Methanol feed for producing olefin streams Number:7,102,048 from the United States Patent and Trademark Office (PTO) owispatent This invention provides a methanol composition, a method of making the composition, and a method of using the composition. The methanol composition of this invention is supplemented with certain additional alcohols and/or aldehydes, and serves as a particularly desirable feed stream for use in the manufacture of olefins such as ethylene and propylene. Such feed streams result in increased production of ethylene or in the increased production of both ethylene and propylene.<H producing, Methanol, Methanol, feed, f, 7102048.html, Patent, pto, 7102048

Title: Methanol feed for producing olefin streams

Abstract: This invention provides a methanol composition, a method of making the composition, and a method of using the composition. The methanol composition of this invention is supplemented with certain additional alcohols and/or aldehydes, and serves as a particularly desirable feed stream for use in the manufacture of olefins such as ethylene and propylene. Such feed streams result in increased production of ethylene or in the increased production of both ethylene and propylene.

Patent Number: 7,102,048 Issued on 09/05/2006 to Van Egmond, et al.

Inventors: Van Egmond; Cor F. (Pasadena, TX), Xu; Teng (Houston, TX)
Assignee: ExxonMobil Chemical Patents Inc. (Houston, TX)

Appl. No.: 10/321,215

Filed: December 17, 2002

Current U.S. Class: 585/638 ; 585/324; 585/639; 585/640

Current International Class: C07C 1/00 (20060101)

Field of Search: 585/324,638-640

References Cited [Referenced By]

U.S. Patent Documents


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Foreign Patent Documents


28 09 082	Nov., 1978	DE

Primary Examiner: Griffin; Walter D.
Assistant Examiner: Bullock; In Suk

Claims

The invention claimed is:

1. A process for forming an olefin stream, the process comprising the steps of: a) contacting a synthesis gas stream with a methanol synthesis catalyst to form a crude methanol stream containing methanol, ethanol and acetaldehyde; b) separating a methanol composition from the crude methanol stream, wherein the methanol composition comprises a majority of the methanol and a majority of the acetaldehyde contained in the oxygenate containing stream; and c) contacting the methanol composition with an olefin forming catalyst to form an olefin stream.

2. The process of claim 1, wherein the synthesis gas stream is made by contacting a carbon containing compound with water or oxygen.

3. The proccss of claim 2, wherein the carbon containing compound is selected from the group consisting of biomass, natural gas, C.sub.1 to C.sub.5 hydrocarbons, naphtha, heavy petroleum coils, coke, and mixtures thereof.

4. The process of claim 1, wherein the methanol composition is separated by distillation.

5. The process of claim 1, wherein the methanol composition separated in step b) comprises: i. at least 50 wt % and less than 99.85 wt % methanol, based on total weight of the methanol composition; ii. greater than 10 wppm and not greater than 15 wt % ethanol, based on total weight of the methanol composition; and iii. greater than 10 wppm, and not greater than 15 wt % acetaldehyde, based on total weight of the methanol composition.

6. The process of claim 5, wherein the methanol composition comprises at least 75 wt % methanol, based on total weight of the methanol composition.

7. The process of claim 6, wherein the methanol composition comprises at least 80 wt % methanol, based on total weight of the methanol composition.

8. The process of claim 7, wherein the methanol composition comprises at least 85 wt % methanol based on total weight of the methanol composition.

9. The process of claim 8, wherein the methanol composition comprises at least 90 wt % methanol, based on total weight of the methanol composition.

10. The process of claim 5, wherein the methanol composition comprises not greater than 99 wt % methanol, based on total weight of the methanol composition.

11. The process of claim 10, wherein the methanol composition comprises not greater than 98 wt % methanol, based on total weight of the methanol composition.

12. The process of claim 11, wherein the methanol composition comprises not greater than 97 wt % methanol, based on total weight of the methanol composition.

13. The process of claim 12, wherein the methanol composition comprises not greater than 96 wt % methanol, based on total weight of the methanol composition.

14. The process of claim 5, wherein the methanol composition comprises at least 100 wppm ethanol, based on total weight of the methanol composition.

15. The process of claim 14, wherein the methanol composition comprises at least 1,000 wppm ethanol, based on total weight of the methanol composition.

16. The process of claim 15, wherein the methanol composition comprises at least 10,000 wppm ethanol, based on total weight of the methanol composition.

17. The process of claim 16, wherein the methanol composition comprises at least 0.1 wt % ethanol, based on total weight of the methanol composition.

18. The process of claim 5, wherein the methanol composition comprises not greater than 12 wt % ethanol, based on total weight of the methanol composition.

19. The process of claim 18, wherein the methanol composition comprises not greater than 10 wt % ethanol, based on total weight of the methanol composition.

20. The process of claim 19, wherein the methanol composition comprises not greater than 8 wt % ethanol, based on total weight of the methanol composition.

21. The process of claim 5, wherein the methanol composition comprises at least 100 wppm acetaldehyde, based on total weight of the methanol composition.

22. The process of claim 21, wherein the methanol composition comprises at least 1,000 wppm acetaldehyde, based on total weight of the methanol composition.

23. The process of claim 22, wherein the methanol composition comprises at least 10,000 wppm acetaldehyde, based on total weight of the methanol composition.

24. The process of claim 23, wherein the methanol composition comprises at least 0.1 wt % anetaldehyde, based on total weight of the methanol composition.

25. The process of claim 24, wherein the methanol composition comprises not greater than 12 wt % acetaldehyde, based on total weight of the methanol composition.

26. The process of claim 25, wherein the methanol composition comprises not greater than 10 wt % acetaldehyde, based on total weight of the methanol composition.

27. The process of claim 26, wherein the methanol composition comprises not greater than 8 wt % acetaldehyde, based on total weight of the methanol composition.

28. The process of claim 1, wherein the methanol composition further comprises ketone at less than 50% that of the acetaldehyde.

29. The process of claim 28, wherein the methanol composition further comprises ketone at less than 60% that of the acetaldehyde.

30. The process of claim 29, wherein the methanol composition further comprises ketone at less than 70% that of the acetaldehyde.

31. The process of claim 1, wherein the methanol composition further comprises at least 0.1 wt % and not greater than 12 wt % water, based on total weight of the methanol composition.

32. The process of claim 31, wherein the methanol composition further comprises at least 0.5 wt % water, based on total weight of the methanol composition.

33. The process of claim 32, wherein the methanol composition further comprises at least 1.0 wt % water, based on total weight of the methanol composition.

34. The process of claim 33, wherein the methanol composition further comprises at least 1.5 wt % water, based on total weight of the methanol composition.

35. The process of claim 34, wherein the methanol composition further comprises not greater than 10 wt % water, based on total weight of the methanol composition.

36. The process of claim 35, wherein the methanol composition further comprises not greater than 8 wt % water, based on total weight of the methanol composition.

37. The process of claim 36, wherein the methanol composition further comprises not greater than 5 wt % water, based on total weight of the methanol composition.

38. The process of claim 1, further comprising the step of transporting the methanol composition separated in step b) to a location geographically distinct from that where the methanol composition was separated from the oxygenate stream.

39. The process of claim 38, wherein the methanol composition is separated at a remote natural gas location, shipped across a body of water, and the methanol composition is contacted with the olefin forming catalyst at a location integrated with a polyolefm manufacturing plant.

40. The process of claim 1, wherein the olefin forming catalyst is a molecular sieve catalyst.

41. The process of claim 40, wherein the molecular sieve catalyst is a silicoaluminophosphate molecular sieve.

42. The process of claim 41, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-5, SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56, ALPO-5, ALPO-11, ALPO-18, ALPO-31, ALPO-34, ALPO-36, ALPO-37, ALPO-46, and metal containing molecular sieves thereof.

43. The process of claim 42, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, SAPO-35, SAPO-44, SAPO-56, ALPO-18, ALPO-34, and metal containing molecular sieves thereof.

44. The process of claim 43, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, ALPO-34, ALPO-18, and metal containing molecular sieves thereof.

45. The process of claim 1, wherein the olefin stream formed in step c) is contacted with a polyolefin forming catalyst to form a polyolefin.

46. A process for forming an olefin stream, the process comprising the steps of: a) providing a crude methanol stream; b) separating a methanol composition from the crude methanol stream, wherein the separated methanol composition contains less than 99.85 wt % methanol and greater than 10 wppm acetaldehyde, based on total weight of the methanol stream; and b) contacting the methanol composition with an olefin forming catalyst to form an olefin stream.

47. The process of claim 46, wherein the methanol composition comprises at least 50 wt % methanol, based on total weight of the methanol composition.

48. The process of claim 47, wherein the methanol composition comprises at least 75 wt % methanol, based on total weight of the methanol composition.

49. The process of claim 48, wherein the methanol composition comprises at least 80 wt % methanol, based on total weight of the methanol composition.

50. The process of claim 49, wherein the methanol composition comprises at least 85 wt % methanol, based on total weight of the methanol coniposition.

51. The process of claim 50, wherein the methanol composition comprises at least 90 wt % methanol, based on total weight of the methanol composition.

52. The process of claim 46, wherein the methanol composition comprises not greater than 99 wt % methanol, based on total weight of the methanol composition.

53. The process of claim 52, wherein the methanol composition comprises not greater than 98 wt % methanol, based on total weight of the methanol composition.

54. The process of claim 53, wherein the methanol composition comprises not greater than 97 wt % methanol, based on total weight of the methanol composition.

55. The process of claim 54, wherein the methanol composition comprises not greater than 96 wt % methanol, based on total weight of the methanol composition.

56. The process of claim 46, wherein the methanol composition comprises at least 100 wppm acetaldehyde, based on total weight of the methanol composition.

57. The process of claim 56, wherein the methanol composition comprises at least 1,000 wppm acetaldehyde, based on total weight of the methanol composition.

58. The process of claim 57, wherein the methanol composition comprises at least 10,000 wppm acetaldehyde, based on total weight of the methanol composition.

59. The process of claim 58, wherein the methanol composition comprises at least 0.1 wt % acetaldehyde, based on total weight of the methanol composition.

60. The process of claim 46, wherein the methanol composition comprises not greater than 15 wt % acetaldehyde, based on total weight of the methanol composition.

61. The process of claim 60, wherein the methanol composition comprises not greater than 12 wt % acetaldehyde, based on total weight of the methanol composition.

62. The process of claim 61, wherein the methanol composition comprises not greater than 10 wt % acetaldohyde, based on total weight of the methanol composition.

63. The process of claim 62, wherein the methanol composition coniprises not greater than 8 wt % acetaldehyde, based on total weight of the methanol composition.

64. The process of claim 46, wherein the methanol composition further comprises ketone at less than 50% that of the acetaldehyde.

65. The process of claim 64, wherein the methanol composition further comprises ketone at less than 60% that of the acetaldehyde.

66. The process of claim 65, wherein the methanol composition further comprises ketone at less than 70% that of the acetaldehyde.

67. The process of claim 46, wherein the methanol composition further comprises at least 0.1 wt % and not greater than 12 wt % water, based on total weight of the methanol composition.

68. The process of claim 67, wherein the methanol composition further comprises at least 0.5 wt % water, based on total weight of the methanol composition.

69. The process of claim 68, wherein the methanol composition further comprises at least 1.0 wt % water, based on total weight of the methanol composition.

70. The process of claim 69, wherein the methanol composition further comprises at least 1.5 wt % water, based on total weight of the methanol composition.

71. The process of claim 46, wherein the methanol composition further comprises not greater than 10 wt % water, based on total weight of the methanol composition.

72. The process of claim 71, wherein the methanol composition further comprises not greater than 8 wt % water, based on total weight of the methanol composition.

73. The process of claim 72, wherein the methanol composition further comprises not greater than 5 wt % water, based on total weight of the methanol composition.

74. The process of claim 46, further comprising the step of transporting the methanol composition separated in step b) to a location geographically distinct from that where the methanol composition was separated from the oxygenate stream.

75. The process of claim 74, wherein the methanol composition is separated at a remote natural gas location, shipped across a body of water, and the methanol composition is contacted wit the olefin forming catalyst at a location integrated with a palyolefin manufacturing plant.

76. The process of claim 46, wherein the olefin forming catalyst is a molecular sieve catalyst.

77. The process of claim 76, wherein the molecular sieve catalyst is a silicoaluminophosphate molecular sieve.

78. The process of claim 77, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-5, SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56, ALPO-5, ALPO-11, ALPO-18, ALPO-31, ALPO-34, ALPO-36, ALPO-37, ALPO-46, and metal containing molecular sieves thereof.

79. The process of claim 78, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, SAPO-35, SAPO-44, SAPO-56, ALPO-18, ALPO-34, and metal containing molecular sieves thereof.

80. The process of claim 79, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, ALPO-34, ALPO-18, and metal containing molecular sieves thereof.

81. The process of claim 46, wherein the olefin steam formed in step c) is contacted with a polyolefin forming catalyst to form a polyolefin.

82. A process for forming an olefin stream, the process comprising the steps of: a) contacting a synthesis gas stream with a methanol synthesis catalyst to form a crude methanol stream containing methanol, ethanol and acetaldehyde; b) separating a methanol composition from the crude methanol stream, wherein the methanol composition comprises a majority of the methanol and a majority of the acetaldehyde contained in the crude methanol stream; c) transporting the methanol composition to a location geographically distinct from that where the methanol composition was separated from the crude methanol stream; and d) contacting the methanol composition with an olefin forming catalyst to form an olefin stream.

83. The process of claim 82, wherein the methanol composition is separated at a remote natural gas location in step b), and transported in step c) by shipping across a body of water, and contaeted with the olefin forming catalyst in step d) at a location integrated with a polyolefin manufacturing plant.

84. The process of claim 82, wherein the olefin forming catalyst is a molecular sieve catalyst.

85. The process of claim 84, wherein the molecular sieve catalyst is a silicoaluminophosphate molecular sieve.

86. The process of claim 85, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-5, SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAFO-56, ALPO-5, ALPO-l 1, ALPO-11, ALPO-31, ALPO-34, ALPO-36, ALPO-37, ALPO-46, and metal containing molecular sieves thereof.

87. The process of claim 86, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, SAPO-35, SAPO-44, SAPO-56, ALPO-18, ALPO-34, and metal containing molecular sieves thereof.

88. The process of claim 87, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, SAPO34, SAPO-44, ALPO-18, and metal containing molecular sieves thereof.

89. The process of claim 82, wherein the olefin stream formed in step d) is contacted with a polyolfin forming catalyst to form a polyolefin.

90. A process for forming an olefin stream, the process comprising the steps of: a) contacting a synthesis gas stream with a methanol synthesis catalyst to form a crude methanol stream containing methanol, ethanol and acetaldehyde; b) separating a methanol composition from the crude methanol stream, wherein the methanol composition comprises: i. at least 50 wt % and less than 99.85 wt % methanol based on total weight of the methanol composition; ii. greater than 10 wppm alcohol supplement that includes at least one alcohol selected from the group consisting of ethanol, propanol and butanol, based on total weight of the methanol composition; iii. greater than 10 wppm alciehyde supplements based on total weight of the methanol composition; c) transporting the methanol composition to a location geographically distinct from that where the methanol composition was separated from the crude methanol stream; and d) contacting the methanol composition with an olefin forming catalyst to form an olefin stream.

91. The process of claim 90, wherein the methanol composition is separated at a remote natural gas location in step b), and transported in step c) by shipping across a body of water, and contacted with the olefin forming catalyst in step d) at a location integrated with a polyolefin manufacturing plant.

92. The process of claim 90, wherein the olefin forming catalyst is a molecular sieve catalyst.

93. The process of claim 92, wherein the molecular sieve catalyst is a silicoaluminophosphate molecular sieve.

94. The process of claim 93, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-5, SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56, ALPO-5, ALPO-11, ALPO-18, ALPO-31, ALPO-34, ALPO-36, ALPO-37, ALPO-46, and metal containing molecular sieves thereof.

95. The process of claim 94, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, SAPO-35, SAPO-44, SAPO-56, ALPO-18, ALPO-34, and metal containing molecular sieves thereof.

96. The process of claim 95, wherein the silicoaluminophosphate molecular sieve is selected from the group consisting of SAPO-18, SAPO-34, ALPO-34, ALPO-18, and metal containing molecular sieves thereof.

97. The process of claim 90, wherein the olefin stream formed in step d) is contacted with a polyolefin forming catalyst to form a polyolefin.

98. The process of claim 90, wherein the methanol composition comprises at least 75 wt % methanol, based on total weight of the methanol composition.

99. The process of claim 98, wherein the methanol composition comprises at least 80 wt % methanol, based on total weight of the methanol composition.

100. The process of claim 99, wherein the methanol composition comprises at least 85 wt % methanol, based on total weight of the methanol composition.

101. The process of claim 100, wherein the methanol composition comprises at least 90 wt % methanol, based on total weight of the methanol composition.

102. The process of claim 90, wherein the methanol composition comprises not greater than 99 wt % methanol, based on total weight of the methanol composition.

103. The process of claim 102, wherein the methanol composition comprises not greater than 98 wt % methanol, based on total weight of the methanol composition.

104. The process of claim 103, wherein the methanol composition comprises not greater than 97 wt % methanol, based on total weight of the methanol composition.

105. The process of claim 104, wherein the methanol composition comprises not greater than 96 wt % methanol, based on total weight of the methanol composition.

106. The process of claim 90, wherein the methanol composition comprises at least 100 wppm alcohol supplement based on total weight of the methanol composition.

107. The process of claim 106, wherein the methanol composition comprises at least 1,000 wppm alcohol supplement, based on total weight of the methanol composition.

108. The process of claim 107, wherein the methanol composition comprises at least 10,000 wppm alcohol supplement, based on total weight of the methanol composition.

109. The process of claim 108, wherein the methanol composition comprises at least 0.1 wt % alcohol supplement, based on total weight of the methanol composition.

110. The process of claim 90, wherein the methanol composition comprises not greater than 15 wt % alcohol supplement, based on total weight of the methanol composition.

111. The process of claim 110, wherein the methanol composition comprises not greater than 12 wt % alcohol supplement, based on total weight of the methanol composition.

112. The process of claim 111, wherein the methanol composition comprises not greater than 10 wt % alcohol supplement, based on total weight of the methanol composition.

113. The process of claim 112, wherein the methanol composition comprises not greater than 8 wt % alcohol supplement, based on total weight of the methanol composition.

114. The process of claim 90, wherein the methanol composition comprises at least 100 wppm aldehyde supplement, based on total weight of the methanol composition.

115. The process of claim 114, wherein the methanol composition comprises at least 1,000 wppm aldehyde supplement, based on total weight of the methanol composition.

116. The process of claim 115, wherein the methanol composition comprises at least 10,000 wpprn aldehyde supplement, based on total weight of the methanol composition.

117. The process of claim 116, wherein the methanol composition comprises at least 0.1 wt % aldehyde supplement, based on total weight of the methanol composition.

118. The process of claim 90, wherein the methanol composition comprises not greater than 15 wt % aldehyde supplement, based on total weight of the methanol composition.

119. The process of claim 118, wherein the methanol composition comprises not greater than 12 wt % aldehyde supplement, based on total weight of the methanol composition.

120. The process of claim 119, wherein the methanol composition comprises not greater than 10 wt % aldehyde supplement, based on total weight of the methanol composition.

121. The process of claim 120, wherein the methanol composition comprises not greater than 8 wt % aldehyde supplement, based on total weight of the methanol composition.

122. The process of claim 90, wherein the alcohol supplement includes ethanol.

123. The process of claim 90, wherein the aldehyde supplement is at least one aldehyde selected from the group consisting of formaldehyde, acetaldehyde, proprionaldehyde, butyraldehyde, and valeraldehyde.

124. The process of claim 123, wherein the aldehyde supplement is acetaldehyde.

125. The process of claim 90, wherein the methanol composition further comprises ketone at less than 50% that of the alcohol supplement or the aldehyde supplement.

126. The process of claim 125, wherein the methanol composition further comprises ketone at less than 60% that of the alcohol supplement or the aldehyde supplement.

127. The process of claim 126, wherein the methanol composition further comprises ketone at less than 70% that of the alcohol supplement or the aldehyde supplement.

128. The process of claim 90, wherein the methanol composition further comprises at least 0.1 wt % and not greater than 12 wt % water, based on total weight of the methanol composition.

129. The process of claim 128, wherein the methanol composition further comprises at least 0.5 wt % water, based on total weight of the methanol composition.

130. The process of claim 129, wherein the methanol composition further comprises at least 1.0 wt % water, based on total weight of the methanol composition.

131. The process of claim 130, wherein the methanol composition further comprises at least 1.5 wt % water, based on total wcight of the methanol composition.

132. The process of claim 128, wherein the methanol composition further comprises not greater than 10 wt % water, based on total weight of the methanol composition.

133. The process of claim 132, wherein the methanol composition further comprises not greater than 8 wt % water, based on total weight of the methanol composition.

134. The process of claim 133, wherein the methanol composition further comprises not greater than 5 wt % water, based on total weight of the methanol composition.

Description

FIELD OF THE INVENTION

This invention is to a methanol composition, a method of making the composition, and a method of using the composition. More specifically, the methanol composition is particularly suited as a feed for converting oxygenates in the composition to olefins, particularly ethylene and propylene.

BACKGROUND OF THE INVENTION

Methanol is a major chemical raw material used to make a variety of products, including acetic acid, formaldehyde, and methyl tertiary butyl ether. Worldwide demand is expected to significantly increase as new applications for the use of methanol become commercialized. Such new applications include the conversion of methanol to gas, such as the Mobil MTG process; the conversion of methanol to olefins, gasoline and distillate, such as the Mobil MOGD process; and the conversion of methanol to olefins, such as the MTO process.

For example, in U.S. Pat. Nos. 6,444,712 B1 and 6,486,219 B1 to Janda, a method for producing olefins from methanol, by way of using natural gas to make the methanol, is described. The method includes converting the methane component of the natural gas to synthesis gas (syngas) using a steam reformer and a partial oxidation reformer. The syngas from each reformer is combined and sent to a methanol synthesis reactor. The combined syngas stream to the methanol synthesis reactor desirably has a syngas number of from about 1.4 to 2.6. The methanol product is then used as a feed in a methanol to olefin production process.

Much of the methanol made today is made under high purity specifications. Grade A and grade AA methanol are commonly produced. U.S. Pat. No. 4,592,806 to Ignore discloses a process for producing the grade AA methanol. The grade AA methanol has a maximum ethanol content of 10 ppm and is produced using a distillation column, and distilling fusel oil at a reflux ratio of at least 5:1.

The use of crude, or substantially unrefined, methanol has been suggested for use in making olefins. In U.S. Pat. No. 5,714,662 to Vora, there is disclosed an integrated process for producing light olefins from a hydrocarbon gas stream by combining reforming, methanol production, and methanol conversion. The methanol produced is a crude methanol, which is essentially unrefined and comprises methanol, light ends, heavier alcohols. The crude methanol is passed directly to an oxygenate conversion zone to produce light olefins.

As the production of methanol continues to increase, and the new commercial uses of methanol also continue to increase, it would be advantageous to produce methanol streams which have particular advantages for specific end uses. It would be particularly beneficial to produce methanol compositions that provide a greater quantity of end product and/or a better quality of end product for the specific end use.

SUMMARY OF THE INVENTION

This invention provides a methanol composition that is particularly suited as a feed for converting oxygenates in the composition to olefins. The methanol composition is particularly suited for producing high concentrations of ethylene and propylene in the catalytic conversion of oxygenates to olefins using a molecular sieve catalyst. Further provided are methods for making and using the methanol composition.

The methanol composition is ideally provided in large scale quantities (e.g., quantities of at least 10,000 gallons) for conversion to a variety of derivative products. An example of one derivate product includes olefins, which is of great advantage for further conversion of the olefins to polyolefins such as polyethylene and polypropylene. In one embodiment, the methanol composition is transported to a location geographically distinct from that where it was manufactured. Preferably, the methanol composition of this invention is loaded onto a vessel, and the vessel is transported over a body of water to a storage facility or directly to a conversion unit.

In another embodiment, the methanol composition comprises at least 50 wt % methanol, based on total weight of the methanol composition. Preferably, the methanol includes less than 99.85 wt % methanol, based on total weight of the methanol composition.

In yet another embodiment, the methanol composition comprises greater than 10 wppm alcohol supplement, based on total weight of the methanol composition. Preferably, the composition comprises greater than 10 wppm aldehyde supplement, based on total weight of the methanol composition. More preferably, the methanol composition comprises not greater than 12 wt % water, based on total weight of the methanol composition.

In other embodiments, the methanol composition comprises at least 75 wt %, 80 wt %, 85 wt %, or 90 wt % methanol, based on total weight of the methanol composition. In yet other embodiments the methanol composition comprises not greater than 99 wt %, 98 wt %, 97 wt %, or 96 wt % methanol, based on total weight of the methanol composition.

The methanol composition optionally comprises at least 100 wppm, 1,000 wppm, 10,000, or 0.1 wt % alcohol supplement, based on total weight of the methanol composition. Alternatively, the methanol composition comprises not greater than 15 wt %, 12 wt %, 10 wt %, or not greater than 8 wt % alcohol supplement, based on total weight of the methanol composition.

Optionally, methanol composition comprises at least 100 wppm, 1,000 wppm, 10,000 wppm, or 0.1 wt % aldehyde supplement, based on total weight of the methanol composition. Alternatively, the methanol composition comprises not greater than 15 wt %, 12 wt %, 10 wt %, or 8 wt % aldehyde supplement, based on total weight of the methanol composition.

In one embodiment, the alcohol supplement is at least one alcohol selected from the group consisting of ethanol, propanol and butanol. Preferably, the alcohol supplement is ethanol.

In another embodiment, the aldehyde supplement is at least one aldehyde selected from the group consisting of formaldehyde, acetaldehyde, proprionaldehyde, butyraldehyde, and valeraldehyde. Preferably, the aldehyde supplement is acetaldehyde.

In another optional embodiment, the methanol composition further comprises ketone at less than 50%, 60%, or 70% of that of the alcohol supplement or the aldehyde supplement. Alternatively, the methanol composition further comprises at least 0.1 wt % water, 0.5 wt %, 1.0, or 1.5 wt % water, based on total weight of the methanol composition. Preferably, the methanol composition further comprises not greater than 10 wt %, 8 wt %, or 5 wt % water, based on total weight of the methanol composition.

There is further provided a process for forming an olefin stream. In one embodiment, the process comprises contacting a synthesis gas stream with a methanol synthesis catalyst to form a crude methanol stream containing methanol, ethanol and acetaldehyde. A methanol composition is separated from the crude methanol stream, wherein the methanol composition comprises a majority of the methanol and a majority of the acetaldehyde or ethanol contained in the oxygenate containing stream. The methanol composition is then contacted with an olefin forming catalyst to form an olefin stream.

In another embodiment, there is provided a crude methanol stream from which a methanol composition is separated. Preferably, the methanol composition is the composition of this invention, and the composition can be used for a variety of uses, particularly as a feedstock in an oxygenate to olefins conversion process to produce an olefin stream.

A variety of hydrocarbons can be used to form the methanol composition of this invention. Examples of such hydrocarbons include biomass, natural gas, C.sub.1 to C.sub.5 hydrocarbons, naphtha, heavy petroleum coils, coke, and mixtures thereof. A methane containing gas is a preferred hydrocarbon to use in making the methanol composition of this invention.

In one embodiment, the hydrocarbon feedstock is converted to synthesis gas, then the synthesis gas is converted to crude methanol. The methanol composition is then separated from the crude methanol.

In another embodiment of the invention, a synthesis gas stream is contacted with a methanol synthesis catalyst to form a crude methanol stream. The crude methanol stream contains, in addition to methanol, a variety of hydrocarbon compounds. As one example, the crude methanol stream contains methanol, ethanol and/or acetaldehyde. The methanol composition of the invention is, preferably, recovered from the crude methanol stream.

DETAILED DESCRIPTION OF THE INVENTION

I. Introduction

This invention is directed to a methanol composition, a method for making the methanol composition, and a method of using the methanol composition. The methanol composition is a robust composition that is suitable for contacting with an olefin forming catalyst to form an olefin stream. It can be made from various carbon materials at a relatively large scale for commercial scale processing and upgrading. Because the methanol composition is fairly robust and can be made at such relatively large scales, it can also be transported to geographically distinct locations which are fairly remote from the site of manufacture for use as a feed stock.

The methanol composition of this invention is supplemented with certain additional alcohols and/or aldehydes, and serves as a particularly desirable feed stream for use in the manufacture of olefins such as ethylene and propylene. Such feed streams result in increased production of ethylene or in the increased production of both ethylene and propylene. The methanol stream is particularly suitable for use as a feed stream in a catalytic process, which uses an olefin forming catalyst to convert the oxygenate components in the methanol steam to ethylene and propylene. The ethylene and propylene are then recovered and used for further processing, such as in the manufacture of polyethylene and polypropylene.

II. Description of the Methanol Composition

The methanol composition of this invention contains less than 99.85 wt % methanol, based on total weight of the composition, and is supplemented with other oxygenates, such as alcohols and/or aldehydes, which are particularly suited for use as a feed component in the catalytic conversion of the oxygenates to olefins. In one embodiment of the invention, the methanol composition comprises at least about 50 wt % methanol, based on total weight of the composition. Desirably, the methanol composition comprises at least about 75 wt % methanol, preferably at least about 80 wt % methanol, more preferably at least about 85 wt % methanol, and most preferably at least about 90 wt % methanol, based on total weight of the composition.

In another embodiment of the invention, the methanol composition comprises not greater than 99 wt % methanol, based on total weight of the composition. Preferably, the methanol composition comprises not greater than 98 wt % methanol, more preferably not greater than 97 wt % methanol, and most preferably not greater than 96 wt % methanol, based on total weight of the composition.

In this invention, the methanol composition is supplemented with other alcohols and/or aldehydes that are particularly effective the manufacture of olefins, particularly ethylene and/or propylene. Such alcohol and aldehyde supplements include those that have a boiling point not lower than that of formaldehyde, but preferably not higher than that of butanol.

Examples of alcohol compounds, which are useful in the methanol composition of this invention, besides methanol, include ethanol, propanol and butanol. Ethanol and propanol are preferred, and ethanol is particularly preferred.

In one embodiment of the invention, the methanol composition comprises greater than 10 wppm alcohol supplement, based on total weight of the composition, the alcohol supplement being an alcohol having a boiling point not lower than that of formaldehyde, but not higher than that of butanol. Desirably, the methanol composition comprises at least about 100 wppm alcohol supplement. Preferably, the methanol composition comprises at least about 1,000 wppm alcohol supplement, more preferably at least about 10,000 wppm alcohol supplement, and most preferably at least about 0.1 wt % alcohol supplement, based on total weight of the composition. Preferably, the alcohol supplement is at least one alcohol selected from the group consisting of ethanol, propanol and butanol.

In another embodiment of the invention, the methanol composition comprises not greater than 15 wt % of the alcohol supplement, based on total weight of the composition. Preferably, the methanol composition comprises not greater than 12 wt % of the alcohol supplement, more preferably not greater than 10 wt % of the alcohol supplement, and most preferably not greater than 8 wt % of the alcohol supplement, based on total weight of the composition.

Examples of aldehyde compounds which are useful in the methanol composition of this invention include, besides formaldehyde, acetaldehyde, proprionaldehyde, butyraldehyde, and valeraldehyde. Preferred aldehydes include acetaldehyde and proprionaldehyde. Particularly preferred is acetaldehyde.

In one embodiment of the invention, the methanol composition comprises greater than 10 wppm aldehyde supplement, the alcohol supplement being an aldehyde a boiling point at least as high as that of formaldehyde, but not higher than that of butanol. Desirably, the methanol composition comprises at least about 100 wppm aldehyde supplement. Preferably, the methanol composition comprises at least about 1,000 wppm aldehyde supplement, more preferably at least about 10,000 wppm aldehyde supplement, and most preferably at least about 0.1 wt % aldehyde supplement, based on total weight of the composition. Preferably, the aldehyde supplement is at least one aldehyde selected from the group consisting of formaldehyde, acetaldehyde, proprionaldehyde, butyraldehyde, and valeraldehyde.

In another embodiment of the invention, the methanol composition comprises not greater than 15 wt % of the aldehyde supplement, based on total weight of the composition. Preferably, the methanol composition comprises not greater than 12 wt % of the aldehyde supplement, more preferably not greater than 10 wt % of the aldehyde supplement, and most preferably not greater than 8 wt % of the aldehyde supplement, based on total weight of the composition.

Although the methanol composition of this invention can include other components, the other components are included in a concentration such that the methanol composition remains suitable for contacting with an olefin forming catalyst to form an olefin stream. In one embodiment, the methanol-composition further includes ketones, but in a concentration less than that of the alcohol supplement or the aldehyde supplement. Preferably the ketone concentration will be less than 50% that of the alcohol supplement or the aldehyde supplement, more preferably less than 60% of the alcohol supplement or the aldehyde supplement, and most preferably less than 70% of the alcohol supplement or the aldehyde supplement. Examples of such ketones include one or more of acetone, methyl ethyl ketone, and any one or more of the pentanones. Preferably, the methanol composition includes not greater than 1 wt % ketones, more preferably not greater than 0.1 wt % ketones, and most preferably not greater than 0.0 1 wt % ketones, based on total weight of the composition.

In another embodiment of the invention, the methanol composition includes ketones at a minimum concentration of 100 wppm, based on total weight of the composition. Preferably, the minimum concentration of ketones in the composition is 10 wppm, more preferably 1 wppm, and most preferably 0.01 wppm, based on total weight of the composition.

In another embodiment, the methanol composition includes water. The water content should not be so high that shipping costs are prohibitive, but of sufficient quantity to exert a positive partial pressure in the methanol to olefin conversion reaction, thereby increasing selectivity to ethylene and/or propylene. Desirably, the water content is at least about 0.1 wt %, based on total weight of the methanol composition. Preferably, the methanol composition contains at least about 0.5 wt % water, more preferably at least about 1.0 wt % water, and most preferably at least about 1.5 wt % water, based on total weight of the methanol composition.

In another embodiment, the methanol composition contains not greater than about 12 wt % water, based on total weight of the methanol composition. Preferably, the methanol composition contains not greater than about 10 wt % water, more preferably not greater than about 8 wt % water, and most preferably not greater than about 5 wt % water, based on total weight of the methanol composition.

III. Method of Making the Methanal Composition

A. Examples of Methanol Synthesis Processes

The methanol composition of this invention can be manufactured from a variety of carbon sources. Examples of such sources include biomass, natural gas, C.sub.1 C.sub.5 hydrocarbons, naphtha, heavy petroleum oils, or coke (i.e., coal). Preferably, the hydrocarbon feed stream comprises methane in an amount of at least about 50% by volume, more preferably at least about 70% by volume, most preferably at least about 80% by volume. In one embodiment of this invention natural gas is the preferred hydrocarbon feed source.

One way of converting the carbon source to a methanol composition is to first convert the carbon source to synthesis gas (syngas), and then converting the syngas to the methanol composition. Any conventional process can be used. In particular, any conventional carbon oxide conversion catalyst can be used to convert the syngas to the methanol composition. In one embodiment, the carbon oxide conversion catalyst is a nickel containing catalyst.

Synthesis gas comprises carbon monoxide and hydrogen. Optionally, carbon dioxide and nitrogen are included. Conventional processes for converting carbon components to syngas include steam reforming, partial oxidation, and autothermal reforming.

The hydrocarbon feed stream that is used in the conversion of hydrocarbon to synthesis gas, is optionally treated to remove impurities that can cause problems in further processing of the hydrocarbon feed stream. These impurities can poison many conventional propylene and ethylene forming catalysts. A majority of the impurities, which may be present, can be removed in any conventional manner. The hydrocarbon feed is preferably purified to remove sulfur compounds, nitrogen compounds, particulate matter, other condensables, and/or other potential catalyst poisons prior to being converted into synthesis gas.

In one embodiment of the invention, the hydrocarbon feed stream is passed to a synthesis gas plant. Synthesis gas refers to a combination of hydrogen and carbon oxide produced in a synthesis gas plant from a hydrocarbon feed, the synthesis gas having an appropriate molar ratio of hydrogen to carbon oxide (carbon monoxide and/or carbon dioxide), as described below. The synthesis gas plant may employ any conventional means of producing synthesis gas, including partial oxidation, steam or CO.sub.2 reforming, or some combination of these two chemistries.

Steam reforming generally comprises contacting a hydrocarbon with steam to form synthesis gas. The process preferably includes the use of a catalyst.

Partial oxidation generally comprises contacting a hydrocarbon with oxygen or an oxygen containing gas such as air to form synthesis gas. Partial oxidation takes place with or without the use of a catalyst, although the use of a catalyst is preferred. In one embodiment, water (steam) is added with the feed in the partial oxidation process. Such an embodiment is generally referred to as autothermal reforming.

Conventional synthesis gas-generating processes include gas phase partial oxidation, autothermal reforming, fluid bed synthesis gas generation, catalytic partial oxidation and various processes for steam reforming.

B. Steam Reforming to Make Syngas

In the catalytic steam reforming process, hydrocarbon feeds are converted to a mixture of H.sub.2, CO and CO.sub.2 by reacting hydrocarbons with steam over a catalyst. This process involves the following reactions: CH.sub.4+H.sub.2O.revreaction.CO+3H (1) or C.sub.nH.sub.m+nH.sub.2O.revreaction.nCO+[n+(m/2)]H.sub.2 (2) and CO+H.sub.2O.revreaction.CO.sub.2+H2 (3) (shift reaction)

The reaction is carried out in the presence of a catalyst. Any conventional reforming type catalyst can be used. The catalyst used in the step of catalytic steam reforming comprises at least one active metal or metal oxide of Group 6 or Group 8 10 of the Periodic Table of the Elements. The Periodic Table of the Elements referred to herein is that from CRC Handbook of Chemistry and Physics, 82.sup.nd Edition, 2001 2002, CRC Press LLC, which is incorporated herein by reference.

In one embodiment, the catalyst contains at least one Group 6 or Group 8 10 metal, or oxide thereof, having an atomic number of 28 or greater. Specific examples of reforming catalysts that can be used are nickel, nickel oxide, cobalt oxide, chromia and molybdenum oxide. Optionally, the catalyst is employed with least one promoter. Examples of promoters include alkali and rare earth promoters. Generally, promoted nickel oxide catalysts are preferred.

The amount of Group 6 or Group 8 10 metals in the catalyst can vary. Preferably, the catalyst includes from about 3 wt % to about 40 wt % of at least one Group 6 or Group 8 10 metal, based on total weight of the catalyst. Preferably, the catalyst includes from about 5 wt % to about 25 wt % of at least one Group 6 or Group 8 10 metal, based on total weight of the catalyst.

The reforming catalyst optionally contains one or more metals to suppress carbon deposition during steam reforming. Such metals are selected from the metals of Group 14 and Group 15 of the Periodic Table of the Elements. Preferred Group 14 and Group 15 metals include germanium, tin, lead, arsenic, antimony, and bismuth. Such metals are preferably included in the catalyst in an amount of from about 0.1 wt % to about 30 wt %, based on total weight of nickel in the catalyst.

In a catalyst comprising nickel and/or cobalt there may also be present one or more platinum group metals, which are capable of increasing the activity of the nickel and/or cobalt and of decreasing the tendency to carbon lay-down when reacting steam with hydrocarbons higher than methane. The concentration of such platinum group metal is typically in the range 0.0005 to 0.1% as metal, calculated as the whole catalyst unit. Further, the catalyst, especially in preferred forms, can contain a platinum group metal but no non-noble catalytic component. Such a catalyst is more suitable for the hydrocarbon steam reforming reaction than one containing a platinum group metal on a conventional support because a greater fraction of the active metal is accessible to the reacting gas. A typical content of platinum group metal when used alone is in the range 0.0005 to 0.5% w/w as metal, calculated on the whole catalytic unit.

In one embodiment, the reformer unit includes tubes which are packed with solid catalyst granules. Preferably, the solid catalyst granules comprise nickel