Solid-liquid Extraction [verified] -

Here’s a comprehensive list of features related to solid-liquid extraction (also known as leaching), covering process characteristics, equipment types, operational parameters, and applications.

1. Core Principles & Mass Transfer Features

Selective dissolution – Target solute transfers from solid to solvent while insoluble matrix remains. Driving force – Concentration gradient between solid surface and bulk liquid. Equilibrium limitation – Maximum extraction limited by solute solubility in solvent. Rate-controlling steps :

Washing of solute from surface Diffusion through solid pores Diffusion through boundary layer Chemical reaction (if applicable) solid-liquid extraction

2. Key Process Parameters (Operational Features) | Parameter | Feature Description | |-----------|----------------------| | Temperature | Increases solubility and diffusion rates (but may degrade thermolabile compounds) | | Solvent type | Polarity, pH, viscosity, toxicity, and selectivity (e.g., water, ethanol, hexane) | | Particle size | Smaller particles increase surface area but may cause compaction or fines | | Solvent-to-solid ratio | Higher ratio improves yield but increases downstream evaporation load | | Agitation/mixing | Reduces boundary layer thickness; essential for suspended solids | | Extraction time | Longer time increases yield up to equilibrium; may extract undesired compounds | | Pressure | Used in pressurized liquid extraction (e.g., PLE, ASE) to keep solvent liquid above boiling point |

3. Equipment Features (Batch & Continuous) Batch extractors

Simple maceration vessel – Low cost, long time, no agitation. Stirred tank extractor – Agitation, heating jacket, often used with filtration. Soxhlet extractor – Continuous recycling of solvent; high efficiency but slow. Here’s a comprehensive list of features related to

Continuous extractors

Rotating drum extractor – Solid moves through solvent spray; good for coarse solids. Basket/belt extractors – Perforated belt carries solids through countercurrent solvent zones. Screw conveyor extractor – Solids transported by screw while solvent flows opposite. Column extractor (fixed or moving bed) – Efficient countercurrent operation; common in sugar and oil industries.

4. Process Intensification & Advanced Features Key Process Parameters (Operational Features) | Parameter |

Ultrasound-assisted extraction – Cavitation disrupts cell walls, improves mass transfer. Microwave-assisted extraction – Rapid internal heating; reduces time and solvent use. Supercritical fluid extraction (e.g., CO₂) – Tunable selectivity, no solvent residue. Pressurized liquid extraction – High temperature and pressure; fast and automated. Enzyme-assisted extraction – Enzymes break down cell walls (e.g., pectinase, cellulase).

5. Downstream Integration Features