of the facility is increased by 20%, then at least the total volume of the reactor needs to increase by 20%, and its diameter needs to increase by 9% ； The reaction conversion rate can be reduced from 0.94 to 0.9, and the reactor volume can be decreased by 95.7% ； If the feed asphaltenes, particularly those with island structures, increase, the reaction activation energy rises, the reaction orders for hydrogen and residue increase, the kinetic constants drop sharply, and a larger effective volume of the reactor will be required.
In fact, the core of a slurry-bed hydrogenation reactor lies in the \"three transfers and one reaction\" – namely momentum transfer, mass transfer, heat transfer – as well as the research and application of reaction mechanisms (such as activated hydrogen overflow). It represents the cutting-edge technology for upgrading heavy oil into lighter fractions.
Indeed, the core of the design and operation of slurry-bed hydrogenation reactors lies in \"three transfers and one reaction\", that is, precise control of momentum transfer, mass transfer, and heat transfer, as well as the understanding and application of the reaction mechanism involving activated hydrogen. In such reactors, efficient momentum transfer ensures thorough contact between gas, liquid, and solid ； Mass transfer involves the effective diffusion and dissolution between hydrogen and the oil products ； Heat transfer ensures a uniform temperature within the system, which helps to control the reaction rate and prevent localized overheating ； The reaction mechanism primarily explores how to effectively activate hydrogen and enable it to react with heavy oil molecules, thereby lightening the oil product. The application of this technology is key to improving the efficiency of heavy oil processing and product quality. .
It’s very profound, with depth, perspective, breadth, and impact!