Kinetic Desorption Algorithm for Selective Thermal Swing Desorption
DEC.KDA™
DEC.KDA™ is DEC's Kinetic Desorption Algorithm for thermal swing desorption of solvents retained on activated carbon. It interprets the relationship between thermal changes and desorption behaviour, with particular attention to desorption plateaus and kinetic transitions, to support selective release of solvent fractions rather than treating regeneration as a fixed-temperature sequence.
When optionally linked to DEC.GCX™, DEC's GC-G gas-phase gas chromatography module, the SRU can also have analytical information on which solvents are entering the adsorption system. This provides chemical composition context that can be combined with adsorption and desorption process behaviour.
What is DEC.KDA™?
DEC.KDA™ is a process-intelligence layer within DEC's Advanced Technology Platform, developed for applications in which solvent mixtures are adsorbed on activated carbon and subsequently desorbed through a controlled thermal swing.
The central concept is that temperature is not treated only as a fixed regeneration setpoint. Changes in temperature are intercepted as process information and evaluated together with the evolving desorption response. This makes it possible to recognize changes in kinetic behaviour and identify relevant desorption plateaus during the thermal swing.
From solvent composition to desorption behaviour
Industrial solvent-recovery systems can receive variable solvent loads. The identity and relative presence of the solvents entering the adsorption stage provide valuable context for interpreting subsequent adsorption and desorption behaviour.
Where GCX™ is integrated, the system can obtain gas-phase chromatographic information about the incoming solvent composition. DEC.KDA™ can then use this information as part of the wider process context while evaluating the thermal response of the activated-carbon bed.
GCX™
What is entering?
Gas-phase chromatographic information identifies or monitors the solvent composition entering the adsorption system.
PDA™
What is expected to be adsorbed?
Predictive Dynamic Adsorption evaluates dynamic adsorption behaviour and loading conditions.
KDA™
How is it desorbing?
Kinetic Desorption Algorithm interprets thermal changes, desorption response and plateau behaviour.
FTR
When full regeneration is required
Full Thermal Regeneration is a periodic regeneration concept distinct from routine selective thermal swing desorption.
The DEC.KDA™ kinetic principle
1. An adsorbed solvent mixture
Different solvents can be simultaneously retained by activated carbon. Their interaction with the adsorbent is not determined by boiling point alone. Adsorption affinity, pore structure, loading, mass transfer, moisture and operating history can influence the subsequent desorption response.
2. A controlled thermal change
During thermal swing desorption, the operating condition is changed in a controlled manner. DEC.KDA™ treats the resulting temperature variation as a process signal rather than simply as a command to reach a predetermined temperature.
3. Temperature-change interception
Temperature-change interception is a central KDA concept. The algorithm evaluates a change in thermal condition together with the resulting desorption response. The relevant information is therefore not the temperature value in isolation, but the relationship between the thermal transition and the behaviour of the adsorbed load.
4. Desorption plateau recognition
The response can pass through regions in which the thermal condition and desorption behaviour become comparatively stable. DEC.KDA™ treats these desorption plateaus as process information that can help distinguish a sustained kinetic regime from a transient thermal response.
5. Kinetic transition and selective release
Once the response indicates a transition between kinetic regimes, the thermal swing can be managed in relation to the desorption behaviour observed by the system. The objective is selective and controlled release of retained solvent fractions, not the assumption that every solvent has one fixed desorption temperature.
Temperature-response control rather than fixed-temperature regeneration
Conventional thermal regeneration can be described as a sequence of predefined operating conditions. DEC.KDA™ introduces a different control philosophy: the temperature change itself becomes an intercepted process signal.
The process question changes from “What temperature should be applied?” to “How is the adsorbent responding to the thermal change, and has the desorption response reached a meaningful plateau?”
This distinction is important when different solvents are retained simultaneously. A solvent's desorption behaviour depends on its interaction with the adsorbent and on the prevailing process condition. KDA is therefore based on the observed response of the adsorption system, not on boiling point alone.
Why boiling point alone is not enough
Boiling point is a useful property for understanding solvent volatility, but it does not fully describe the behaviour of a solvent adsorbed on activated carbon. The adsorption-desorption path can be influenced by pore structure, surface characteristics, solvent loading, co-adsorbed compounds, moisture and mass-transfer limitations.
Consequently, two solvents with different physical properties may not produce a simple one-to-one relationship between boiling point and observed desorption behaviour. DEC.KDA™ addresses this engineering reality by evaluating the kinetic response during the thermal swing.
Optional GCX™ integration: knowing which solvents are entering
DEC.KDA™ can optionally be linked with DEC.GCX™, DEC's GC-G gas-phase gas chromatography module. GCX can provide analytical information about the solvent composition entering the adsorption system, giving the SRU a direct chemical-context layer before the solvents are retained by the activated carbon.
This creates two complementary information streams:
Analytical information
GCX™ provides gas-phase chromatographic information about the solvents entering the adsorption system.
Kinetic information
KDA™ interprets the thermal response, desorption behaviour and plateau transitions of the retained load.
The combination does not imply that each solvent is assigned a universal fixed regeneration temperature. GCX provides chemical identity and composition context, while KDA evaluates actual process response.
PDA™ and KDA™: complementary process intelligence
PDA™ Predictive Dynamic Adsorption and DEC.KDA™ address different sides of the adsorption cycle.
PDA™
Focuses on the dynamic adsorption behaviour of the system, including the evolution of loading and adsorption performance.
KDA™
Focuses on the kinetic desorption behaviour during thermal swing operation, including temperature changes and plateau transitions.
Together, they support a more complete interpretation of the adsorption cycle: predict the adsorption behaviour, then interpret the desorption behaviour.
DEC.KDA™ within DEC.SRU™ solvent recovery
DEC.KDA™ is not itself a solvent recovery unit. It is an intelligence and control concept that can be integrated into an engineered DEC.SRU™ Solvent Recovery Unit architecture.
It is particularly relevant to activated-carbon systems where thermal swing desorption is used to release solvent from the adsorbent. Depending on the application, DEC.SRU™ can employ different regeneration architectures, including RSG™ TSA inert-gas nitrogen regeneration, RSV™ TSA steam regeneration, or RTV™ combined temperature and vacuum regeneration.
KDA is therefore regeneration-architecture independent at the conceptual level: its role is to interpret desorption kinetics and thermal response within the operating architecture selected for the specific solvent-recovery application.
Selective thermal swing desorption
The DEC.KDA™ process can be represented conceptually as:
Incoming solvent composition → adsorption → thermal change → temperature-response interception → desorption plateau → kinetic evaluation → selective desorption transition
When several solvents are retained on the same activated-carbon bed, the thermal swing can therefore be treated as a sequence of kinetic regimes rather than as a single undifferentiated regeneration event.
Process intelligence for changing solvent loads
Industrial emission streams are not always compositionally constant. Production campaigns, product changes, cleaning operations, raw-material changes and operating conditions can alter the solvent load presented to the adsorption system.
Where GCX is available, composition information can help establish what is entering the system. PDA can provide predictive information about adsorption behaviour, while KDA evaluates the response during desorption. This creates a technology architecture connecting incoming composition, adsorption behaviour and desorption kinetics.
Thermal swing and energy optimization
KDA's purpose is not to maximize temperature. The objective is to manage the thermal swing in relation to the desorption response. Recognizing when a desorption regime has stabilized can support a more rational decision about whether the current condition remains useful or whether the process should transition.
Actual energy performance remains application-specific and depends on solvent composition, loading, adsorbent characteristics, heat recovery, cycle design and the selected SRU architecture.
FTR and DTD™: different from routine KDA operation
FTR • Full Thermal Regeneration
FTR, Full Thermal Regeneration, should be distinguished from the selective thermal swing operation informed or controlled by KDA. FTR represents a periodic full-regeneration concept intended to restore the activated carbon more completely than a selective desorption step when the operating strategy calls for it.
DTD™ • Deep Thermal Desorption
DEC.DTD™ Deep Thermal Desorption is different again. DTD is an exceptional maintenance process, not the normal endpoint of every KDA cycle. It is applied periodically when process performance and maintenance assessment indicate the need for deeper thermal treatment of residual solvent and thermally desorbable degradation products.
KDA™
Routine kinetic intelligence
Interprets thermal changes, desorption response and plateaus during selective thermal swing desorption.
FTR
Periodic full regeneration
Provides a full thermal regeneration mode when required by the operating strategy.
DTD™
Exceptional deep treatment
A separate periodic maintenance intervention for residual and strongly retained thermally desorbable compounds.
Engineered around the adsorption system
DEC.KDA™ is part of an engineered process architecture rather than a standalone software feature. Its value depends on the characteristics of the emission stream, solvent composition, activated carbon, adsorption vessel, thermal system, instrumentation, controls and solvent-recovery objective.
This is consistent with DEC's wider engineering approach: start with the actual emission stream, evaluate the process conditions and treatment objective, and engineer the appropriate technology architecture. The DEC.SRU_RSG™ platform is particularly relevant where mixed or water-sensitive solvents are recovered using inert-gas regeneration.
Industrial applications
DEC.KDA™ is relevant wherever activated-carbon adsorption and thermal swing desorption are used for solvent recovery or VOC control and where solvent composition and desorption behaviour can vary during operation.
- Flexible packaging and rotogravure printing
- Flexographic printing and converting
- Coating and lacquering processes
- Adhesive and adhesive-tape production
- Pharmaceutical and specialty chemical processes
- Chemical processing and solvent-intensive manufacturing
- Cosmetics and formulation processes
- Polymer and resin processing
- Other industrial VOC solvent-recovery applications using activated carbon
DEC technology architecture
DEC.KDA™ fits within the DEC.ATP™ Advanced Technology Platform as a kinetic desorption technology connecting analytical information, adsorption behaviour and thermal desorption control.
GCX™
Know what enters.
Optional gas-phase chromatographic information on the incoming solvent load.
PDA™
Understand adsorption.
Predictive dynamic interpretation of the adsorption stage.
KDA™
Understand desorption.
Kinetic interpretation of thermal changes, plateaus and desorption transitions.
FTR / DTD™
Manage regeneration strategy.
Periodic full regeneration and exceptional deep thermal treatment are kept distinct from routine KDA operation.
Key advantages of DEC.KDA™
- Kinetic: evaluates desorption behaviour rather than relying on volatility alone.
- Response-driven: intercepts temperature changes as process information.
- Plateau-aware: recognizes comparatively stable desorption regimes and kinetic transitions.
- Composition-aware: can optionally use GCX™ information on the solvent load entering the adsorption system.
- Integrated: complements PDA™ and DEC.SRU™ solvent-recovery technologies.
- Architecture-independent: can be considered within different thermal regeneration configurations according to application requirements.
- Engineering-oriented: connects process information with the actual adsorption and desorption system.
Related DEC technologies and technical resources
- DEC.ATP™ • Advanced Technology Platform
- PDA™ • Predictive Dynamic Adsorption
- HSU™ • Hybrid Sorption Unit
- SRU™ • Solvent Recovery Units
- RSG™ • TSA Inert Gas Nitrogen Regeneration
- RSV™ • TSA Steam Regeneration
- RTV™ • T+VSA Vacuum Regeneration
- ACA™ • Activated Carbon
- Activated Carbon Performance
- Adsorption & Desorption Concepts • DEC APC Glossary
- Solvent Recovery Engineering Guide • VOC Emission Control
- DTD™ • Deep Thermal Desorption
FAQs • Frequently Asked Questions
DEC.KDA™ FAQs
What is DEC.KDA™?
DEC.KDA™ is DEC's Kinetic Desorption Algorithm for interpreting thermal changes, desorption response and kinetic plateaus during selective thermal swing desorption from activated carbon.
What does KDA intercept during thermal swing desorption?
KDA intercepts changes in the thermal condition and evaluates them together with the evolving desorption response. The purpose is to identify meaningful kinetic transitions and desorption plateaus rather than treating temperature only as a fixed setpoint.
What is a desorption plateau?
A desorption plateau is a comparatively stable region of the thermal and desorption response. DEC.KDA™ uses plateau behaviour as process information when evaluating whether a kinetic regime is sustained or whether the system is moving toward another desorption condition.
Why is boiling point alone not sufficient for selective desorption?
Boiling point describes volatility, but adsorption and desorption from activated carbon are also influenced by adsorbent structure, adsorption affinity, loading, co-adsorbed compounds, moisture and mass-transfer effects. KDA therefore focuses on the observed kinetic response during the thermal swing.
How does optional GCX™ integration improve the process information?
GCX™, DEC's GC-G gas-phase gas chromatography module, can provide information about the solvent composition entering the adsorption system. KDA can then combine this chemical-context information with the observed thermal and desorption response of the activated-carbon bed.
What is the difference between PDA™ and KDA™?
PDA™ focuses on predictive dynamic adsorption behaviour, while KDA™ focuses on kinetic desorption behaviour during thermal swing operation. Together they address complementary sides of the adsorption cycle.
Is KDA™ a type of activated carbon?
No. DEC.KDA™ is a process-intelligence and control concept. It does not replace the activated-carbon adsorbent or the physical SRU equipment.
Is KDA™ the same as thermal regeneration?
No. KDA™ is the kinetic desorption intelligence applied to the thermal swing. It interprets process response and supports the management of desorption conditions; it is not itself a regeneration medium or physical regeneration unit.
What is FTR in the DEC adsorption architecture?
FTR means Full Thermal Regeneration. It is a periodic full-regeneration concept and should be distinguished from routine selective thermal swing desorption informed or controlled by KDA™.
How is DTD™ different from KDA™ and FTR?
DEC.DTD™ Deep Thermal Desorption is an exceptional periodic maintenance process for deeper thermal treatment of residual solvent and thermally desorbable degradation products. It is not the normal endpoint of every KDA cycle. FTR is the full thermal regeneration concept, while KDA is the kinetic desorption intelligence used during thermal swing operation.
Can DEC.KDA™ be integrated into a DEC.SRU™?
Yes. KDA™ is intended as an intelligence layer within an engineered solvent-recovery architecture. It can be considered with DEC.SRU™ activated-carbon systems and the regeneration configuration selected for the specific application.
Does KDA™ assign one fixed temperature to each solvent?
No. The KDA concept is specifically based on kinetic response rather than a universal fixed-temperature table. Actual desorption behaviour depends on the solvent, adsorbent, loading and operating conditions.
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