Lubricating oil analysis

Abstract

A method of analyzing a lubricating oil may include: measuring a first concentration of components in the lubricating oil using x-ray fluorescence prior to introduction into a cylinder of a two-stroke engine, the components including: sulfur and total calcium; collecting the scraped lubricating oil corresponding to the lubricating oil after having passed through the cylinder during combustion of a fuel containing 0.5 wt% or less of sulfur; measuring a second concentration of a component in the scraped lubricant using x-ray fluorescence; and calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component. Based on the analysis, a change to the property of the scraped lubricant and / or a change to the lubricant feed rate into the cylinder may be performed based on the amount of neutralized acid.

Description

Field of the Invention

[0001] The present disclosure relates to methods and systems for analyzing lubricating oils, particularly marine lubricating oils used in combination with low sulfur fuels. Background Art

[0002] Many conventional marine fuels correspond to fuels with a large amount of sulfur content. During combustion to run a diesel engine, sulfur can be oxidized to form sulfuric acid. If sulfuric acid can condense on the surface, this can cause undesirable corrosion of surfaces and / or seals in the engine. In order to alleviate this problem, alkalis such as calcium carbonate can be added to lubricants for marine engines. Fuel and lubricant can interact in the combustion cylinder, so if enough alkali is added to the lubricant, the sulfuric acid formed during the fuel combustion process can be neutralized when it condenses. The total base number is generally used as an indicator of the ability of a lubricant (or other hydrocarbon fluid) to neutralize additional acid. In other words, the total base number is a measure of reserve alkalinity. Used lubricating oil can refer to lubricating oil that has passed through the engine cylinder and simultaneously carried out a combustion reaction to run the engine. Scrape-down oil is an example of a used marine lubricating oil.

[0003] Traditional determination of Total Base Number uses techniques such as titration, chemical reactions, chemometric modeling, and more recently based on elemental measurements of calcium and sulfur combined with elemental iron measurements. These measurements are typically performed in a laboratory rather than on the engine site, which often means that it takes at least a week to report the results. If the oil analysis indicates that a change in operating conditions is needed, the delay in reporting can lead to potential damage and wear to the engine.

[0004] An alternative method for characterizing whether enough alkali has been added to the lubricant is based on the total base number of the scraped oil left after combustion. U.S. Patent No. 7,741,122 describes a method for estimating the total base number of marine scraped oil by measuring the sulfur content of the scraped oil using x-ray fluorescence. Optionally, calcium in the scraped oil can also be determined, where the measured value is used to normalize the sulfur value between samples. Although this method is able to estimate the residual total base number, the minimum amount of sulfur in the fuel required for a reliable estimate of the residual total base number is relatively high, typically about 2% by weight or more. However, recent policies limit the amount of sulfur in marine fuel to 0.5% by weight unless the ship is equipped with a scrubber to remove sulfuric acid from the exhaust. Less sulfur in the fuel means less acid is produced during the combustion process. Therefore, less total base is required in the lubricant. If a lubricating oil with too low a base number is used, unneutralized sulfuric acid can cause corrosion. If too high a base number is used, excess inorganic bases such as calcium carbonate may form deposits that accumulate inside the engine, which can cause physical wear and damage to engine components and lead to reduced efficiency. SUMMARY OF THE INVENTION

[0005] A non-limiting exemplary method of the present disclosure includes: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence prior to introduction into a cylinder of a two-stroke engine, the component comprising: sulfur and total calcium; collecting scrape-down lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; calculating an amount of acid neutralized during combustion based on the first and second concentrations of the component; and making changes to a property of the scraped lubricating oil and / or changing a lubricating oil feed rate into the cylinder based on the amount of acid neutralized.

[0006] Another non-limiting exemplary method of the present disclosure includes: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence prior to introduction into a cylinder of an engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; calculating an amount of acid neutralized during combustion based on the first and second concentrations of the component; calculating a remaining useful base number of the scraped lubricating oil; and making changes to properties of the scraped lubricating oil and / or changing a lubricating oil feed rate into the cylinder based on the remaining useful base number.

[0007] Yet another non-limiting exemplary method of the present disclosure includes: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence prior to introduction into a cylinder of an engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less of sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; calculating an amount of acid neutralized during combustion based on the first and second concentrations of the component; calculating a total base number of the scraped lubricating oil; and making changes to properties of the scraped lubricating oil and / or changing a lubricating oil feed rate into the cylinder based on a correlation between the amount of acid neutralized during combustion and the total base number of the scraped lubricating oil.

[0008] Another non-limiting exemplary method of the present disclosure includes: measuring a first metal concentration in a marine lubricating oil using x-ray fluorescence prior to introduction into a cylinder of an engine, wherein the first metal concentration includes a concentration of a soluble metal and a concentration of an insoluble metal; collecting scrape-down marine lubricating oil corresponding to the marine lubricating oil after it has passed through the cylinder during fuel combustion of a fuel containing 0.5 wt % or less sulfur; measuring a second metal concentration in the scraped marine lubricating oil using x-ray fluorescence; calculating a change in the metal concentration during combustion based on the first and second metal concentrations; and when the change in metal concentration is an increase in metal concentration above a threshold, making a change in a property of the scraped marine lubricating oil and / or changing a lubricating oil feed rate into the cylinder to reduce the base number of the lubricating oil in the engine.

[0009] These and other features and properties of the disclosed methods and systems of the present disclosure and their advantageous applications and / or uses will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To assist one of ordinary skill in the relevant art in making and using the subject matter of the present invention, reference is made to the accompanying drawings. The following drawings are included to illustrate certain aspects of the present disclosure and should not be construed as an exclusive configuration. The disclosed subject matter is capable of obvious modifications, variations, combinations, and equivalents in form and function as would occur to one of ordinary skill in the relevant art having the benefit of the present disclosure.

[0011] Figure 1 is a graph of the Total Base Number of a scrape-down marine lubricant oil versus the amount of acid generated by the combustion of sulfur-containing fuels that is neutralized by the lubricant oil.

[0012] Figure 2 Graphical illustration of the total base number used (TBN) from various marine lubricant samples. used Four plots of ) (EQ. 3) or neutralized acid (AN) versus average total iron (as measured by x-ray fluorescence) or percent fuel sulfur, respectively.

[0013] Figure 3 is the TBN of various marine lubricant samples used A graph of the difference between the 100% and Day Tank BN (Day Tank Base Number) versus the fuel sulfur percentage.

[0014] Figure 4 is the TBN of various marine lubricant samples used Or a graph of AN versus fuel sulfur percentage.

[0015] Figure 5A - B is a graph of iron concentration (A) and calcium concentration (B) of Engine 1 versus time.

[0016] Fig. 6A -B is a graph of iron concentration (A) and calcium concentration (B) of Engine 2 versus time.

[0017] Figure 7 Included are four graphs showing the amount of acid neutralized or the change in calcium concentration versus load percentage or fuel sulfur. Details

[0018] The present disclosure relates to methods and systems for analyzing lubricating oils, particularly marine lubricating oils used in combination with low sulfur fuels in two-stroke engines.

[0019] All numerical values ​​in the detailed description and claims herein are modified by "about" or "approximately" the indicated value, and take into account experimental errors and variations expected by a person of ordinary skill in the art. The phrase "major amount" or "major component" as it relates to a component included in the lubricating oil of the specification and claims means greater than or equal to 50 weight %, or greater than or equal to 60 weight %, or greater than or equal to 70 weight %, or greater than or equal to 80 weight %, or greater than or equal to 90 weight %, based on the total weight of the lubricating oil. The phrase "minor amount" or "minor component" as it relates to a component included in the lubricating oil of the specification and claims means less than 50 weight %, or less than or equal to 40 weight %, or less than or equal to 30 weight %, or greater than or equal to 20 weight %, or less than or equal to 10 weight %, or less than or equal to 5 weight %, or less than or equal to 2 weight %, or less than or equal to 1 weight %, based on the total weight of the lubricating oil. The phrase "substantially free" as it relates to a component included in a lubricating oil of the specification and claims means that the particular component is present at 0% by weight in the lubricating oil, or at an impurity-type level in the lubricating oil (less than 100 ppm, or less than 20 ppm, or less than 10 ppm, or less than 1 ppm). The phrase "other lubricating oil additives" as used in the specification and claims refers to other lubricating oil additives that are not specifically listed in a particular portion of the specification or claims. For example, other lubricating oil additives may include, but are not limited to, antioxidants, detergents, dispersants, anti-wear additives, corrosion inhibitors, viscosity improvers, metal passivators, pour point depressants, seal compatibility agents, defoamers, extreme pressure agents, friction modifiers, and combinations thereof.

[0020] Diesel engines can generally be classified as slow, medium or high speed engines, with the slow speed variety being used for the largest, deep draft marine vessels and industrial applications. Slow speed diesel engines are typically direct coupled, direct reversing, two-stroke cycle engines that operate in the range of about 57 rpm to 250 rpm and typically run on residual fuels. These engines are crosshead construction with diaphragms and stuffing boxes that separate the power cylinders from the crankcase to prevent combustion products from entering the crankcase and mixing with the crankcase oil. Medium speed engines typically operate in the range of 250 rpm to about 1100 rpm and can operate in a 2-stroke or 4-stroke cycle. These engines are trunk piston designs, and many engines also run on residual fuels. They can also run on distillate fuels that contain little residual. On deep sea vessels, these engines may be used for propulsion, auxiliary applications, or both.Slow and medium speed marine diesel engines are also widely used in power plant operations, and the methods disclosed herein are also applicable to these applications.

[0021] Each type of diesel engine uses lubricating oil to minimize component wear, dissipate heat, neutralize and disperse combustion products, prevent rust and corrosion, and prevent sludge formation or sediment. For some lubricant applications, such as in the cylinder lubrication in the low-speed crosshead diesel engine using a total loss lubrication system and burning heavy fuel oil with a very large sulfur content, the main cause of engine wear is acid-induced corrosive wear. The lubricants used for these fuels are formulated to have a high total base number (TBN) to neutralize the acid formed by burning these fuels, thereby minimizing the corrosive wear of these engines. TBN is an index of the ability of lubricants (or other hydrocarbon fluids) to neutralize additional acids. In other words, total base number is a measure of reserve alkalinity. In this article's discussion, the measured value of total base number is measured according to ASTM D2896. The unit of total base number corresponds to mgKOH / g lubricant.

[0022] However, in low-sulfur fuels (e.g., fuels containing less than 0.5 wt % or less sulfur), less sulfuric acid is produced during combustion, and unconsumed alkali present in the lubricant, especially calcium carbonate, may precipitate during use and form deposits that accumulate inside the engine (e.g., two-stroke engine), which may affect efficiency and may cause physical wear and damage to engine parts. Conventional methods for determining the TBN of scraped oils generally use non-aqueous titrations, and the measurement of elemental calcium concentration is generally performed using inductively coupled plasma (ICP). Both techniques do not take into account insoluble (or precipitated) calcium carbonate. Therefore, the TBN used to adjust the lubricant composition (e.g., by including more alkali, changing the feed rate of fresh lubricant, etc.) is wrong, and in some cases is significantly lower than expected. Therefore, more alkali may be added, which further contributes to the insoluble calcium carbonate wear problem.

[0023] Since low sulfur fuels may result in incorrect TBN values ​​for lubricants, this disclosure uses the neutralized acid amount to characterize scraped lubricating oils. The neutralized acid amount (AN) can be calculated according to the following formula: Where AN is the neutralized acid (mg KOH / g lubricant), α is a constant value of 35 (mg KOH) / (g lubricant*wt%S) used to convert from sulfur concentration units to mg KOH / g lubricant units, and S used is the sulfur concentration in the scraped lubricating oil (wt%), S fresh is the sulfur concentration (wt%) in the lubricating oil before introduction into the engine cylinder, M used is the concentration (weight %) of metals (such as Ti, Ca, etc.) in the scraped lubricating oil, and M fresh is the metal concentration (wt%) in the lubricating oil before introduction into the engine cylinder.

[0024] A metal-specific AN may be EQ.2, which is calcium-specific. Where AN is the neutralized acid (mg KOH / g lubricant), α is a constant value of 35 (mg KOH) / (g lubricant*wt%S) used to convert from sulfur concentration units to mg KOH / g lubricant units, and S used is the sulfur concentration (weight %) in the scraped lubricating oil, S fresh is the sulfur concentration (weight %) in the lubricating oil before it is introduced into the engine cylinder, Ca used is the calcium concentration (wt%) in the scraped lubricating oil, and Ca fresh is the calcium concentration (weight %) in the lubricating oil before introduction into the engine cylinder.

[0025] If the total base number is expressed relative to a different base (such as NaOH), the value of α changes accordingly.

[0026] The above calcium concentration should be the total calcium (i.e., soluble calcium and insoluble calcium) in the sample. In order to reduce the error of this value caused by the precipitation of insoluble calcium, it is preferably measured shortly after obtaining the scraped lubricating oil sample. The time between collecting the scraped lubricating oil sample and measuring can be about 4 hours or less (or about 1 minute or less, or about 5 minutes or less, or about 10 minutes or less, or about 15 minutes or less, or about 30 minutes or less, or about 1 minute to about 1 hour, or about 30 minutes to about 4 hours, or about 1 minute to about 10 minutes, or about 5 minutes to about 30 minutes, or about 20 minutes to about 1 hour, or about 1 hour to about 4 hours).

[0027] The measurement of sulfur and calcium concentrations can be performed using x-ray fluorescence (XRF). XRF can be used to measure the concentrations of calcium and sulfur as well as other elements such as iron, chromium, vanadium, magnesium, phosphorus, chlorine, potassium, manganese, aluminum, silicon, titanium, copper, nickel, zinc, lead, tin or other elements. XRF can be performed according to the method in ASTM D6443-14 (2019) e1. It should be noted that ASTM D6443-14 (2019) e1 is traditionally used to determine the amount of elements in fresh lubricating oil, but in some aspects, it can also be used to determine the element content in scraped lubricating oil so that the same method is used for the determination of the element content in fresh lubricant oil and the corresponding scraped lubricating oil. For elements not specifically specified in ASTM D6443-14 (2019) e1, XRF elemental analysis can be performed in a similar manner.

[0028] The amount of acid neutralized during the combustion process measured for the scraped lube oil can be used to determine changes to the properties of the scraped lube oil and / or to change the lube oil feed rate into the cylinder based on the amount of acid neutralized.

[0029] For example, if the amount of acid neutralized during combustion is above a first threshold, the high value may indicate the possibility of sulfuric acid in the combustion cylinder environment. This can lead to undesirable corrosion of the cylinder wall. Alternatively, if the amount of acid neutralized during combustion is below a second threshold, the low value may indicate that too much oil is delivered to the cylinder and / or there is too much alkali in the lubricating oil. Therefore, after calculating the amount of acid neutralized during combustion, the resulting value can be used to perform one or more corrective measures. In some aspects, the corrective measure may correspond to adjusting the oil flow to the cylinder. If the amount of acid neutralized during combustion is too high, such as greater than the first threshold (or a higher threshold), the flow of lubricant to the cylinder can be increased. Although the fresh oil is not changed, a higher flow means that more alkali is delivered to the cylinder. Similarly, if the amount of acid neutralized during combustion is too low, such as less than the second threshold (or a lower threshold), the flow of lubricant to the cylinder can be reduced. This can save the operating costs of the ship and reduce the volume of used waste oil generated. In some aspects, the first threshold value and / or the second threshold value of the scraped lubricating oil can be selected based on the total base number of the corresponding fresh oil. An example of selecting the threshold value based on the total base number of the corresponding fresh oil can be a percentage selection threshold value based on the total base number of the corresponding fresh oil (that is, the total base number of the fresh oil is multiplied by a proportional factor). In various aspects, the second threshold value can be 20mg KOH / g or lower, or 15mg KOH / g or lower, or 10mg KOH / g or lower, such as as low as about 0mg KOH / g. If the calculated acid number is reduced to below the second threshold value, less alkali or detergent (such as CaCO3) can be added to the fresh oil to reduce the total base number of the fresh oil by 5mg KOH / g or higher, or 10mg KOH / g, or 15mg KOH / g or higher, such as up to 25mg KOH / g or higher.

[0030] Thus, one method of the present disclosure may include: measuring a first concentration of a component in a lubricating oil (e.g., a marine lubricating oil) using XRF prior to introduction into a cylinder of an engine (e.g., a two-stroke engine), the component comprising: sulfur and total calcium; collecting a scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during a fuel combustion process of a fuel comprising 0.5 wt % or less sulfur (or 0.1 wt % or less sulfur, or 0.01 wt % to 0.5 wt % sulfur, or 0.01 wt % to 0.1 wt % sulfur); measuring a second concentration of the component in the scraped lubricating oil using XRF within approximately 4 hours of collecting the scraped lubricating oil; calculating an amount of acid neutralized during the combustion process based on the first and second concentrations of the component; and making changes to the properties of the scraped lubricating oil and / or changing the lubricating oil feed rate into the cylinder based on the amount of acid neutralized.

[0031] In another example using the amount of acid neutralized during the combustion process, the remaining useful base number in the scraped lubricant can be calculated. From this, the operator can change the properties of the scraped lubricant and / or change the feed rate of the lubricant. The remaining useful base number (RUBN) can be calculated according to EQ. 3, where TBN fresh Calculated according to EQ. 4 using XRF or conventional measurement techniques (eg, titration by ASTM D2896-21 or ICP techniques). RUBN=TBN fresh -AN EQ.3 TBN fresh =A*Ca fresh +B EQ.4 Where A and B are factors that can be determined experimentally, with A being a weighting factor for calcium (typically about 26.8 per wt % calcium) and B being a correction for other base components in the lubricating oil (e.g. other metals or ashless sources of base number).

[0032] A high RUBN may indicate that less base is needed (eg, by reducing the feed rate and / or by using a lower base number lubricant) to neutralize the acid.

[0033] A method of the present disclosure may include: measuring a first concentration of a component in a lubricating oil (e.g., a marine lubricating oil) using x-ray fluorescence prior to introduction into a cylinder of an engine (e.g., a two-stroke engine), the component comprising: sulfur and total calcium; collecting scraped lubricating oil (e.g., scraped marine lubricating oil) corresponding to lubricating oil after it has passed through the cylinder during a fuel combustion process of a fuel comprising 0.5 wt % or less sulfur (or 0.1 wt % or less sulfur, or 0.01 wt % to 0.5 wt % sulfur, or 0.01 wt % to 0.1 wt % sulfur); measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence within approximately 4 hours of collecting the scraped lubricating oil; calculating an amount of acid neutralized during the combustion process based on the first and second concentrations of the component; calculating a remaining useful base number of the scraped lubricating oil; and making changes to properties of the scraped lubricating oil and / or changing a lubricating oil feed rate into the cylinder based on the remaining useful base number.

[0034] In yet another example of using the amount of acid neutralized during the combustion process, the relationship between the total base number of a scraped lubricating oil (e.g., scraped marine lubricating oil) and the amount of acid neutralized during the combustion process can be used to determine potential problems (e.g., the presence of high concentrations of calcium carbonate deposits). For example, a high TBN value of the scraped lubricating oil (e.g., higher than the TBN of fresh oil) together with a low value for the amount of acid neutralized during the combustion process can indicate that insoluble calcium is being formed and corrective measures should be taken to the composition of the lubricating oil and / or the feed rate of the lubricating oil to reduce the amount of insoluble calcium, which reduces wear on the engine. Wear can be indicated by measuring metals (e.g., iron, chromium, or other metals) in the scraped oil. Reducing excess calcium in the used oil can show a reduction in wear metals. The TBN (TBN) of the scraped lubricating oil used ) can be determined according to EQ.5 or EQ.6, where the sulfur and calcium concentrations are determined using XRF as discussed above, and TBN can be measured using XRF or conventional measurement techniques (e.g., by ASTM D2896-21 titration or ICP techniques) fresh (TBN 新鲜 ).

[0035] For example, a high TBN corresponds to a low AN (e.g., less than about 30 mg KOH / g lubricant) when using a lubricant with a fresh BN of 100. used (e.g., greater than about 100 mg KOH / g lubricant) may indicate that a large amount of calcium carbonate is forming solid particles and causing wear in the engine. In addition, low TBN used (eg, less than about 50 mg KOH / g lubricant) and low AN (eg, less than about 30 mg KOH / g lubricant) may indicate that proper conditions and composition are in place and should be maintained.

[0036] A method of the present disclosure may include: measuring a first concentration of a component in a lubricating oil (e.g., a marine lubricating oil) using x-ray fluorescence prior to introduction into a cylinder of an engine (e.g., a two-stroke engine), the component comprising: sulfur and total calcium; collecting scraped lubricating oil (e.g., scraped marine lubricating oil) corresponding to lubricating oil after it has passed through the cylinder during a fuel combustion process of a fuel comprising 0.5 wt % or less sulfur (or 0.1 wt % or less sulfur, or 0.01 wt % to 0.5 wt % sulfur, or 0.01 wt % to 0.1 wt % sulfur); measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence within about 4 hours of collecting the scraped lubricating oil; calculating an amount of acid neutralized during the combustion process based on the first and second concentrations of the component; calculating a total base number of the scraped lubricating oil; and making changes to the properties of the scraped lubricating oil and / or changing a lubricating oil feed rate into the cylinder based on a correlation between the amount of acid neutralized during the combustion process and the total base number of the scraped lubricating oil.

[0037] In alternative embodiments, metals may be used alone, or optionally in combination with AN (using calcium and sulfur concentrations), when analyzing lubricating oils. In this example, changes in metal concentrations may be used, wherein a threshold change in metal concentration is set so that excessive changes in metal concentrations may indicate that base and / or calcium deposits are accumulating in the lubricating oil (e.g., marine lubricating oil). Thus, changing the nature of the scraped lubricating oil and / or changing the lubricating oil feed rate into the cylinder to reduce the base number of the lubricating oil in the engine may mitigate the formation of deposits that cause engine wear. A non-limiting exemplary equation for analyzing changes in metal concentrations is provided in EQ. 7 (specifically calcium in EQ. 8). Where ΔM and ΔCa are percentages, and M is the metal.

[0038] Examples of metals may include, but are not limited to, calcium, iron, chromium, vanadium, magnesium, phosphorus, chlorine, potassium, manganese, aluminum, silicon, titanium, copper, nickel, zinc, lead, tin, etc. The threshold may depend on the metal. For example, when calcium is used, the threshold for the percentage change in metal concentration (according to EQ. 7) may be 20% (or 18% or 15%). Exceeding the threshold (e.g., reporting a 22% change in calcium) may trigger remedial action to reduce the base number of the lubricating oil in the engine, such as by increasing the feed rate of fresh lubricating oil and / or by changing to fresh lubricating oil with a lower base number but maintaining (or also increasing) the feed rate of fresh lubricating oil.

[0039] The method of analyzing lubricating oil using metals can be used for ultra-low sulfur fuels and sulfur-free fuels having 0.1 wt % or less sulfur, although it can be used in conjunction with fuels having any amount of sulfur, including low sulfur fuels having 0.5 wt % or less sulfur. For example, the fuel can have 0.5 wt % or less sulfur, or 0.1 wt % or less sulfur, or 0 wt % to 0.5 wt % sulfur, or 0.01 wt % to 0.5 wt % sulfur, or 0.01 wt % to 0.1 wt % sulfur, or 0 wt % to 0.1 wt % sulfur.

[0040] Thus, one method of the present disclosure may include: measuring a first metal concentration (e.g., calcium or another metal described herein) in a lubricating oil (e.g., a marine lubricating oil) using x-ray fluorescence prior to introduction into a cylinder of an engine (e.g., a two-stroke engine), wherein the first metal concentration includes a concentration of a soluble metal and a concentration of an insoluble metal; collecting scraped lubricating oil (e.g., scraped marine lubricating oil) corresponding to the lubricating oil after it has passed through the cylinder during combustion of a fuel (e.g., containing 0.5 wt % or less sulfur, containing 0.1 wt % or less sulfur, or containing no sulfur); measuring a second metal concentration in the scraped marine lubricating oil using x-ray fluorescence; calculating a change in metal concentration between the lubricating oil and the scraped marine lubricating oil during combustion based on the first and second metal concentrations; and when the change in metal concentration is an increase in metal concentration above a threshold, making a change in a property of the scraped marine lubricating oil and / or changing a lubricating oil feed rate into the cylinder to reduce the base number of the lubricating oil in the engine.

[0041] The analysis of the lubricating oil in the present disclosure may include determining one or more of the following: (a1) the amount of acid neutralized during combustion of the scraped lubricating oil, (b1) the amount of acid neutralized during combustion of the scraped lubricating oil and the remaining useful base number of the scraped lubricating oil, (c1) the amount of acid neutralized during combustion of the scraped lubricating oil and the total base number of the scraped lubricating oil, or (d1) the change in metal concentration between the lubricating oil and the scraped lubricating oil. Based on one or more of the above, changes in the properties of the scraped marine lubricating oil and / or changes in the feed rate of the lubricating oil can be implemented to reduce the formation of deposits in the lubricating oil in the engine (for example, by reducing the base number of the lubricating oil in the engine). Exemplary embodiments

[0042] Embodiment 1. A method comprising: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence before introduction into a cylinder of a two-stroke engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; and calculating an amount of acid neutralized during combustion based on the first and second concentrations of the component.

[0043] Embodiment 2. The method of embodiment 1, further comprising: making changes to the properties of the scraped lubricant based on the amount of neutralized acid and / or changing the lubricant feed rate into the cylinder.

[0044] Embodiment 3. The method of any of Embodiments 1-2, wherein the second concentration of the component is measured within about 4 hours of collecting the scraped lubricant.

[0045] Embodiment 4. The method of any one of embodiments 1-3, wherein the change in the property and / or the change in the feed rate is further implemented based on the remaining useful base number, which is equal to the total base number (TBN) of the lubricating oil before introduction into the cylinder. fresh ) minus the amount of acid neutralized.

[0046] Embodiment 5. The method of any of Embodiments 1-4, wherein the fuel comprises 0.1 wt% or less sulfur.

[0047] Embodiment 6. The method of any of Embodiments 1-5, further comprising: measuring the concentration of one or more elements of iron, chromium or vanadium; and wherein the implementation of the change in the property and / or the change in the feed rate is further based on the concentration of the one or more elements.

[0048] Embodiment 7. A method comprising: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence before introduction into a cylinder of an engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less of sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; and calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; calculating a remaining useful base number of the scraped lubricating oil.

[0049] Embodiment 8. A method comprising: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence before introduction into a cylinder of an engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; and calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; calculating a total base number of the scraped lubricating oil.

[0050] Embodiment 9. A method comprising: measuring a first concentration of a component in a lubricating oil using x-ray fluorescence before introduction into a cylinder of an engine, the component comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to the lubricating oil after it has passed through the cylinder during fuel combustion of a fuel comprising 0.5 wt % or less sulfur; measuring a second concentration of the component in the scraped lubricating oil using x-ray fluorescence; and calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; calculating (a) a remaining useful base number of the scraped lubricating oil and / or (b) a total base number of the scraped lubricating oil.

[0051] Embodiment 10. The method of any one of embodiments 7-9, further comprising: making changes to the properties of the scraped lubricating oil and / or changing the lubricating oil feed rate into the cylinder (for example, based on the remaining useful base number for embodiment 8, based on the correlation between the amount of acid neutralized during combustion and the total base number of the scraped lubricating oil for embodiment 9, or based on (a) the remaining useful base number and / or (b) the correlation between the amount of acid neutralized during combustion and the total base number of the scraped lubricating oil for embodiment 10).

[0052] Embodiment 11. The method of any of Embodiments 7-10, wherein the second concentration of the component is measured within about 4 hours of collecting the scraped lubricant.

[0053] Embodiment 12. The method of any of Embodiments 7-11, wherein the fuel comprises 0.1 wt% or less sulfur.

[0054] Embodiment 13. The method of any of Embodiments 7-12, further comprising: measuring the concentration of one or more elements of iron, chromium or vanadium; and wherein the implementation of the change in the property and / or the change in the feed rate is further based on the concentration of the one or more elements.

[0055] Embodiment 14. A method comprising: measuring a first metal concentration in a marine lubricating oil using x-ray fluorescence before introduction into a cylinder of an engine, wherein the first metal concentration includes a concentration of a soluble metal and a concentration of an insoluble metal; collecting a scraped marine lubricating oil corresponding to the marine lubricating oil after it has passed through the cylinder during fuel combustion of a fuel containing 0.5 wt % or less sulfur; measuring a second metal concentration in the scraped marine lubricating oil using x-ray fluorescence; calculating a change in the metal concentration during combustion based on the first and second metal concentrations; and when the change in metal concentration is an increase in metal concentration above a threshold, making a change to a property of the scraped marine lubricating oil and / or changing a lubricating oil feed rate into the cylinder to reduce the base number of the lubricating oil in the engine.

[0056] Embodiment 15. The method of Embodiment 14, wherein the fuel contains 0.1 wt% or less sulfur.

[0057] Embodiment 16. The method of any of Embodiments 14-15, wherein the fuel is sulfur-free.

[0058] Embodiment 17. The method of any of Embodiments 14-16, wherein the metal is selected from: iron, chromium, vanadium, magnesium, phosphorus, chlorine, potassium, manganese, aluminum, silicon, titanium, copper, nickel, zinc, lead, tin or other elements.

[0059] Embodiment 18. The method of any of Embodiments 14-17, wherein the metal is calcium.

[0060] Embodiment 19. The method of Embodiment 18, further comprising: wherein the fuel contains sulfur, measuring a first concentration of sulfur in the lubricating oil; measuring a second concentration of sulfur in the scraped lubricating oil; calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; and wherein the change in the property and / or the change in the feed rate is further implemented based on the amount of acid neutralized.

[0061] Embodiment 20. The method of embodiment 19, further comprising: calculating a remaining useful base number of the scraped marine lubricating oil; and wherein the change in the property and / or the change in the feed rate is implemented further based on the remaining useful base number.

[0062] Embodiment 21. The method of embodiment 19, further comprising: calculating the total base number of the scraped lubricating oil; and wherein the implementation of the change in the property and / or the change in the feed rate is further based on the correlation between the amount of acid neutralized during the combustion process and the total base number of the scraped lubricating oil.

[0063] Unless otherwise indicated, all numerical values ​​used in this specification and the associated claims to indicate amounts of ingredients, properties such as molecular weight, reaction conditions, etc., should be understood as being modified in all cases by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that may vary depending on the desired properties sought to be obtained by embodiments of the present invention. At least, and not in an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0064] One or more exemplary embodiments comprising one or more elements of the present invention are proposed herein. For the sake of clarity, all features of physical implementation are not described or shown in this application. It is to be understood that in the development of physical implementations comprising one or more elements of the present invention, many decisions specifically for the implementation must be made to achieve the developer's goal, such as meeting the constraints associated with the system, the constraints associated with the business, the constraints associated with the government, and other constraints, which vary from time to time with specific implementation. Although the efforts of the developer may be time-consuming, such efforts are routine work for those of ordinary skill in the art who benefit from the disclosure.

[0065] Although compositions and methods are described herein as "comprising" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" the various components and steps. Additional Implementation

[0066] In order to facilitate a better understanding of the embodiments of the present invention, the following examples of preferred or representative embodiments are given. The following examples should not be construed in any way to limit or define the scope of the present invention. Example

[0067] Example 1. Several bunker oil samples (fresh and scraped) with different treatments were analyzed by titration and by TBN (EQ. 6, using XRF unless otherwise stated). Table 1

[0068] This series of analyses showed that the delay between sample collection and analytical determination of TBN caused the TBN value to become more inaccurate, likely due to calcium carbonate settling out and not being accounted for in the measurement.

[0069] Example 2. Using data from various marine lubricant samples, TBN usedThe graph of (EQ.3) versus neutralized acid (AN) is shown in Figure 1 Use Figure 1 The correlation provided in corresponds to a high TBN with a low AN (e.g., less than about 30 mgKOH / g lubricant). used (e.g., greater than about 100 mg KOH / g lubricant) may indicate that a large amount of calcium carbonate is forming solid particles and causing wear in the engine. In addition, low TBN used (eg, less than about 50 mg KOH / g lubricant) and low AN (eg, less than about 30 mg KOH / g lubricant) may indicate that proper conditions and composition are in place and should be maintained.

[0070] Example 3. Using data from various marine lubricant samples, TBN used 3) or neutralized acid (AN), respectively, versus average total iron (determined by XRF) or percent fuel sulfur. Figure 2 Use Figure 2 The correlation provided in corresponds to the high TBN of HSR used (e.g., greater than about 100 mg KOH / g lubricant) may indicate wear on the engine and corresponds to high TBN with high fuel sulfur percentages used It may indicate that a large amount of calcium carbonate is forming solid particles and causing wear on the engine. In contrast, using AN instead of TBN used Similar graphs of do not illustrate these features, thus illustrating the use of the TBN of the present disclosure. used The advantages of relevance.

[0071] Example 4. Figure 3 The TBN of various marine lubricant samples used At low fuel sulfur percentages, some of the differences are positive, indicating that Day Tank BN is higher than TBN. used .

[0072] Example 5. Figure 4 Graphical illustration of TBN of various marine lubricant samples used Or a plot of AN versus fuel sulfur percentage. At low fuel sulfur percentages, all samples have similar AN values. However, when using TBN used When , additional information can be extracted from the data.

[0073] Example 6. A vessel with two identical engines was run with 0.09% sulfur fuel with 100 BN and 40 BN lubricants. Engine 1 was started with 100 BN lubricant oil and then switched to 40 BN lubricant oil. Engine 2 was started with 40 BN lubricant oil and switched to 100 BN lubricant oil. Table 2 provides the data collected for each engine and lubricant. Figure 5A 6A-B and 6A-B are graphs of iron concentration (A) and calcium concentration (B) versus time for Engines 1 and 2, respectively. Table 2

[0074] The 100BN lubricant oil showed excess calcium in both engines, and the higher the excess calcium, the higher the iron wear value was also visible. The 40BN oil with high net power to help dissolve the excess calcium showed less excess calcium and lower iron wear values. The low acid value and high residual BN in the 100BN lubricant oil can indicate potential high wear caused by excessive deposit formation. For these two cylinder oils, the neutralized acid remains relatively constant, indicating that the 40 lubricant BN oil is more suitable for this level of fuel sulfur and acid production. The lower laboratory D2896 measured base number can indicate what the laboratory analysis missed compared to being able to analyze the sample fresh on board, and indicates that the laboratory analysis did not reveal the deposits that caused the wear. Engine 2 has a system oil contamination problem, which causes the residual base number to be lower than expected.

[0075] Example 7. Two vessels using similar engines with the same bore size were run with 40 BN lubricant using either 0.02% or 0.03% sulfur fuel. Vessel 2 used an exhaust gas recirculation (EGR) system. Table 3 provides the data collected for each engine and lubricant. Table 3

[0076] Based on the changes in calcium concentration, Vessel 2 exhibited signs of wear and tear that resulted in the accumulation of calcium deposits.

[0077] Figure 7Four graphs are included showing the amount of acid neutralized or the change in calcium concentration (according to EQ. 8) versus load percentage or fuel sulfur. At higher fuel sulfur values, both the amount of acid neutralized and the change in calcium concentration provide insight into the formation of calcium deposits in the lubricating oil. However, at lower sulfur fuels (below 0.1 wt%), the amount of acid neutralized appears stable and within a reasonable range. In contrast, the change in calcium concentration for Vessel 2 has several data points above 20%, which indicates the formation of calcium deposits. This example shows that at fuel sulfur levels of less than 0.1%, where very little sulfuric acid is produced, calcium concentration provides a better indicator of calcium deposit formation than acid neutralization.

[0078] Upon visual inspection of portions of the engine, Boat 1 showed minor calcium deposits. In contrast, Boat 2 showed signs of severe deposit buildup in the engine.

[0079] Therefore, the present invention is well suited for achieving the purposes and advantages mentioned and the purposes and advantages inherent therein. The specific examples and configurations disclosed above are exemplary only, as the present invention can be modified and implemented in different but equivalent ways that are obvious to those skilled in the art who benefit from the teachings herein. In addition, except as described in the following claims, it is not intended to be limited to the details of the construction or design shown herein. It is therefore obvious that the specific exemplary examples disclosed above can be changed, combined or modified, and all such changes are considered to be within the scope and spirit of the present invention. The present invention disclosed exemplarily herein can be implemented in the absence of any element not specifically disclosed herein and / or any optional element disclosed herein. Although compositions and methods are described in a manner of "comprising", "containing" or "including" various components or steps, compositions and methods can also be "essentially composed of" or "composed of" various components and steps. All numbers and ranges disclosed above can vary by a certain amount. As long as a numerical range with a lower limit and an upper limit is disclosed, any numerical value and any included range falling within the range are clearly disclosed. In particular, each numerical range disclosed herein (in the form of "about a to about b" or similarly, "about a to b" or similarly, "about ab") should be understood to recite each value and range contained within that broader numerical range. The terms in the claims also have their plain ordinary meaning unless otherwise explicitly and clearly defined by the patentee. In addition, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more than one of the elements they set forth.

Claims

1. A method comprising: measuring a first concentration of components in a lubricating oil prior to introduction into a cylinder of a two-stroke engine using x-ray fluorescence, the components comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to lubricating oil after having passed through the cylinder during fuel combustion of a fuel containing 0.5 wt % or less of sulfur; measuring a second concentration of a component in the scraped lubricant using x-ray fluorescence; and The amount of acid neutralized during the combustion process is calculated based on the first concentration and the second concentration of the component.

2. The method according to claim 1, further comprising: Changes are made to the properties of the scraped lubricant based on the amount of acid neutralized and / or the lubricant feed rate into the cylinder is changed.

3. The method of claim 1, wherein the second concentration of the component is measured within about 4 hours of collecting the scraped lubricant.

4. The method of claim 1, wherein the change in the property and / or the change in the feed rate is further implemented based on a residual useful base number, which is equal to the total base number (TBN) of the lubricating oil before introduction into the cylinder. fresh ) minus the amount of acid neutralized.

5. The method of claim 1, wherein the fuel contains 0.1 wt% or less sulfur.

6. The method according to claim 1, further comprising: Measuring the concentration of one or more of the elements iron, chromium or vanadium; and Wherein the changing of the property and / or the changing of the feed rate is implemented further based on the concentration of the one or more elements.

7. A method comprising: measuring a first concentration of components in a lubricating oil prior to introduction into a cylinder of an engine using x-ray fluorescence, the components comprising: sulfur and total calcium; collecting scraped lubricating oil corresponding to lubricating oil after having passed through the cylinder during fuel combustion of a fuel containing 0.5 wt % or less of sulfur; measuring a second concentration of a component in the scraped lubricant using x-ray fluorescence; calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; and (a) the remaining useful base number of the scraped lubricating oil and / or (b) the total base number of the scraped lubricating oil are calculated.

8. The method according to claim 7, further comprising: Changes are made to the properties of the scraped oil and / or the oil feed rate into the cylinder based on a correlation between (a) the remaining useful base number and / or (b) the amount of acid neutralized during combustion and the total base number of the scraped oil.

9. The method of claim 7, wherein the second concentration of the component is measured within about 4 hours of collecting the scraped lubricant.

10. The method of claim 7, wherein the fuel contains 0.1 wt% or less sulfur.

11. The method according to claim 7, further comprising: Measuring the concentration of one or more of the elements iron, chromium or vanadium; and Wherein the changing of the property and / or the changing of the feed rate is implemented further based on the concentration of the one or more elements.

12. A method comprising: measuring a first metal concentration in the marine lubricating oil using x-ray fluorescence prior to introduction into a cylinder of an engine, wherein the first metal concentration includes a concentration of a soluble metal and a concentration of an insoluble metal; collecting scraped marine lubricating oil corresponding to the marine lubricating oil after having passed through the cylinder during fuel combustion of a fuel containing 0.5 wt % or less of sulfur; measuring a second metal concentration in the scraped marine oil using x-ray fluorescence; calculating a change in metal concentration during combustion based on the first and second metal concentrations; and When the change in metal concentration is an increase in metal concentration above a threshold, a change is made to the properties of the scraped marine lubricating oil and / or the lubricating oil feed rate into the cylinder is changed to reduce the base number of the lubricating oil in the engine.

13. The method of claim 12, wherein the fuel contains 0.1 wt% or less sulfur.

14. The method of claim 12, wherein the fuel contains no sulfur.

15. The method of claim 12, wherein the metal is selected from the group consisting of iron, chromium, vanadium, magnesium, phosphorus, chlorine, potassium, manganese, aluminum, silicon, titanium, copper, nickel, zinc, lead, tin or other elements.

16. The method of claim 12, wherein the metal is calcium.

17. The method according to claim 16, further comprising: measuring a first concentration of sulfur in the lubricating oil; measuring a second concentration of sulfur in the scraped lubricating oil; and calculating an amount of acid neutralized during combustion based on the first concentration and the second concentration of the component; and Wherein said changing of properties and / or said changing of feed rate is performed further based on the amount of acid being neutralized.

18. The method according to claim 17, further comprising: Calculating the remaining useful base value of the scraped marine lubricating oil; and Wherein the change in properties and / or the change in feed rate is further implemented based on the remaining useful base value.

19. The method of claim 17, further comprising: Calculating the total base number of the scraped lubricating oil; and The change in the property and / or the change in the feed rate is further implemented based on a correlation between the amount of acid neutralized during the combustion process and the total base number of the scraped lubricating oil.

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