Chemistry. and Technology of Fuels and Oils, Vol. 32, No. 3, 1996

CURRENT PROBLEMS

ALTERNATIVE RAW MATERIAL FOR THE PRODUCTION OF PARAFFIN/MICROCRYSTALLINE

WAX COMPOUNDS

K. M. Badyshtova, T. N. Shabalina, O. M. Elasheva, S. V. Tyumkin, D. E. Diskina, G. S. Leskov, and M. V. Kitova

UDC 665.41:665.43:547.21

With the decreasing volumes of oil production and refining, and with the general use of hydrogenation processes to obtain high-viscosity-index lube stocks, the available resources of paraffins, microcrystalline waxes, and their components have been sharply curtailed; these materials are used in the manufacture of lubricating greases and many consumer products. The shortage of these high-melting components of petroleum has prompted a search for an alternative raw material for their production. Experience in the United States has shown that oilfield ""ax plugs may be a source of high-melting microcrystalline wax (MCW). Also, in the oil-producing regions of Russia, large amounts of asphaltic-resinous wax deposits (ARWD) are available. These deposits are formed in the production and transportation of oil -- in the production strings of flowing and pumped wells, in oilfield and cross-country pipelines, and in oilfield and pumping-station tanks. Every year wimesses the accumulation of some 150-200 thousand metric tons of ARWD, and no application has been found for this material, which is simply buried in swamps, dumps, pits, or accumulators, or part of the material may be burned. In either case, disposal of the material contributes to pollution of the environment with oily materials and disrupts the ecological balance in nature. In the United States and other countries, either burning or burying the ARWD is illegal. Wax plugs from oilfields are handled by a processing scheme that includes pretreating the raw material (dehydration and removal of light fractions and particulate contaminants), followed by treatment by traditional methods (propane deasphalting, crystallization in acetonebenzene, acid/clay treatment). The commercial product from these operations is an MCW with a melting point as high as 80°C. In order to determine the economic feasibility of processing ARWD, as well as the product mix and product quality, we investigated various samples of these deposits obtained in a number of regions of Russia from pits, accumulators, and oilfield piping. The characteristics of these samples are shown in Table 1. It will be noted that the samples contained paraffin and MCW components with melting points of 66-84°C in amounts of 40-70% by weight, indicating promise for their use as an alternative raw material. We investigated more thoroughly certain samples of ARWD taken from oilfields of Samara Oblast (Chapaevskneft', Kinel'neft') and West Siberia (Nizhnevartovskneft', Kogalymneft'). These samples consisted largely of organic matter, 72-90% (Table 2). The inorganic part consisted mainly of silicon and iron oxides (sand and corrosion products), with small amounts (less than 1%) of compounds of sodium, aluminum, zinc, lead, and other metals. The organic part of these samples was analyzed by liquid adsorption chromatography. As shown in Table 2, the organic part of the ARWD contains 29-75% by weight of high-purity paraffin-MCW componentst with melting points of 70-78°C, whereas the original crudes contain only a few percent of high-melting hydrocarbons.

*Expansions of organization names unverified; possibly Middle-Volga Scientific-Research Institute for Petroleum Processing, and Scientific-Research Institute for the Development and Service Performance of Oilfield Tubular Goods, respectively -Translator. tAs in Russian original; statement is inconsistent with the data of Table 2 -- Translator. SvNII NP. NIITneft'.* Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 13-14, May-June, 1996. 0009-3092/96/3203-0119515.00 ©1996 Plenum Publishing Corporation

119

TABLE I Cofllents of components in ARWD, wt. % Region. field (and geological hor=zon)

para!:fin-MCW (and mp, °C)

asphalts and resins

Samara Oblast

Dmttrov (AO), NPU Pervomainefl'

23,0 4,1 10,5

Mukhanovo (DI-D3), NPU Pervomaineft' Lebyazh'e (D-3), NPU Bogatuvskneft' Lebyazh'e (D-3), NPU Bogatovsknefl' Pokrovka (D2 + VZ), NGDU Chapaevskneft' Gorbatov (B2), NGDU Chapaevst'neft '

53,3 (83) 59,4 (75) 59,9 (83) 69,1 (84) 61,5 (82) 61,4 (83)

From reservoir, NGDU Chapaevskneft' Uvarov, NGDU Kinel'neft'

67,4 (63) 52,8 (72)

22,1 11,0 25,7 10,7

42,7 (75)

33,0

54~1 (69)

18,3

Saratov Oblast

Urutsk. NGDU Saratovneft' Udmurtia

Kingan (A4L NGDU Udmurmefl' Orenburg Oblast

22

Pokrovka (]32), NGDU Buzuluknel~'

56,2 (75)

Bobrovka (A4), NGDU Buzulukneft'

69,5 (66)

29,3

66,8 (79)

12,9

50,8 (68) 55,1 (69)

25,4

Komi Republic

Zapadno-T6buk, NGDU KominefY Tatarstan

Severo-Al'met'evo area, NGDU Al'met'evskneft'

Ponamarov, NGDU Buguruslanneft'

12

Bashkorto~;tan

Pavkhov, Production Association Bashneft'

15,9

39,9 (83)

Note. NPU = Oilfield Administration; NGDU = Oil and Gas Production Administration - Translator,

TABLE 2 Orgamc part of ARWD sample taken from indicated field Index

Nizhnevar- ~ lovsknefl' (from pit)

Yield, wl. % on ARWD Needle penetration at 25 ~C Temperature. *C softening point

flash point Component composition. wt. % paraffin (and mp, ~C) paraffinMCW (and mp, °C) asphalts and resins insoluble in orgamc solvents

"-~Kinel'ne~

I .... J ~

I ~Ilen )

I from produc-I I tiontubing I

. fromp~

72,5 27

37,2 66

75,4 8

90,0 26

81,8 42

83 197

74 183

83 221

66,5 178

75 223

29 (73) 43,8 (75)

67.3 (70,4) 12,7 (77)

75,6 (78} 9,4 (95)

70,9 (64) 21.9(48,5)

34,0 (72.5) 47,0 (76)

19,2 8,0

6,4 13,6

6,6 8,4

5,3 1,9

13,6 5,4

In addition, in processing the ARWD, components with melting points of 75-90°C can be classed as high-melting MCW; the content of these components varies from 9% to 47% by weight. Since the ARWD contains considerable amounts of asphaltic and resinous compounds (see Tables 1 and 2), we can predict that it will be possible to obtain various asphalts from these raw materials. Our investigation of the composition and properties of ARWD from different fields has pointed out the significant differences among this group of materials and hence the need for choosing the optimum processing method. The advisability of processing ARWD to obtain paraffin-MCW compounds and asphalts, based on U.S. experience, is very obvious in spite of the complexity of such processing, which can be carried out only at the refinery. However, transportation of the ARWD involves technical difficulties and economic costs: hence it is necessary to develop technology for the primary treatment of these materials at the sites of their accumulation, i.e., in the oil-producing districts. 120

The following operations are involved in any successful solution of the problem of ARWD utilization: Removal of the solid oil sludge from pits, accumulators, etc.; primary treatment of the ARWD to remove water and particulate contaminants, while segregating the organic part. Experience here and abroad in processing similar products confirms in principle the possibility of designing a mobile module for primary treatment of ARWD. Organization of ARWD recovery and processing in Russia will make it possible to expand the resources of raw material for the production of lubricating greases, various consumer products, insulation, and structural materials, and also to improve significantly the ecological situation in oil-producing regions. The idea of developing and fabricating a module for such processing should be of interest to directors in both the oil producing and refining branches of the industry.

121