Engineering approach for industrial VOC recovery systems, including solvent selection, operating conditions, absorber/stripper design and heat integration.

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Engineering approach for industrial VOC recovery systems, including solvent selection, operating conditions, absorber/stripper design and heat integration.

Talk to a Process Engineer Learn More

95–99.9%Recovery efficiency

45 YrsProcess Engr. Exp

50+Industrial sites studied

500×Pilot to commercial

95–99.9%Recovery efficiency

45 YrsProcess Engr. Exp

50+Industrial sites studied

500×Pilot to commercial

01 · Why VOC Emissions Matter

An economic loss before it's a compliance one

Industrial VOC emissions contribute to air pollution, resource loss, and increasing environmental pressure. Modern regulations — enforced strictly across Europe, the US, and Japan — encourage recovery, sustainability, and efficient resource utilisation rather than simple destruction.

Recovering solvents improves both environmental performance and operating economics at once: every kilogram of solvent captured is a kilogram that doesn't need to be purchased, burned, or accounted for as a compliance cost.

The scale of the problem

Some sources emit a single solvent at modest concentration; others — gravure printing lines, paint shops, flexible-packaging plants — emit mixtures of up to six solvents at once, at flows from a few hundred to 200,000 Nm³/hr.

200,000

Nm³/hr max flow

Solvents simultaneously

<100

Nm³/hr minimum

Two approaches to the problem

Process modification

Changing or modifying the process chemistry and processing steps to reduce VOC generation at source.

End-of-pipeline treatment

Treating the exhaust stream after it leaves the process to meet emission standards without changing the upstream chemistry.

End-of-pipeline: two types

Destruction — converts pollutants to CO₂ / water to meet compliance. Nothing is recovered.

Recovery & recycle

Returns pollutants to the process or recovers them for use elsewhere — turning a liability into an asset.

Three broad technology categories

1 · Oxidation systems

Thermal or catalytic. Must operate below LEL, always require supplemental fuel (NG or LPG), and need thermal recovery — recuperative (40–70%) or regenerative (up to 95%). Achieves 95%+ destruction, but increases CO₂ / GHG output and eliminates any chance of solvent recovery.

2 · Reactive absorption

Converts pollutants into a saleable or disposable compound via liquid-phase reaction. Examples: formaldehyde → urea pre-condensates; H₂S / SO₂ → caustic soda; NOx → ammonia. Can reach non-detectable emission levels, but is chemistry-specific rather than general-purpose.

3 · Physical systems

Our approach

Capture VOCs without destroying or chemically altering them. A high-boiling absorbent dissolves VOC from the gas stream, then releases it in a stripping step for condensation and reuse.

Enables recovery. Runs at lower energy cost. Works across a broad range of chemistries.

02 · Non-Destructive Recovery Systems

Non-destructive, non-reactive systems recover and recycle the VOC as a liquid or in concentrated form — nothing is burned or chemically converted. Three principal technologies exist:

Adsorption

Gas adsorbed onto activated carbon (or zeolite / molecular sieve) beds. Near-100% removal possible. Ketones and mixed streams are problematic — high heats of adsorption risk fire. Cyclic operation requires at least two beds. High maintenance; large footprint.

Refrigeration & Cryogenic

Reduces gas temperature until VOC condenses out. As concentration falls, cryogenic temperatures may be needed. Best for high-concentration, intermittent streams — tank farms, loading stations, marine unloading. Requires only power; smallest footprint.

Physical Absorption — Genosorb®

Our technology

A high-boiling PEG ether absorbent dissolves VOC at ambient conditions, then releases it in a stripping column for condensation and reuse. Ambient temperature, low pressure, no carbon beds, no periodic replacement. Works across polar, non-polar VOCs and gases such as CO₂, H₂S and SO₂.

Table 1 — Comparison among non-destructive technologies

Parameter	Refrigeration	Absorption ✦	Adsorption
Process	Condensation	Separation and condensation	Separation and condensation
Operating temp.	Very low temp.	Ambient or below ambient	Ambient and above
Pressure	Very low	Low	High
Vacuum	Not required	Optional	Required
Operations	Automatic / continuous	Automatic continuous	Automatic batch process
Maintenance	Low	Low	High
Power cost	On demand only	Even at no load	Even at no load
Installation cost	Very low	Low	Large
Conc. measurement	Not required	Required (outlet)	Required (outlet)
Space	Smallest	Small	Large
Steam	Not required	Required	Required
Inert gas	Not required	Special circumstances	Required for safety
Carbon replacement	Not required	Not required	Periodic replacement

✦ Genosorb® physical absorption — recommended for mixed-solvent, continuous-process streams.

03 · Why Recovery Is Better Than Destruction

Lower raw material costs

Recovered solvent goes straight back into production instead of being purchased fresh.

Lower greenhouse gas emissions

~1.315 kg CO₂-equivalent avoided per kg of VOC recovered, net of the recovery process's own utility inputs.

Reduced operating cost

No supplemental fuel requirement of the kind oxidation needs. Genosorb make-up loss as little as 2% of inventory per year.

Resource conservation

Solvent that would otherwise be lost to atmosphere or converted to waste heat is kept in productive use.

Circular economy support

Turns what used to be an emissions liability into a recurring, reusable input stream.

04 · Why Genosorb

Most of the physical absorbents are specific for a few VOC or for gases like CO₂, H₂S etc. Apart from single solvents recent work is reported on use of deep eutectic solvents (DES) and ionic liquids; they are still to reach commercial scale.

The desired properties would be high affinity for the VOC to be recovered, high boiling point so that separation can be done easily and the product will not be contaminated, low viscosity so that heat and mass transfer is not hindered, and low heat capacity to lower the energy needs. A low surface tension is desirable as it makes for easy spreading — a larger surface area is obtained in the mass transfer equipment. High selectivities can be an advantage as separation of VOC is possible.

VOCs to be recovered have wide-ranging chemical and physical properties such as boiling point and polarity — there may not be a single "one size fits all" solvent. Among glycol ethers, Clariant A.G. has developed a range of polyethylene glycol ethers under the brand Genosorb® — mixtures of varying chain lengths tuned for polar and non-polar VOC as well as gases like CO₂, H₂S and SO₂. Various inhibitors prevent oxidation and give a long life. All Genosorbs have good affinity for water, so the treated gas gets dehydrated.

Engineered for the job

Genosorb is a family of polyethylene glycol ether absorbents developed by Clariant A.G., engineered specifically against the properties that make a physical absorbent effective.

Boiling point

Absorbent stays liquid through stripping — no loss alongside the VOC

>250 °C

Vapour pressure

Minimal absorbent carryover into the treated gas stream

<0.002 mbar

Density at 20 °C

Stable across operating temperature range

0.93–1.03 g/cm³

Viscosity at 20 °C

Moderate — keeps heat and mass transfer efficient

4–7 mm²/s

Specific heat

Well-understood thermal behaviour for heat-integration design

2.13–2.26 J/g·K

Thermal conductivity

Supports efficient inter-stream heat exchange

0.149–0.169 W/m·K

Annual make-up loss

Inhibitors prevent oxidation; long service life

~2% of inventory

Genosorb Grades

Grade	Target	Examples
Genosorb 300	Polar solvents	Alcohols, ketones, esters, ethers
Genosorb 1843	Non-polar solvents	Aliphatics, aromatics, chlorinated
Genosorb 1753	H₂S / CO₂	Biogas upgrading, sour gas
Genosorb 1900	SO₂	Sulphur dioxide capture

Simultaneous dehydration

Genosorb's strong affinity for water means the treated gas stream comes out dehydrated as a side benefit of VOC removal — no extra process step required.

05 · Circular Economy

Large-scale chemical plant

Skid-mounted recovery unit

Industrial absorption facility

3-D process model

Lower greenhouse gases

Recovery avoids the combustion CO₂ that destruction technologies generate. Documented net reduction: ~1.315 kg CO₂-equivalent per kg of VOC recovered.

Resource conservation

Solvent that would otherwise be lost to atmosphere is captured and returned to productive use rather than purchased as fresh raw material.

Circular manufacturing

Recovered solvent goes directly back into the same process it came from, closing the loop rather than creating a one-way waste stream.

Reduced waste

Applies equally to VOC-laden effluent water — COD loads cut by over 99% through stripping and recovery, from ~200,000 to under 1,000 in pilot runs.

ESG performance

Measurable emissions reductions and resource-efficiency gains translate directly into environmental, social, and governance reporting metrics.

06 · How the Process Works

Gas enters absorber

VOC-laden process gas is fed into the absorption column at ambient or below-ambient temperature.

Genosorb absorbs VOCs

The liquid absorbent contacts the gas and dissolves the VOC out of it, driven by Genosorb's high affinity for the target compound(s).

Clean gas exits

Treated gas — now within emission-compliant VOC levels and incidentally dehydrated — is released or sent onward.

Rich solvent regenerated

The VOC-loaded absorbent is pumped to a stripper column and heated, driving the VOC back out of solution.

Solvent condensed

The now-concentrated VOC vapour leaving the stripper is easily condensed into recoverable liquid product.

Genosorb recycled

The lean, regenerated absorbent is cooled and returned to the absorber, with heat exchanged between rich and lean streams and pressure energy recovered via turbine pumps.

General flow sheet for Genosorb VOC recovery system

Energy conservation

Heat is exchanged between the VOC-rich stream heading to the stripper and the lean stream returning to the absorber, cutting the net energy purchased. Pressure energy between the two columns can be recovered with turbine pumps.

07 · Engineering Design

Every Genosorb installation is engineered around six interlocking variables — not a one-size-fits-all skid.

NE Isometric · 3-D Plant Model

Solvent selection

Matching the Genosorb grade or blend to the specific VOC mixture, since affinity varies by compound class.

Temperature

Absorber and stripper each run at temperatures chosen to maximise absorption on one side and clean regeneration on the other.

Pressure

Absorption and stripping can run at different pressures as well as temperatures — sometimes both — to optimise separation.

VOC concentration

Inlet concentration drives sizing decisions; very low concentrations at high volume call for a rotary-concentrator pre-stage.

Heat integration

Exchanging heat between the VOC-rich stream heading to the stripper and the lean stream returning cuts net energy purchased.

Energy recovery

Pressure energy between the two columns can be recovered with turbine pumps, further lowering operating cost.

08 · Multiple Process Integration

One system, many sources

Multiple pieces of process equipment — batch reactors, dryers, printing stations, coating lines — can be manifolded into one centralised recovery system.

Lower capital cost

One recovery train serving several sources costs less than duplicating equipment at each point of emission.

Centralised recovery

Solvent from multiple process steps is captured and regenerated in one place rather than scattered across the plant.

Automatic operation

The combined system runs on automation rather than requiring manual intervention at each source.

Simplified maintenance

One system to maintain instead of several smaller, dispersed ones.

Plant-wide emission control

Demonstrated to maintain compliance even as individual feed flows and concentrations vary significantly across connected sources.

Connecting multiple process sources to one recovery unit

50+ sites studied

More than 50 industrial sites studied across India, with VOCs encountered individually or in mixtures of up to six components.

09 · Industries Served

ChemicalsPharmaceuticalsFlexible PackagingPaintAutomotivePetrochemicalsPrintingSemiconductorsAdhesivesBattery ManufacturingSpecialty ChemicalsAgri-processingCoatingsInk ManufacturingTextiles

VOCs encountered in Indian industries

Ethanol	Ethyl acetate	Hexane	Carbon disulphide	Styrene	MIBK
Hexane	Methyl acetate	Benzene	Sulphur dioxide	Acrylonitrile	Ethyl cellosolve
Benzene	Butyl acetate	Toluene	Isobutanol	Dioxolane	Methyl iodide
Toluene	Acetone	Xylenes	Ethylene dichloride	Ethane	VCM
Xylenes	MEK	n-Butanol	Gasoline (MS)	—	Methylene dichloride

Organic VOCs recoverable with Genosorb

AcetoneDioxalaneDioxaneMIBKCyclohexaneGasolineHexaneHeptaneMineral spiritsAcrylic acidEthyl acetateIsopropyl acetatePetroleum solventsTetrahydrofuranMEKBenzeneTolueneXyleneMethanolEthanolIsopropanolVinyl acetaten-ButanolIso Butyl BenzeneDiethyl etherCarbon disulphideAcetonitrileEthyl CellosolveHydrogen sulphideAcetic acidIsobutyleneDimethyl sulphideAcrylonitrile (ACN)Acetaldehyde

Halogenated compounds

ChlorethyleneMethyl chloroformMethylene DichlorideEthylene dichlorideMonochlorobenzeneCarbon tetrachlorideVCMMethyl IodideChlorofluorocarbons

10 · Beyond VOC Recovery

Genosorb's absorption chemistry extends past organic solvent capture into a range of gas-treatment applications.

Biogas upgrading

Removes CO₂, H₂S, COS, and mercaptans from raw biogas, producing purified biomethane. Operates at ~7 bar, methane loss <3%, Genosorb loss ~2%/yr.

H₂S removal

From syngas and IGCC plant feeds — recoverable as elemental sulphur via a low-energy ferrous EDTA process established since 1987.

CO₂ removal

From mixed low-molecular-weight hydrocarbon streams such as natural gas and raw biogas.

Natural gas sweetening

Selective absorption of acid gases from natural gas, the same approach applied to biogas.

Syngas purification

H₂S and sulphur-compound removal integrated into synthesis-gas production loops at large plants.

Sulphur recovery

H₂S captured and converted to elemental sulphur rather than simply scrubbed and disposed of.

Gas dehydration

A built-in side benefit of Genosorb's strong water affinity, delivered simultaneously with VOC or acid-gas removal.

Effluent water — COD reduction

Effluent waters generated from many synthetic organic chemical production processes have high COD content. The COD content is mainly due to high concentrations of solvents in the effluent stream.

The solvents are stripped with air giving a low-concentration VOC stream, that is fed to a Genosorb plant or rotary concentrator and the solvents recovered. The gases coming from the concentrator can also be incinerated at a low cost. High air volumes are needed for efficient stripping.

Efficient recovery is possible using a rotary concentrator followed by a Genosorb plant.

Pilot solvents tested

different solvents

COD reduction

200,000 → <1,000

>99.5% reduction

11 · Rotary Concentrator — Low Concentration, High Volume

Making dilute streams economic

It frequently happens that the concentration of VOC is very low and the volume is high — such as in flexible packaging, gravure printing, paint booths, battery and semiconductor manufacturing. Volumes may range from 10,000 m³/hr to 200,000 m³/hr with concentrations of only a few hundred to a few thousand ppm. The equipment shown in Fig. 1 becomes extremely large and the process uneconomic. Recourse is made to a device called a rotary concentrator to increase the concentration to a viable level.

The main equipment is a large, very slowly rotating wheel with a honeycomb structure filled with zeolite or activated carbon. The VOC-laden gas passes through the cooled face of the rotor where VOC is adsorbed and clean air exits to the chimney. A small portion (3–10%) of the air is heated and passed back through the rotor as the desorbing fluid — it emerges with a high concentration of VOC and is then cooled before going to the Genosorb recovery system. The concentration increase can be as high as 30×, limited to about 50–60% of the LEL for safety. A 100,000 Nm³/hr flow is thus reduced to 5,000–7,000 Nm³/hr at the Genosorb plant inlet, cutting equipment cost by 75–85% as well as operating cost — as shown in the table below.

Figure 3

Rotary concentrator schematic

Image to be supplied

Economics: with vs without concentrator

Parameter	Without	With concentrator	Saving
Steam demand	1,250 kg/hr	180 kg/hr	↓ 86%
Cooling water	200 m³/hr	35 m³/hr	↓ 83%
Refrigeration load	200 TR	60 TR	↓ 70%
Genosorb make-up	80 g/hr	20 g/hr	↓ 75%

12 · Case Studies

Methanol Recovery

27 emission points · 200–700 Nm³/hr · 90% recovery

Attached to a batch organic synthesis plant. Recovered product runs 90–92% methanol purity and is recycled without distillation, at an operating cost of a few rupees per kilogram.

Acrylonitrile Recovery

>99% recovery · 950–1,100 t/yr recovered

A process plant consuming and recycling hundreds of tonnes per day. The system achieved over 99% recovery across multiple equipment emission points.

Hexane Recovery

100 Nm³/hr · outdoor installation

Acidic hexane emissions from a phase-transfer reactor. Installed as an outdoor unit mounted on the first floor — compact footprint on a working plant.

Carbon Disulphide (CS₂)

20,000–45,000 Nm³/hr · 90% recovery · 500× scale-up

Proven first on a pilot plant, then scaled up 500× to commercial capacity. CS₂ at 5–15 g/Nm³ alongside 2–5 g/Nm³ H₂S; CS₂ and H₂S recovered separately.

Methylene Dichloride (MDC)

950 kg/hr · 99% recovery · skid-mounted

Plant skid-assembled and shipped to site for installation outside the process plant. Achieved 99% recovery of the full stream.

Gravure Printing

100,000+ Nm³/hr · mixed solvent blend

High-speed operation with a shifting mix: ethyl acetate, ethanol, n-propyl acetate, MEK, toluene, isopropanol. Recovered mixed solvent dehydrated and re-blended to original formulation.

Flexible Packaging

Laminating machines · single and mixed solvents

Laminating-machine-scale installations recovering single or mixed solvents from high-speed packaging lines. See Section 10 economic data for detailed figures.

Paint Shops

Automotive · household · appliance paint lines

Rotary concentrator paired with Genosorb absorption. Recovered solvents reused in paint formulation, as diluent, or as cleaners — an alternative to the incineration route common in Europe.

COD Reduction

7 solvents · COD reduced from 200,000 to <1,000

Effluent water carrying high chemical-oxygen-demand loads was treated by stripping the solvent with air, then recovering it through a rotary concentrator and Genosorb plant.

13 · Why CCDC

Indian engineering

Every system is designed, engineered, and fabricated in India, backed by 45 years of process engineering experience.

Skid-mounted systems

Plants are shipped fully skid-mounted and erected outdoors — no covered shed required, minimising civil construction cost.

Automated operation

Fully instrumented for automatic operation, minimising manual intervention and providing continuous monitoring.

Pilot demonstrations

A trailer-mounted mobile pilot plant, designed by CCDC and operated with Clariant, has run numerous on-site demonstrations including mixtures of up to six solvents.

Commercial scale-up

Technology proven at pilot scale has been scaled up as much as 500× into full commercial plants across a wide range of industries.

Custom engineering

Solvent selection, temperature, pressure, and heat integration are engineered around each specific stream — not sold as an off-the-shelf fit.

CCDC

Commercial, Chemical And Development Company

41/42/3 1st Main Road West, Shenoy Nagar
Chennai – 600030, India
+91 98401 42990 · voc@ccdcindia.com

Technology partnership

Developed in-house with technical input from Clariant A.G., Germany. Pilot plant designed by CCDC and constructed and operated by Clariant — with demonstrations including recovery from mixtures of up to six solvents simultaneously.

Frequently asked questions

What is Genosorb® VOC recovery?

It is a physical absorption process. VOC-laden gas passes through an absorber where a liquid Genosorb® absorbent dissolves the solvent out of the gas. The loaded absorbent is then heated in a stripper, the released VOC is condensed as a recoverable liquid, and the regenerated absorbent is cooled and recycled to the absorber.

Which solvents can be recovered?

Both polar and non-polar solvents, including acetone, MEK, MIBK, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, toluene, xylene, hexane, heptane, tetrahydrofuran, methylene chloride, acrylonitrile, styrene and carbon disulphide. Genosorb 300 is used for polar solvents and Genosorb 1843 for non-polar, aromatic and chlorinated solvents.

What recovery efficiency can be achieved?

Genosorb systems are designed for 95–99.9% recovery. CCDC installations have achieved over 99% recovery on acrylonitrile and methylene dichloride streams, and around 90% on multi-point methanol and carbon disulphide streams.

How is VOC recovery different from thermal oxidation?

Thermal and catalytic oxidisers destroy the solvent, need supplemental fuel such as natural gas or LPG, and add CO₂ emissions. Genosorb recovers the solvent so it can be returned to production, turning an emission-control cost into a material saving.

Can low-concentration, high-volume streams be treated economically?

Yes. For streams of 10,000–200,000 m³/hr at only a few hundred to a few thousand ppm, a rotary concentrator is added ahead of the Genosorb unit. It raises concentration by up to 30×, so a 100,000 Nm³/hr flow reaches the recovery plant as 5,000–7,000 Nm³/hr, cutting equipment cost by 75–85%.

Which industries use Genosorb VOC recovery?

Chemicals, specialty chemicals, pharmaceuticals, petrochemicals, flexible packaging, gravure printing, paints, coatings, inks, adhesives, automotive, textiles, battery manufacturing and semiconductors.

What gas flows has CCDC designed for?

Reference installations range from a compact 100 Nm³/hr hexane recovery unit to gravure-printing streams above 100,000 Nm³/hr, including a carbon disulphide system scaled up 500× from pilot to 20,000–45,000 Nm³/hr.

How do I get started?

Request a feasibility study. Share the solvent(s), gas flow, VOC concentration and operating conditions, and CCDC will prepare a preliminary recovery evaluation. Contact voc@ccdcindia.com or +91 98401 42990.

14 · Request a Feasibility Study

Ready to recover more than emissions? Tell us about your stream — or, if you don't have that data yet, ask us to come measure it for you.

Option A

Request a Feasibility Study

Tell us about your VOC stream — components, concentration, flow rate — and we'll return a technology recommendation with a rough cost range.

Start →

Option B

Don't know your vent losses?

Not a problem — we can measure it for you. We visit your plant, measure VOC emissions from each vent, and give you a kg/day figure with a rupee-value loss estimate.

Book a site visit →

VOC Recovery System Design & Engineering

Solvent selection

Temperature

Pressure

VOC concentration

Heat integration

Energy recovery

An economic loss before it's a compliance one

The scale of the problem

Lower raw material costs

Lower greenhouse gas emissions

Reduced operating cost

Resource conservation

Circular economy support

Engineered for the job

Simultaneous dehydration

Lower greenhouse gases

Resource conservation

Circular manufacturing

Reduced waste

ESG performance

Gas enters absorber

Genosorb absorbs VOCs

Clean gas exits

Rich solvent regenerated

Solvent condensed

Genosorb recycled

Energy conservation

Solvent selection

Temperature

Pressure

VOC concentration

Heat integration

Energy recovery

One system, many sources

Lower capital cost

Centralised recovery

Automatic operation

Simplified maintenance

Plant-wide emission control

Biogas upgrading

H₂S removal

CO₂ removal

Natural gas sweetening

Syngas purification

Sulphur recovery

Gas dehydration

Effluent water — COD reduction

Making dilute streams economic

Methanol Recovery

Acrylonitrile Recovery

Hexane Recovery

Carbon Disulphide (CS₂)

Methylene Dichloride (MDC)

Gravure Printing

Flexible Packaging

Paint Shops

COD Reduction

Indian engineering

Skid-mounted systems

Automated operation

Pilot demonstrations

Commercial scale-up

Custom engineering

Technology partnership

Frequently asked questions

Request a Feasibility Study

Don't know your vent losses?