SRC conversion for

Comparing the 750°F+ and 850°F+ residual feed conversion above indicates sizable conversion for the 850°F+ SRC (26-47%) and considerably smaller conversion for 750°F-(- SRC feed (4-35%). This leads to the conclusion that the major product from SRC conversion was material boiling between 750° and 850°F. For samples taken at 76 and 83 hr on-stream, approximately 20% of the feed SRC went to 750°-850°F distillate. Only about 5% went to 750° F distillate since further conversion to 750° F material was much slower. For the sample taken at 101 hr on-stream, the residual SRC conversion for 850°F and 750°F cut points,... 

The proposed NSPS can be met by hydrotreating the coal liquids obtained by filtering the product from the coal dissolution stage. The desulfurization kinetics can be presented by two parallel first-order rate expression, and hydrogen consumption kinetics can be presented by a first-order rate expression. A linear relationship exists between total sulfur content and SRC sulfur content of the hydrotreated product. For the Western Kentucky bituminous 9/14 coal studied here, the maximum selectivity and lowest SRC conversion to oil for a fixed SRC sulfur content are obtained using the highest reaction temperature (435°C) and the shortest reaction time 7 min.). ... 

Schmid, B. K. Jackson, D. M. "Recycle SRC Processing for Liquid and Solid Fuels", presented at the Fourth Annual International Conference on Coal Gasification, Liquefaction Conversion to Electricity, University of Pittsburgh, Pittsburgh, Pennsylvania, August 2-4, 1977. 

The relative change in SRC conversion vs. hydrogen consumption is seen in Figure 3 for both 750° and 850°F cut point data. As hydrogen consumption increases, SRC conversion also increases. The intercept for the 750°F cut point data suggests that 0.8 wt % hydrogen addition to the feed is necessary before any conversion of the residue is observed. This type of result also has been observed in our studies on synthetic filtrate. 

Converted product selectivity on a carbon basis is compared for Ni-W and Ni-Mo in Figure 13 for 850°F+ SRC feed. The yield of hydrocarbon gases from Ni-W is much greater than for Ni-Mo. Part of the reason for the difference may be the higher temperature necessary to attain the same level of conversion for Ni-W than for Ni-Mo. In any case the much higher selectivity of Ni-Mo for liquid distillate at the same level of hydrogen consumption to reach a particular conversion makes the Ni-Mo the preferred catalyst over Ni-W. 

Coal liquefaction under supercritical (or subcritical) water condition has some advantages over organic solvents. Supercritical water is miscible with H2, CO, aromatics, and oils, which provides a unique, homogeneous reaction medium for coal liquefaction. CTL process with supercritical water is more environment-friendly than SRC-II process and has higher conversion for low-rank coal [31,32]. 

The classic work of Storch and co-workers showed that essentially all coals below 89% C f can be converted in high yields to acetone soluble materials on extended reaction (12). We have investigated the behavior of coals of varying rank toward short contact time liquefaction. In one series of experiments, coals were admixed with about 5 volumes of a solvent of limited H-donor content (8.5% Tetralin) and heated to 425°C for either 3 or 90 minutes. The solvent also contained 18% p-cresol, 2% y-picolene, and 71.5% 2-methylnaphthalene and represented a synthetic SRC recycle solvent. The conversions of a variety of coals with this... 

Table III shows that hydrogenated and unhydrogenated SRC recycle solvents were equally effective for the conversion of a western subbituminous coal at low reaction severity. At higher severity but at times shorter than 10 minutes, significantly higher conversions were achieved only with the hydrogenated solvents which could donate more hydrogen.

Kleinpeter and Burke have recently reported (24) that solvents can also be over hydrogenated and thus become less effective in short time processes. Figure 19 shows some of their work in which a process-derived SRC recycle solvent was hydrogenated to various severities and used for the conversion of an Indian V bituminous coal. The results clearly show a maximum at intermediate hydrogenation severities. Our assessment of this observation is that the loss in conversion was due primarily to the loss in condensed aromatic nucleii rather than conversion of hydrogen donors to saturates. 

The product workup consisted of continuously extracting the filter cake with tetrahydrofuran (THF) and combining the THF and filtrate to make up a sample for distillation. In some experiments the THF extracted filter cake was extracted with pyridine and the pyridine extract was included in the liquid products. Extraction with pyridine increased coal conversion to soluble products by an average of 1.6 weight percent. The hot filtrate-THF-pyridine extract was distilled. Distillation cuts were made to give the following fractions, THF (b.p. <100 C), light oil (b.p. 100-232 C), solvent (b.p. 232-482), and SRC (distillation residue, b.p. >482 C). 

Table I compares the conditions and results of this operation to those for conventional SRC for Illinois 6 coal. At the short residence time, the coal conversion determined by pyridine solubility is 89% compared to 95% at conventional SRC conditions. The hydrogen consumption and production of light gases are reduced significantly at short residence time, while the SRC yield is increased.

The crystal structure clearly shows that Src kinase is held by intramolecular interactions in an inactive conformation, in which the binding surfaces of the SH2 and SH3 domains are sequestered. Several paths for conversion to the active, open form are under discussion. Ibis could take place by activation via dephosphorylation of the C-terminal tail. It could also take place by the apposition of a high affinity ligand for the SH2/SH3 domains. In addition, phosphorylation of Tyr416 is also needed for full activation. 

The products were solvent fractionated into hexane soluble (HS), hexane insoluble-benzene soluble (HI-BS), and benzene insoluble (Bl) fractions. The yields of these solvent-fractionated products after hydrotreatment of SRC are plotted against the reaction time in Fig. 13. The overall activities of the catalysts were very similar to those of the commercial catalyst in spite of their lower surface areas. Both exploratory catalysts (Cat-A and Cat-B) showed similar reaction profiles, which were markedly different from those of the commercial catalyst. The BI fraction decreased over the exploratory catalysts equally as well as the over the commercial catalyst. However, the HS fraction hardly increased as long as the BI fraction was present. As the result, the HI-BS fraction increased to a maximum just before the BI fraction disappeared and then rapidly decreased to complete conversion after about 9 hr. The rate of HS formation increased correspondingly during this time. Thus, the exploratory catalysts were found to exhibit a preferential selectivity for conversion of heavier components of SRC, compared to the commercial catalyst. These results emphasize that the chemical and physical natures of the support are important in catalyst design (49). 

The SRC process, in its two forms, is one of the major processes under current study in programs sponsored by the DOE for conversion of coal to either (1) a solid deashed low sulfur product or (2) a low boiling liquid. 

Another processing option for maximum gasoline is use of the catalytic cracking process rather than hydrocracking as the major conversion process. Our experiments indicate that conversions in catalytic cracking of SRC-II are low unless the... 

The investments shown are estimated for an urban midcontinent location. As mentioned above, the estimate for the boiler plant is based on coal-fired burners with attendant stack gas sulfur dioxide (SC ) removal facilities. As indicated on Table XX, no allowance is made for (a) coal resource costs, (b) coal mining or handling, (c) conversion of coal to oil by SRC-II process, (d) SRC-II oil transportation to, or (e) refined product distribution and transportation from the refinery. These additional costs are not required to evaluate refinery processing costs. However, they should be included if it is desired to determine the overall economics of a specific synthetic crude oil refining project. 

The SRC-II process is one of several coal liquefaction processes currently under development in programs funded by the Department of Energy (DOE). Product from this process is a distillate that is relatively attractive as a feed for conversion to transportation fuels. Essentially all of the nitrogen, sulfur, and oxygen can be removed in a single catalytic hydro-treating stage to yield a naphtha that is an excellent feed for a catalytic reformer and a middle distillate fraction that is a... 

Figures 3 and 4 show the weight percent 850°F+ conversion as a function of the relative space velocity for PDU Run 2LCF-16 (SCT feedstock) and PDU Run 2LCF-17 (SRC-I feedstock), respectively. The 780°F check points used to measure catalyst activity are defined by the symbols C and CL, where the subscripts B and E refer to the beginning ana end ot the run. It was concluded that higher pressure was significantly contributing to a reduction in catalyst deactivation and both PDU Runs 2LCF-16 and 2LCF-17 were assumed to have a neglible catalyst deactivation.

---