Propane periodic processing

Thermal polymerization is not as effective as catalytic polymerization but has the advantage that it can be used to polymerize saturated materials that caimot be induced to react by catalysts. The process consists of the vapor-phase cracking of, for example, propane and butane, followed by prolonged periods at high temperature (510—595°C) for the reactions to proceed to near completion. Olefins can also be conveniendy polymerized by means of an acid catalyst. Thus, the treated olefin-rich feed stream is contacted with a catalyst, such as sulfuric acid, copper pyrophosphate, or phosphoric acid, at 150—220°C and 1035—8275 kPa (150—1200 psi), depending on feedstock and product requirement. 

Figure 6.2 shows two process units. Process Unit 1 handles propane vapor at relatively low pressure, while Process Unit 2 periodically handles large volumes of nitrogen gas at elevated pressures. Six buildings are situated in or near the process units. These are ... 

Process vessels and equipment should be provided with identification in the field that is legible from approximately 30 meters (100 ft.) away. It should be viewable from the normal access points to the facility or equipment and is of colors contrasting with the surrounding background. The identifications normally consist of the equipment identification number and the common name of the equipment, e g., "V-200, Propane Surge Drum". This is beneficial during routine and emergency periods where the quick identification of process equipment is critical and necessary from a distance. 

A pilot-scale demonstration remediating harbor sediment was conducted 1 year before the SITE demonstration. Based on the pilot-scale demonstration, the processing costs for a fuU-scale, 110-ton/day unit were projected to be 230/ton (September 1992 U.S. dollars). It is assumed that the unit will be down approximately 30% of the time for maintenance and design improvements in the first year of operation. Based on this system availability, 28,105 tons can be processed in one year. This cost included estimates for variable costs, fixed costs, and deprecia-tion/insurance. Variable costs include diesel fuel for a mobile generator, hydrogen, and caustic. Fixed costs include labor diesel fuel for pumps, heaters, process equipment, and instrumentation propane, water and sewer and parts and supplies. Depreciation/insurance costs include capital cost depreciated over a 3-year period, general insurance costs, and pollution liabihty insurance. This analysis does not include costs for setup and demobilization (D128007, pp. 5.12-5.14). 

While the recovery processes used in extracting natural gas liquids from our gas production have improved enormously in the past 25 years, there has really been no new fundamental development in this period. Use of higher pressures and lower temperatures has permitted higher levels of recovery. Thus in today s technology recovery of 70 to 80% of the propane contained in the gas is a common attainment and higher recoveries are known. Similarly, 95% of the butanes may be readily recovered as liquid and substantially 100% of the pentanes and heavier volatiles. 

It can be seen that while this particular crude oil contains over 95t by volume pentanes and heavier, these constituents only contribute about 201 to the vapor pressure. Most of the vapor pressure of this oil is contributed by the propane and butanes, since it contains very little methane and ethane. This oil stream is the product of an extremely selective separation process. Crude oil streams, unless they have "weathered" in an open tank for some period of time,... 

A stream ofpropane at an average temperature r = 566 R and absolute pressure P = 6.8atmflows from a hydrocarbon processing plant to a nearby customer s production facility. A technician at the processing plant periodically measures the volumetric flow rate of the stream, V(ft /h), and reports the value to the billing office. The customer is charged for the propane at a rate... 

The point has recently been made that the kinetic data which indicate that the cyclic intermediates are involved are also compatible with mechanisms in which the true reaction is a bimolecular one and the complexes of reactants are inert. In support of this reinterpretation is the observation of an induction period in the reaction with propane-1,2-diol. Although the point is valid, there are two reasons why the Bunton mechanism of Figure 6.65 should be maintained. The first is the rapid-reaction work, which clearly showed the kinetic competence of an absorbing complex. The second is Occam s razor, which would reject the parasitic equilibria plus unspecified bimolecular process in favour of the simpler Bunton proposals. 

The certified gas is prepared by purifying namral gas taken from a medium-pressure service main. The purification is accomphshed by passing the gas over activated charcoal to remove hydrocarbons heavier than ethane, in order to improve gas stability. The processed gas, containing methane, ethane, nitrogen and carbon dioxide, is then adjnsted to the desired calorific value or specific gravity before compression to 2000 psi into evacuated cyhnders. Quahty control is maintained by periodic gas analysis, and by regenerating the charcoal towers when propane breaks through. 

Catalysts based on other metals, such as gallium and vanadium oxides, can be also employed in DH processes [8, 9]. For example, silica-supported gallium oxide catalyst has been found to be moderately active, but quite selective in propane dehydrogenation (up to 80%) and results in much less coking, 1/10 of that using a silica-supported chromium oxide [8], There is an extensive research aimed to find new DH catalysts that will perform well at moderate temperatures, suffer less from coke deposition and maintain catalytic activity for long periods of time without regeneration. 

The rate of formation of tritiated products in the propane-tritium system at a total jS-particle activity of 2.2 Ci depends linearly on time (20-100 h period). The yields decreased to about half when T2 was replaced by HT. Irradiation of the propane-T2 system with an external Co y- source (1 x 10" Ci) has increased the L(X) values due to an increase in the rate of electron production. The tritium-labelling process is initiated by two reactive species the ion (so-called decay labelling ) and the electron (j5-labelling) . ... 

A final example is depicted in Figure 1. The enantiomeric discrimination of 1- and d-aspartic acids is based on the inhibition of the process of crystallization of 1- and d-histidine. A sample with the pFl adjusted at 3-10 (the variation in pFl resulted in a plateau) is mixed with 1- or d-histidine, and the resulting mixture is injected into a carrier of propan-2-ol and entrapped in a closed-loop circuit. The absorbance versus time plot, which reflects the crystal growth, is recorded at 550 nm. The induction period before the onset of crystallization is used to calculate the analyte concentration. A similar strategy can be used employed for the resolution of structural isomers of arginine and ornithine in pharmaceutical formulations. 

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