US2369558A

US2369558A - Process for sweetening sour hydrocarbon oil

Info

Publication number: US2369558A
Application number: US468685A
Authority: US
Inventors: George R Gilbert
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1942-12-11
Filing date: 1942-12-11
Publication date: 1945-02-13
Anticipated expiration: 1962-02-13

Description

Fermented Feb. 13, A945 IPEQCEES FUR SWEETENING SQUB HYDRUCARJBGN GIL George R. Gilbert, Elizabeth, N. 5., asaignor to Standard @il Development Company, a corporation 02 Delaware No Drawing. Appiication December 11, 119412,

Beriai No. 468,685

4 Claims.

This invention relates to treating hydrocarbon fluids and more particularly relates to finishing or treating hydrocarbons such as gasoline and kerosene to remove undesirable components therefrom.

One of the steps used in finishing hydrocarbons is the removal or conversion of malodorants such as mercaptans into other compounds which have no odor. The usual doctor sweetening process converts mercaptans into disulfldes and unless extreme care is used the total sulfur in the treated hydrocarbon is increased. Various catalytic processes have been used for removing sulfur from hydrocarbon products. Bauxite has been used to reduce mercaptans and total sulfur in hydrocarbon products but in such a process high temperatures are necessary to obtain adequate removal of the mercaptan and total sulfur. At lower temperatures relatively large volumes of bauxite per volume of oil treated are necessary.

My invention comprises an improvement on the bauxite treatment of hydrocarbons such as kerosene or gasoline. According to my invention sour hydrocarbons are sweetened by using granular bauxite containing or impregnated with lead oxides. I have found that bauxite impregnated with lead oxides sweetens sour hydrocarbons to a greater extent than activated granular bauxite which has not been so impregnated and the sweetening process is carried out at about room temperature and with relatively small amounts of bauxite impregnated according to my invention.

More specifically, I mix or agitate a sour hydrocarbon oil such as kerosene with a sodium plumbite solution for a time sufiicient to obtain soluble lead mercaptides and then percolate the lead-mercaptide-containing hydrocarbon mixture through a quantity of bauxite which has been activated. The first volumes of the filtrate from the percolation vessel or zone are lead free and sweet but eventually the hydrocarbon material coming through contains lead compounds indicating that the bauxite is saturated with lead mercaptides. When this occurs the flow of hydrocarbon through the percolation zone or percolator is stopped and the bauxite in the percolator is purged free of adsorbed hydrocarbons. The purged bauxite is then burned in the presence of air to reduce the lead mercaptides to lead oxides and in this way the bauxite is impregnated with lead oxides. This impregnated bauxite is superior to bauxite not so treated.

The invention will now. be more specifically described. In treating and finishing hydrocarbon oils such as kerosene and gasoline it is necessaryto remove evil smelling sulfur compounds or to convert sulfur compounds to other compounds which do not have an objectionable odor. My invention specifically relates to producing an activated bauxite impregnated with lead oxide or oxides and using such an impregnated bauxite for treating sour hydrocarbons. While other processes of impregnating oxides may be used, I prefer to saturate an activated bauxite with lead mercaptides, oxidize the lead mercaptides to lead oxides and then use this impregnated bauxite to treating sour hydrocarbon oils.

The preparation of the granular bauxite impregnated with lead oxides will be first described. Iagitatea sour hydrocarbon such as kerosene containing about 36 milligrams of mercaptan sulfur per 100 cc. of kerosene and about 0.155% by weight of total sulfur with a. sodium plumbite solution for a time sufficient to convert all mercaptan sulfur in the kerosene to soluble lead mercaptides. The sodium plumbite solution is the usual doctor sweetening reagent known in the art. During this treatment the temperature is about F. and the time of treating is about 5 minutes. The hydrocarbon mixture containing lead mercaptides is then percolated through a quantity or bed of bauxite which has been activated by heating in the presence of air for a period of about 3 hours at a temperature between about 750 F. and 900 F. During percolation the temperature of the bauxite is about 85 F.

The first few volumes of filtrate come through the activated bauxite lead free and sweet but eventually after about 1 to 3 volumes of kerosene per volume of bauxite have been passed through the bauxite, the kerosene contains lead compounds indicating that the bauxite is saturated with lead mercaptides. The flow of kerosene through the bauxite is then stopped and the bauxite is purged with an inert gas such as steam, hydrocarbon gas, flue gas or the like to remove adsorbed hydrocarbons from the bauxite which may be separately recovered if desired.

The bauxite containing the lead mercaptides is then burned by blowing air through the bauxite for about 3 hours at a temperature between about 750 F. and 900 F. and in this way I obtain a bauxite impregnated with lead oxides. While I am not certain of the actual composition of the lead oxide or oxides, I believe that I obtain mainly lead oxide (PbO) or a mixture of lead oxides. such as PbO, PbOz, PbcOa, Pb304.

The bauxite impregnated with lead oxides according to my invention differs from the usual activated bauxite and is an improvement thereover as shown by the following data.

Example 1 cc. of kerosene and about 0.077 weight per cent oi total sulfur.

Eaompie ii I percoiated about 3 volumes or kerosene contaming about 36 milligrams of mercaptan sulfur per 100 cc. oi kerosene and about 8.155 weight per cent of total sulfur to about 1 volume of bauxite which differed from the bauxite used in Example 1 in that it was impregnated with lead oxides according to my invention, under the same rate conditions and temperature as employed in Example 1. I blended the 3 volumes together and the finally treated kerosene had less than about 0.5 milligram oi mercaptan sulfur per 100 cc. of kerosene and only about 0.067 weight per cent total sulfur.

From the above examples, it will be seen that the bauxite prepared according to my invention and containing lead. oxide or oxides sweetens the hydrocarbon oil and reduces the total suliur more eiiectively than bauxite prepared according to customary procedure and the sweetening and reduction in sulfur can be eiiected at a relatively low temperature.

In the preparation or my impregnated bauxite it will be seen that I first use an activated bauxite and the first few volumes of oil or about i to 3 volumes of oil per volume of bauxite coming from the percolator are lead free and sweet. The oil which is first passed through the activated bauxite is preferably separately collected and blended with the sweetened product resulting from the treatment of oils with my bauxite imprefinated with lead oxides. In this way I can also sweeten and remove sulfur from a portion or the oil with the activated bauxite before the bauxite is impregnated according to my invention.-

When my impregnated bauxite becomes contaminated in use, it is only necessary to stop the flow of oil, purge the contaminated bauxite in the vessel with a purging gas and then burn the impregnated bauxite with air to remove contaminants and leave lead oxides on the bauxite. The bauxite is regenerated in situ in the treating vessel.

While I have set forth the best form of my invention known to me at this time and have given two examples of treating sour kerosene, it is to be understood that changes and modifications may be made in my invention and that the examples are by way or illustration only and specific details may be varied when using diflerent stocks.

I claim:

1. A process or treating sour hydrocarbon liquids which comprises passing the sour liquid hydrocarbon containing mercaptans and sulfur over a calcined contact agent comprising bauxite and a lead oxide, at a relatively low temperature and recovering a sweetened liquid hydrocarbon, the contact agent being produced by impregnating bauxite with lead mercaptide and oxidizing the lead mercaptide to lead oxide.

2. A process of treating sour hydrocarbons which comprises passing a sour hydrocarbon containing mercaptans and sulfur over a calcined contact agent comprising bauxite impregnated with lead oxide, at a relatively low temperature and recovering a sweet hydrocarbon, the contact agent being produced by impregnating an activated bauxite with lead mercaptides and oxidizing the mercaptides to lead oxides.

3. A process according to claim 2 wherein the hydrocarbon during the treatment is at a temperature of about 85 F.

4. Process according to claim 1 in which the contact agent is prepared by impregnating bauxite with lead mercaptide and heating the same in the presence of air to oxidize the mercaptide to an oxide.

GEORGE R. GILBERT.