489 23rd International Colloquium Tribology - January 2022 489 Addressing sustainability needs of the lubricants industry: Innovative base stocks with significant greenhouse gas emissions reduction potential Sabrina Stark BASF SE, Ludwigshafen, Germany Edith Tuzyna BASF SE, Ludwigshafen, Germany Christian Prokop BASF SE, Ludwigshafen, Germany Cristina Vilabrille Paz BASF SE, Ludwigshafen, Germany 1. Introduction Sustainability has become a major driver in the lubricant industry. The topic of sustainability encompasses many aspects like toxicity, biodegradability, renewable raw materials, energy efficiency, lifetime improvements and product carbon footprint (PCF). Lubricants will have a big impact on the overall decarbonization journey of the industry, with synthetic base stocks and lubricant oil additives offering high potential to reduce the overall greenhouse gas (GHG) emissions and PCFs of lubricant formulations. This paper covers sustainability criteria at the individual product level and give an insight into a new portfolio of biomass balanced base stocks and lubricant oil additives with significantly reduced carbon footprint. 2. Biomass Balance Methodology Driven by the need to reduce GHG emissions and dependence on fossil resources, the chemical and other industries are gradually starting to develop products derived from renewable feed-stocks. For the introduction of renewable feedstocks in existing production pathways in a cost-effective way, a simplified approach based on a feedstock accounting principle has been proposed by BASF [1]. This concept is known as the biomass balance (BMB) approach (Fig. 1) and the resulting products are called BMB products. The main fossil feedstocks in the chemical industry are naphtha and natural gas, which are further processed either by cracking or part-oxidation at high temperatures. For the production of BMB products, these feedstocks are replaced by renewable feedstocks, i.e. bio-naphtha and/ or bio-methane at certain amounts calculated through a material flow analysis [1]. BMB products are chemicals that are produced using both fossil and renewable feedstocks in an integrated chemical production facility. The output is a mix of fossiland renewable based products which are not distinguishable based on their composition or technical characteristics. As the renewable feedstock is processed together with fossil feedstock, it might not be physically traceable throughout the production processes. Therefore, there is a need to attribute the applied renewable feedstock volumes to an end-product in a fully transparent and auditable way, which is achieved by a certification according to the requirements of the RedCert2 scheme. Figure 1: The biomass balance (BMB) approach This solution enables the use of renewable feedstocks to produce products with the same properties as those manufactured from fossil feedstock while saving fossil resources and reducing CO2 emissions. This methodology offers hundreds of BMB products across various industries, including components for the lubricants industry. 490 23rd International Colloquium Tribology - January 2022 Addressing sustainability needs of the lubricants industry: 3. Calculation of product carbon footprint (cradleto-gate) of biomass balanced products Cradle-to-gate PCF assessments cover part of a product life cycle, from material acquisition (“cradle”) to the factory gate (i.e., before it is transported to the customer). Subsequent production steps at the customer, the use phase and disposal phase of the product are not considered. BASF calculates the PCFs in alignment with the GHG Protocol Product Standard and based on the global warming potential for a 100-year evaluation period (GWP100) using characterization factors from the 2013 IPCC Assessment Report (AR5) including climate carbon cycle feedback [2]. When co-producing chemical products with varying proportions of bioand fossil feedstocks in integrated production facilities, collection of all the required data for life cycle assessment (LCA) for a segregated product becomes challenging. As a result, such data are often obtained based on simulation models. To conduct an LCA of a BMB product, an existing ISO 14040 compliant LCA model [3] for the fossil-based product is used as a starting point and estimations of the environmental burdens of the BMB product are calculated. The life cycle impact assessment (LCIA) modelling in this study has been carried out in GaBi Software-System and Database for Life Cycle Engineering by thinkstep [4] using BASF’s primary data combined with GaBi’s cradle-togate background. Life cycle inventory (LCI) data for biomethane have been also sourced from the GaBi database [4]. Biomethane produced from food (kitchen) waste via anaerobic digestion, according to BASF responsible procurement policies, which follow the sustainability criteria as in EU RED (Renewable Energy Directive of EU Commission) was considered. In this model, food waste is considered as burden-free. If the bio-feedstocks have the same chemical properties as their fossil counterparts, hence being totally interchangeable, the life cycle environmental burdens of natural gas are subtracted from the total burdens of the fossil-based product and the burdens of biogas are added to the model. However, some bio-feedstocks may have different carbon content, energetic value, or other chemical properties from the fossil feedstocks to be replaced. In such situations, it is necessary to consider the equivalent quantities of bio-feedstocks. For these purposes, it is suggested to use an equivalent factor, based on the lower heating value (LHV) of fossil and bio-feedstocks as an approximation of the chemical properties [5]. Although LCIA addresses only the environmental issues that are specified in the scope and is therefore not a complete assessment of all environmental issues of the product system under study, its results quantify and make transparent benefits such as significant CO2eq. savings of the biomass balanced products compared to the fossil counterparts. Two examples from the BASF portfolio on biomass balanced products that bring such sustainability benefits for the lubricants industry are the high performance water-soluble polyalkylene glycol (PAG) base stocks (Breox® 60 D BMBcert™ series) and the polyisobutene (PIB) portfolio (Glissopal® BMBcert™). In the case of the PAG base stocks, a product carbon footprint reduction of up to 81% is achieved in comparison to a standard Breox® 60 D product by using biomethane as feedstock in a biomass balance approach. The Breox® 60 D products find use in a variety of industrial lubricant applications, due to their low friction coefficient and excellent lubricity (low wear scar), offering energy savings and durability benefits, combined with biodegradability and a strong health and safety profile. In addition to all proven benefits mentioned above, the biomass balanced Breox® BMBcert™ product family with significantly lower PCF and 100% sustainably sourced renewable feedstocks is a unique solution and a sustainability leader on the market today. Another example for BMB products is BASF’s polyisobutene (PIB) portfolio of PIB homopolymers that has been designed to meet the demanding requirements of the lubricant industry as cost attractive high viscosity components for thickening or co-thickening of lubricants. The high performance PIB grades are suitable for thickening mineral oil base stocks and are also compatible with Poly Alpha Olefins and Ester base stocks. They can be used in a variety of industrial, driveline and grease applications, e.g., axle and transmission lubricants, hydraulic and gear lubricants as well as metalworking fluids (MWF). They do not contain any chlorine and are thus not promoting any corrosion. Glissopal® BMBcert™ grades show a PCF reduction of 100% in comparison to the corresponding non-BMB product. With the same principle, further PAG and ester base stocks, MWF components and lubricant oil additives are being launched by BASF and providing the lubricant industry with solutions for a sustainable future. 4. Conclusion Based on an established and independently certified method, the biomass balanced products enable transparency for sustainable purchasing decisions and a faster transition to a carbon-neutral circular economy. Providing the benefits of sustainably sourced renewable feedstock, flexible scale-up and identical product quality, the new biomass balanced product range BMBcert™ provide base stocks and lubricant oil additives that help save fossil resources and reduce overall greenhouse gas emissions, while maintaining the same performance. The biomass balance approach creates unique solutions for the lubricant industry, enabling customers to differentiate their lubricant solutions from competition and helps towards achieving industry sustainability goals. 23rd International Colloquium Tribology - January 2022 491 Addressing sustainability needs of the lubricants industry: References [1] Krüger, C., Kicherer, A., Kormann, C., Raupp, N., “Biomass balance: An innovative and complementary method for using biomass as feedstock in the chemical industry”. In: “Designing Sustainable Technologies, Products and Policies: From Science to Innovation”. Benetto, E., Gericke, K., Guiton, M. (Eds.), Springer International Publishing, Cham, 2018. [2] Stocker, T.F., Qin D., Plattner G.-K., Tignor M., Allen S.K., Boschung J., Nauels A., Xia Y., Bex V. and Midgley P.M. (Eds.), “IPCC Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change”, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2013. [3] ISO, “ISO 14040: Environmental Management - Life Cycle Assessment - Principles and Framework (Geneva, Switzerland)”, 2006a. [4] Thinkstep, GaBi ts (Software version 9.2, SP 37 Database 2019). https: / / www.thinkstep.com/ . [5] Jeswani H.K., Krüger C., Kicherer A., Antony F., Azapagic A., “A methodology for integrating the biomass balance approach into life cycle assessment with an application in the chemicals sector”, Science of The Total Environment, 687, 2019.