Effect of Catalytic Hydropretreatment of Petroleum Vacuum Resid on Coprocessing with Coal

Abstract

The coprocessing of coal with petroleum vacuum resids can be used to produce distillable oils. Improved coprocessing performance by using hydrotreated resids as host oils in coprocessing with coal was studied. Four host oils were prepared from petroleum vacuum resids (538 °C+/1000 °F+) by catalytic hydrogenation and hydrocracking. The untreated and pretreated resids were then thermally coprocessed with an Illinois No. 6 and with a Wyodak coal. Using solubility in tetrahydrofuran (THF) and pentane, products were separated into asphaltenes, pentane-soluble oils (PSO), coke, and gas. Phenolic compounds, derived mainly from coal, were present in the PSO products and their concentration, measured by IR spectroscopy, was used to estimate the fraction of coal liquids in the PSO products. The yield of PSO was strongly affected by the concentration of coal in the feed; depending on the pretreatment used, the yields of PSO from a 33% coal/resid mixture varied from 48 to 78 wt %. The yield of PSO from Illinois No. 6 coal and untreated resid, as well as resids hydrogenated at temperatures where cracking was low, was greater than that predicted from runs made when the resids and coal were processed separately for coal-feed concentrations up to about 33 wt %. Coal conversion during thermal coprocessing with petroleum vacuum resid can be significantly increased if the resid is first hydrogenated at conditions where cracking is suppressed. However, pretreatment of the resids, by methods used in this study, resulted in only minor improvements in PSO yields.

Hydrotreatment Activities of Supported Molybdenum Nitrides and Carbides

“…Reaction rate measurements were made using a batch microreactor system. This type of system has been employed by several other groups in recent studies. − The catalytic reactions were performed in 2 mL stainless steel reactors. The reactor was made of Swagelok components including two caps ( 3 / 8 in.)…”

Pyrolysis of oil sludge with additives of sodium and potassium compounds

“…For both economic and environmental reasons, the transformation of wastes such as waste oil (Sanjay et al, 1994), petroleum vacuum residues (Hajdu et al, 1996;Joo et al, 1999;Mochida et al, 1990), oil sludge (Ayen and Swanstorm, 1992;Chang et al, 2000;Shie et al, 2000), spent plastics (Lin et al, 1996;Maksimova and Krivoruchko, 1999;Shie et al, 2002a;Wu et al, 1993) and biomass (Samolada et al, 2000;Shihadeh and Hochgerb, 2000) to effective energy sources has became important recently. Energy recycling into fuel oils is attractive and has been commercially tested and operated.…”

“…Addition of a useful catalyst or additive in the catalytic cracking process at adequate reaction conditions has a great potential to shorten the cracking time, lower the required temperature, increase the cracking ability of wastes, reduce the proportion of solid residue, and/or narrow the product distribution (Chiu and Cheng, 1999;Maksimova and Krivoruchko, 1999). Coprocess of coal with petroleum wastes that contained dispersant additives can improve the dispersion of the coal particles and the catalysts during liquefaction (Hajdu et al, 1996). For the improvement of pyrolysis oil, upgrading the pyrolysis oil or adding catalysts or additives in oil sludge to advance the pyrolysis reactions is necessary.…”

Use of Inexpensive Additives in Pyrolysis of Oil Sludge

“…Due to the minimal alternative energy sources, like hydraulic, solar, windmill, geothermal, and civilian-unacceptable nuclear fission energies, fossil fuels are the main energy sources in Taiwan. For both economic and environmental reasons, the transformation of wastes, such as waste oil, petroleum vacuum residues, − oil sludge, − and spent plastics − to effective energy sources has became important recently. Among the crude oil refining processes, a lot of oil sludge accumulate from petroleum refineries.…”