I. Process Conditions (Intermittent Production)

Raw materials: 40-50% aqueous glucose solution, pH = 6-7, with a charge of 60-70% of the vessel volume

Catalysts: Raney nickel (mainstream), ruthenium-based catalysts

Operating temperature: 120-150°C

Operating pressure: 3.5-10 MPa, typically 4-7 MPa in industry

Reaction time: 1-3 h; endpoint: no further hydrogen absorption, residual sugar ≤ 0.5%

Operating procedure: N₂ displacement of air → H₂ displacement of nitrogen → heating and pressurizing → stirring and hydrogenation → cooling and depressurizing → discharging the material and separating the catalyst.

II. Core Structure and Key Components

Vessel body and head

Pressure vessel with a large flange opening for easy maintenance and catalyst loading and unloading; nozzles include hydrogen inlet, feed, discharge, vent, sampling, and temperature and pressure measurement ports.

Sealing System (Top Priority)

Industry universally adopts magnetic coupling static seals with no mechanical seal, eliminating the risk of hydrogen leakage and explosion; essential for high-pressure hydrogenation.

Mixing System (determines production capacity)

The self-priming hollow-shaft impeller (specific to sorbitol reactors) draws hydrogen from the upper part of the vessel into the liquid phase, breaking it into fine bubbles and intensifying gas-liquid-solid mass transfer; an ordinary impeller gives low hydrogenation efficiency and a long reaction time.

Stirring speed: 80-220 r/min; explosion-proof variable-frequency motor, DIICT4.

Heat Exchange System

Jacket/half-pipe: Steam heating raises the temperature; cooling water is circulated to remove the strong heat of the hydrogenation reaction.

Some large reactors are fitted with internal cooling coils to control the temperature quickly and prevent runaway.

Discharge method: The material is discharged by the residual pressure in the vessel; catalyst settling and filtration connections can be provided at the bottom.

Safety interlocks: overpressure alarm interlock, overtemperature interlock, pressure transmitter, safety valve, rupture disc, hydrogen alarm.

III. Commonly Used Materials (Product-Contacting Parts)

Small and medium reactors: 316L (S31603) stainless steel

Large-scale industrial units (5-20 m³): Q345R + 316L clad steel plate (to reduce cost)

Special operating conditions: Hastelloy C276 can be selected for ruthenium catalyst service; ordinary carbon steel must not come into direct contact with the sugar solution.

IV.Mainstream Specifications (Industrial)