How to beat the AQA

Providing a well-considered view is Mark Liptrot, Afripack’s group sustainability manager, who doubles up as chairman of Printing SA’s Environmental Interest Group.

‘The proposed legislation, based on strict emission limits, is environmentally sound, has been shown to reduce air pollution in industrialised countries, and is the ethical way to do business,’ Mark insists.

‘However,’ he continues, ‘the legislation has the potential to affect profit margins and could result in lay-offs and even plant closures owing to high initial costs and the cost of maintenance of emission control technologies.’

He points out that even a small operation with one or two flexo or gravure presses could fall foul of proposed legislation. ‘This is a major concern. Most converters’ equipment is not designed to minimise emissions, and they’d need to retrofit the necessary systems. Many would simply not be able to afford to adapt to the regulations – we’re talking millions of rands to set up and maintain effective emission controls.’

As Mark explained in an earlier article in PPM, the options are either a change in technology (eg to water- or UV-based inks) or an end-of-pipe solution (eg thermal oxidation). The former is not always technically feasible, and the latter could run into a +R10-million capex bill and an annual operating bill of up to R2-million.

‘Most operations would be severely compromised by such a financial burden, so it’s a serious issue,’ Mark warns.

Additionally, the legislation would require strict policing and necessitate companies to voluntarily state their solvent use. Do we have enough inspectors?

This is a particularly apt question, given that a recent survey undertaken by Printing SA garnered a pitiful response from the country’s printers – even netting a nil response from some well-known major and medium emitters. This begs the question: How will regulators ensure that all companies report and comply?

‘It would be unfair for some to fly under the radar, while others make a significant investment in an effort to comply, making themselves less competitive, at least in the short-term,’ Mark argues.

Retrofitting headaches

Turning the spotlight on retrofitting, Mark notes that there may not be enough space on the ground or sufficient strength in a roof to accommodate large installations.

In his view, the advantage of RTO systems is that they’re probably the most compact and have the lowest installation costs among available systems.

‘However,’ he continues, ‘they don’t have the lowest maintenance costs, since LPG gas is used to destroy solvent fumes by combustion when solvent levels fall to a level that doesn’t support a flame. Ironically, this combustion leads to the emission of CO2, the most common greenhouse gas next to water vapour, which obviously increases carbon footprint!’

Mark agrees that biological solutions are also in the mix, where solvents are destroyed by passing the air through microorganisms in water. The solvents are literally used as a food source. ‘These systems are also costly with high maintenance implications,’ he remarks. ‘But another solution is to capture the solvent mix in the air and use this mixture for wash-up purposes, electricity generation or redistillation.’

In Mark’s view, each plant needs individual assessment to confirm which technology is most suitable – it’s not a case of ‘one size fits all’.

Although some printers have already taken steps to reduce their emissions, it’s fair to say that most have not.

‘When the legislation is promulgated, we hope a reasonable time will be allowed for adjustment, either to switch from solvent-based inks/coatings/adhesives, or to install a system with a high initial cost but a low maintenance bill and a short payback period if the captured solvents can be reused to replace “virgin” solvents, or to generate electricity. These would be acceptable ways of compensating for the high installation costs, and are good examples of “closed-loop” systems for which industry strives,’ Mark remarks.

The next question is why not change immediately to water-based technologies? ‘It’s easier said than done,’ Mark replies. ‘There are adhesion issues on plastic film; they require more energy to dry, they’re costly to dispose of and slow down press speeds. Water-based technologies have the best chance of success on paper, but this requires a dedicated press – paper only – not a press that runs both paper and plastic, owing to the incompatibility of water-based with solvent-based inks,’ Mark explains.

‘The same applies to laminators and adhesives. At Afripack we’d see water-based as only a partial solution unless we see significant advances in drying speeds and adhesion. UV printing and laminating is generally done on narrow-web equipment, is expensive to retrofit and significantly more expensive than solvent printing, owing to higher ink costs,’ he adds.

Mark sums up: ‘Printing is a highly competitive business, with tight margins, and little spare cash for non-profit making equipment (such as emission control). Once regulations and time-frames are in place, we can decide which route to follow, and hopefully technologies in both printing and solvent reduction/destruction/capture will improve to give solutions and ensure our industry’s long-term sustainability.’

Megtec’s broad portfolio

For many years, UK-based Megtec Systems has been closely aligned with the printing industry across a swathe of technologies – heatset, publication gravure, and gravure and flexographic packaging – offering a portfolio of biological, thermal, carbon adsorption and solvent recovery systems.

With many hundreds of installations in the EU, the US and Asia, Megtec is now making inroads into South Africa with thermal oxidisers and integrated dryer oxidation systems for the heatset printing sector – a prime example being Paarl Media KZN’s installation of Megtec’s Dual Dry III (standard dryer) and Epsilon RTO (regenerative thermal oxidiser) technology on its web presses (as reported in PPM August 2010).

‘Key drivers for RTO installations in South Africa have been to control the local nuisance caused by unabated fumes, to future-proof against possible future legislation, and to maximise energy (gas) efficiency,’ explains Megtec’s MD, Colin Morris.

‘In recent years, the market for new heatset web offset presses in South Africa has been buoyant with a number of installations,’ he also notes. ‘Rising gas energy costs, particularly LPG, led printers to reassess their drying techniques and to move from a standard dryer to one that incorporated an integrated dryer/thermal oxidiser into a single unit. Solvents evaporated from the web are used as a fuel source in the combustion chamber of the oxidiser section, drastically reducing gas consumption; and the heat necessary for drying the web is taken from the combustion chamber.

‘Importantly,’ Colin continues, ‘this takes place while meeting strict emission limits similar to those adopted by the EU (carbon <20mg/Nm3, carbon monoxide and oxides of nitrogen <100mg/Nm3).’ Aside from Paarl Media KZN’s installation already mentioned, Megtec has worked with several Paarl Media sites and it makes for an interesting story! Paarl Media Gauteng was originally set up with a 48-page Lithoman and 16-page Rotomans with standard dryers coupled to a thermal oxidiser. During Paarl Media’s ‘reallocation of print capacity’ project, the 48-page Lithoman was replaced with a 72-page Lithoman with a Dual Dry TNV (the internal after-burner obviating the need for an external oxidiser). The 48-page Lithoman in turn was relocated to Paarl Media Cape where it was equipped with a new Dual Dry RTO. The dryer on the one Rotoman in Gauteng, a Dual Dry III system, was relocated to Paarl Media KZN where it’s running in combination with an RTO. The remaining two Rotomans were originally installed with TNVs. This means the Gauteng site runs only TNVs while the Cape Town site runs an RTO on the 48-page Lithoman and a Dual Dry TNV on the 64-page Lithoman.

Choosing the system

So how exactly is the decision made?

Taking up the story, Kevin Jones, Megtec’s sales manager, with particular expertise in the flexographic and gravure printing sectors, explains: ‘Typically, our service starts with a desk-based study of a plant, including analysis of annual solvent usage, solvent types and the emission targets to be achieved. For further information gathering, we undertake a factory tour and then draw up a short list of abatement options. From this we ascertain the best choice.

‘We also assist in gathering emission data,’ Kevin continues, ‘and advise on what should be measured and how, as surveying for abatement plant and measuring emissions for legislative compliance can often differ and the data required can be insufficient from emission tests alone.’

Megtec quickly identifies which types of abatement will suit a particular printing plant; and then assists in the development of capital budgets to assist the approval process.

According to Kevin, for printers using 5 to 10t/annum of solvents, disposable carbon can provide a lower-cost abatement option, while for those using less than 30t/annum, biological solutions can be employed. Typically for plants with presses under 20 years old and solvent use below 20t/annum and 1 000t/annum of mixed solvent use (alcohols and acetates), the most popular solution has been thermal oxidation.

‘We have systems offering high thermal efficiencies of more than 94% that enable the oxidation plant to operate fuel-free under many process conditions. Where VOC emissions are from modern presses, the option of secondary or tertiary energy recovery systems can be considered for process heating, cooling or other on-site energy,’ Kevin explains.

‘For larger printers (above 1 000 t/annum), the use of solvent recovery systems warrants consideration, as recovered solvents can be reused in the printing process. For those using a single solvent such as toluene, there’s an economic justification for solvent recovery to be employed regardless of emission legislation. For larger users with mixed emissions of alcohols and acetates, there’s usually a requirement to distil the recovered solvent back to its constituent parts for reuse,’ he adds.

Summarising, Kevin says: ‘We’re able to offer a multiple solution review, development of costs and costs of ownership, the establishment of total plant installation costs and press exhaust optimisation, consideration of energy recovery techniques, as well as support for installation and in the case of solvent recovery, economic justification reviews for solvent reuse and solvent blend optimisation.’

With an installed base of many hundreds in the flexographic printing sector, a broad solution portfolio that includes all established abatement techniques in the market, Kevin insists that Megtec offers a non-axe-grinding review and equipment selection. ‘We’re also able to comment quickly on “blue sky” options offered in the early stages of legislative adoption, avoiding a dead-end solution or, worse, a system that has little if any chance of meeting legislative requirements.’

Going the biological route

A discussion with André Schoonhoven, a partner in Netherlands-based Pure Air Solutions, unveils an innovative biological solvent emission system. 

Being promoted at last year’s drupa was Pure Air’s Vocus system that treats atmospheric VOCs to cut emissions. Already installed at flexo printing companies throughout Europe, Vocus has been shown to achieve stipulated emission levels in a cost-effective and sustainable manner. It reduces VOCs using a biological process and, according to André, is competitive when compared with other technologies, such as RTO (regenerative thermal oxidisers) and other incineration technologies.

Now, however, the company has moved a step further in its quest for the perfect solution, most especially for the benefit of flexographic printing works, particularly those engaged in flexible packaging conversion, with its newly-released Boncus system.

We have to laugh at this rather odd name which may sound OK in Dutch but doesn’t translate so well into English! Semantics aside, however, this next-generation biological system treats high loads of VOCs and uses the solvents to produce renewable energy – turning emissions into a profit for the printer.

‘This development, funded by the EU’s Madame Curie FP7 framework, represents a paradigm shift. With existing methods, such as RTO, the medicine is often worse than the disease,’ André quips.

By this he means that regenerative thermal oxidisers are costly to run in terms of energy inputs but also emit pollutants such as NOx, CH4 and CO2 that contribute to smog formation – the main reason behind the implementation of VOC legislation. The Boncus system, on the other hand, sees VOC emission as a waste stream with considerable potential for conversion into energy, making a profit for the printer.

That’s a bold statement, but André backs it up with facts.

‘Boncus is currently undergoing beta testing at Altacel, a flexible packaging printer in The Netherlands that operates six flexo presses. It’s currently at a level where an equivalent of 100 tons of solvents (as VOC emissions) generate 40% of the total energy demand for the facility, equal to a net gain of  around €30 000,’ André maintains.

The idea of using solvents to print packaging and then using those same solvents to produce energy is compelling. ‘The Holy Grail is to discover a neutral cost system of reducing atmospheric VOCs, but our system goes beyond that – producing a return on investment. It’s an exciting prospect,’ André maintains.

What is Boncus?

The system (patent pending) is a biological system that combines different technologies and is designed specifically for the abatement of VOC emissions in the flexo industry. It’s a far cry from other conventional technologies.

For instance, this end-of-pipe solution doesn’t interfere with the printing process as do other technologies (RTO, EB-curing, water-based inks, etc). This means the converter can continue working at high-speed using solvent-based inks.

Boncus converts VOC emissions into energy that can be directly or indirectly used in the factory – the first VOC abatement system that creates a financial gain for the converter.

There’s a return on investment – turning VOC emissions into profit – but as well as direct economic benefits, there’s an excellent marketing message for converters who can advertise their ‘green credentials’ since they significantly reduce their carbon footprint. In André’s view, this pioneering technology will make history in flexible packaging printing.