Base Stock Research Articles

Investigating the rheological and tribological properties of polyurea grease via regulating ureido amount

The ureido amount of polyurea strongly influences the properties of polyurea grease. Here, four polyurea greases (diurea, tetraurea, hexaurea, and octaurea) were synthesized via regulating the proportion and adding order of reactants (diphenylmethane diisocyanate, octadecylamine, and 1,6–ethylenediamine), using polyalphaolefin (PAO 40) as the base stock. The effects of ureido amounts on the physicochemical, rheological and tribological properties were evaluated. More importantly, the correlation of structure and performance characteristics was explored. Results show that the tetraurea with a granular structure presents optimal physicochemical properties and structural strength. The diurea grease with rodlike structure presents the optimal tribological properties due to the synergies of polyurea deposited film and tribolchemical reaction film (ferric oxide and nitrides), as well as oil film.

Evaluation of physicochemical, tribological and oxidative stability properties of chemically modified rice bran and karanja oils as viable lubricant base stocks for industrial applications

The lubricating properties of the two vegetable oils with distinct free fatty acid content were studied in the work i.e., Rice bran oil (RBO) with low free fatty acids and Karanja oil (KO) with high free fatty acids. The main aim of the present work is to improve the oxidative stability of RBO and KO, using the transesterification and epoxidation method. The physicochemical, tribological, and oxidative stability of pure and modified oils were evaluated as per standards. The study revealed the effectiveness of epoxidation over the transesterification process on the selected oils.

Characterization of transcription factor activator pretein-1 (AP-1) and its association with cold tolerance in Pinctada fucata martensii

AP-1 is an important transcription factor for cell proliferation/differentiation and animal immunity/development; however, its role in research in shellfish is poorly understood. Here, the cDNA of AP-1 gene from Pinctada fucata martensii was characterized. Its expression was detected in all six examined tissues, and a high level was observed in the gill and hepatopancreas. Analysis of the developmental transcriptomes showed that the PmAP-1 gene expression levels were high during D-stage larval and spat stages. The gene also exhibited a significantly high expression under cold tolerance stress. SNP analysis of the exon region and 5′ flanking region of PmAP-1 revealed 19 SNPs of which 8 showed significant differences between cold tolerance selection line and base stock. Furthermore, three haplotypes generated by the SNPs of PmAP-1 were significantly associated with cold tolerance, respectively.These results suggest that the PmAP-1 gene plays an important role in the response of P. f. martensii to low temperature stress. These SNPs and haplotypes of PmAP-1 may be related to the cold tolerance of P. f. martensii, and could be candidate markers potentially for further selective breeding.

On the stationary stochastic response of an order-constrained inventory system

We investigate the stochastic response of a base stock inventory system where the order quantity is either upper- or lower-constrained. This system can represent many real-world settings: forbidden returns, minimum order quantities, and capacity constraints for example. We show that this problem can be translated into a stopping time problem where the distributions of orders and inventory can be represented by a countably infinite mixture of truncated and convoluted demand distributions. This result can be extended to the cases of arbitrary lead time and auto-correlated demand. A state space algorithm is developed to approximate the first- and second-order moments of the order quantity and inventory level. Via a numerical analysis, we investigate the performance of the approximation, as well as the operational and economic impact of the order constraint. In particular, the constraint impacts order and inventory variances via different combinations of the mixture and truncation effects. We show how tuning the constraint can improve the operational and financial performance of the inventory system by acting as a smoothing mechanism.

HYDROCRACKING OF VACUUM DISTILLATE AND LUBRICANT BASE STOCK PRODUCTION

Hydrocracking of vacuum distillate for middle distillate and lubricant base stock production has been carried out with temperature (from 400° to 420°). Hourly Liquid Space Velocity (from 0.422 to 0.88), Pressure (100 kg/cm2) and H2/Hydrocarbon ratio (1000 It/lt), by using a Catatest unit apparatus.

Enzymatic Synthesis of Fatty Acid Isoamyl Monoesters from Soybean Oil Deodorizer Distillate: A Renewable and Ecofriendly Base Stock for Lubricant Industries.

In this study, soybean oil deodorizer distillate (SODD), a mixture of free fatty acids and acylglycerides, and isoamyl alcohol were evaluated as substrates in the synthesis of fatty acid isoamyl monoesters catalyzed by Eversa (a liquid formulation of Thermomyces lanuginosus lipase). SODD and the products were characterized by the chemical and physical properties of lubricant base stocks. The optimal conditions to produce isoamyl fatty acid esters were determined by response surface methodology (RSM) using rotational central composite design (RCCD, 23 factorial + 6 axial points + 5 replications at the central point); they were 1 mol of fatty acids (based on the SODD saponifiable index) to 2.5 mol isoamyl alcohol, 45 °C, and 6 wt.% enzymes (enzyme mass/SODD mass). The effect of the water content of the reactional medium was also studied, with two conditions of molecular sieve ratio (molecular sieve mass/SODD mass) selected as 39 wt.% (almost anhydrous reaction medium) and 9 wt.%. Ester yields of around 50 wt.% and 70 wt.% were reached after 50 h reaction, respectively. The reaction products containing 43.7 wt.% and 55.2 wt.% FAIE exhibited viscosity indices of 175 and 163.8, pour points of −6 °C and −9 °C, flash points of 178 and 104 °C, and low oxidative stability, respectively. Their properties (mainly very high viscosity indices) make them suitable to be used as base stocks in lubricant formulation industries.

WA INFLUENCE OF HYDROCARBON COMPOSITIONS OF THE HYDROCRACKING FEEDSTOCKS ON THE HYDROCRACKED PRODUCTS OF LUBRICANT BASE STOCK AND MIDDLE DISTILLATE

An experiment has been carried out to study to influence of hydrocarbon composition of the hydrocracking feedstocks on the hydrocracked products of lubricant base stock and middle distillate with bi-functional catalyst. The operating conditions are; temperature: from 400° to 420°C pressure: from 100 kg/cm2 and H2/HC ratio: 1000 Ilt/lt using a Catatest unit, operated with a continuous system. Experimental data show that the high content of paraffin hydrocarbon in the hydrocracked feedstock tends to increase the viscosity index of lubricant base stock, smoke point of kerosene and diesel index of gas oil products.

SELECTIVE HYDROCRACKING OF HEAVY DISTILLATE TO HIGH VISCOSITY INDEX OF LUBE BASE STOCK USING BI-FUNCIONAL CATALYSTS

Selective hydrocracking of heavy distillate to high viscocity index of lube base stock has been carried out at the operating conditions: temperatures: 380° - 410°C, pressure: 100kg/cm2, H2/HC = 1000 lt/lt with bifunctional catalysts having various acidity using a catasest unit operated with a continuous system.

Hydroconversion Of Heavy Distillate Into Lube Base Stock Using Bi-Functional Catalysts

Hydroconversion process replaces the furfural stage and dewaxing part of conventional processs of lube base stock production. To study the ability of this hydroconversion process to weed low viscosity index component out of heavy distillate fraction to produce high viscosity index lube base stock, an experiment has been carried out on the hydroconversion of three feedstock types, I,e,: non-paraffinic vacuum distillate (NPVD), paraffinic vacuum distillate (PVD) and paraffin-wax (WAX), using three bifunctional catalysts having low, medium abd high acidities. The experiment was done at the following operating conditions: temperature from 380° to 420°C, pressure: 100 kg/cm² and H₂/HC ratio: 1000 L/L using a Catatest Unit operated in continuous system.The experimental data shows that at 50% by wt. feedstock conversion, the yields and viscosity index of lube base stock product are 20.7% by wt. and 118; 25.5% by wt. and 136; and 29.5% by wt. and 164 for NPVD, PVD and high acidity bifunctional catalysts, respectively. By conventional process, PVD feedstock produces 10-15% by wt. lube base stock with viscosity index lube 90 to 100.The high viscosity index of lube base stock product, obtained by hydroconversion process, suggest that a part of condensed aromatics is converted into naphthenes, which are then selectivity hydrocracked into single alkyl aromatics by both the metal site and acid site of the bifunctional catalysts. With medium and high acidity bifunctional catalysts, isomerization and cyclization of wax feedstock into isoparaffins and single ring alkyl-naphthene ring of vacuum distillate feedstock into single ring alkyl-aromatic is quite dominant with medium acidity catalyst.

PRODUCTION OF ENVIRONMENTAL FRIENDLY FUEL IN INDONESIAN REFINERY

Worldwide crude supplies are experiencing a mod- est trend toward heavier and high sulfur content. The average annual demand growth rate for light products (gasoline, kerosene and diesel oil) is higher than that for residual fuel oil, Therefore, converting additional bot- toms into light product by either thermal or catalytic pro- cesses will be needed. Vehicles and fuels have been developed simulta- neously and nowadays vehicles demand a very sophisti- cated fuel indeed. Environmental restriction, and efforts to minimize the pollutant problem by exhaust gases are causing design and changes in cars that in turn are hav- ing some effects on fuel quality. To reduce exhaust emission by fuel combustion, the specification of gasoline and diesel oil is now stricter. Various term in the models address qualities of the re- formulated gasoline, such as benzene, total aromatics and olefin content, RVP, the T of distillation range, sul- fur content, and oxygenate contents (Table 1)18.13.16). Diesel oil specification is limited as follows: aromatics, polyaromatics, sulfur content, T and cetane number (Table 2) (19.23,26) To improve the specification of commercial gasoline into the stricter specification of reformulated gasoline, refiners are forced in install new facilities to increase the production for high-octane mogas components. For the stricter diesel oil specification in the years 2000's, over 50% by volume of the total gas oil components (ex- cept hydrocracked gas oil) must undergo improvement by hydrotreating processes in order to achieve a suitable specification. In Indonesia, there are seven refineries with total crude oil capacity of 1,063 MBCD to produce fuel oils, lube base stocks and petrochemical products. Process- ing units and fuel oil production in Indonesia's refineries are given in Table 3 and 4, respectively. The production of gasoline and diesel oil components is review in this paper. Influence of hydrocarbon composition of those fuel components on their performances is discussed. A brief discussion is offered on the impact of the changing specification of gasoline and diesel oil on the refinery configuration.

Selective Hydrocracking Of Heavy Distillate To High Viscosity Index Lube Base Stock By Using Bi-Functional Catalysts

Hydroprocessing is the catalytic reaction of hydrogen with petroleum or other hydrocarbon materials. It may be carried out for a variety of objectives, including: saturation of olefins or aromaties, molecular rearrangement, or removal of impurity (1).Selective hydrocracking is one of this hydroprocessing to convert higherboiling distillate to lube base stock using a bi-functional catalyst containing both acid site and metal site. Those two active sites of bi-functional catalyst should promote the correct combination of hydrogenation, isomerization and limited hydrocracking function, resulting in the maximum yield of product in the lube oil range (2). The kinetics of this selective hydrocracking greatly depends on the operating conditions: such as feedstock composition, type of catalyst, temperature, pressure, hydrogen to hydrocarbon ratio, and space velocity (6).The versatility of the hydroconversion process with respect to the variety of feedstock are case to study: i.e. the feasibility of the hydroconversion of obtaining lube base stock from heavy distillate.In order to gain more information, an experiment has been carried out to study the selective hydrocracking of vacuum distillate (paraffinic and non paraffinic) by using bifunctional catalysts with various acidity at the following operating conditions: temperature: from 380 to 410 ° C, pressure: 100 kg/cm2 and hydrogen to hydrocarbon ratio: 1000 l/lt. A catatest unit operated in a continuous system was used in this experiment.Gas and liquid product samples were taken from gas and liquid samples, respectively. Liquid product was fractionated to get the following cuts: IBP-380°C and380°C with 30 theoretical plate fractionator, operating at 4/1 reflux ratio. The 380°C bottom product was treated by dewaxing, using methylisobutyl ketone as a solvent to obtain the lube base stock and wax.

Optimal Policies for a Multi-Echelon Inventory Problem with Service Time Target and Expediting

Problem definition: We study the optimal inventory ordering, expediting, and allocation decisions in a multiechelon supply chain over a finite horizon, in which customer orders are quoted with a fixed fulfillment time window, termed the service time target (STT). Academic/practical relevance: Service time target is commonly used as a marketing strategy to increase customer satisfaction and strengthen firms’ competitive edge. However, how to efficiently manage a multistage supply chain to meet the target has received relatively scant attention in the literature. Our study fills this gap. Methodology: We use dynamic programming to characterize the optimal policy. Results: We show that an echelon base stock policy and a rationing policy are optimal for inventory ordering and inventory allocation/expediting, respectively. We also develop a polynomial-time algorithm to compute the optimal policy. To derive these results, we uncover a new functional property named the decomposable of degree 2 property, which is a nontrivial generalization of the celebrated Clark-Scarf decomposition. This property further allows us to derive induced penalty and compensation to coordinate a decentralized serial system with STT and expediting. Managerial implications: Our result provides an efficient decision tool for managing centralized and decentralized serial supply chains with STT and expediting. Our model can be used to quantify the tradeoff between marketing and operational decisions, such as the impact of a marginal reduction in STT on system cost and expedition frequency, as explored in our numerical studies.

Dynamic pricing and inventory management of a dual-channel supply chain under different power structures

This paper studies a periodic review, joint dynamic pricing and inventory problem for a dual-channel supply chain with one manufacturer and one retailer, where the demand is stochastic and price sensitive. Three possible power structures between manufacturer and retailer in the dual-channel supply chain, i.e., Manufacturer Stackelberg, Retailer Stackelberg and Vertical Nash, are considered. Under each of the three power structures, decision models are developed with stochastic dynamic programming to determine how to adjust the pricing and inventory decisions in every period so that each member’s total expected discounted profit over the planning horizon is maximized. The effects of the power structure are analyzed by comparing the optimal dynamic pricing and inventory policies under different power structures. Our main findings include: (i) the optimal dynamic pricing and inventory policy of a dual-channel supply chain is an inventory-dependent base-stock-list-price policy; (ii) base stock levels and reduced prices are affected by starting inventory levels; (iii) the influence rules on reduced prices under different power structures are the same, while the influence rules on base stock levels vary according to the power structure; (iv) optimal pricing and inventory decisions are affected by the power structure, although the structural properties of the optimal policies under different power structures are the same. Results from numerical examples show that, for the two-period dual-channel supply chain, manufacturer and retailer prefer Vertical Nash when the wholesale price is low, while they prefer Manufacturer Stackelberg when the wholesale price is high.

Prospects of Plant-Based Trimethylolpropane Esters in the Biolubricant Formulation for Various Applications: A Review

Biodegradable lubricants from renewable feedstocks have been successfully developed to meet the demands of new machines with stringent requirements of the global standards, which address sustainability and environmental policy. Trimethylolpropane ester (TMPE) has been extensively evaluated as a biolubricant base stock and occasionally used as an additive, due to their low toxicity and excellent biodegradability. The formulation of high-performance TMPE-based lubricants involves addition of surface additives, multifunctional additives, and solid nano particles. This review focuses on the development of plant-based TMPE formulation for various applications, namely food-grade lubricant, engine oil, drilling fluid, insulating fluid, metal working fluid, hydraulic and heat transfer fluids. Even though plant-based TMPE lubricants have huge advantages over mineral oils, they have other challenging issues such as limited load-bearing capacity, hygroscopic properties, and high risk of toxic emission owing to additives selection. The details on the performance characteristics of TMPE as base stocks and additives are discussed, including the current prospects and challenges in the respective areas. This review concludes with a brief discussion on suggestions and recommendations for future advancement in the usage of TMPE and the remaining issues that must be overcome to allow for its full potential to be realized.

Machine learning integrated design and operation management for resilient circular manufacturing systems

The implementation of smart manufacturing devices in the manufacturing industry has provided an effective and intelligent way to monitor their facilities and thus control their integrated manufacturing processes. Despite the ongoing technological advancements, the same industry is often involved with complex problems that are associated with increasing costs related to the persistent deterioration of the manufacturing/remanufacturing systems. In literature, these systems are often called “circular manufacturing systems”. Furthermore, this deterioration affects the quality of the manufactured products. To address these problems, a novel integrated design and operation management-based framework is introduced in order to obtain joint policies for the authorization of production, recycling, maintenance and remanufacturing activities in the context of deteriorating circular manufacturing systems. This framework utilizes a reinforcement learning technique and ad-hoc production control policies, such as Base Stock and CONWIP, in an effort to improve the flexibility and the resilience of the examined systems to the ever-changing customer demand. Finally, a series of simulation experiments evaluate the behavior and the efficiency of the proposed mechanism within the context of single-stage and 2-stage deteriorating manufacturing/remanufacturing systems. Results suggest that the presented approach can effectively generate sufficient inventory of ready-to-be-sold products due to the enhanced awareness of the ongoing customer demand compared to the traditional reinforcement learning joint control.

A comparative study on the lubricant properties of chemically modified Calophyllum inophyllum oils for bio-lubricant applications

The trend of using non-edible vegetable oils as a potential base stock for industrial lubricants is increasing due to environmental issues and fossil fuel depletion. Calophyllum inophyllum oil (CIO) is a non-edible tree seed oil available in various parts of the world. The major disadvantage of CIO is the high acid and peroxide value, which leads to poor oxidation stability. This study focused on the chemical modification of CIO by epoxidation and transesterification processes to improve its oxidation stability. The fatty acid profile of CIO used in the study was obtained using Gas chromatography - Mass spectroscopy technique and the functional groups present in CIO and chemical modified CIO were identified using Fourier transform infrared spectroscopy. The lubricant properties such as tribological, rheological, physicochemical, thermal properties, and oxidative stability of pure CIO, epoxidized CIO (ECIO), and transesterified CIO (TCIO) have been evaluated and compared in this study. The experimental results indicated that there is a significant improvement in the chemical properties and oxidative stability of CIO after the transesterification and epoxidation process. The viscosity and wear scar diameter of ECIO was observed to be better than that of CIO by 42.81% and 7.97%, respectively. TCIO has shown the least viscosity increment ie., 25.45% after 120 h of heating which shows better oxidative stability. The modified CIO can be considered as a potential base-stock for bio-lubricant formulation.

New Zealand Base Stock goats

This datasheet on New Zealand Base Stock goats covers Identity.

Inhibition of Micro-pitting by Tribofilm-Forming ZrO2 Nanocrystal Lubricant Additives: A Micro-pitting Rig and Transmission Electron Microscope Study

The drive to reduce fuel consumption in transportation has encouraged the emergence of low viscosity lubricants to reduce viscous losses in the engine, drivetrain, and other components. However, viscosity reduction increases the risk of surface damage, thus motivating the development of new anti-wear (AW) additives. Capped ZrO2 nanocrystals (NCs) in base oils have been shown to form AW tribofilms within microscale sliding contacts. However, the potential of ZrO2 NCs to protect surfaces subjected to rolling-sliding contact from macroscale damage, such as micro-pitting, remains unexplored. Here, we explore the ability of ZrO2 NCs to form protective tribofilms under harsh conditions using a micro-pitting rig (MPR), consisting of a three ring-on-roller configuration. The experiments were conducted in polyalphaolephin (PAO) base oil, with and without 5 nm diameter ZrO2 NCs, at two levels of slide-to-roll ratio (SRR) (30% and 0%) and at variable test durations up to long durations (119 h). MPR results showed the use of ZrO2 NCs gives rise to the formation of a tribofilm covering the roller surfaces and decreases the initiation and propagation of micro-pits compared to tests in pure PAO base stock. Transmission electron microscopy (TEM) performed on focused ion beam (FIB) milled cross-sectional samples of the roller surfaces revealed the growth of dense and 50–100 nm thick ZrO2-based tribofilms independent of (SRR), indicating the potential for robust micro-pitting fatigue protection. Nevertheless, small cracks localized within the near surface region of the roller tested at the most severe conditions (30% SRR and 119 h) were observed. The initiation of these cracks was directly related to the presence of manganese sulphide (MnS) inclusions in the steel, revealed using TEM combined with energy dispersive spectroscopy (EDS). The results highlight the benefits of the protective tribofilms formed by ZrO2 NCs and suggest approaches for further optimizing their use.Graphical Abstract

Partially Dehydrated Castor Oil-Based Isoalkyl and Polyol Esters as Potential Base Stocks for Industrial Applications

Partially dehydrated castor oil (PDCO) which is of less use in the paint and furniture coating formulations has been modified to develop biolubricant base stocks. PDCO (44.1%, non-conjugated linoleic acid; 32%, conjugated linoleic acid (18:2) isomers and 15.3% ricinoleic acid) obtained from a local industry was hydrolyzed under alkaline conditions. The fatty acids obtained (PDCFAs) in 98% yields were reacted with polyols namely 2-ethyl hexanol, neopentyl glycol, trimethylol propyl, pentaerythritol to obtain respective isoalkyl erters and esters of polyol with >95% yield. The base stocks exhibited very high viscosity indices (187.288 to 187.687), excellent pour point (-25 to -40 ºC) and high flash points (212 to 317 ºC) required for a variety of industrial applications namely metal working, hydraulic, forging, cutting fluid, gear oil applications. The tribological properties of PDCO, exhibited very low WSD (0.72-0.79 mm) and WSVs (0.82-0.83 mm3) with high load carrying capacities (180-220 kg) indicating low friction and less energy losses between the sliding surfaces. This was also accompanied by very high thermo-oxidation stabilities [Oxidation stability (230-242 ºC); Onset temperature (300-381 ºC)] of the base stacks due to branching. Overall all the PDCO isoalkyl and polyol esters exhibited excellent properties suitable for a wide range of industrial applications on par with mineral oil based lubricants.

Echelon Base Stock Policy for Symbiotic and Reverse Logistic Flows

The main objective of this paper is to determine the base stock levels within the framework of an industrial symbiosis. At the operational level, we define the replenishment policies for finished and used products. The system is composed by two main warehouses and three enterprises located in the same industrial region, an eco-industrial park. For the first enterprise, we have two plants (or simply two manufacturing lines): the first plant manufactures finished products and the second one recovers used (wasted) finished products after collection and restores them. For the other enterprises, one enterprise consumes only finished products made by the first enterprise and the second one consumes by-products which could be used finished products or part of these used finished products coming from the second enterprise. This means that one enterprise consumes only finished products and generates wasted finished products and the second one could use these wasted finished products as inputs for its production. To simplify the study, we present only one kind of finished product but a generalization to several products and several customer and producer companies can simply be defined. The demands are uncertain such as the number of collected used finished products. The objective is then to define the base stock levels that minimize the long-run average expected total function, which is the sum of all economic, environmental and social costs. Numerical results are proposed to highlight our results.