Synthoil

Synthetic waxes Synthine process Synthoil Synthol... 

Granoff, B. Baca, T. M. Thomas, M. G. Noles, G. P. "Chemical Studies on Synthoil Mineral Matter Effects", Sandia Labs. Energy Rept. No. SAN-78-1113, 1978. 

Coal Products Isotopic Distribution by Structural Position. Other workers have also investigated deuterium uptake in coal pro-ducts by structural position. Schweighardt, et al. (26) examined a centrifuged liquid product from a Synthoil run which was heated to 450°C with deuterium gas, Kershaw and Barrass (27) examined the products from the reaction of coal with deuterium gas using SnCl2 as catalyst, and Franz (10) examined the products from the reaction of a subbituminous coal with Tetralin-1,l-d2 at 427°C and 500°C. 

CSF [Consol Synthetic Fuels] A two-stage coal liquifaction process. In the first stage, the coal is extracted with process-derived oil and the ash removed. In the second, the extract is catalytically hydrogenated. Piloted by the Consolidation Coal Company, Cresap, WV, from 1963 to 1972. See also H-Coal, SRC, Synthoil. 

H-Coal A coal gasification process. Crushed coal is mixed with process-derived oil and catalytically hydrogenated in an ebullated bed under pressure at 455°C. The catalyst is a mixture of cobalt and molybdenum oxides on alumina. Developed by Hydrocarbon Research from the 1960s and piloted in Catlettsburg, KY, from 1980 to 1982. See also CSF, H-Oil, CSF, Synthoil. 

Synthoil A coal liquifaction process in which coal, suspended in oil from the process, is hydrogenated over a cobalt/molybdenum catalyst on alumina. The process was piloted by the Pittsburgh Energy Research Center at Bruceton, PA in the 1970s using several types of coal, but it was abandoned in 1978. See also CSF, H-Coal. 

Figure 6. SEC of coal liquids using the SEC-GC interface online (Figure 2). Fraction collection timing is similar to one used for Wyodak (Figure k) except for Western Kentucky Synthoil where 2M fractions were collected.

The so-called cobalt molybdate catalyst has been used much in the petroleum industry for hydrotreating and hydrodesulfurization. More recently, these catalysts have been employed in coal liquefaction and synthoil upgrading. The latter probably accounts for the recent rash of publications on this very interesting catalyst system. Indeed, of the papers surveyed for this review, the majority have been published in the past 5 years with no letup in sight. 

The flowsheet of a 1/2-ton (slurry) per day SYNTHOIL bench scale plant, currently in operation at the Energy Research and Development Administration laboratory in Bruceton, Pennsylvania, is shown in figure 1. The vertically placed reactor is made of two interconnected stainless steel tubings of 1.1-inch ID x 14.5-ft long each. The upper end of the first section is connected to the lower end of the second section with a 5/16-inch ID empty tubing. Thus, the plant may be operated with one or both sections of the reactor packed with catalyst while the fluids flow upwards through each. 

Figure 1. Synthoil pilot plant flow sheet...

In the Energy Research and Development Administration s SYNTHOIL process, slurries of coal in recycle oil are hydrotreated on Co-Mo/Si02 Al203 catalyst in turbulent flow, packed-bed reactors. The reaction is conducted at 2,000 to 4,000 psi and about 450° C under which conditions coal is converted to low-sulfur liquid hydrocarbons and sulfur is eliminated as E2S. 

Product oils from SYNTHOIL runs carried out at 415° and 450° C and 2,000 and 4,000 psi H2 pressures were analyzed with respect to asphaltene and oil content, elementary compositions (C, E, S, N), ash and physical properties (specific gravity and viscosity). Asphaltenes exert a large effect on the viscosity of the product oil, the viscosity increasing exponentially with asphaltene content. Viscosity of product oil is not only dependent on the amount but also on the molecular weight of asphaltenes present. At 415° C, asphaltenes with a molecular weight of 670 are formed and at 450° C asphaltenes with a molecular weight of 460. 

SYNTHOIL product FB-39 (lower scale,right ordinate) SYNTHOIL product FB-40 (upper scale. left ordinate )... 

Akhtar, Sayeed, Lacey, James J., Weintraub, Murray, Reznik, Alan A., and Yavorsky, Paul M. The SYNTHOIL Process—Material Balance and Thermal Efficiency. Presented at the 67th Annual AIChE Meeting, December 1-5, 1974, Washington, D.C. 

Akhtar, Sayeed, Mazzocco, Nestor J., Weintraub, Murray, and Yavorsky, Paul M. SYNTHOIL Process for Converting Coal to Nonpolluting Fuel Oil. Presented at the 4th Synthetic Fuels from Coal Conference of the Oklahoma State University, Stillwater, Oklahoma, May 6-7, 1974. 

The objective of this work was to study the activity of the Monolith catalyst for removing sulfur and nitrogen from a Synthoil process liquid (heavy stock) and Raw Anthracene Oil (light feedstock), and to make a preliminary assessment of the advantages and/or disadvantages of the Monolith catalyst over a commercial catalyst used in the petroleum industry. 

Feedstocks. The Raw Anthracene Oil was obtained from the Reilly Tar and Chemical Corporation, and the Synthoil liquid from the Pittsburgh Energy Research Center. The properties of these two liquids are given in Table I. The feedstocks were used as received from suppliers without pretreatment. As is clear... 

Figure 6. HDS and HDN responses to the change in the volume hourly space time, synthoil liquid, 1500 psig, 371° C (700° F) (A) Monolith catalyst, (O)...

The precision of sulfur and nitrogen analyses was determined by multiple analysis of Raw Anthracene Oil and Synthoil liquid. The results of sulfur analysis of Raw Anthracene Oil were found to be precise within 0.25%. But the precision of other results was within 5.0%. 

Figures 5 and 7 indicate that on the volume and weight bases, the activity of the monolith catalyst when tested on Raw Anthracene Oil was less than that of Nalcomo 474 catalyst. On the other hand, Figures 6 and 8 show that when tested on Synthoil liquid, the desulfurization activities of the two catalysts were approximately the same on a volume basis, whereas on a weight basis, the Monolith catalyst was more effective. The denitro-genation activity of Nalcomo 474 was somewhat better even on this feedstock.

Figure 10 shows the comparison of the surface activities of the two catalysts on the heavier feedstock, Synthoil liquid. In this case the unit surface area activity of the Monolith catalyst is greater than that of the Nalcomo 474 catalyst. This behavior is different from that observed on the Raw Anthracene Oil, and as further discussion will show, this difference in the superiorities of the Monolith catalyst on the two feedstocks throws light on some interesting observations of this study. 

If one considers that the Monolith catalyst was intrinsically more active than the Nalcomo 474 catalyst then the observed superiority of the Monolith catalyst should be essentially the same, or at least be comparable, when tested on two different feeds. But as explained earlier the observed surface activities of the two catalysts for HDS are almost equal in the case of Raw Anthracene Oil, while, on Synthoil liquid the observed surface activity of the Monolith is about four times that of the Nalcomo 474 catalyst. Therefore, there is some basis to... 

Thus intraparticle diffusion was likely responsible for showing higher activity, on unit surface area basis, of the Monolith catalyst when processing the Synthoil liquid. 

To have a quantitative idea of the problem of intraparticle diffusion, effectiveness factors for the two catalysts were calculated from the observed second order rate constants (based on surface area) using the "triangle method" suggested by Saterfield (4). The effectiveness factors for Monolith and Nalcomo 474 catalysts on Synthoil liquid at 371°C (700 F) were calculated to be 0.94 and 0.216, respectively. In applying the relationship between the "Thiele Modulus," 4>> and the "effectiveness factor," n> the following simplifying assumptions were made ... 

The effectiveness factors calculated in this study are under the experimental conditions utilized in this study and give an idea of the magnitude of pore diffusion problem in the case of the Nalcomo 474 catalyst when Synthoil liquid is processed. On the other hand, the Monolith catalyst shows promise in this regard and warrants further investigation regarding its activity under different compositions of the catalyst and different reactor operating conditions. 

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