Solvent Emissions From the Organic Coating Process

Jim RowbothamPexa Ltd.

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Nearly there© Pexa 2009

What’s the Problem?

Climate Change

Carbon Footprint

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Leadership

“a step that will also reduce our carbonemissions 80% by 2050”.

“commits Britain to cut carbon emission by 34 per cent by 2020”

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Contribution

Paints based on organic solvents

Carbon derived from fossil sources

Used as a carrier in paints, evaporates and adds to the environmental carbon compound concentration

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Regulation

This paper focuses on The EU Solvent Emission Directive 13/1999.

Embodied in the UK for Aerospace as guidance notes.

- PG6-40 Painting- PG6-45 Surface Cleaning

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Thresholds Defined for Coating by Size of Activity

0 - 5000 Kg of solvent used - Not controlled

5 – 15,000 Kg – “small process”

15 – 200,000 Kg – “large process”

>200,000 Kg - special process(IPPC)

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Objectives of Presentation

Simplify the directive Focus on most important items Desktop methods for estimating current emissions Propose simple tools for evaluating compliance Some ideas for improvement Sound basis for regulator

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Painting Process

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Painting Activity – How to Comply?

“Non toxic” (non CMR R40 etc) solvents

1) Reduce to < 5000Kg 2) Control of emission concentrations 3) Mass reduction scheme4) (BAT)

CMR R40 solvents (essentially not used)

1) Control of emission concentrations2) Nothing

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Painting Process – 2 Emission Control

VOC’s (as carbon) must be <50 mg/cubic metre of air. For R40s etc is <20 mg/cubic metre (as compound)

Particulates must be <50 mg/cubic metre of air Can be continuously monitored, or periodically monitored,

must be retested when process changed Can be reduced by rate management, incineration,

cryogenics, carbon/polymer absorption, biodegradation. NOT by Dilution.

Time weighted average, batch vs continuous process Previous rules will not be relaxed

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Painting Process - 3 Mass Reduction Scheme

Annual solvent emission to be less than target emission (Te)

Te = M x F1 x (FEV + F2) 100

M = mass of solids/year F1 = multiplication factor (sector related) FEV = fugitive emission value (solvent use related) F2 = 15 or 5 (solvent use related)

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Worked Back to 100 Tonnes (%)

FactorSolvent Usage (TPA) 5 - 15 >15Tonnes Solids/ann. [M] 100 100Multiplication Factor [F1] 2.33 2.33Fugitive Emission Value [FEV] 25 20Solvent Use Factor [F2] 15 5Target Emission [Te] (TPA) 93.2 58.3equivalent av. VOC content*% (less water) 48.2 36.8g/l (less water) 531 405

Aerospace Sector

Input Factors

Output results

* using SG 1.1

Te = M x F1 x (FEV + F2) 100

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Conclusion Painting

Process Size Max average VOC into process

5,000 – 15,000 Kg 531 g/l

>15,000 Kg 405 g/l

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Whole Aircraft Painting

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Whole Aircraft Painting 3 – Mass Reduction Using High

Solids paint System

Product VOC g/lVolume required

Total VOC Kg

Total (average) (688) 385 265

Total (average) (447) 245 110Paint Stripping Excluded

Boeing 737 Estimated typical VOC consumptionsConventional

High Solids

Compare to Max 531 g/l or 405 g/l

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Whole Aircraft Painting 2 – Emission Concentration

Note – Regulation is weighted over 30 minutes

Conventional 3,600,000 265,000 74 mg/M3 53 mg/M3High Solids 3,600,000 111,000 31 mg/M3 22 mg/M3

Potential average VOC emission concentration during total paint process

Model for B737 in hangar 50,000 M3Processing time 6 days, average number of air changes 0.5 per hour

Total air emitted M3

Total VOC emission g

Average emission

concentration

Average emission concentration Carbon

Paint system

* = taking compound as 1.4 x total mass of Carbon

Limit 50mg/M3 as carbon

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Whole Aircraft Painting 1 – Thresholds

VOC threshold

Average VOC

Conventional 688 g/l 18 56

High Solids 447 g/l 45 136

Does not include paint removers

Number of B737 aircraft painted to achieve VOC threshold

System Choice 5000 Kg 15000 Kg

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Whole Aircraft Painting

4 – BAT

• Article 5 (3) (b) allows that processes which cannot be contained e.g. aircraft painting, may be exempted from the annex II A controls. Providing that BAT can be demonstrated.

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Surface Cleaning Process

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Surface Cleaning – Permit Required

Group Description

1. either, 1 tonne or more of cleaning solvents that are labelled (classified) with any of the R phrases R45, 46, 49, 60 or 61 (the product label and Safety Data Sheet give this information)

2. or, 1 tonne or more of halogenated cleaning solvents that are labelled (classified) with the R phrase R40 (the product label and Safety Data Sheet give this information)

3. or, 2 tonnes or more of any other organic cleaning solvent

BCF Guidance Note E018© Pexa 2009

Surface Cleaning – Emission Limits

BCF Guidance Note E018

group: 12 month usage Stack (e.g. exhaust flue) emissions

Fugitive (all other)emissions

Group 1: 1-5 tonnes

2 mg cleaning solvent/m3 (20 mg if mass flow below 10g/hour)

15% of solvent used

Group 1: more than 5 tonnes

2 mg cleaning solvent /m3 (20 mg if mass flow below 10g/hour)

10% of solvent used

Group 2: 1-5 tonnes

20 mg cleaning solvent/m3 (mass flow above 100g/hr)

15% of solvent used

Group 2: more than 5 tonnes

20 mg cleaning solvent/m3 (mass flow above 100g/hr)

10% of solvent used

Group 3: 2-10 tonnes

75 mg carbon/m3 20% of solvent used

Group 3: more than 10 tonnes

75 mg carbon/m3 15% of solvent used

Note: the Group 3 limits do not apply if the average organic solvent content of cleaning solvents is below 30%

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Practical Reductions

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Structural Paint System VOCs

HS vs Water BasedWith an average 70% primer and 30% topcoat

HS Primer 37092 350 g/lHS Topcoat 67348 420 g/l 371 g/l

Aerowave Primer 2001 250 g/lAerowave Finish 3003 250 g/l

250 g/l

Conclusion – Mass reduction is well within limits and the best way to comply – water based = HEADROOM

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Laminar Flow Spray Technology

Dux British Patented Design

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Laminar Flow Spray Technology

Particle Image Velocimetry Images

Particle Density is greatest where image is darkest

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Laminar Flow Spray Technology

Application at Major UK Based Aero-Engine MRO

Cascade Vents

Paint consumption reduced from 225ml to 125ml = 44%

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Impregnated Cleaning Wipes vs. Solvent Washing

- In European Aerostructures manufacture we have reduced solvent consumption by 75%-95% changing from traditional fluid solvent (MEK) and cotton rags to Satwipes Diestone DLS.

- Presaturated wipes with controlled surface area and controlled measure of solvent applied to each wipe.

- Self closing Lids

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Aqueous Cleaning vs Vapour Degreasing

Moving from vapour degreasing with Trike (and other solvents) to aqueous washing using a new generation of approved aqueous cleaning products such as Sococlean A3433, gives a 100% reduction in VOC emission.

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Recommendations

Understand the requirements. Use the desktop exercises to determine thresholds

and actual contributions. Implement proven, practical VOC reduction methods

and recalculate contributions. Get ahead of the regulator.

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