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Abstract Metallurgical evaluations were performed on samples of Type 310 and aluminized 304 SS after long-term, high temperature exposure in methanol reforming service. The secondary phases were identified and the effectiveness of aluminizing at inhibiting metal dusting was examined. Secondary phases adversely affect the materials service life and reparability. Aluminizing effectively inhibits metal dusting for at least 13-14 years. Metal dusting is most severe in crevices on bare metal. INTRODUCTION Typical feed gases for methanol production include hydrogen, carbon monoxide and carbon dioxide. Many times these components are produced at one source in a reformer furnace. Depending upon the pressure, outlet gas temperature, and steam-to-gas ratio, these components can be produced in relative quantities such that they can be converted directly to methanol. The economics at individual plants usually dictate the source of feed gases. For the process described below, the methanol reformers primarily produce carbon monoxide and hydrogen. Carbon dioxide is produced at an external source and introduced into the system downstream of the reformers. Methanol reformers are generally operated at a somewhat higher temperature and lower pressure as compared to hydrogen reformers. This produces a high CO content in the reformed gases and high-temperature components in the system are more vulnerable to metal dusting than if it were producing primarily hydrogen. Some of the materials used in the high-temperature components such as Type 310 stainless steel have reasonable resistance to metal dusting. However, after extended periods of time at high temperatures, they suffer from sigma phase embitterment. This paper reviews the performance of materials chosen for the high-temperature components in 2 reformer sets. Data are available for up to 17 years of life. The materials chosen for these high-temperature components included Type 310 stainless steel (SS), Type 304 aluminized material, and some Type 310 aluminized SS. Process Description Figure 1 shows the hot portion of the methanol process for this plant. There are 4 reformers; 2 each in the #1 and #2 sets. For the #1 set, the reformed gas flows through a waste heat boiler and then to a high-temperature preheater. There is a bypass line around this waste heat boiler which controls the temperature of the feedgas exiting the high-temperature preheater. Reformed gas exits the #2 set into a waste heat boiler and combines with the #1 set reformed gas stream for further heat recovery. The configuration of the reformer tubes is shown in Figure 2. Each reformer has 40 tubes arranged in 2 rows perpendicular to each other. Feed gas enters the top of the tube (Figure 3) and flows down an annular space which contains the reformer catalyst. At the bottom, the flow is reversed and the reformed gas flows up through the center tube and preheats the incoming gases. The reformed gas exits the catalyst tube at a temperature between 1050°F (565°C) and 1150° F (620°C) and about 90 psig(6.2 x 10 Pa). The most recent reformer tube material was specified as HP 50 modified alloy.
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Energy > Oil & Gas (1.00)
A phase diagram showing boundary curve and quantity of liquid in thetwo-phase region was determined for a mixture of natural gas and naturalgasoline in the region of its critical conditions. The temperatures andpressures of phase measurements were in the range of 850 to 2120 F. and 1300 to2600 lb. per sq. in., respectively, with the critical conditions at 169.50 F.and 2615 lb. per sq. in. abs. Color phenomena were observed in the region ofthe boundary curve from 1020 to 1920 F. Approximate densities of thesingle-phase and two-phase regions and analysis of the system areincluded. Boundary curves between the single-phase and the two-phase regions have beendetermined for several binary mixtures containing hydrocarbons. Theseinvestigators did not report the relative amounts of liquid and vapor withinthe two-phase region. The equilibrium values obtained from the dew-point andbubble-point data can be used to compute the lines showing percentage of liquidon the pressure-temperature phase diagram but the positions of the lines nearthe critical temperature and pressure are uncertain. Relative amounts of vaporand liquid were obtained for a gasoline and a naphtha within the two-phase areabut not in the region of the critical temperature and pressure. Thebubble-point and dew-point lines, as well as the percentage liquid lines withinthe two-phase region, were determined by visual observations in glassapparatus. Apparatus An arrangement of the apparatus is given in Fig. 1, showing the Jerguson gaugeA with glass windows B. T.P. 1114
- Energy > Oil & Gas > Upstream (1.00)
- Energy > Oil & Gas > Downstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.48)
Sempra has amended and restated the fixed-price engineering, procurement, and construction contract for the proposed Port Arthur LNG Phase 1 liquefaction project with engineering firm Bechtel. The contract includes an updated price of approximately $10.5 billion. The companies signed the initial agreement in March 2020, but Sempra delayed a final investment decision on the new plant by at least a year due to a COVID-19-induced drop in demand. The original price was never disclosed. Under the EPC contract, Bechtel will perform the detailed engineering, procurement, construction, commissioning, startup, performance testing, and operator training activities for Phase 1 of the project.
Improvement of Natural Gas Liquefaction Process by Application of Carbon Dioxide Boiling in Triple Point
Gulkov, Aleksander N. (Far Eastern Federal University) | Lapshin, Victor D. (Far Eastern Federal University) | Morozov, Aleksey A. (Far Eastern Federal University) | Vlasenko, Victor S. (Far Eastern Federal University) | Alembaev, Akeksey N. (Far Eastern Federal University)
Abstract The most capital-intensive phase of technology LNG has been found: it is the main cryogenic heat exchanger with mass-dimensional parameters which depend on the efficiency of gas pre-cooling process. Improving the efficiency of this process will reduce the cost of LNG production, hardware costs and size of the equipment. The analysis showed that carbon dioxide with triple point coordinates can be used for natural gas pre-cooling before supplying it into the cryogenic exchangers. The usage of carbon dioxide at the triple point coordinates increases the efficiency of pre-cooling due to the energy of the phase transition. Introduction Improvement of natural gas liquefaction process in order to cut specific capital costs is a relevant issue. The most capital intensive element in natural gas liquefaction cycle is the main cryogenic heat exchanger, the dimensions of which are predominantly defined by efficiency of precooling process. Application of phase transition in triple-point conditions can be one of the ways to intensify heat exchange processes. Existing Technologies Nowadays the most common ways of liquefaction of natural gas are:Classic cascade cycle with consequential application of propane, ethylene and methane as refrigerants gradually lowering their boiling -Optimized Cascade process (ConocoPhillips Company, 2015). Mixed refrigerant cycle - AP-SMR, AP-C3MR (Air Products and Chemicals Inc., 2013). Expansion liquefaction cycles. Autorefrigerant cascade cycle (ARC), in which hydrocarbons condense in stages and are used as refrigerants at further stages of cooling with simultaneous circulation of non-condensing nitrogen. Liquefaction processes developed by Air Products make up the majority of methods utilized in production of LNG and their only rival is Optimized Cascade. Expansion liquefaction cycles and ARC don't have a serious market share. Therefore, according to the current paradigm of liquefaction technologies, processes deploying precooling will be further improved. These processed are developed by Air Products & Chemicals.
- Europe (0.49)
- North America > United States > Illinois (0.15)
Abstract During a recent phase study of a natural gas, two stable equilibrium liquid phases were observed at temperatures below –200F and pressures above 200 psi. This paper reviews the published literature on the occurrence of multiple equilibrium liquid phases and presents analytical data for the vapor and two equilibrium liquid phases of the liquefied natural gas at five experimental conditions. In addition, data for 30 conditions of two-phase equilibria are included. Introduction The low-temperature phase behavior of gases, most of which contained helium, has been investigated in the laboratories of the Helium Activity for many years. Since 1952, experimental studies of these systems have been continuous as part of the research program at Amarillo, Tex. Because of their value to private industries interested in participating in the Helium Conservation Program, several "Open File" reports containing phase equilibria data for helium-bearing natural gases have already been released by the helium Activity. A paper containing information on the general phase behavior, operating criteria and extensive vapor-liquid data for two helium-containing systems was recently published. Additional publications presenting experimental data on the phase relationships of various gas systems are now in process and will be available in the near future. PREVIOUS EXPERIMENTAL WORK Although the formation of multiple liquids has been reported for various systems, to our knowledge this paper is the only substantiated evidence of a vapor-liquid-liquid equilibria in a naturally occurring gas. In 1940, Vink, Ames, and others reported the presence of two liquid phases in a hydrocarbon system consisting of mixtures of crude oils, solvents and natural gas. Eilerts and co-workers published data on the recombined fluids from a gas-condensate well. This condensed gas, containing approximately 76 per cent methane and 24 per cent ethane-plus, exhibited two distinct liquid phases. Weinaug and Bradley observed "unusual" phase behavior in a reservoir mixture. These workers postulated that the anomalous phase behavior was due to the "imminent formation of a second liquid phase". Botkin, Reamer, Sage and Lacey studied two California crude oils that exhibited multiple phases. Kohn and Kurata recently reported two equilibrium liquid phases in the methane-hydrogen sulfide system. Roof and Crawford and Eakin, et al, also have reported experiments with binary systems that formed two stable equilibrium liquid phases. APPARATUS AND PROCEDURE A U. S. Bureau of Mines Phase Equilibrium Apparatus was used in conducting this study. The apparatus and procedures employed in its operation have been previously described and will not be repeated in detail in this report. Briefly, the apparatus consists of a windowed cell which can be maintained within +/−0.5F for temperatures between room temperature and –320F. Pressure within the cell can be maintained within 0.1 per cent of gauge reading up to 800 psig. Equilibrium vapor and liquid samples are obtained in special containers for analysis by a mass spectrometer. Although the accuracy of the analyzer is about +/−0.1 mol per cent, the reproducibility of the phase-equilibrium apparatus is considered relatively Poor. Values reported from methane and nitrogen are considered accurate to +/−1.0 and +/−0.6 mol per cent. Data for ethane-plus in the vapor are accurate within 0.2 mol per cent; liquid-phase data for this aggregate component are accurate within 1.5 mol per cent. For helium in the vapor phase, the analytical data are accurate within 0.2 mol per cent; liquid-phase analyses for this component were obtained by the charcoal adsorption method described by Frost and are accurate within 0.006 mol per cent. All of these references to the accuracy of reported values are conservative estimates based upon a statistical treatment of reproducibility data obtained with the apparatus.
- North America > United States > Texas > Potter County > Amarillo (0.25)
- North America > United States > California (0.24)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.34)