The invention pertains to a compact, single or multistage vapour recompression system and process for efficient solvent recovery from liquid or solid feedstocks. The system features jacket-insulated horizontal extraction chambers equipped with rotating contacting disks, screws, or stationary multi-level heat transfer elements to enhance mass and heat transfer. Vapourised solvent is compressed using oil-free devices capable of two-phase compression, and the recovered vapour is condensed via integrated heat exchange. This modular system enables continuous or batch-wise operation with improved energy efficiency, reduced complexity, and suitability for sensitive applications like food and pharmaceuticals.
Figure (1) EEJM Bench Scale Unit v3 with reciprocating compressor capacity 0.5 kg/h jaggery making (Raw juice flow rate 2 kg/h, working 360 rpm, Cylinder bore 32 mm, Stroke length 160 mm, Gear ratio 5:1, Weight 44 kg); (2) EEJM with Two-Stage Regenerative Turbine Blower capacity 8 kg/h jggery making (Raw juice flow rate 36 kg/h, Heat exchanger size ~315 mm x 315 mm x 3,150 mm long, Compressor power 0.75 kW)
Conventional vapour recompression systems for solvent recovery suffer from high energy consumption, complex configurations, and the use of oil-lubricated compressors, limiting their applicability in sensitive sectors like pharmaceuticals and food processing. They are often incapable of handling wet compression, require additional gas-liquid separators, and perform inefficiently with high-viscosity or crystallizing feedstocks.
There is a need for a simplified, energy-efficient, oil-free vapour recompression solution that can operate effectively across diverse feed conditions and enable continuous solvent recovery.
- High Energy Efficiency: The internal heat recovery exchangers and staged compression reduce energy demand and rotating contacting disks enhance heat and mass transfer, reducing process time.
- Low Operating and Capital Costs: This invention reduces the need for auxiliary equipment like gas-liquid separators, external condensers, or complex piping.
- Versatility across Feed Types and Industries: It is capable of handling two-phase (vapour + liquid) streams without wet compression issues, suitable for high-viscosity, crystallizing, solid-forming feeds and also oil/lubricant-free compression which avoids contamination.
- Continuous and Flexible Operation: It has multi-stage compression with adjustable pressure ratios that accommodates changing feed concentrations. It also allows continuous processing without harsh thermal cycling or batch-mode inefficiencies, and optional inert gas integration supports low-oxygen or anaerobic processing.
- Improved Safety and Environmental Compliance: It ensures no fuel firing or open flames; entirely enclosed process eliminates operator exposure. The system operates on photovoltaic power so a solar-powered compressor reduces carbon footprint.
The prototype consists of at least two horizontal extraction chambers, each equipped with a rotor having rotating contacting disks or a screw for enhanced heat and mass transfer. Feedstock is preheated using an internal heat recovery exchanger. Vaporized solvent is extracted and compressed by a pressurizing device, then condensed via heat transfer jackets on the extraction chambers. The system operates in multiple stages with vapour compression and solvent recovery repeated sequentially to maximize solvent extraction efficiency. Vacuum breakers introduce inert gas to assist temperature rise and vaporization.
Preconcentration of sugarcane juice is demonstrated using the single-stage Vapour recompression system. A demonstration project can be initiated for a specific application and to confirm the techno-economic benefits. After successful trials, the technology can be licensed.
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The multistage vapour recompression system significantly reduces reliance on fossil fuels and improves energy efficiency, leading to lower environmental impact. Its compact, mobile design enables affordable and decentralised processing, especially beneficial for rural and small-scale producers. The technology enhances workplace safety by eliminating exposure to open flames and harsh conditions.
- Food processing
- Pharmaceutical
- Agro-based industries
- Chemical engineering
- Crystallising feedstocks
- Waste management and solvent recovery
Geography of IP
Type of IP
201721008251
383112