Advancing VOC Emission Control in banknotes & currency industries
Best Practices and Environmental Considerations
The banknotes & currency printing is a process used in the Banknote Printing Industry (or Currency Printing Industry): this industry specializes in the production of paper and polymer banknotes, as well as other security documents such as passports, postage stamps, and secure certificates. The sector encompasses various printing companies and organizations that are contracted by governments and central banks to design, print, and distribute currency notes.
Polymer banknotes are a type of currency made from a polymer substrate, typically biaxially oriented polypropylene (BOPP): these banknotes are more durable, resistant to wear and tear (determining a substantial decrease in environmental impact and a reduced cost of production and replacement), and difficult to counterfeit compared to traditional paper banknotes.
The printing of polymer banknotes involves a combination of various printing methods, including rotogravure printing and coating, intaglio, offset printing, and sometimes screen printing: the full spectrum of technologies coupled with the use fugitive, metameric, luminescent, fluorescent and iridescent solvent-based inks, tactile marks, see-through registers, allows to produce sharp, raised images enhancing machine-readibility and security.
Volatile Organic Compounds (VOCs) are emitted from a variety of industrial sources, including banknotes & currency printing industries.
VOCs are a major source of air pollution, directly and indirectly contributing to smog, ground-level ozone formation and acid rains: VOC emissions also show harmful effects on human health, causing respiratory problems and other health effects.
VOC emission control is mandatory in several countries, with specific limits at the stack of every industry. In this document we will cover the specific needs and solutions for the banknotes & currency printing sector.
The Industrial Emissions Directive (IED) is a European Union directive that sets limits on VOC emissions from industrial processes. The IED includes a Best Available Techniques (BAT) Reference Document (BREF) for the banknotes & currency sector, which outlines the best practices for controlling VOCs.
The US Clean Air Act (CAA) is a federal law that regulates air pollution in the United States. The CAA includes a number of provisions that address VOC emissions.
There are a number of VOC emission control technologies that can be used in banknotes & currency printing, to comply with environmental regulations.
The most performing technologies include:
SRU™ • solvent recovery units
SRU, Solvent Recovery Unit (also known as SRP, Solvent Recovery Plant) is a gas phase VOC adsorption system, based on activated carbon, complete of onsite desorption technology, typically employed as VOC Emission Control, allowing to respect VOC emission limits with a typical efficiency up to 99%, while recovering the solvents for direct reuse, at a fraction of their purchase cost, generating a very interesting ROI (a sustainable technology and a true path to decarbonization). They can cover from small to large SLA (solvent laden air) volumes and deal with a wide variety of VOCs, including water-miscible, non-water-miscible solvents.
XTO™ • thermal oxidizers
RTO, Regenerative Thermal Oxidation works by burning VOCs at high temperatures in a closed combustion chamber: through the oxidation reaction VOCs are converted to GHG (green house gasses, CO2, NOX, CO, and H2O). The heat generated during the combustion process is then captured and used to preheat incoming air (SLA, solvent-laden air), which in turn reduces fuel consumption and enhances energy efficiency compared to traditional thermal oxidation methods. The multi-tower design of RTO allows for continuous operation. Please note that catalytic oxidation is generally not applicable in banknotes & currency industries, being the catalyst may be poisoned by some chemicals in the VOC emissions, which can make it quickly ineffective. Please note that catalytic oxidation is generally not applicable in banknotes & currency printing, being the catalyst could be poisoned by some compounds in the chemicals (e g. inks, varnishes, lacquers, adhesives, etc), which can make it quickly ineffective. Any thermal oxidation processes will dramatically contribute to increasing your GHG (green house gasses) emissions and your fuel consumptions.
conclusions
Selecting a VOC emission control technology that is appropriate for your specific needs and that will help you to comply with VOC emission regulations while minimizing the overall environmental impact (as VOCs and GHGs), avoiding any form of greenwashing. You have to consider different factors, including the type of VOCs being emitted (type of solvents used), the size of the facility (quantity of solvents used per year), the area available for the installation and the budget (CAPEX) constraints for the selected VOC abatement system.
However, even if all of the VOC Emission Control Technologies listed above are effective in complying with VOC regulations, only SRU, solvent recovery unit technology is aligning with both environmental compliance requirements and environmental responsibility. SRU, solvent recovery units offer a sustainable and efficient solution for DECarbonization and circular economy implementation. By capturing and reusing solvents that would otherwise be wasted, these VOC emission control systems not only reduce the environmental impact of the banknotes & currency printing industries but also contribute to cost savings (ROI) and regulatory compliance. Compared to thermal oxidation systems, solvent recovery units demonstrate superior energy efficiency, reduced GHG emissions, versatility, and a commitment to long-term sustainability (reduced resource consumption). Embracing such innovative technologies is crucial for industries to meet their environmental goals, drive sustainability (economic growth and environmental stewardship), and pave the way for a greener future.
