September 23, 2015

VOC Sources

>3 VOC CompoundsRecovery/Reuse

Not Feasible

Thermal OxidizersCatalytic Oxidizers

Adsorbers

≤ 3 VOC CompoundsRecovery/Reuse not

Feasible

AdsorbersThermal OxidizersCatalytic Oxidizers

≤ 3 VOC CompoundsRecovery/Reuse

Feasible

Adsorbers

VOC

Concentration

(%LEL*)

Technology Options Typical Flow Thermal

Efficiency

(%)

0 - 10 Regenerative Thermal

or Catalytic Oxidation

(RTO / RCO)

80 - 97

0 – 10 Adsorption 0

10 - 40 Recuperative Thermal

or Catalytic Oxidation

or RTO

50 - 95

>40 Afterburner 0

*LEL = Lower Explosive Limit

Also known as direct fired thermal oxidizer (DFTO)

At the simplest level, a combustion chamber and burner

Can be deployed as an alternate to enclosed flare but has the design flexibility for both oxygenated and non-oxygenated process exhaust gases.

Design volumes vary widely often relating to control/quench of heat of combustion from burning VOC.

Extremely high destruction efficiency achievable up to 99.99%

Typically energy efficient due to temperature and pressure of VOC rich inlet gas stream.

Various secondary heat recovery devices are commonly integrated after the DFTO.

After an analysis of the process exhaust gases, they have to be assigned to an ex-classified zone: 0 – 2

Secondary explosion relief measures are:

Static safeguards such as deflagration arresters and flame arresters

Fluid flame arresters

Backflash-safe injection into combustion chamber

Analytical surveillance

Explosive Process Gas Applications

Exhaust

gas

Zone 0

Compres

sed air

Residual

liquid

N2

Combustion

air

PC

PC

PI

PI

PSA_

PSA_

PDIA+

PICscM

TSA+

FIC

Natural

gas

PC

PI

PSA_FIC

sc

M

TSA+

PC

PIC TIC

FIC

Exhaust

gas

Zone 1

N2

PIPDIA+

TSA+

PC

PDIA+

TSA+

1.000-1.200 °C

Combustion chamber

SNCR*-stage

Steam boiler Quench Scrubber Demister

Waste water treatment Adsorption Stack

SCR**-stageDedioxi-nation

Exhaust gas/air

Fuel

Steam

Water supply

Reduction agent

Chemicals

Chemicals

Residual materials

Reduction agent

Sorptionagent

Waste water

X

X X X X X X X X

X X X

X X X X X X X

X X X X X X X

X X X X X X X

X X X X X X X

X

X

Organic solvents

Halogenated compounds

Compounds containig nitrogen

Sulphurous compounds

Heavy metals, e.g. mercury

Other liquids containing salts

Liquids containing particles (ash)

Liquid residue

Combustion air

Fields of Application

......many configurations

Typically pre-assembled and compact oxidizer with capacity up to 30,000 scfm.

Consists of:

Combustion chamber

Burner

Shell and tube heat exchanger

> 99% destruction efficiency

Variable heat exchanger designs available from 45% to 70% TER

Low pressure drops

Simple to operate and maintain

Standard raw gas burner offers lower operating costs than similar units installed with combustion blowers

Hot By-pass Damper

Burner

Solvent Laden Air

Clean Exhaust Air

TAR Compact unit

Exh. air

heat

exchanger

Stack

Purification of VOC-laden air

Exhaust air pre-heating

Steam generation

Thermal oil heating

Hot water or warm water generation

Fresh air heating

Direct hot heating

M

X

X

X

X

X

X

X

X

Direct hot

heating

Fresh air

heat

exchanger

Water boiler

or

economiser

Steam

boiler

Thermal-oil

boiler

Steam

Feed water

Residual

liquid

Fields of Application

Capacity:

3,000 – 80,000 scfm per unit

> 80,000 scfm = multiple integrated modules

Destruction Efficiency:

2-tower system - up to 98% destruction efficiency

3-tower system - > 99% destruction efficiency

Rotary valve - > 99% destruction efficiency

Thermal Efficiency:

Standard 95% thermal efficiency

> 97% thermal efficiency achievable

Auto-thermal operation on process VOC (no supplemental fuel required)

Burner

Purge air

solvent-laden exhaust

air

Regenerative

heat exchanger

Purified

exhaust air

Fields of Application

Water

supply

X

XX

Pre-

Scrubber

Gas

injectionAerosol

seperator Pre-

heat

Liquid

Injection

RTO

Oxidizer

Bake

out

Heat

recovery Stack Scrubber

Gas

Waste water

Steam

Chemicals

X

Organic solvents

Halogenated compounds

Explosible gases

Ammonia, Sulfur, oils

or dustAerosols, droplets or

condensate

Organic dust

Liquids

Waste water

Chemicals

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Rotary valve

Single rotary valve replaces all butterfly or

poppet valves

Fewer moving parts increases reliability

Skid mounted, pre-piped, pre-wired

Smaller footprint allows for location in tighter

areas

Electric diverter valve drive system

Offline bake-out standard; online bake-out

optional

Rotary valve

Twelve Chambers

5 Inlet, 5 Outlet, 1 Purge, 1 Idle

Operates as an odd tower standard unit

Single rotary valve indexes 30 degrees each 15

seconds to change flow path from inlet to purge

to outlet

Standard ≥ 99% destruction efficiency

≥ 95% thermal efficiency

Solvent loads up to nominal 25% LEL

No pressure fluctuations at the process

Exhaust in contact with Rotary Valve,

thus eliminating condensation

https://www.youtube.com/watch?v=G_8eqd3Fue8

Carbon or Zeolite ConcentratorsHigh gas volume, low VOC concentration process exhaust

is converted to low gas volume, high VOC concentration

for efficient VOC destruction in an oxidizer. Typical

conversion ratio is 10:1 (IE; 50,000 Scfm process

concentrated into 5,000 Scfm oxidizer)

Limited to ambient temperature process exhaust streams

up to 110ºF.

Solvents are adsorbed at ambient temperature onto the

adsorbent material and the purified air exits the unit

through the outlet plenum

Solvents are desorbed from the media in an isolated

plenum at elevated temperatures to liberate the VOC from

the media.

System efficiency; 96% - 98% concentrator removal

efficiency x 99% oxidizer destruction efficiency =

95% - 97% overall.

50,000 Scfm10 lbs/hr VOC

5,000 Scfm100 lbs/hr VOC

Fields of Application

Solvent-

Recovery

Solvent with

Dust < 3 mg/Nm³

Overspray 3-5 mg/Nm³

Overspray 5-10 mg/Nm³

Overspray > 10 mg/Nm³

Dust < 10 mg/Nm³

Dust + Aerosoles

Dust > 10 mg/Nm³

TAR

Compact

Unit

RTO

Oxidation

Unit

Ventury Dryfilter WESP

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

XX

X

X

X

X X

KPR System

Catalytic reaction process – “catalysis” enhances chemical reactions

Reduces the amount of energy required to activate the reaction

Causes reaction to occur at lower temperatures and higher rates

Application determines the catalyst –selection depends upon the process

19DRAFT 8 5/2/2013

VOC’s

Products

CO2 & H2O

E

ΔH

E – Activation EnergyΔH – Heat of Combustion

E’

E’ – Activation Energy required with catalyst

ΔE – Change in Activation Energy

21

5/2/2013

Active sites for catalysis

Washcoat material provides high surface area Substrate

Active ingredient (e.g. precious or base metal) dispersed through a high surface area coating on a substrate, such as a ceramic block or a corrugated metal foil.

DRAFT 8

High surface area

Low pressure drop

Well suited for washing to extend useful life

Resistant to acid gas environments

Ceramic structure does not crush or create

fines

substrate

washcoatCeramic element Cross-section SEM

Installation – ceramic blocks

IPAMethanol

EthanolButanol

Toluene

MEK

Acetone

Ethyl acetatePropyl acetateIsobutyl acetate

Each VOC has its

own unique conversion curve

There are a wide range of applications for which catalysts are in use, including:

Power generation emissions◦ Natural gas turbines◦ Natural gas and diesel engines◦ Biomass boilers

Industrial waste gas emissions◦ Petrochemicals◦ Paint booths

Kitchen fume purification◦ Fast cook ovens, charbroilers

Aircraft cabin air purification

Various technologies reviewed at the start of VAM investigation in 2005

◦ Catalytic Thermal Oxidation not applicable as the methane concentrations and heat of

combustion result in temperatures above maximums allowed for existing catalysts

◦ Flares significant supplemental heat would be required resulting in

high operating cost

◦ Regenerative Thermal Oxidation Applicable to oxidize methane above 0.3% without using a

supplemental fuel source during normal operation

At methane concentrations above 0.4% excess heat is available

By now proven technology to reduce VAM emissions by 95% to 97%

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Regenerative Thermal Oxidizer utilizes high mass, internal ceramic heat exchanger beds to hold heat

Bed #1 gives up heat to incoming VAM process air

Methane oxidation begins in the top of Bed #1 just prior to entering the oxidizer combustion chamber

Oxidation is completed in the oxidizer combustion chamber

26

1628 °F 1750 °F

70 °F142 °F

‣ Bed #2 pulls heat from the cleaned air exiting the combustion chamber‣ When the heat in bed #1 has been depleted and Bed #2 is fully charged,

airflow is reversed‣ Combustion chamber temperature operates at 1750F when self

sustaining at 0.3% methane

Excess heat available at methane concentrations above 0.4%

Oxidation of methane gives off more heat than required to maintain typical combustion chamber temperature of 1550F Combustion chamber temperature will begin to rise.

Evacuation of excess heat through a hot gas bypass -combustion chamber temperature to be stabilized at 1750F.

The evacuated hot air bypasses the outlet heat exchange bed and is transported directly to the stack – or to be used for…

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0

10,000

20,000

30,000

40,000

50,000

0.20% 0.40% 0.60% 0.80% 1.00% 1.20% 1.40%

Hot

Byp

ass A

irfl

ow

scfm

VAM Exhaust Methane Concentration

VAM RTO System

VAM CH4 Concentration vs. Hot Bypass Airflow

Total RTO Airflow = 160,000 scfm at 70°F

Hot Bypass Flow

(Tcc = 1750F)

‣ Hot air or water in combination with a coil‣ Electricity generation in combination with a boiler and turbine or a ORC or a CPS

VAM Volume –160,000 scfm

VAM Methane Concentration –0.4% to 1.1%

Collection Point –16.4 ft x 16.4 ftcollection hoods

No CMM

3 RTO Oxidation System

No excess heat utilization – but theoretically possible

97% oxidation of methane

28

In operation since Summer 2012