Integrated process for making propene oxide and an alkyl tert-butyl ether

1. An integrated process for making propene oxide and an alkyl tert-butyl ether comprising;

a) a step of dehydrogenating a feed stream, S 1 , comprising propane and iso-butane, to provide a stream, S 2 , comprising propene, iso-butene and hydrogen;

b) a separation step separating stream S 2 into a stream, S 3 , consisting essentially of hydrogen and a stream, S 4 , comprising propene and iso-butene;

c) a separation step separating stream S 4 into a stream, S 5 , comprising propene and a stream, S 6 , comprising iso-butene;

d) a step of reacting a part or all of stream S 5 with hydrogen peroxide in the presence of an epoxidation catalyst to provide a stream, S 7 , comprising propene oxide;

e) a separation step separating propene oxide from stream S 7 ;

f) a step of reacting a part or all of stream S 6 with an alkanol in the presence of a solid acid catalyst, to provide a stream, S 8 , comprising an alkyl tert-butyl ether; and

g) a separation step separating the alkyl tert-butyl ether from stream S 8 .

2. The process of claim 1 , wherein the alkanol is methanol.

3. The process of claim 1 , wherein unreacted propane is separated from stream S 5 and recycled as a stream, S 9 , to step a) before stream S 5 is reacted in step d).

4. The process of claim 1 , wherein a stream, S 10 , comprising unreacted iso-butane is separated in step g), a stream, S 11 , comprising more than 80% by weight iso-butane is separated from said stream S 10 and said stream S 11 is recycled to step a).

5. The process of claim 1 , wherein the feed stream S 1 to step a) comprises n-butane, a stream, S 10 , comprising 1-butene is separated in step g) and a stream, S 12 , consisting essentially of 1-butene is separated from said stream S 10 .

6. The process of claim 1 , wherein the feed stream S 1 to step a) comprises n-butane and wherein 1,3-butadiene is removed from stream S 6 before reacting it in step f).

7. The process of claim 1 , comprising the additional steps:

h) separating a feed stream comprising propane and n-butane into a stream, S 13 , comprising propane and a stream, S 14 , comprising n-butane;

i) subjecting stream S 14 to an isomerization reaction to provide a stream, S 15 , comprising n-butane and iso-butane; and

j) combining the iso-butane of stream S 15 with a part or all of stream S 13 to give feed stream S 1 to step a).

8. The process of claim 7 , wherein n-butane is separated from stream S 15 and is recycled as stream S 16 to said isomerization reaction before combining the iso-butane of stream S 15 with a part or all of stream S 13 .

9. The process of claim 1 , wherein a titanium silicalite catalyst is used as epoxidation catalyst in step d).

10. An integrated process for making propene oxide and methyl tert-butyl ether comprising:

a) a step of dehydrogenating a feed stream, S 1 , comprising propane and iso-butane, to provide a stream, S 2 , comprising propene, iso-butene and hydrogen;

b) a separation step separating stream S 2 into a stream, S 3 , consisting essentially of hydrogen and a stream, S 4 , comprising propene and iso-butene;

c) a separation step separating stream S 4 into a stream S 5 comprising propene and a stream, S 6 , comprising iso-butene;

d) a step of reacting a part or all of stream S 5 with hydrogen peroxide in the presence of an epoxidation catalyst, providing a stream, S 7 , comprising propene oxide;

e) a separation step separating propene oxide from stream S 7 ;

f) a step of reacting a part or all of stream S 6 with methanol in the presence of a solid acid catalyst, providing a stream, S 8 , comprising methyl tert-butyl ether; and

g) a separation step separating the methyl tert-butyl ether from stream S 8 .

11. The process of claim 10 , wherein unreacted propane is separated from stream S 5 and recycled as a stream, S 9 , to step a) before stream S 5 is reacted in step d).

12. The process of claim 11 , wherein a stream, S 10 , comprising unreacted iso-butane is separated in step g), a stream, S 11 , comprising more than 80% by weight iso-butane is separated from stream S 10 , and stream S 11 is recycled to step a).

13. The process of claim 11 , wherein the feed stream S 1 to step a) comprises n-butane, a stream, S 10 , comprising 1-butene is separated in step g) and a stream, S 12 , consisting essentially of 1-butene, is separated from stream S 10 .

14. The process of claim 13 , wherein 1,3-butadiene is removed from stream S 6 before reacting it in step f).

15. The process of claim 11 , wherein a titanium silicalite catalyst is used as epoxidation catalyst in step d).

16. An integrated process for making propene oxide and an alkyl tert-butyl ether, comprising:

a) a step of dehydrogenating a feed stream, S 1 , comprising propane, n-butane and iso-butane, to provide a stream, S 2 , comprising propene, 1-butene, iso-butene and hydrogen;

b) a separation step separating stream S 2 into a stream, S 3 , consisting essentially of hydrogen and a stream, S 4 , comprising propene, 1-butene and iso-butene;

c) a separation step separating stream S 4 into a stream, S 5 , comprising propene and a stream, S 6 , comprising 1-butene and iso-butene;

d) a separation step separating unreacted propane from stream S 5 and recycling it as a stream, S 9 to step a);

e) a step of reacting a part or all of stream S 5 from which propane has been separated in step d) with hydrogen peroxide in the presence of an epoxidation catalyst, to provide a stream, S 7 , comprising propene oxide;

f) a separation step separating propene oxide from stream S 7 ;

g) a step of reacting a part or all of stream S 6 with an alkanol in the presence of a solid acid catalyst, to provide a stream, S 8 , comprising an alkyl tert-butyl ether;

h) a separation step separating the alkyl tert-butyl ether and a stream, S 10 , comprising 1-butene from stream S 8 ; and

i) a separation step separating a stream S 12 consisting essentially of 1-butene from stream S 10 .

17. The process of claim 16 , wherein 1,3-butadiene is removed from stream S 6 before reacting it in step g).