IN
DEGREE PROJECT
MATERIALS DESIGN AND ENGINEERING,
SECOND CYCLE, 30 CREDITS
,
STOCKHOLM SWEDEN 2020
Comparative LCA between
bio-based and petroleum-bio-based
lubricants
Identification of data gaps to consider when
providing decision support
PATRIK WILLIAM-OLSSON
KTH ROYAL INSTITUTE OF TECHNOLOGY
Comparative LCA between
bio-based and petroleum-bio-based
lubricants
Identification of data gaps to
consider when providing decision
support
Patrik William-Olsson
Supervisor
Miguel Brandão
Examiner
Miguel Brandão
Supervisor at RISE
Jutta Hildenbrand
Degree Project in Sustainable technology KTH Royal Institute of Technology
School of Architecture and Built Environment
Abstract
Sammanfattning
Table of Content
1 Introduction ... 1
1.1 Aim and objectives ... 1
1.1.1 Aim ... 2
1.1.2 Objectives ... 2
2 Methodology ... 3
2.1 Methodology part 1: Assessing the relationship between lubricants and the foreground system 3 2.1.1 Industrial Visits ... 3
2.1.2 Lab tests: Differences of oil loss through chips ... 3
2.1.3 Lab tests: Differences of oil loss through filters ... 4
2.1.4 Scenarios ... 4
2.2 Methodology part 2: LCA methodology ... 4
2.2.1 Foreground system boundaries ... 5
2.2.2 Background system boundaries: bio-based lubricant ... 6
2.2.3 Background system boundaries: petroleum-based lubricant ... 7
2.2.4 General system boundaries ... 8
2.2.5 Functional unit ... 8
2.2.6 Impact assessment method ... 8
3 Modeling: The foreground system ... 9
3.1 Physical properties ... 9
3.1.1 Density ... 9
3.1.2 Viscosity ... 9
Volatility ... 9
3.2 Company system: The pathway of lubricants, lab tests and company information ... 10
3.2.1 The pathway of lubricants ... 10
3.2.2 Results from lab tests ... 11
3.2.3 Company lubricant consumption and comparisons ... 12
3.2.4 Quantifying the relative amounts of lubricant carried out with chips. ... 13
4 Modeling: The lubricants LCA systems ... 15
4.1 The bio-based lubricant system ... 15
4.1.1 Raw material and unchanged input ... 16
4.1.2 Rapeseed oil ... 16
4.1.3 Olive oil ... 16
4.1.4 Sunflower oil ... 17
4.1.5 Oil Mill... 18
4.1.6 Fatty acid extraction process ...20
4.1.7 Pentaerythritol ... 22
4.1.8 Esterification process ... 24
4.1.9 Swedish rapeseed oil ... 25
4.1.10 Antioxidant additive ... 25
4.1.12 Transport ... 28
4.1.13 Waste management ... 28
4.2 Petroleum-based lubricant system ... 29
4.2.1 Data specific to the system under consideration ... 29
4.2.2 Supplier of the group III base oil ... 29
4.2.3 The petroleum-based lubricant... 29
4.2.4 End of life ... 30
4.2.5 Industrial lubricant process in Ecoinvent ... 30
4.3 life cycle inventory ... 31
4.3.1 Crude oil extraction ... 31
4.3.2 Refinery activities and diesel production ... 34
4.3.3 Group III base oil production ...40
4.3.4 The lubricant mix with synthetic ester ...40
4.3.5 The use at Gnosjö ... 41
5 Results ... 42
5.1 Selection of impact categories ... 42
5.1.1 Definition of impact categories that are used: ... 43
5.2 Comparative results ... 44
5.3 Hot spot results ... 45
6 Discussion ... 48
6.1 Hot spot: production of oil ... 48
6.2 Climate change sensitivity to ILUC ... 50
6.2.1 ILUC: Extrapolation from historical data ... 50
6.2.2 ILUC: Economic modelling ... 51
6.2.3 Interpreting the incorporation of ILUC ... 51
6.3 Potential limitation of results due to system boundaries ... 51
6.4 Uncertainty of data ... 51
6.5 Other literature ... 52
6.6 Single score and endpoint ... 53
6.7 The results as decision support ... 54
1
Introduction
The world has entered a state referred to as the Anthropocene which defines an era where human activities are the main driving force on the functionalities of the earth’s eco-systems. The Planetary boundaries are a concept developed to show the earth’s carrying capacity within nine different domains and how we are faring in comparison to the limits. The results show that we are living beyond the carrying capacity of our planet implying that we currently are living on borrowed resources. Two out of the nine boundaries are crossed; three more are in a state of uncertainty and two are not yet quantified leaving only three out of nine boundaries within a safe operating space (Rockström & Klum, 2012). Aside from the planetary boundaries, research suggests that we are living on resources requiring one and a half planet (WWF, 2016). It is suggested that industrial actors as well as individuals and governments work towards reducing their impacts on the environment.
The company under consideration in this project is a specialized turning company interested in working with the further development of reducing their environmental impacts, they have already implemented a system of photovoltaic panels as a source for renewable energy and more activities are ongoing. The area of consideration for this thesis follows that aim and is to assess the environmental impacts due to a change of lubricant in their metal turning process. This master thesis is part of a bigger project by Chalmers, Rise IVF and other industrial actors to assess the possibilities of using alternative process liquids more adapted to the future while considering environmental and work environment related aspects. The lubricant currently in use is petroleum-based and the potential replacement product is based on a vegetable oil. The idea of process liquids more adapted to the requirements of the future is like every other product or function to a great extent dependent on an idea of increased performance in areas of sustainability such as environmental aspects. The switch is of interest due to the possibility of lowering the environmental impacts.
An analysis of potential environmental impacts due to a change of lubricants is a task necessary to complete when assessing product performance with regards to future environmental sustainability. Such an analysis is therefore an important part of the project. The function under consideration for the project is the production of a metallic steel component. This thesis aims to complete the task of assessing what the significant contributors to the environmental impacts for the function of producing such a component. This in relation to the change in usage of lubricant that is likely to occur. Life cycle assessment (LCA) is an environmental system analysis tool well adapted to use when conducting environmental impact assessments in relation to products or functions (Finnveden & Moberg, 2005) and is therefore the tool of choice for this report.
Another factor that is a part of the bigger project is an analysis of how different lubricants affect the life span of the tools. This analysis would be of importance to the LCA however at this time it has not been completed. Changes in the lifespan of tools as a result of which lubricant that is used can therefore not be incorporated into the analysis. And the results will be presented as if there was no difference. The systems will however be designed so that an analysis including tool wear can be incorporated
1.1 Aim and objectives
The overarching aim of the thesis was to provide an LCA as decision support in the issue of potentially switching from the usage of a petroleum-based lubricants to the usage of bio-based lubricants. This was to be achieved through conducting a comparative LCA modified to fit the technical system at the company in Gnosjö. More specifically it had to reach all objectives presented in section (1.1.2).
1.1.1 Aim
Old aim: Assess the potential environmental impacts of the two lubricant systems, identify the hot spots and to provide decision support based on the findings
New aim: Provide information on potential data-gaps and what to consider when using Ecoinvent database data for comparing bio-based lubricants to petroleum-based lubricants.
1.1.2 Objectives
As objective 3 and 4 could not be achieved a new objective 5 has been made to fulfill the new aim. - Identify and compare the behavior of the two lubricants into the specific technical system
(based on physical properties) (1)
- Identify the environmental impacts and key hot spots for the two systems through LCA (2) - Identify the main reason for the significance of the most important hot spot/spots (3) not
achieved
- Based on the context, give a recommendation as to which lubricant that according to this study would be most likely to contribute with the lowest environmental impact (4) not achieved - Provide information on data gaps that compromise data quality and how to proceed with
2
Methodology
The thesis work has been carried out by Patrik William-Olsson supervised by Jutta Hildenbrand and Miguel Brandão. The lubricants under consideration are a bio-based lubricant and a petroleum-based lubricant. Continuous dialogues were upheld with the producers of the lubricants to first gather information and later to verify the representativeness of the systems designed to model the potential environmental impacts of their products. There are fundamentally two different areas where methodological explanations are necessary. The first is with regards to the assessment of the lubricant’s relationship to the facilities at the company. Meaning to provide an explanation of the steps taken to identify what the internal consequences of changing the oil could be. The second explanation is regarding the framework for the LCA, how the LCA is conducted and the overarching systems.
2.1 Methodology part 1: Assessing the relationship between lubricants and the foreground system
To determine how the effect of the bio-based lubricant and the petroleum-based lubricant might differ, it is vital to understand the physical properties affecting the mineral and bio-based lubricant as well as how the two different lubricants act in the surrounding technical system that is connected to the production of metallic components. Information on the system of which the lubricant operate in was documented while visiting the facility and observing the processes as well as taking photos and talking with operators this led to the possibility to create a mapping of the pathway of oil. For more information on the pathway of oil see section (3.2.1)
Information on the physical properties which might affect the technical system was gathered by a literature review. The literature review had two purposes the first purpose was to investigate further on what the most important physical properties were. The second to assess how these physical properties might contribute to the behavior of the lubricant within the system. The physical properties that was suspected to be of importance were assumed to be the properties which were likely to be connected to the biggest sources to losses of lubricants. Company information could verify metal chip disposal as being one of the biggest contributors to lubricant losses. and for more information on the company information see section (3.2.3). Investigations in literature led to information from (Chand & Kumar, 2017) suggesting that volatility might be a factor. When these factors to lubricant losses were established, a further investigation was made to identify a physical property that could be connected to lubricant losses due to metal chip disposal. The book written by (Mang & Wilfried, 2017) connected viscosity to layer thickness of lubricants on chips and components. Consequently, the two physical properties that have been used to determine the relative consumptions of lubricants are viscosity and volatility.
2.1.1 Industrial Visits
The primary reasons for the visits were to figure out information that would be needed and how/where it can be applied to assess how the function of lubricants might differ, the pathway it moves through in the facility as well as the potential losses of oil and to map these onto the pathways. This was done by dialogues with a company contact person who demonstrated the machinery and how the oil functioned within the systems as well as how the lubricant moves within the system: between the different machines filtering units in between etc. moved. The aim was to map the movement and identify the pathways the oil uses to leave the system.
2.1.2 Lab tests: Differences of oil loss through chips
the test was carried out as follows: First the chips were weighed with oil. The oil was thereafter separated from the chips with the Wira method. Afterwards the oil was weighed. This enabled an assessment of oil weight relative to the weight of chips containing the oil which enabled a calculation of weight percentage oil to chips. Values for the weight percentage oil relative to chips can be seen in section (3.2.2)
2.1.3 Lab tests: Differences of oil loss through filters
Lab tests were also conducted to assess the tendency of oil to leave the systems through the filters. The Filters are used to separate chips and other solid objects from oil as the oil flows through the system. The used filters are stored for waste treatment which is likely to be incineration. Test filters could only be obtained for petroleum-based lubricant. During the tests the filters containing chips and oil were weighed, then burned. Chips were removed from the ashes and weighed. Filter weight was obtained by weighing separate filters which were clean. The relative weight of oil to weight of filter for disposal could then be approximated and the weight percentage of oil could then be calculated. Values for the weight percentage of oil relative to the filters for disposal can be seen in section (3.2.2.)
2.1.4 Scenarios
To handle the uncertainties within the foreground system, different scenarios as how the system behavior might differ were created. These scenarios are based on lab tests, the literature review and information from the company and suppliers. The scenarios and the reasoning behind those are presented in section (3.2.4).
2.2 Methodology part 2: LCA methodology
The LCA will be conducted according to (ISO 14044, 2006). An overview of the framework is presented in (figure 1). The three overarching steps are as follows: Goal and scope definition, inventory analysis, impact assessment phase. After the assessment is made an interpretation is made. The process of conducting an LCA is as described in (figure 1) an iterative process, meaning that all the steps are constantly improved until a satisfactory results quality have been achieved. The content associated with each category is incorporated into the thesis as described below.
Goal of the study: Incorporated into the introduction is the aim of the study, reason for the study to be carried out, intended application and audience (ISO 14044, 2006). Usually written together with the scope but has been separated due to being described in different parts of the study.
Scope of the study: Detailing exactly what this study considers in the context of system, function, data requirements, assumptions, life cycle impact assessment methodology, to what degree the results are applicable and more (ISO 14044, 2006). The scope section has been incorporated into the methodology part of the study.
Life cycle inventory analysis: This part revolves around describing the data which is used as a basis for the system design, the design of the system itself as well as the input, emission, waste, products and co products of the system (ISO 14044, 2006). This part has been incorporated into the results part of the thesis.
Life cycle impact assessment: The purpose of this step is to provide contextual information to assist in a deeper understanding of the significance of the life cycle inventory results (ISO 14044, 2006). This part has been incorporated into the results part of the thesis.
Life cycle interpretation: As a final step it aims to summarize the results of earlier steps and provide a basis for discussions and conclusions (ISO 14044, 2006).This part has been incorporated into the discussion part of the thesis and includes sensitivity and uncertainty analysis.
2.2.1 Foreground system boundaries
Environmental impacts related to the differences on effects of lubricants on equipment are not accounted for. Neither are the environmental impacts of other equipment that might have to be replaced to run the systems optimally. This report will only account for differences in oil loss because of changing the lubricant. A visualization of the system is presented in (figure 2) below.
2.2.2 Background system boundaries: bio-based lubricant
The information provided about the general structure behind the manufacturing process of the bio-based lubricant suggest that the lubricant is made of rapeseed oil, synthetic ester and antioxidants. The synthetic ester was stated to be produced in Europe and the rapeseed oil used was stated to be from Sweden close to the lubricant manufacturing facility. An ester is made from an alcohol and an acid. The alcohol part of the system is of unknown substance and origin however polyols are common. The acid part is made from oleic fatty acid from rapeseed oil, olive oil and sunflower oil. The system will mainly consider cradle-to-gate (figure 3). However, waste management will be incorporated in the assessment of climate change since it where most of the carbon dioxide emissions occur for fossil-based sources while it is not the case for biogenic sources (figure 4).
Figure 3, Visualization of the basic bio-based lubricant cradle-to-gate system.
2.2.3 Background system boundaries: petroleum-based lubricant
It could be verified from the supplier that the petroleum-based lubricant is based on a hydrocracked and hydro-isomerized group-three-base-oil (section 3.2.4) from Finland in combination with a synthetic ester additive. The difference between the lubricant and the additive is different fractions of group three base oil and synthetic ester oil. The system to be studied includes the unit processes all the way from crude oil extraction, to refining, lubricant manufacturing and use phase, these unit processes have however had the electricity and transportation modified as well as some added emissions. More information on these changes in section (4.2). Information about the country of origin or producer of the synthetic ester oil was not disclosed. A description of the system is presented below in (figure 5). Waste management will only be included in the assessment with regards to climate change since it is during the waste management step that most of the relevant carbon dioxide is emitted from petroleum-based sources, (figure 6).
Figure 5, basic visualization of the Petroleum-based lubricant system
2.2.4 General system boundaries
Background processes used in this report are from Ecoinvent 3 and the system model chosen follows the approach “Allocation cut-off by classification”, there is one exception regarding gaseous nitrogen which is from the ELCD dataset. The distinctive principle for this approach is that primary production is exclusively linked to the primary use and any recycling is handled separately; hence no credit is given to primary producer/user for the product as a result of lower impacts by recycling or second use (Ecoinvent1, u.d.). In allocation scenarios the general (ISO 14044, 2006) rules apply meaning that allocation by physical relationships are preferred, if it is not possible to establish any, then other allocation methods might be considered. However, it is always preferable to avoid allocation all together.
2.2.5 Functional unit
The Functional unit is how the environmental impacts are tied to the function of the lubricant. As the lubricants are assumed to have similar impact on the product quality the question can be narrowed down to whether the oil loss differs for a specific amount of piston drums, when system boundaries are considered. The functional unit is therefore: The production of 100 piston drums. Piston drums are a regular output of the machine where the change of lubricants was tested within a pilot.
2.2.6 Impact assessment method
3
Modeling: The foreground system
The foreground system will be included into the assessment by conducting the following 4 steps. (1) analyzing the physical properties (density, volatility and viscosity), (2) analyze the system and where the properties would be of importance, (3) own tests, data from literature and data from companies will be described and compared (4) the decision on how to adapt the foreground system will be described.
3.1 Physical properties
The physical properties described in data sheets which have been selected to analyze further are density and viscosity. From literature the volatility is also assumed to be of importance. The three properties are described in more detail below.
3.1.1 Density
Density is the measurement of how compact a substance is. The higher the density the more weight per volume unit of substance. The density factor will have to be considered in to make sure the streams are correctly described to the functional unit. The density of both the petroleum-based lubricant and the bio-based lubricant was provided from their respective suppliers. The values for density are described in table 2.
3.1.2 Viscosity
Viscosity is the measurement of how resistant to deformation a fluid is. The hypothesis is that all else being equal: higher viscosity implies more oil losses due to the disposal of chips. This is because a higher viscosity is assumed to correlate with more oil sticking to the chips after centrifuging. Values for viscosities for both lubricants were provided by the suppliers. Viscosity can be connected to drag out losses from chips and components (Mang & Wilfried, 2017). This is considered to potentially influence oil losses. The values for viscosity are presented in table x below.
Table 1: Information on viscosity for both the bio-based lubricant and the petroleum-based lubricant from product data sheets given by the supplier. Comparable values are highlighted.
Substance
Density value
Petroleum-based lubricant 40 degrees Celsius 8,3 𝑚𝑚2/𝑠 Petroleum-based lubricant 100 degrees Celsius 2,4 𝑚𝑚2/𝑠
Bio-based lubricant 25 degrees Celsius 17 𝑚𝑚2/𝑠
Bio-based lubricant 40 degrees Celsius 10 𝑚𝑚2/𝑠
Petroleum-based lubricant additive at 40 degrees Celsius
118 𝑚𝑚2/𝑠
The viscosity of the mixture of petroleum-based lubricant and the additive is calculated using the Gambill method which states that ν^1/3=xaνa^1/3+xbνb^1/3. The viscosity of the mixture of petroleum-based lubricant and the additive at 40 degrees is with the method calculated to be about 10𝑚𝑚2/𝑠. This is approximately the same value as for the bio-based lubricant.
Volatility
degrees Celsius for 60 minutes (ASTM International, 2019).There is a requirement that no more than 15% of losses is allowed as a result of volatility under the Noack test for motor oils (AMS OIL, 2013). The article written by (Rudnick, et al., 2006) found that there were consistent differences in losses during the Noack test between different groups of base oil but no consistent difference within the groups. It also concluded that the best performing motor oil was synthetic oils. Biological oils were not tested in this study. As a complement to include biological oils Another study by (Johnson Duane L. & Allen, 2002) was investigated. The study concluded that granola-based lubricants performed better than synthetic lubricants under the Noack volatility test. No specific data on volatility was found for any of the products. The information does however suggest that the losses due to volatility would be lower for the bio-based lubricant than for the petroleum-based lubricant since granola-based lubricant were better than synthetic which were better than group III base oils.
3.2 Company system: The pathway of lubricants, lab tests and company information This section considers two parts. First the pathway that the lubricant takes in the system and where it can make an exit. Secondly it describes the results from tests that have been made both recently but also an earlier test and compares it to the company data for total lubricant consumption.
3.2.1 The pathway of lubricants
There are six main pathways which the chips might take to leave the system. The six pathways are illustrated in (figure 7) and further described thereafter.
Chips: Identified as the most common pathway that lubricants take to leave the system. Further testing has therefore been made to assess if there are any differences between the mineral and biological based lubricant to leave the system through this pathway. The viscosities of the two lubricants are of similar values indicating that the oil loss with chips could be similar.
Products and filters: Some of the lubricant leaves with the products and filters. Further testing has been done on how much lubricant that potentially leaves with the filters. However, the tests only consider petroleum-based lubricant since filters used with the bio-based system could not be obtained. Filters in the ventilation system were not considered, only filters used in the machines.
Wastewater: Some of the lubricant can be recovered from the water. Nonetheless there are lubricant losses due to the disposal of wastewater. Which could not be quantified.
Ventilation: Some of the lubricant leaves as airborne. The exact amount of lubricant losses due to ventilation is not known. However, it can be expected to be lower for bio-based lubricants since they seem to do better at Noack tests (Johnson Duane L. & Allen, 2002).
Other: Other refers to lubricant leaving the system through washing of hands, laundry or other activities that are due to human interactions. The total amounts of lubricant losses due to other sources are unknown. It could be related to volatility
.
3.2.2 Results from lab tests
For the procedure of the lab tests see section (2.1.2 and 2.1.3). Results from Lab tests at RISE IVF facility at Mölndal can be seen in (table 2) for metal chips and (table 3) for filters.
Table 2: Lubricant weight percentage relative to Chips Petroleum-based lubricant (lubricant +hydraulic oil)
Sample A: 5.09 w% Sample B: 11.0 w% Sample C: 5.83 w% Biological based lubricant (lubricant)
Sample 2: 2.03 w% Sample 1: 2.12 w% Sample 3: 1.86 w%
There is uncertainty regarding the source of the difference in results. Varying results from the petroleum-based lubricant might suggest that grain size is an important factor. However, the difference between the biological and the petroleum-based lubricants is likely unrelated to viscosity differences between the biological and petroleum-based lubricant, however the hydraulic oil that is used has a high viscosity of x and leaks into the system. The mineral oil blend of lubricant and hydraulic oil is therefore likely to have a higher viscosity value than the bio-based lubricants This could be a reason along with grain size differences in the test samples, time in centrifuge or other unknown sources.
Table 3: weight percentage of lubricant content in filter for disposal W% lubricant in filter
Average
Filter 1: 64,31 w% Filter 2: 64,34 w% Filter 3: 61,11 w% 63,25 w%
3.2.3 Company lubricant consumption and comparisons
To get an understanding of how important the different physical properties and pathway might be they have been benchmarked to the total input of lubricant which over time has been assumed to approximate the total losses. The lubricant input to the company is quantified in units of volume while the lubricant losses are quantified in units of mass. The density of each relevant input is presented in (table 4).
Table 4: Density of the lubricants Substance
Density value
Bio-based lubricant 880 kg/m3 Petroleum-based lubricant 841 kg/m3 Petroleum-based lubricant additive 983 kg/m3 Hydraulic oil 879 kg/m3
The hydraulic oil operates in a system not directly linked to the machine under consideration in this study. However, it does influence the system since there is a leakage of hydraulic oil system to the lubricant system that results in different actual values for the viscosity of the lubricants within the system. The amount of hydraulic oil in the system under consideration is together with company workers assessed to be 20%. The additive is a necessity if the petroleum-based lubricant is to be used in the process and the fractions of input regarding volume is 7.5% additive and 92.5% lubricant. The bio-based lubricant needs no additives. (Table 5) shows the values of density for the actual petroleum-based lubricant system and the bio-petroleum-based lubricant system. The assumption is that the blend does not affect volume that is that the sums of the isolated volumes equal the sum of the total volume when blended.
Table 5: Density values for the systems if they correlate linearly with the fractions Substance
Density value
Petroleum-based system 857,12 kg/m3 Bio-based system 879,8 kg/m3
The yearly use of lubricant filters and chips related to the petroleum-based lubricant system is shown in (table 6) below.
Table 6: Information on the annual use of filters, chips and lubricant
Filters (kg) chips (kg) Lubricant (l) Year
1213 580787 19350 2017
386 545693 23600 2016
329 554468 11450 2015
Assuming a potential upper limit by connecting all lubricant losses to chips for the petroleum-based system shows that the test result from petroleum-based lubricant since they are drastically higher than 2,71w% are not representative for the average lubricant spill. If lubricant is assumed to account for all lubricant loss, the production data amounts to about:
19350 + 23600 + 11450 + 15400 = 69800 (𝑙) Lubricant density = 0.8798𝑘𝑔
𝑙 0.8798 ∗ 69800
580787 + 545693 + 554468 + 582506= 𝑐𝑎 2.71 𝑤%
The lubricant loss through chips should be less than 2.71w%, unless total lubricant content in the system has been vanishing. Lubricant content within the system is however assumed to be relatively constant over time. Information from previous test made with the petroleum-based lubricant on brass chips showed that a lubricant loss of about 1.26 w% of brass chips for disposal occurred. This looks like a more believable result. The test results and workers stating that the biggest source of lubricant losses would be due to chip disposal, the lubricant losses due to chips have been assumed to account for about 50% based of the total oil losses.
3.2.4 Quantifying the relative amounts of lubricant carried out with chips.
The question to be answered here is as follows: If 100 products are made, how much of each
of the lubricant would leave the system with chips. However, it can be further narrowed down
by using the following logic:
𝑥 𝑙𝑖𝑡𝑟𝑒𝑠 𝑜𝑓 𝑏𝑖𝑙𝑜𝑔𝑖𝑐𝑎𝑙𝑙𝑦 𝑏𝑎𝑠𝑒𝑑 𝑐𝑢𝑡𝑡𝑖𝑛𝑔 𝑜𝑖𝑙 𝑖𝑠 𝑙𝑜𝑠𝑡 𝑝𝑒𝑟 100 𝑘𝑜𝑙𝑣𝑡𝑟𝑢𝑚𝑚𝑜𝑟
𝑦 𝑙𝑖𝑡𝑒𝑟𝑠 𝑜𝑓 𝑚𝑖𝑛𝑒𝑟𝑎𝑙 𝑏𝑎𝑠𝑒𝑑 𝑐𝑢𝑡𝑡𝑖𝑛𝑔 𝑜𝑖𝑙 𝑖𝑠 𝑙𝑜𝑠𝑡 𝑝𝑒𝑟 100 𝑘𝑜𝑙𝑣𝑡𝑟𝑢𝑚𝑚𝑜𝑟
𝑥
𝑦
= 𝑎
𝑊ℎ𝑒𝑟𝑒 "a" 𝑖𝑠 𝑡ℎ𝑒 𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑚𝑖𝑛𝑒𝑟𝑎𝑙 𝑏𝑎𝑠𝑒𝑑 𝑐𝑢𝑡𝑡𝑖𝑛𝑔 𝑜𝑖𝑙 𝑠𝑝𝑖𝑙𝑙
𝑤ℎ𝑒𝑛 1 𝑙𝑖𝑡𝑒𝑟 𝑜𝑓 𝑏𝑖𝑜𝑙𝑜𝑔𝑖𝑐𝑎𝑙 𝑏𝑎𝑠𝑒𝑑 𝑐𝑢𝑡𝑡𝑖𝑛𝑔 𝑜𝑖𝑙 𝑖𝑠 𝑙𝑜𝑠𝑡
It is evident from the calculations above that the functional unit can be expressed by comparing 1 liter of bio-based lubricant with 1 liter of petroleum-based lubricant based on lubricant loss information from the investigation of the foreground process. Since the value for loss of lubricant is going to be assumed to be moving towards a constant over time, the method of comparison can be changed. Instead of comparing lubricant loss per product it will be compared in scenarios of relative lubricant spill. Fractions of oil loss for each scenario will be determined with consideration to information from lab tests, literature and suppliers. The bio-based lubricant would have less oil losses due to the literature review revealing that volatility would be lower for the bio-based lubricant than for the petroleum-based lubricant (Rudnick, et al., 2006) (Johnson Duane L. & Allen, 2002) . The values for viscosity from suppliers as well as using the Gambill method would suggest that the petroleum-based oil and biological based oil would have similar oil losses due to having a similar value for viscosity. The latest lab tests were not consistent with earlier tests and data from the company at Gnosjö. A reasonable reason for this variation could be visible differences on chip sizes. Smaller chips would have more surface area and higher oil content consequently. The information is not conclusive in showing which lubricant that would result in lower oil losses. It does however suggest that the biologically lubricant would have lower oil losses with regards to the volatility. Data from the supplier showing that about 2.71w% of chips are used as input and earlier tests showing that about 1.26w% of oil is lost with chips suggest that sending the chips to recycling are one of the biggest sources of oil loss. Further information on centrifuges suggest that the oil losses due to disposal of chips is likely to be within the 1w% to 2w% range (Lubriserv, u.d.).
and after. Unfortunately, such tests were not conducted and the knowledge about volatility is less than what it could have been.
Scenarios have been created to try and account for most of the potential differences due to the uncertainties. The scenarios are structured as followed: The first scenario will be a 1:1 lubricant loss carry-out ratio between the two systems. However, another analysis will cover scenarios were half of the losses due to volatility will be applied to the petroleum-based lubricant, the losses due to volatility will be assumed to be about 50%. This is due to the fact that losses from the Noack test were showed about half of the losses for the bio-based lubricant as for the petroleum-based lubricant (Johnson Duane L. & Allen, 2002) and that an article considering a lubricant hazard effects on human health dictate that volatility, oil spills and accidents amount to the largest contributors to oil ending up in the environment (Chand & Kumar, 2017), chips can be assumed to amount to approximately 35-70%, due to earlier test showing 1.26w% to about 2w% and technology indicating that 1-2w% is a reasonable oil content of chips after centrifuging (Lubriserv, u.d.). then the volatility is likely to be large factor, about an average of 50% could be a reasonable but value on the higher end. If the dominant physical property determining losses of lubricant due to chips would be viscosity, then two scenarios which are 1:1 and 1:3/4 could be reasonable qualified guesses due to the fact that the viscosity for the two lubricants are of similar value and the loss to volatility losses during the Noack test was about 50%.
Standard Scenario 1: 1 kg (1.14 l) loss of petroleum-based lubricant equals 1kg (1.17 l) lubricant
loss of biological based lubricant.
Sensitivity Scenario 2: 1 kg (1.14 l) loss of petroleum-based lubricant equals 3/4 kg (0.88 l) oil
loss of biological based lubricant.
4
Modeling: The lubricants LCA systems
The background system consists of two parts, the two different lubricants. This section will describe the production process and LCI of these two systems. The results from this part will be used to assess the cradle to gate perspective of both the petroleum-based lubricant system and the bio-based lubricant system.
4.1 The bio-based lubricant system
Since it is known that lubricant contains Swedish rape seed, synthetic ester and additives it is appropriate to disclose how those systems are designed as well as the fractions. An ester is created by combining an acid with an alcohol. It was confirmed that the acid part of the ester consists of oleic fatty acid from rape seed oil, olive oil and sunflower oil. Information of a specific alcohol for the ester was not disclosed by the supplier and the choice has therefore been pentaerythritol, a polyol as it is represented in literature as a valid option (Våg, et al., 2002). Polyols as suitable alcohol components specifically to lubricants were also indicated by (Suda, et al., 2002). Following the esterification process, it was stated that an addition of 2w% antioxidants were appropriate. The oil market strongly correlates with the protein meal market. Both allocation by mass and system expansion will therefore be used to design and analyze the system which produces both vegetable oil and protein meal (Arienzo & Violante, 2007). Waste other than co-products and water are omitted from the process, except for climate change. A description of the system is presented within the model below (figure 8).
Following sections provide further description of the processes and their respective inventories. Data will only be shown for processes that were changed in any way. If the process data is unchanged it will only be referred to in sources of the LCI tables and will not be explained further.
4.1.1 Raw material and unchanged input
All the raw material and unchanged input processes for the biological based lubricant will be taken
from the Ecoinvent 3 data sets with cut-off criteria unless gaseous nitrogen which could not be found except for in the ELCD dataset.
4.1.2 Rapeseed oil
Harvested rape seeds are first dried and metallic particles are removed via a magnet, the seeds are
then de-hulled and thermally pretreated. The proceeding step is the pressing of oil, with an approximate 60 to 70% oil separation from the rape meal. Solvent extraction with hexane is used to extract the remaining oil from the rape meal. The rape meal is then used as a potential source of animal feed. The mass balance is approximately 40% rape oil and 60% rape meal. The system will be designed both with an analysis of allocation by mass as well as substitution (McManus, et al., 2003). A visualization of the system is depicted in (figure 9). The allocation values will be presented in (section 4.1.5) regarding the oil mill. The information on rapeseed will be based on Rape seed {GLO}| market for | Cut-off, U.
Figure 9: Rapeseed oil manufacturing process, both allocation scenarios 4.1.3 Olive oil
Figure 10: Olive oil manufacturing process, both allocation scenarios
4.1.4 Sunflower oil
Sunflower seed enters the seed preparation process. This yields sunflower hulls, sunflower oil and sunflower meal. Connected to this process is a sunflower solvent extraction process which helps producing the sunflower oil using sunflower cakes and transporting back the rest product which is sunflower meal. Between 25-40% (32% assumed as an average) of sunflower oil recovered from the seed depending on process. The sunflower byproduct called de-oiled meal is usually used as animal feed. Sunflower hull is about 14w% leaving 46-61% (54% assumed as an average) as de-oiled meal. The sunflower hull can be used as fuel source. The system process in SimaPro will be at the oil mill with allocation by mass as well as a system expansion perspective. A visualization of the system is depicted in (figure 11). The sunflower hulls can be used for energy for a value of 17000kJ/kg through (Le Clef & Kemper, 2015). The allocation values will be presented in (section 4.1.5) regarding the oil mill. The information regarding sunflower seeds will be based on Sunflower seed {RoW}| sunflower production | Cut-off, U
4.1.5 Oil Mill
Environmental impacts of the oil mill will be assumed to be the same for all the biological oils and will be according to the Ecoinvent data for rape seed oil. Essentially it is some product input and product output changes while energy and emission values are largely assumed to be similar. The values for the oil mill process presented in (table 7) is based on the “Rape oil, crude {RoW}| rape oil mill operation | Cut-off, U” system which describes the input and emission inventory of producing 1 kg of rape oil. The assumption is that the production of olive oil and sunflower seed oil is sufficiently close to the values of the production of rape oil to not need further analysis. The process is therefore modified according to remove any rapeseed related input data. The input this process is presented in (table 8), the output to in (table 9).
Table 7: The quantities of different input to the oil mill process. Only one of the substitution/ mass allocations is used I each system
Resources Input Quantity Unit Source
Rapeseed (mass allocation)
Mass 1.00 kg Rape seed {GLO}| market for | Cut-off, U, | Ecoinvent 3, used in SimaPro
Rapeseed (substitution)
Mass 2.50 kg Rape seed {GLO}| market for | Cut-off, U, | Ecoinvent 3, used in SimaPro
Sunflower seed (mass allocation)
Mass 1.00 kg Sunflower seed {RoW}| sunflower production | Cut-off, U | Ecoinvent 3, used in SimaPro
Sunflower seed (substitution)
Mass 3.13 kg Sunflower seed {RoW}| sunflower production | Cut-off, U | Ecoinvent 3, used in SimaPro
Olive
(mass allocation)
Mass 1.94 kg Olive {GLO}| market for olive | Cut-off, U | Ecoinvent 3, used in SimaPro
Olive (substitution)
Mass 3.70 kg Olive {GLO}| market for olive | Cut-off, U | Ecoinvent 3, used in SimaPro
Table 8: The quantities of different output to the oil mill process (including waste). Only one of the substitution/ mass allocations is used I each system
Resources Output Quantity Unit Comment
Rapeseed oil (mass allocation)
Mass 1.00 kg Used with Rapeseed | (mass allocation) Value from mass allocation, figure 5| Ecoinvent 3, used in SimaPro Rapeseed oil
(substitution)
Mass 1.00 kg Used with Rapeseed (substitution) | Value from substitution, figure 5| Ecoinvent 3, used in SimaPro Rapeseed meal
(substitution)
Mass 1.50 kg Used with Rapeseed (substitution) | Value from substitution, figure 5 | Substitution source: Protein feed, 100% crude {GLO}| market for | Cut-off, U| Ecoinvent 3, used in SimaPro
Sunflower seed oil
(mass allocation)
Mass 1.00 kg Used with Sunflower seed (mass allocation) | Value from mass allocation, figure 6 | Ecoinvent 3, used in SimaPro
Sunflower seed oil
(substitution)
Mass 1.00 kg Used with Sunflower seed (substitution) | Value from substitution, figure 6| Ecoinvent 3, used in SimaPro Sunflower seed
meal
(substitution)
Mass 1.69 kg Used with Sunflower seed (substitution) | Value from substitution, figure 6 | Substitution source: Protein feed, 100% crude {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Sunflower seed hull
(substitution)
Energy 7.840 MJ Used with Sunflower seed (substitution) | Value from substitution, figure 6 | Substitution source: Heat, from steam, in chemical industry {RoW}| market for heat, from steam, in chemical industry | Cut-off, U| Ecoinvent 3, used in SimaPro
Olive oil (mass allocation)
Mass 1.00 kg Used with Olive (mass allocation) | Value from mass allocation, figure 7 | Ecoinvent 3, used in SimaPro Olive wastewater
(mass allocation)
from vegetable oil refinery {GLO}| treatment of | Cut-off, U | Ecoinvent 3, used in SimaPro
Olive oil (substitution)
Mass 1.00 kg Used with Olive (substitution) | Value from mass allocation, figure 7 | Ecoinvent 3, used in SimaPro Olive cake
(substitution)
Mass 0.90 kg Used with Olive (substitution) | Value from mass allocation, figure 7| Substitution source: Protein feed, 100% crude {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Olive wastewater (substitution)
Volume 1.81 l Used with Olive (substitution) | Value from
substitution, figure 7 | Substitution source:Wastewater from vegetable oil refinery {GLO}| treatment of | Cut-off, U | Ecoinvent 3, used in SimaPro
Table 9: Input and emission values related to the oil mill process
Resources Input Quantity Unit Comment Source
Water (cooling) (Rest-of-World)
Volum e
5,051 E-5 m3 Water, cooling, unspecified natural origin, RoW | Ecoinvent 3, used in SimaPro
Water (process) (Rest-of-World)
Volum e
1,262 E-5 m3 Water, unspecified natural origin, RoW | Ecoinvent 3, used in SimaPro
Bentonite (Global)
Energy 0,0007524 kg Activated bentonite {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Australia)
Energy 0,001309 kWh Electricity, medium voltage {AU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(New Zealand)
Energy 0,0002535 kWh Electricity, medium voltage {NZ}| market for electricity, medium voltage | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Africa)
Energy 0,004181 kWh Electricity, medium voltage {RAF}| market group for | Cut-off, U Ecoinvent 3, used in SimaPro | Ecoinvent 3, used in SimaPro
Electricity (Asia)
Energy 0,06342 kWh Electricity, medium voltage {RAS}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Latin America and Caribbean)
Energy 0,008182 kWh Electricity, medium voltage {RLA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Northern America
Energy 0,02801 kWh Electricity, medium voltage {RNA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Rest-of-World)
Energy 1,072 E-5 kWh Electricity, medium voltage {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Russia)
Energy 0,005724 kWh Electricity, medium voltage {RU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat (Québec)
Energy 0,003842 MJ Heat, district or industrial, natural gas {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Switzerland)
Energy 7,097 E-5 MJ Heat, district or industrial, natural gas {CH}| market for heat, district or industrial, natural gas | Cut-off, U | Ecoinvent 3, used in SimaPro Heat
(Rest-of-World)
Energy 0,2234 MJ Heat, district or industrial, natural gas {RoW}| market for heat, district or industrial, natural gas | Cut-off, U | Ecoinvent 3, used in SimaPro Hexane
(Global)
Mass 0,0003524 kg Hexane {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Factory (Global)
pieces 6,315 E-10 p Oil mill {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Phosphoric acid (Global)
Waste Hexane Mass 0,0003524 kg Hexane Wastewater Volum e 2,508 E-5 m3 Water/m3 Wastewater (Rest-of-World) Volum e
3,806 E-5 m3 Water, RoW Wastewater Volum
e
8,663 E-7 m3 Wastewater, from residence {RoW}| market for wastewater, from residence | Cut-off, U | Ecoinvent 3, used in SimaPro
4.1.6 Fatty acid extraction process
The process of converting vegetable oil to fatty acid esters is represented in the Ecoinvent 3 process “Fatty acid {RoW}| production, from vegetable oil | Cut-off, U”. This process converts vegetable oil from palm, soy and coconut to their fatty acids. The process data has been assumed to be able to extend to the vegetable oils considered in this report. The allocation of vegetable oil to fatty acid will be assumed as 1:1 (mass allocation). The other fatty acids that are not oleic fatty acid and therefore not used for the specific purpose of creating an ester are assumed to be of equal value in a different process and should therefore share environmental impacts accordingly. The environmental data to produce 1kg of fatty acid is presented in (table 10). The fractions of oil input into the fatty acid process are assumed to be 1/3 of each as suggested by. The values that correlate with (table 11) are presented in (table 9). Note that only one of each oil type is to be chosen as input.
The sum of adding 1kg vegetable oil mix (1/3 of each) with the process data of producing fatty acid from vegetable oil is the cradle to gate of the oleic fatty acid production. This oleic fatty acid will be used as resource for the esterification process.
Table 10: Vegetable oil input to the oleic fatty acid manufacturing process. See comments for compatibility. Only one of the substitution/ mass allocations is used I each system
Resources Input Quantity Unit Comment
Rapeseed oil (mass allocation)
Mass 1/3 kg Used with Sunflower seed oil (mass allocation) and Olive oil (mass allocation)
Rapeseed oil (substitution)
Mass 1/3 kg Used with Sunflower seed oil (substitution) and Olive oil (substitution)
Sunflower seed oil (mass allocation)
Mass 1/3 kg Used with Sunflower seed oil (mass allocation) and Rapeseed oil (mass allocation)
Sunflower seed oil (substitution)
Mass 1/3 kg Used with Rapeseed oil (substitution) and Olive oil (substitution)
Olive oil (mass allocation)
Mass 1/3 kg Used with Sunflower seed oil (mass allocation) and Rapeseed oil (mass allocation)
Olive oil (substitution)
Mass 1/3 kg Used with Rapeseed oil (substitution) and Sunflower seed oil (substitution)
Table 11: Input and emission data for fatty acid manufacturing from vegetable oil Resources Input Quantity Unit Source
Water (cooling) (Rest-of-World)
Volume 0,024 m3 Water, cooling, unspecified natural origin, RoW | Ecoinvent 3, used in SimaPro
Water (process) (Rest-of-World)
Volume 7,0E-5 m3 Water, unspecified natural origin, RoW | Ecoinvent 3, used in SimaPro
Chemical factory (Global)
Pieces 4,0E-10 p Chemical factory, organics {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Australia)
Energy 0,0003203 kWh Electricity, medium voltage {AU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Turkey)
Energy 0,001362 kWh Electricity, medium voltage {TR}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
(Africa) Cut-off, U Ecoinvent 3, used in SimaPro | Ecoinvent 3, used in SimaPro
Electricity (Asia)
Energy 0,01161 kWh Electricity, medium voltage {RAS}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Latin America and Caribbean)
Energy 0,001280 kWh Electricity, medium voltage {RLA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Northern America
Energy 0,006261 kWh Electricity, medium voltage {RNA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Rest-of-World)
Energy 0,003516 kWh Electricity, medium voltage {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Russia)
Energy 0,001362 kWh Electricity, medium voltage {RU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Québec, natural gas)
Energy 0,0006044 MJ Heat, district or industrial, natural gas {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro Heat
(Québec, non-natural gas)
Energy 0,02063 MJ Heat, district or industrial, other than natural gas {CA-QC} | market for | Cut-off, U| Ecoinvent 3, used in SimaPro
Heat
(Rest-of-World, non-natural gas)
Energy 1,409 MJ Heat, district or industrial, other than natural gas {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Rest-of-World, natural gas)
Energy 1,199 MJ Heat, district or industrial, natural gas {RoW}| market for heat, district or industrial, natural gas | Cut-off, U | Ecoinvent 3, used in SimaPro
Emission Output Quantity Unit Source
Wastewater Volume 0,009314 m3 Water/m3 Wastewater
(Rest-of-World)
4.1.7 Pentaerythritol
Pentaerythritol constitutes the alcohol part of the synthetic ester. Pentaerythritol is produced by reacting Formaldehyde, Acetaldehyde and Caustic soda (50%). To yield 1 kg of pentaerythritol 1.040 kg of formaldehyde, 0.360kg of Acetaldehyde and 0.750kg of caustic soda (50%). The co-products in this process are 0.63kg of sodium formate, 0.1 kg of sodium formate solution and 0.07% of other polyols (Chudacoff & Kunst, 2007). Sodium formate has multiple uses (PubChem1, 2018); this makes system expansion quite hard to manage. A visualization of the system is depicted in (figure 12), allocation by mass is the system which the LCI is based on.
(Table 12) is showing the data for the system that correlates with the production of 1kg pentaerythritol, information excluding allocation is based on the process “Pentaerythritol {RoW}| production in sodium hydroxide solution | Cut-off, U”. (Table 12) show the cradle to gate system for pentaerythritol based on Ecoinvent 3 data as well as mass balances from (figure 12).
Figure 12: Pentaerythritol production system
Table 12: Input and emission data for pentaerythritol manufacturing from vegetable oil Resources Input Quantity Unit Source
Peat Mass 0,01325 kg Peat Water, cooling
(Rest-of-World)
Volume 0,01248 m3 Water, cooling, unspecified natural origin, RoW Water, river
(Rest-of-World)
Volume 0,0006547 m3 Water, river, RoW Water, well in
ground
(Rest-of-World)
Volume 0,0003203 kWh Water, well, in ground, RoW
Acetaldehyde Mass 0.212 kg Acetaldehyde {GLO}| market for | Cut-off, U Ecoinvent |
3
, used in SimaProChemical factory (Global)
Pieces 3,045E-10 p Chemical factory, organics {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Australia)
Energy 0,003732 kWh Electricity, medium voltage {AU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(New Zealand)
Energy 0,0007225 kWh Electricity, medium voltage {NZ}| market for electricity, medium voltage | Cut-off, U| Ecoinvent 3, used in SimaPro
(Africa) for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Asia)
Energy 0,1808 kWh Electricity, medium voltage {RAS}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Latin America and Caribbean)
Energy 0,02332 kWh Electricity, medium voltage {RLA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Northern America)
Energy 0,07984 kWh Electricity, medium voltage {RNA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Rest-of-World)
Energy 3,056 E-5 kWh Electricity, medium voltage {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Russia)
Energy 0,01632 kWh Electricity, medium voltage {RU}| market for | Cut-off, U | Cut-Cut-off, U | Ecoinvent 3, used in SimaPro Formaldehyde Mass 0.612 kg Formaldehyde {GLO}| market for | Cut-off, U |
Ecoinvent 3, used in SimaPro Heat
(Québec, natural gas)
Energy 0,05150 MJ Heat, district or industrial, natural gas {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Rest-of-World, natural gas)
Energy 2,993 MJ Heat, district or industrial, natural gas {RoW}| market for heat, district or industrial, natural gas | Cut-off, U | Ecoinvent 3, used in SimaPro Heat
(Québec, non-natural gas)
Energy 0,0006527 MJ Heat, district or industrial, other than natural gas {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Rest-of-World, non-natural gas)
Energy 1,522 MJ Heat, district or industrial, other than natural gas {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Nitrogen (liquid) Mass 0,01446 kg Nitrogen, liquid {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Sodium Hydroxide Mass 0.441 kg Sodium hydroxide, without water, in 50% solution state {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Tap water (Québec) Mass 3,709E-5 kg Tap water {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Tap water (Rest-of-World)
Mass 0,01976 Tap water {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Tap water, de-ionized
(Rest-of-World)
Mass 0,2854 kg Water, deionised, from tap water, at user {RoW}| market for water, deionised, from tap water, at user | Cut-off, U
Emission Output Quantity Unit Source
Ammonia Volume 2,497E-5 kg Ammonia
Carbon dioxide Volume 0,09896 kg Carbon dioxide, fossil Carbon monoxide Mass 0,0007841 kg Carbon monoxide, fossil Nitrogen oxides Mass 0,0005017 kg Nitrogen oxides
Atmospheric Nitrogen
Mass 0,01446 kg Nitrogen, atmospheric
Particulates Mass 2,946 E-5 kg Particulates, > 2.5 um, and < 10um Sulphur dioxide Mass 0,0002444 kg Sulphur dioxide
Water Volume 0,001066 m3 Water/m3
BOD Mass 0,0003535 kg BOD5, Biological Oxygen Demand COD Mass 0,0007070 kg COD, Chemical Oxygen Demand DOC Mass 0,0002619 kg DOC, Dissolved Organic Carbon TOC Mass 0,0002619 kg TOC, Total Organic Carbon Water
(Rest-of-World)
Volume 0,01271 m3 Water, RoW Waste Output Quantity Unit Source
Wastewater (Rest-of-World)
Product
Output Quantity Unit Source
Pentaerythritol Mass 1 kg Mass balance
4.1.8 Esterification process
As previously stated, the synthetic ester consists of vegetable oil (rapeseed oil, olive oil and sunflower oil) mixed with an alcohol (pentaerythritol). Each pentaerythritol molecule will be assumed to connect to four oleic fatty acid molecules since pentaerythritol has four functional groups (PubChem2, 2018). Oleic fatty acid has a molecular weight of 282.486g per mole (PubChem3, 2018) and pentaerythritol has a molecular weight of 136.147g per mole (PubChem2, 2018). Consequently, the weight fractions of alcohol to fatty acid become approximately from (figure 13) it can be deduced that 10.75% alcohol and 89.25% fatty acid. The ester is created by a transesterification process (Våg, et al., 2002). The esterification inventory of the esterification process is standardized to the output of 1kg synthetic ester. The Input and emissions of the process is described in (table 13).
Figure 13: Transesterification system, no allocation needed Table 13: The LCI values for the esterification process
Resources Input Quantity Unit Source
Natural Gas Energy 0.96 MJ Input value provided by (Våg, et al., 2002) | Ecoinvent 3 system - Heat, central or small-scale, natural gas {GLO}| market group for | Cut-off, U
Electricity Energy 0.18 MJ Input value provided by (Våg, et al., 2002) | Ecoinvent 3 system - Electricity, medium voltage {GLO}| market group for | Cut-off, U
Water
Mass 4 kg Input value provided by (Våg, et al., 2002) | Ecoinvent 3 system - Water, deionised, from tap water, at user {Europe without Switzerland}| market for water, deionised, from tap water, at user | Cut-off, U
Air Mass 3 kg Input value provided by (Våg, et al., 2002) | Ecoinvent 3 system - Compressed air, 1000 kPa gauge {GLO}| market for | Cut-off, U
Nitrogen Mass 1 kg Input value provided by (Våg, et al., 2002) | ELCD system - Nitrogen, via cryogenic air separation, production mix, at plant, gaseous EU-27 S
Emission Input Quantity Unit Source
organic compounds
COD Mass 0.00004 kg Input value provided by (Våg, et al., 2002) | COD, Chemical Oxygen Demand
Waste Input Quantity Unit Source Fatty acid
waste
Mass 0.05 kg Input value provided by (Våg, et al., 2002) | Waste, organic
Solid waste Mass 0.01 kg Input value provided by (Våg, et al., 2002) | Waste, solid
4.1.9 Swedish rapeseed oil
The Swedish rapeseed oil will be handled as previous rape seed oil with the difference being that transport to the supplier factory is neglected.
4.1.10 Antioxidant additive
Phenol-based antioxidant additives are viable as option for lubricants (Girotti, et al., 2011). Since no specification regarding location were presented, the global standard for phenol is assumed to be a good representation as we also assumed by (Girotti, et al., 2011). The Ecoinvent 3 global process includes the production of acetone (Althaus, et al., 2007). This is considered and is corrected by mass allocation. The system for phenol is shown in (figure 14). The synthetic ester is mixed with an additive at supplier Manufacturing plant. The additive is as earlier mentioned an antioxidant based on Phenol which is considered a common alternative (Girotti, et al., 2011). (Table 14) Present the cradle to gate system of Phenol based on the process “Phenol {RoW}| phenol production, from cumene | Cut-off, U”.
Figure 14: Phenol reaction process, note the mass balance approach to correct for acetone. No loss worth mentioning is assumed since the standard process takes this approach.
Table 14: Inventory data of the cradle to gate system for the phenol-based antioxidant, including mass balance Resources Input Quantity Unit Source
Water, cooling (Rest-of-World)
Volume 0,01173 m3 Water, cooling, unspecified natural origin, RoW
Water, river (Rest-of-World)
Volume 0,0006151 m3 Water, river, RoW Water, well in ground
(Rest-of-World)
Volume 0,0005936 kWh Water, well, in ground, RoW
Cumene Mass 0.789474 kg Cumene {GLO}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Chemical factory (Global)
Electricity (Australia)
Energy 0,003561 kWh Electricity, medium voltage {AU}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(New Zealand)
Energy 0,0006789 kWh Electricity, medium voltage {NZ}| market for electricity, medium voltage | Cut-off, U| Ecoinvent 3, used in SimaPro
Electricity (Africa)
Energy 0,01120 kWh Electricity, medium voltage {RAF}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Asia)
Energy 0,1699 kWh Electricity, medium voltage {RAS}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity
(Latin America and Caribbean)
Energy 0,02191 kWh Electricity, medium voltage {RLA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity
(Northern America)
Energy 0,07502 kWh Electricity, medium voltage {RNA}| market group for | Cut-off, U | Ecoinvent 3, used in SimaPro
Electricity (Rest-of-World)
Energy 2.872 E-5 kWh Electricity, medium voltage {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro Electricity
(Russia)
Energy 0,01533 kWh Electricity, medium voltage {RU}| market for | Cut-off, U | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Québec, natural gas)
Energy 0,02601 MJ Heat, district or industrial, natural gas {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Heat
(Rest-of-World, natural gas)
Energy 1.5117 MJ Heat, district or industrial, natural gas {RoW}| market for heat, district or industrial, natural gas | Cut-off, U | Ecoinvent 3, used in SimaPro Heat, Steam in chemical
industry, (Rest-of-world)
Energy 0,1430 MJ Heat, from steam, in chemical industry {RoW}| market for heat, from steam, in chemical industry | Cut-off, U | Ecoinvent 3, used in SimaPro
Nitrogen, liquid (Rest-of-World)
Mass 0,01359 kg Nitrogen, liquid {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Tap water (Québec) Mass 3,484E-5 kg Tap water {CA-QC} | market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Tap water (Rest-of-World)
Mass 0,01856 Tap water {RoW}| market for | Cut-off, U | Ecoinvent 3, used in SimaPro
Emission Output Quantity Unit Source
Carbon dioxide Volume 0,1505 kg Carbon dioxide, fossil Atmospheric Nitrogen Mass 0,01359 kg Nitrogen, atmospheric Water Volume 0,001001 m3 Water/m3
BOD Mass 0,007373 kg BOD5, Biological Oxygen Demand COD Mass 0,007373 kg COD, Chemical Oxygen Demand Cumene Mass 0.002404 kg Cumene
DOC Mass 0,002159 kg DOC, Dissolved Organic Carbon TOC Mass 0,002159 kg TOC, Total Organic Carbon Water
(Rest-of-World)
Volume 0,01194 m3 Water, RoW Waste Output Quantity Unit Source
Wastewater (Rest-of-World)
Volume 1,931 E-6 m3 Wastewater, average {RoW}| market for wastewater, average | Cut-off, U Product Output Quantity Unit Source
Phenol Antioxidant Mass 1 kg Mass balance Avoided Product Output Quantity Unit Source
4.1.11 The bio-based lubricant process
The bio-based lubricant is stated to consist of 78.4w% synthetic ester, 19,6w% rapeseed oil and 2w%
phenol-based antioxidants. The location for production is at southern Sweden. Inventory information related to the process of producing bio-based lubricant from these resources could not be recovered from the manufacturer, thus only material input directly linked to the production is presented in (table 15)
Table 15: inventory of input and output data of the bio-based lubricant, process data is omitted. Only one of the substitution/ mass allocations is used I each system
Resources Input Quantity Unit Comment
Synthetic ester (mass
allocation)
Mass 0.784 kg Used with Rapeseed oil (mass allocation)
Synthetic ester (substitution)
Mass 0.784 kg Used with Rapeseed oil (substitution) Rapeseed oil
(mass allocation)
Mass 0.196 kg Used with synthetic ester (mass allocation)
Rapeseed oil (substitution)
Mass 0.196 kg Used with synthetic ester (substitution) Phenol
Antioxidant
Mass 0.02 Kg Used with both systems Resources output Quantity Unit Comment
Bio-based lubricant (substitution)
Mass 1 kg Used with synthetic ester (substitution) and Rapeseed oil (substitution)
Bio-based lubricant (mass allocation
