2.D.3.i - Other Solvent Use

In source category 2.D.3.i - Other Solvent Use, emissions from various product groups and processes and also from lubricants use in stationary and mobile applications are reported. Relevant pollutants are NMVOC and some heavy metals.

In sub-category 2.D.3.i - Other product use: Other solvent use the following product groups and processes are taken into consideration:

• Glass and mineral wool enduction
• Fat, edible and non-edible oil extraction
• Application of glues and adhesives (paper and packaging; wood; footwear; transport; Do-it-yourself-applications; others)
• Preservation of wood
• Underseal treatment and conservation of vehicles
• Vehicles dewaxing
• Other:
  • Plant protectives
  • Dichloromethane in strippers
  • Removal of paints from incorrectly coated aluminium parts
  • Removal of paint from steel parts
  • Concrete additives
  • De-icing (Aircraft de-icing; De-icing of operated areas; Other de-icing applications)
  • Applications in scientific laboratories (R&D; analyses; universities)

NMVOC emissions are calculated in accordance with a product-consumption-oriented approach. In this approach, solvent-based products or solvents are allocated to the source category, and then the relevant NMVOC emissions are calculated from those solvent quantities via specific emission factors. Thus, the use of this method is possible with the following valid input figures for each product group:

• Quantities of VOC-containing (pre-) products and agents used in the report year,
• The VOC concentrations in these products (substances and preparations),
• The relevant application and emission conditions (or the resulting specific emission factor).

The quantity of the solvent-based (pre-)product corresponds to the domestic consumption which is the sum of domestic production plus import minus export.

The calculated NMVOC emissions of different product groups for a source category are then aggregated. The product / substance quantities used are determined at the product-group level with the help of production and foreign-trade statistics. Where possible, the so-determined domestic-consumption quantities are then further verified via cross-checking with industry statistics.

Since 1990, so the data, NMVOC emissions from use of solvents and solvent-containing products in general have decreased by nearly 55%. The main emissions reductions have been achieved in the years since 1999. This successful reduction has occurred especially because of regulatory provisions such as the 31st Ordinance on the execution of the Federal Immissions Control Act (Ordinance on the limitation of emissions of volatile organic compounds due to the use of organic solvents in certain facilities – 31. BImSchV), the 2nd such ordinance (Ordinance on the limitation of emissions of highly volatile halogenated organic compounds – 2. BImSchV) and the TA Luft.

Until 1999, data of the present source categories 2.D.3.a, 2.D.3.h and 2.D.3.i were treated as one source group. Since 2000, a more detailed data collection enables to follow the development of source group 2.D.3.i, which accounts for about 1/5 to 1/4 of total NMVOC emissions from solvent-based products. Compared to 2005, emissions went down mainly due to a clearly reduced consumption of concrete additives.

A decrease in the NMVOC emissions of Category 2.D.3.i can be observed since 2005. The following product groups cause major emissions in category 2.D.3.i:

• Concrete additives,
• Underseal treatment and conservation of vehicles,
• Application of glues and additives,
• Deicing and
• Fat, edible and non-edible oil extraction

These six activities comprise together 88 – 93% of total emissions of 2.D.3.i depending on the considered years.

Uncertainties for emissions for each technology / application were obtained by error propagation and refer to the 95% confidence interval.

Domestic Consumption: The applied relative uncertainty was ±10% for all applications.

Solvent content: For each application / product, a relative error at ±15% was applied (exception: lubricants at 25%), but not exceeding 100% or falling below 0%.

Emission factors: A relative error at ±15% was applied, but not exceeding 100% or falling below 0%. Exceptions were de-icing applications, applications in scientific laboratories and lubricants with a relative error at 25%.

Hence, the overall uncertainty of emissions caused by application of products of this source group is between 40% and 60%.

As the emission data for the 2021 reporting could not be completely revised due to staff constraints and for these reasons the emission data for 2018 had to be updated in last year's reporting, a complete recalculation of the emission data for 2019 and 2020 was carried out for this year's reporting. In doing so, it was also possible to take into account the current changes in the systematics of the national production statistics and the foreign trade statistics.

No category-specific improvements are planned.

Sub-category 2.D.3.i - Other product use: Use of lubricants in stationary applications comprises the entire use phase including the process stages of input and output. The products or lubricants covered here, are:

• Compressor oils
• Turbine oils
• Gear oils (automotive oils including automatic transmission fluids, industrial-gear oils)
• Hydraulic oils
• Insulating oils
• Machine oils
• Process oils
• Other industrial oils not for lubricating purposes
• Metal working fluids fluids (hardening oils, water-miscible and not water-miscible metal working fluids, anticorrosive oils)
• Greases
• Base oils
• Extracts from lubricant refining

The emissions calculation method follows a Tier-2 approach. It uses national statistical data ^{[Lit. 1]} for the quantities placed on the market specific per lubricant types as activity rate and specific emission factors for each lubricant type. It is assumed that the amount of lubricants placed on the market per year equals the lubricant use (consumption) in the same year.

The consumption of lubricants in Germany has remained at a relatively constant level since 1990, apart from a sharp decrease in 2009 and in 2020.

Along the life cycle of the different lubricant types, different kinds of losses occur. Only some types of losses are of relevance with regard to air emissions and the different lubricants types differ significantly from each other. Relevant emitted pollutants identified for lubricants are NMVOC and CO₂. But only for engine oils used in machinery and in vehicles emission of both could be accounted for due to combustion of a small fraction of lubricating oils directly resulting in CO₂ emissions.

For Insulating oils ^{[Lit. 3, 5]}, Process oils ^{[Lit. 4, 10, 11]}, Greases ^{[Lit. 10, 11]} and Extracts from lubricant production ^{[Lit. 2, 10, 11]} no emissions expected.

All emission factors are are constant in the entire time series. They were determined in a research project (UBA, 2018) ^{[Lit. 14]}.

Table 1: Tier 2 emission factors for specific lubricant-type groups in percent

In 1995 four categories fell away/ceased to exist (Table 2) and three type groups were newly introduced due to modifications/changes in the Mineral Oil Statistics concerning lubricants. A slight adjustment of the procedure for the years 1990-1994 was needed. Table 2 shows the affected categories as well as the ways in which they were handled in the calculation procedure.

Table 2: Handling of categories in the Mineral Oil Statistics, 1990-1994