Solvent Recovery Unit | activated carbon | Nitrogen regeneration • SRU RSG™ • DEC

Solvent Recovery Unit • activated carbon
Nitrogen regeneration (TSA) | DEC.RSG™ | DEC.SRU™

Solvent Recovery Units, based on activated carbon adsorption, hot inert gas (N₂, Nitrogen) regenerated, are using a core technology which has been proven in thousands industrial applications, treating variable volumes of gaseous effluent (typically 5.000 ÷ 1.000.000 Nm³⁄h); the regeneration of the adsorption media (activated carbon) is using Nitrogen as desorption media [DEC.RSG™ process, alternating different phases, as adsorption and TSA (thermal swing) regeneration, with N₂, Nitrogen desorption], determining this process to be the ideal choice and the top performer when dealing with variable SLA volumes and variable (low-medium-high) concentrated VOC streams (mono and multi-solvent).

Back in 1980s, DEC developed its own revolutionary steamless technology (DEC.RSF™) for regenerating the adsorbent, using an inert gas. Today, this legacy lives-on in the powerful DEC.RSG™ (and its versatile high performance variant DEC.RSX™). With hundreds of successful applications across diverse industries and continents, DEC.RSG™ tackles both mono-solvent and multi-solvent systems, delivering direct recovery of anhydrous solvents with zero process water discharge.

For different process conditions, and/or type of solvents, and/or SLA flowrates, please check the available solvent recovery processes.

challenging solvent recovery made possible

Azeotropes, where solvents and water mix inextricably (binary and ternary - e.g. acetates and alcohols ), often pose a recovery challenge: DEC.RSG™ steps in as a game-changer, allowing the direct recovery with a no compromise purity. With its ability to tackle azeotropes and various miscibility challenges, DEC.RSG™ redefines solvent recovery allowing the application of this sustainable solution to a wide range of industrial applications.

The DEC.RSG™ process also represents the solution for the recovery of problematic solvents (due to their volatility, flammability, or reactivity), which are deemed "NOT RECOVERABLE" or "DANGEROUS": DEC.RSG™ can handle solvents that other conventional methods might struggle with, expanding your recovery options. Typical application, is the recovery process of ketones (such as MEK - methylethylketone): check for our DEC.FPS™ process control modules.

The Technology Readiness Level (TRL) of DEC SRUs equipped with DEC.RSG™ process reached a high level of maturity, classified nowadays as TRL 9 (actual system proven in operational environment, according to ISO 16290:2013): the DEC.SRU™ technology is commercially available and has been proven to work effectively in real-world applications.

the solvent recovery process: how it works?

Here is a simplified overview of how an activated carbon solvent recovery plant DEC.RSG™ (SRU | SRP | SRS) works:

Filtration: the SLA is filtered to remove most of the particulate matter; this is important to prevent the particulate matter from clogging the adsorption bed in the static concentrator;

Temperature control: the SLA is temperature-controlled to ensure that it is at the optimal temperature for adsorption; the optimal temperature will vary depending on the type of solvents being removed and the desired adsorption efficiency;

Adsorption: the SLA is driven through the static concentrator to adsorb the solvents; the activated carbon in the static concentrator adsorbs the solvents, thanks to its large surface area and variable porous structure;

Regeneration: once an AC adsorber is saturated with solvents, it is taken offline and regenerated; in-situ regeneration is used to (desorb) drive the solvents off of the activated carbon; a hot inert gas (Nitrogen, N₂) flow, in a closed loop circulation, gives heat to the activated carbon bed, desorbing the solvents.

Condensation: the desorbed solvents are condensed in a heat exchanger, recovered in a tank;

Reuse: the recovered solvents can then be reused in the production process.

hydrolysis minimized, recovery maximized

DEC.RSG™'s "dry" Nitrogen-based desorption process ensures a negligible impact from hydrolysis reactions, safeguarding solvent integrity and purity for unprecedented recovery efficiency.

direct anhydrous recovery of solvents

DEC.RSG™ units can be equipped with DEC's exclusive gas-phase pre-dehydration process, based on DEC's exclusive selective desorption algorithm (DEC.PHD™): this innovative process offers the advantage of directly recovering a mixture of solvents with an extremely low water content, without the drawbacks of condensing / freezing important quantities of water, delivering outstanding energetic advantages and avoiding waste-water (contaminated by solvents) disposal or additional treatment, minimizing operational and environmental impact.

For increased dehydration performances, additional modules are available [see dehydration modules (DEC.ADM™) and/or distillation systems (DEC.DST™)].

The Solvent Laden Air (SLA) stream processed by the SRU carries not only VOCs but also water vapor (humidity), typically ranging from 5 ÷ 18 g/m³ depending on season and location. Partial adsorption of humidity on the activated carbon, can affect the purity of the recovered solvent: DEC.RHC™ modules address this challenge by reducing the impact of humidity and optimizing energy consumption.

best-in-class recovery efficiency

Not only does DEC.RSG™ offer exceptional solvent recovery rates (ultra-low TVOC stack emissions), but it also stands as a beacon of sustainability. Its innovative design achieves the lowest emission values in the industry, ensuring minimal environmental impact, and compliance with any global VOC emission standards. This means you can protect the planet, while maximizing your solvent recovery, achieving a recovery yield of up to 99% or more.

Reduced air pollution: minimized emissions contribute to cleaner air quality and a healthier environment;

Enhanced compliance: Meet stringent environmental regulations with confidence, demonstrating your commitment to sustainability;

Optimized resource use: Recover more solvents, reducing waste and conserving valuable resources.

best-in-class energy efficiency

Efficient DEC.ERS™ (Energy Recovery Systems) are available, to lower operating costs (OPEX): check DEC.ULP™ (Ultra-Loop) modules, for more details.

DEC.RSG™ with DEC.ULP™ (Ultra-Loop) modules delivers unmatched operational and maintenance cost savings compared to any other technology on the market: up to a 30% reduction in O&M costs compared to traditional solvent recovery methods.

simplicity meets power: expert performance, without complexity

While DEC.RSG™ solvent recovery units boast advanced technology and impressive capabilities, their operation and maintenance remain surprisingly straightforward. You don't need a team of dedicated specialists to harness its power. DEC SERVICE remotely monitors your SRU, ensuring optimal performance and freeing your resources for other priorities. This seamless remote support (DEC.HDS™) allows you to run the SRU efficiently with minimal operator involvement. It's a testament to DEC's commitment to making cutting-edge technology accessible and user-friendly, letting you focus on what matters most while your SRU quietly delivers exceptional performances.

choose from our Smart Modular or Custom Built Systems

DEC Solvent Recovery Units (SRUs) are available in both skid modular layout (DEC.SMS™ • Smart Modular Systems, pre-built and pre-tested at our workshops) or in full customizable version (DEC.CBS™ • Custom Built Systems, with on-site erection).

get a free consultation

If you are looking for a reliable and efficient solvent recovery unit, DEC.SRUs™ (Solvent Recovery Units) are the right and best option: DEC.SRUs™ are the most advanced and reliable Solvent Recovery Units on the market, with processes, configurations and options to meet the needs of different applications, present and future challenges.

Contact DEC for a free consultation: we can help you assess your needs and recommend the best SRU for your operation.