Sulfur Chevron

Fig. 21.25-27 The GCOAED carbon and sulfur Chevron Research and Technology Co., Rich-profiles of three different light processed pet- mond, CA, USA. roleum distillates. Courtesy ofj. Iwamoto,...

Chevron Chemical Co. began commercial production of isophthahc acid in 1956. The sulfur-based oxidation of / -xylene in aqueous ammonia at about 320°C and 7,000—14,000 kPa produced the amide. This amide was then hydrolyzed with sulfuric acid to produce isophthahc acid at about 98% purity. Arco Chemical Co. began production in 1970 using air oxidation in acetic acid catalyzed by a cobalt salt and promoted by acetaldehyde at 100—150°C and 1400—2800 kPa (14—28 atm). The cmde isophthahc acid was dissolved and recrystallized to yield a product exceeding 99% purity. The Arco technology was not competitive and the plant was shut down in 1974. 

Figure 3-5. Flow diagram of a Chevron Rheiniforming unit (1) sulfur sorber, 2-A) reactors, (5) separator, (6) stabilizer.

RDS Isomax [Residuum desulphurization] A hydrodesulfurization process for removing sulfur compounds from petroleum residues, while converting the residues to fuel oil. Developed by Chevron Research Company in the early 1970s. Ten units were operating in 1988. See also VGO Isomax, VRDS Isomax. 

Note According to Chevron Phillips Company s (2005) Technical Data Sheet, 99.0-99.4 wt % / -heptane (pure grade) contains the following components c/s-l,2-dimethylcyclopentane -1- methyl-cyclohexane (< 1 wt %), /rafl5-l,2-dimethylcyclopentane (< 0.25 wt %), 3-methylhexane (< 0.25 wt %), sulfur content (< 1 wt %), and the largest other single impurity at a concentration of (<0.15 wt %). 

Note According to Chevron Phillips Company s (2004) Technical Data Sheet, 97.0-98.5 wt % octane typically contains 1.5 wt % isooctanes, <1 ppm sulfur content, and trace amounts of isononanes. 

K.D. Nelson and F. Plavac, Sulfurized polyisobutylene based wear and oxidation inhibitors, US Patent 7 414 013, assigned to Chevron Oronite Company LLC (San Ramon, CA), August 19, 2008. 

The Chevron deasphalted oil hydrotreating process is designed to desulfurize heavy feedstocks that have had the asphaltene fraction removed by prior application of a deasphalting process (Chapter 7). The principal product is a low-sulfur fuel oil that can be used as a blending stock or as a feedstock for a fluid catalytic unit (Table 9-7). 

Chevron RDS and VRDS processes processes designed to remove sulfur, nitrogen, asphaltene, and metal contaminants from heavy feedstocks consisting of a once-through operation of the feedstock coming into contact with hydrogen and the catalyst in a downflow reactor (q.v.). 

Table I. Properties of a Typical Chevron Sulfur Composite...

Chevron s emphasis has been directed mainly toward high-strength, sprayable composites which are chemically modified sulfur that contains organosulfur plasticizers, fillers, and other additives. The type and amount of each additive is selected to impart the properties required for each end use. 

The properties of a typical Chevron sulfur composite are shown in Table I. One desirable feature is the low melt viscosity in the 250°-300°F range. This provides considerable latitude in the choice of application methods. Spray has proven to be effective for many uses. Brush, roller, and dipping have also been used for some coating applications. Most composites can be put into service immediately after application because they attain most of their strength and durability shortly after they solidify from the melt. 

Sulfur s coefficient of thermal expansion can be reduced significantly when modified with plasticizers and fillers. Most Chevron composites have coefficients of expansion about one-half that of elemental sulfur. Even lower coefficients are possible with very high levels of filler. These lower coefficients contribute to the improved thermal shock resistance of sulfur composites and to their reduced tendency to crack or craze. 

Figure 2. Chemical resistance of typical Chevron sulfur composites to water, sea water, NagSOk (saturated), HgSOk (2N), and HCl (2N).

Canal Lining. Sulfur composite was used to line an earthen irrigation canal in southern Alberta, Canada (7,8) (Figures 4 and 5). This installation was a joint project between Chevron, The Sulphur Development Institute of Canada, and the Eastern Irrigation District. 

Chevron has demonstrated that it is commercially feasible to use sulfur composites as protective coatings and construction materials. This was done with large-scale field installations using special equipment and application procedures. Future efforts will focus on the commercial development of Chevron Sucoat products for these and other practical uses. 

Two field tests were conducted in 1974 to evaluate the above applications of sulfur foam. These tests were jointly sponsored by Chevron and the Sulphur Development Institute of Canada (SUDIC). 

Large-scale uses for this type of foamed-in-place insulation and application equipment are anticipated as the Canadian Arctic is developed. Successful results from these field tests and the prospects of commercial uses of the sulfur foam prompted Chevron Chemical Co. to proceed with the design, engineering, construction, and demonstration of a commercial-scale sulfur foam field application unit. 

The proprietary process for making sulfur foam was developed at Chevron Research Co. and uses carbon dioxide as the preferred blowing... 

Figure 4. Chevron Chemical Co. commercial sulfur foam unit...

On March 8, 1977 the Chevron Chemical Co. commercial field foaming equipment was demonstrated in Calgary to over 100 spectators representing local, provincial, and federal government, as well as local contractors and Canadian oil and gas companies (Figures 7, 8, and 9). This demonstration, jointly sponsored by Chevron and the Sulphur Development Institute of Canada (SUDIC), illustrated the practical application of sulfur foam in the field. 

Figure 7. Chevron Chemical Co. s winterized commercial sulfur foam...

Figure 8. Demonstration of Chevron Chemical Co s commercial sulfur foam field application unit in Calgary, March 8,1977...

Kluksdahl, H.E., inventor Chevron Research Company, assignee. "Reforming a sulfur-free naphtha with a platinum-rhenium catalyst." U.S. Patent 3,415,737. 8 pages. 1968. 

An 80-hour test with ultra-low sulfur ( 5 ppm) diesel, a developmental product obtained from Chevron Phillips Chemical, was also successfully completed (Figure 3). The use of this product permits... 

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