Phillips 66 (United States)

Abstract Ethylene/1-olefin copolymers have held industrial significance for a considerable period. A series of copolymers with identical molar mass and varying 1-hexene levels were synthesized using supported metallocene catalyst. Various analytical techniques were used to characterize the copolymers, focusing on the effect of increasing 1-hexene content on their chemical properties, specifically chemical composition distribution (CCD). Initially, the investigations carried out by differential scanning calorimetry (DSC) revealed broad and asymmetric thermograms with the presence of a distinct shoulder in samples with higher 1-hexene content. Furthermore, HT-GPC with IR5 detector revealed uniform chemical composition (1-hexene concentration) along the molar mass axis. Examination of the chemical composition distribution (CCD) was conducted using two variants of high-temperature liquid adsorption chromatography (HT-LAC), namely solvent gradient interaction chromatography (SGIC) and thermal gradient interaction chromatography (TGIC). Initial testing by employing solvents common to HT-LAC showed that the elution behavior did not correspond with the distinct thermal properties DSC. In the next step, new desorption-promoting solvents were identified using a recent approach that integrates structure retention relationships (SRR), a measure of solvent–stationary phase interactions, with Hansen solubility parameters (HSP), assessing polymer–solvent interactions. The broad and asymmetric CCD in samples with higher SCB, characterized by a main peak and a shoulder, was confirmed by SGIC using newly identified desorption-promoting solvents identified via the SRR–HSP method. This CCD profile was also corroborated by TGIC using a binary solvent mixture as the mobile phase.

Abstract In this report, the initiation of the Phillips commercial polymerization catalyst has again been probed, this time using its simpler cousin, Cr(II)/silica. This divalent catalyst is already reduced and therefore needs only an alkylation reaction to initiate the first polymer chain. Alkane and aromatic solvents, usually considered inert, were found in this study to chemisorb onto the Cr(II) catalyst and yield reactive species, possibly live alkyls. Quenching the catalyst by exposing it to dry air for 30 s generated many oxidized products, suggesting the existence of live alkyls on the Cr. Several potential explanations were considered and tested, by varying Cr‐alkane reaction order and time. Since the commercial Cr(II) catalyst is always stored in alkane prior to ethylene contact, this reaction provides a new insight into how initiation might occur industrially. The Cr(II) catalyst was also reacted with alkenes, which were then similarly air‐quenched. Once again, a preference for reaction with the allylic H was observed. Among the resulting oxidation products were found oxidized oligomers, representing oligomeric chains which were alive on the Cr at the time of air introduction. This provides a simple and effective way of counting active sites, which seem to constitute a relatively large portion of the total Cr content.

Recovery efforts for endangered masked bobwhites Colinus virginianus ridgwayi rely on the reintroduction of captive-reared birds. Using foster parents to brood and escort chicks as they gain experience has been more successful than hard releases of older pen-reared juvenile or adult masked bobwhites. Survival of foster parents likely has implications for survival of chicks that become the founding population. Pre-release conditioning influences survival of foster parents. We compared survival of foster parents with differing histories to inform management decisions. Foster parents were from 3 sources: captive masked bobwhites from (1) an indoor flock and (2) an outdoor flock, and (3) wild northern bobwhites C. v. taylori. We radio-tagged 129 foster parents and bonded them with chicks prior to release. Our results indicated that survival at 120 d post-release of wild birds was 1.6-1.9 times greater than of outdoor conditioned birds, and indoor birds had the lowest survival (<0.08). Daily survival probability increased as day since release increased, indicating acclimation to their new environment. Extremely low survival (<0.02) of any foster parent types in 2020 was likely due to severe drought conditions. Wild birds exhibited advantages over the other 2 types of foster parents by showing greater survival even as drought conditions worsened and a greater proportion of overwintering juveniles in coveys over the course of the study. Improvements in conditioning by modifying reintroduction efforts for masked bobwhites such as providing longer outdoor experience for captive birds or the use of wild foster parents should increase survival in favorable years.

Abstract Selective seam weld corrosion presents a set of unique circumstances that results in difficulty in accurately determining the groove depth. Classification and measurement of in-the-ditch selective seam weld corrosion (SSWC) has proved difficult due to many factors. On the classification side, lack of fusion (LOF) and SSWC often look similar and distinguishing between the two can prove challenging. Visual difficulties can then result in an incorrect classification which may affect the determined remaining life or repair criteria. On the sizing side, narrow SSWC may prevent sizing by pit gauges and surrounding corrosion may prevent phased array UT from measuring the depth. Surrounding external corrosion creates a difficult surface to land the NDE equipment and tight features prevent the use of hand tools, such as pit gages from reaching the bottom of the groove. Lack of a defined procedure can lead to a varying level of success when inspecting these features. Accurate depth measurements are critical when determining a fitness for service, remaining life, or even the appropriate repair method. This paper focuses on the main task of a recent Pipeline Research Council International project, PRCI NDE 2-15, whereby the goal was to develop in-the-ditch evaluation methods and necessary tools to address difficulties associated with determining SSWC depth. Through a series of targeted NDE, a specialized NDE procedure was developed to identify external SSWC verses other defects such as lack of fusion or seam trim and measure external SSWC depth and length. In some cases, this NDE procedure combines multiple NDE techniques, each building on each other to determine the grooving depth. Finally, this protocol was validated through metallurgical examination. This paper provides a first of its kind to provide the pipeline industry with guidance when attempting to inspect and properly classify SSWC. This paper provides the first step to gaining a better understanding of SSWC inspection.

Abstract Hard carbon (HC) is the most promising anode for the commercialization of sodium‐ion batteries (NIBs); however, a general mechanism for sodium storage in HC remains unclear, obstructing the development of highly efficient anodes for NIBs. To elucidate the mechanism of sodium storage in the pores, operando synchrotron small‐angle X‐ray scattering, wide‐angle X‐ray scattering, X‐ray absorption near edge structure, Raman spectroscopy, and galvanostatic measurements are combined. The multimodal approach provides mechanistic insights into the sodium pore‐filling process for different HC microstructures including the pore sizes that are preferentially filled, the extent to which different pore sizes are filled, and how the defect concentration influences pore filling. It is observed that sodium in the larger pores has an increased pseudo‐metallic sodium character consistent with larger sodium clusters. Furthermore, it is shown that the HCs prepared at higher pyrolysis temperatures have a larger capacity from sodium stored in the pores and that sodium intercalation between graphene layers occurs simultaneously with the pore filling in the plateau region. Opportunities are outlined to improve the performance of HC anodes by fully utilizing the pores for sodium storage, helping to pave the way for the commercialization of sodium ion batteries.

Metal–organic frameworks (MOFs) with metal nodes and organic linkers have significant potential as reaction catalysts. However, one major factor impeding the development and use of MOFs as organic reaction catalysts is the detailed under-standing of catalytically active sites and their molecular reaction mechanism and selectivity. Experimentally, sulfated and Brønsted acidic MOF-808 catalyzes isobutylene dimerization. Here we report a density functional theory (DFT) based mul-ti-chemical model (cluster and periodic) transition-state study that reveals the likely active catalytic sites/species and the resulting reaction mechanism and selectivity for isobutylene dimerization catalyzed by sulfated MOF-808. Surprisingly, while there are dozens of acidic sites within a single MOF crystal, catalysis is likely the result of only a few specific active sites. Of the two-dozen acidic sites we extensively examined, only one aqua group from the tri-sulfated MOF-808 Zr6 node exhibits strong enough acidity to produce a dimerization barrier consistent with the experiment. Reaction coordinate and transition state models indicate a novel concerted dimerization process that couples C–C bond formation, C–H bond cleav-age, and proton shuttling. The selectivity between terminal and internal alkene dimerization products is likely kinetically controlled with negligible influence from the steric effects of the MOF framework.

Abstract The Charpy V-notch (CVN) impact test has been widely used by operators and pipe mills to measure steel pipe resistance to fracture propagation. The tests are generally conducted at multiple temperatures to capture the transition from low impact energy nonductile regime to the high impact energy ductile regime. Due to the limitation of wall thickness and curvature of the pipe cross section, the CVN test for thin-walled line pipe generally can only be conducted with reduced size CVN coupons. The reduced size CVN coupon both decreases the measured impact energy and lowers the apparent transition temperature. Prior work (1996) developed a procedure to interpret the CVN data from various size of coupons. The procedure is also able to estimate the entire transition curve even based on a single test data point. This procedure has been widely used since then and been adopted in Section 9F.2.2 of ASME FFS-1/API 579 (2016). In this procedure, the difference between SATT from a given size CVN and the SATT of full pipe wall thickness drop weight tearing test (DWTT) was described by an equation derived from data fitting. Since the SATT of DWTT is fixed, the relationship between SATT from two different sizes of CVN coupons can be correlated through this equation. However, the wall thickness of the pipe is left in this correlation, which implies an artificial impact of pipe dimensions to the changes of SATT among CVN coupons sizes. In this paper, the equation between SATT of CVN and DWTT is updated, which both removes the pipe wall thickness from the correlation among different CVN sizes and achieves better data fitting. This update maintains all the capability of the prior procedure while improving the accuracy and clarity. Worked examples are provided at the end the paper to demonstrate the application of the updated procedure.

Reliable electrical power is critical to the petrochemical industry. Power disruptions to petrochemical facilities have adverse safety, environmental, and economic impacts to the employees, surrounding communities, and businesses. To facilitate an understanding of the impact from electrical power events, this article suggests a set of electrical reliability analytics with the intent of improving reliability through the reduction of process upsets and electrical power disruptions. This improvement in reliability can be achieved through a standardization of event and causal factor categorization along with capturing economic, environmental, and safety impact data.