The production of printing products using heat-set web offset printing has an impact on the environment in many ways. European legislation, additional requirements from print customers and the wishes of end consumers are forcing printing companies to precisely control and continuously reduce these effects. However, a number of companies have already recognised without this external pressure that ecologically effective measures can also be economically advantageous.
In this blog post, we look at which aspects of heat-set web offset printing are environmentally relevant, where CO2 emissions are generated and how web offset printers can measure and influence CO2.
The following are particularly relevant to the environment
Paper consumption: The production of web offset printing products requires large quantities of paper, which consists primarily of mechanically and/or chemically treated wood (mechanical pulp or cellulose) and whose production requires large quantities of water and energy.
Energy consumption: The process of heat-set web offset printing requires substantial amounts of energy (electricity and natural gas) to operate the equipments and especially to dry the web after printing.
Water consumption: Printing companies need water for the printing process and for cleaning machines.
Waste production: Printing companies that use the heat-set web offset process mainly produce paper waste, ink residues and sludge.
Solvents and chemicals: Solvents and chemicals are used in the printing process and their residues must also be disposed of.
Due to the use of solvents, web offset printing presses may be subject to authorisation in accordance with Annex 5.1.2. Of the 4th Ordinance on the Federal Immission Control Act (BImSchG). The applicable limit values to be complied with are then regulated by the 31st Ordinance to the Federal Immission Control Act (BImSchG) and the Technical Instruction of Air Quality Control (TA Luft) and Technical Instructions on Noise (TA Lärm).
Companies can take the appropriate measures to reduce the environmental impact of heat-set web offset printing. This includes
- use of more environmentally friendly printing inks and paper,
- optimisation of energy and water consumption,
- minimising the consumption of chemicals and
- minimising the amount of waste.
They can also consider alternative production technologies that are more environmentally friendly.
The energy usage in web offset printing companies essentially related to production. Electricity consumption depends on production. This includes, for example, electricity for the printing presses, compressed air generation, lighting and plate production.
Natural gas consumption is determined by the use of the dryers in which the paper web is dried after the printing process. Excess heat can be fed into the heating system through heat recovery.
Most web offset printing companies work with hot air dryers that are fuelled by natural gas. The oil components of the paints expelled in the dryer are oxidised (burned) and emitted in the course of an exhaust gas purification process (thermal post-combustion) at a high temperature.
Alternative dryer technologies work, for example, by curing the printing inks with UV light and require correspondingly reactive ink systems.
Various emissions are caused by the operation of printing presses. Indirectly through the consumption of natural gas and electricity and directly through operation of the production equipment.
Where do CO2 emissions occur during the operation of web offset printing companies?
Emissions are not just generated during the direct production process. In the Greenhouse Gas Protocol (GHG Protocol), an internationally recognised standard for recording and reporting greenhouse gas emissions, the various categories of greenhouse gas emissions relating to companies and organisations are grouped into three categories (Scope 1, 2 and 3). These categories are used to classify and identify the sources of emissions. This helps companies to comprehensively record, report and reduce their total greenhouse gas emissions.
Scope 1 (direct emissions):
This category covers the direct greenhouse gas emissions of a company or organisation that originate from its own sources and are under its direct control. This generally includes emissions from combustion processes, such as the use of company-owned vehicles and heating systems, as well as emissions from industrial processes.
Examples of Scope 1 emissions are: combustion of fossil fuels (e.g. petrol, diesel, natural gas) in company-owned vehicles and plants; emissions from industrial processes, such as the combustion of coal in a power plant.
Scope 2 (indirect emissions from purchased energy):
This category includes greenhouse gas emissions that are indirectly associated with the generation of electrical energy, steam or heat that a company or organisation purchases from third parties. This generally includes emissions caused by the production of electricity or heat supplied by an energy supplier.
Examples of Scope 2 emissions are: The greenhouse gas emissions associated with the production of electricity in a coal or gas-fired power plant from which a company purchases electrical energy; emissions associated with the production of steam or heat by an external provider.
Scope 3 (other direct emissions):
Scope 3 emissions are a broad category of indirect greenhouse gas emissions that originate from activities and sources outside the direct control of a company or organisation. These emissions are generally more difficult to quantify as they are linked to a company’s entire supply chain and business activities. They include emissions generated during the production and use of a company’s products and services, as well as emissions from business travel, supply chains and other indirect sources.
Examples of Scope 3 emissions are: Emissions caused by the production and transport of products sold by a company; emissions caused by business travel and daily commuting by employees; emissions associated with the procurement of raw materials and services in a company’s supply chain.
CO2 emissions are calculated using consumption data and emission factors for conversion into CO2 equivalents. Service providers such as Climate Partner are available for the calculation. Emission factors can in turn be taken from databases such as Ecoinvent and Gemis.
Quantifying CO2 emissions in connection with web offset printing
Direct emissions from web offset printing companies include carbon monoxide, nitrogen oxides, and organic substances (total carbon), the limit values of which are regulated in the authorisation notices for the production facilities.
The extent of VOC (volatile organic compounds) emissions is usually determined within a solvent balance in accordance with the 31st Ordinance on the Implementation of the Federal Immission Control Act (BImSchV). However, the solvent content of input materials (printing inks, detergents, damping solution additives, isopropanol) and their consumption have declined in recent years.
However, the most significant CO2 emissions do not occur in the printing company environment, but in producing printing stock and the energy required for production.
Environmental reports from various German web offset printing companies show, for example, that Scope 1 CO2 emissions (from the use of heat or refrigerants in the printing plant and operating the vehicle fleet) are only responsible for around 1 to 2 per cent of CO2 equivalents. Electricity procurement and the CO2 emissions resulting from its generation (Scope 2) account for 5 per cent of CO2 equivalents.
Around 94 per cent of CO2 emissions come from Scope 3: Production materials and consumables (specifically: substrates such as paper), incoming logistics, upstream chain electricity, employee travel, upstream chain heating/cooling, disposal, water.
On the other hand, up to 95 per cent of the emissions attributable to manufacturing production materials and consumables is related to the substrates in web offset printing plants.
Economy and Ecology
Many printing companies have long recognised that environmentally friendly measures, such as reducing energy consumption or paper waste, also reduce costs and therefore make both ecological and economic sense.
Scope 1 and 2 emissions that can be directly influenced are specifically addressed here.
Scope 1 emissions (direct emissions) can be reduced through changes in production technology used and/or offset through suitable certified compensation projects. In this way, calculated climate neutrality can be achieved.
Scope 2 emissions, which are primarily the (indirect) emissions caused by generating electricity, gas or district heating supplied by third parties, can be reduced by selecting energy suppliers (and their electricity sources, e.g. hydropower, wind energy) accordingly.
In order to constantly monitor success, many companies carry out an efficiency calculation. This sets out the amount of CO2 equivalents and the amount of VOCs emitted in relation to the amount of printed material (emissions in kg per 16 pages). Even changes to the energy supplier’s electricity mix can result in direct changes to CO2/VOC efficiency due to the greater influence of Scope 2 emissions.
Management and audit systems such as the European Eco-Management and Audit Scheme (EMAS), which is based on Regulation (EC) No 1221/2009, help printing companies to systematically reduce their environmental impact and carbon footprint.
This is why numerous printing companies have already decided to undergo this voluntary audit, which results in an exact determination of environmental impact, emissions and emission efficiency.
Regular “environmental declarations” are part of EMAS. They are not only used to ensure transparency in the measures taken to reduce the carbon footprint. They are of course also used as a marketing tool. They help to put the environmentally friendliness of print production in the right light.
If you would like more information on this topic, download the White Paper “The European Green Deal - Effects on web offset printing”.
