DE1645845A1 - Steam reforming process - Google Patents

Description

concerning: "Steam Reforming Process"

Priority: January 21, 1966 and January 9, 1967

The invention relates to a steam reforming process using a hydrocarbon feedstock is reacted with water vapor to create an oas mixture »which with or without anreieherurg for a delivery as Town gas is suitable, and relates inabespecial to a modification of such a method, which is particularly suitable for an intermittent To meet the need for fuel gas *

The inventive method for the production of a carbon dioxide, hydrogen and gaseous hydrocarbons containing fuel gas through the conversion ring of a hydrocarbon «

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Substance starting material with water vapor under überataosphX-rendruok comprises a stage in which a small amount of the carbon oxide contained in this gas is converted in a catalytic manner with hydrogen to synthesis methanol .

With the method according to the invention, a usable methanol output can be produced in a simple plant, since the amount of fuel gas generated is very large and the Oas not converted to methanol is the main product of the method. Thus, the various forms of the invention do not encounter the difficulties associated with high pressure operation, the use of multi-stage catalysts, methanol extraction stages, and reoyole loops; These measures and devices are necessary to ensure high sales in plants that are only intended for the production of methanol. The process is particularly valuable when the fuel gas system is equipped to go from general hydrocarbon feedstocks to methanol hydrocarbon feedstocks to :? Increase of the output can be switched at peak demand times, since this system allows in this way to accumulate a methanol charge on cheap catfish during the longer periods of normal or reduced demand.

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The Qasaenge, which in elnea such a system is to be converted on catalytic catfish for the production of methanol » can therefore! ■ be determined with regard to the expected XY days of the peak load margin. The use of iron Methanol al · starting material co-component for a peak load operation is in the German patent (Patent application filed on the same day as the present application under the processing number Case B Ιθ9β4 / Ι9θ26 / Ι9θ% 6 was submitted). The subject of the invention is a simple methanol synthesis unit for a number of gas-generating strums Delivering methanol in the same factory.

The conversion of the small amount of Oasaenge for the production of methanol can be carried out in that a rare flow the oasis is withdrawn by a methanol synthesis system, which enables a corresponding conversion in the case of thermosetting; one can also proceed in such a way that the whole oas is passed through «In Methanolsynthesesystea · At the the latter procedure is usually the conversion considerably less than with the first-mentioned method.

The methanol synthesis can optionally take place at high pressure (e.g. 100 to 400 atmospheres); however, it is preferable "under a pressure of less to work as 100 atmospheres, since on these catfish the com-

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award costs of the oasis are reduced. According to an important form of the process, the oas is generated at a pressure above about 7 atmospheres "with the ethanol thesis being carried out under the same pressure" so that no compression is required. For this form of the process, a catalyst is preferably used which is active at temperatures below 300 ^° C., for example a copper-containing catalyst. According to a modification of this form of the process, the oas is compressed moderately, for example by a factor of the order of magnitude of 3, in order to increase the conversion to methanol that takes place during the thermosetting process and to compensate for the pressure drop in the methanol synthesis units. Processes for producing methanol at such temperatures are described in British Patent 1,010,871.

The stage in the production of fuel gas "at which the methanol synthesis is carried out" should be calibrated to the Connect the removal of excess water vapor; she However, on the other hand, it depends on the type of catalyst « which is used for methanol synthesis «If a conventional zinc chromite catalyst is used» then the Synthesis should preferably be carried out with a gas which is essentially freed from carbon dioxide, however there is still some carbon monoxide in it, as such catalysts

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develop their highest activity in the absence of carbon dioxide. If a copper-containing catalyst is used, then the synthesis should preferably be carried out with a Gas are carried out «the carbon dioxide and carbon monoxide contains «because such catalysts are more active in the presence of carbon dioxide; however, it is preferable To keep the carbon dioxide content low (i.e. below half the carbon monoxide content) "since the production of methanol from carbon oxide is less economical in this respect" when valuable hydrogen is converted into water and this water is either separated off or together with the methanol must be stored.

The one produced by the method according to the invention Methanol can be purified if necessary; however, it is intended to be used as a raw material for a peak load operation in one stage «in which the normal feed is a hydrocarbon "then it is usually not necessary" purification to carry out "since the impurities" which are mainly higher oxygenated hydrocarbons "are simply converted to carbon oxides" methane and hydrogen. It falls within the scope of the invention " carry out the methanol synthesis with the recovery of some methyl formate which does not need to be removed.

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The method according to the invention is applicable to any fuel gas production method applicable to whatever carbon dioxide and hydrogen is a constituent of the gas at some of its stages of manufacture. Specific examples are as follows:

(l) The implementation of a natural gas with water vapor or Oxygen;

ψ (2) the conversion of refinery gases or liquefied petroleum gases with water vapor or oxygen;

(J5) the reaction of liquid hydrocarbons with Steam to generate a "lean gas" with a low to moderate methane content «for example 5 to 20Ji, of getting an enrichment duish adding a fed Natural gas * Refinery gas «liquefied petroleum» gases or hydrocarbon «rich gases that by reacting liquefied hydrocarbons with water vapor at temperatures of for example manufactured below 600 ° C, connected;

Conversion of liquid hydrocarbons with water vapor to generate a lean gas, or the injection of further liquid hydrocarbons connected » who gassed at the same tent # 3. rd, in which the Carbon oxides and the hydrogen to convert methane

react (see the German patents

and (patent applications I 24 298 IVl / 20

or I 27 182 IVd / 26a). In such procedures the methanol from the tail gas or from a rare stream of the lean gas are withdrawn?

(5) Conversion of liquid hydrocarbons with water vapor to produce a methane-rich gas in one step

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(see for example the German patent specification

(I 23 787 IVd / 26 ·)) *

(6) The conversion of liquid hydrocarbons sows water vapor below 600 * C, which is the implementation of the obtained Oases have a high Hethane content with water vapor in one Temperature above 600 * 0 to reduce its methane content.

Example

line plant, the 424 50Ow? (15,000,000 cubic feet) per day town gas ( ^{4,445 kcal / · 3} (500 B.Th.U. per eubio foot)) by converting a naphtha starting material into water vapor at a temperature of 750 * 0 under a * pressure of 31.6 attt (450 peig). Cooling the oasis to 400 ° C, examining the oasis of a carbon monoxide conversion and a partial carbon dioxide removal as well as enrichment of the oasis old methane "which is supplied from a natural gas source" is modified by the fact that the oasis is cooled down 400 ° C, but before the carbon dioxide treatment, in a larger 3troB iS2jt), which is treated in the catfish described above "and in a smaller stream (8 £)" which is cooled to condense the main throat of the waseerdajqpfs and with potassium carbonate to reduce it its carbon dioxide content is washed to 1%. Although a separate carbon dioxide absorber is used for this purpose, the exhausted cooling solution is regenerated in the same regenerator as the main solution. The Qas is then over a heat

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Exchanger fed to a methanol synthesis unit «in which it is passed ^{once through a Fellet catalyst at an inlet temperature of 240 0} C, which consists of the product, which in the reduction of co-precipitated oxides of copper» zinc and chromium in an atomic ratio of 6: 3: 1 is obtained. The methanol is condensed out by cooling and fed to a storage container W. After accumulating about 300 tons of methanol, it was found necessary to meet a peak town gas demand. This wi: * d dadureh durv drive-. that the supplied to the plant: -aphtha-Bege ^ i ' - by a mixture of this methane,?! mV: normal »Hethane used for a fortification replaced-we at the same time is used during the
the methanol synthesis stopped.

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Claims (4)

Claims 11 Process for the production of a fuel gas, which contains carbon oxides, hydrogen and gaseous hydrocarbons, by reacting a hydrocarbon starting material with water vapor under superatmospheric pressure, thereby marked "that a stage is switched on" in which a small amount of the carbon oxide in the 6as is converted into synthetic methanol in a catalytic manner. 2. The method according to claim Ij, characterized in that daS the methanol synthesis is carried out at a pressure of less than 100 atmospheres. 3 · Method according to claim 1 to 2, characterized in that that a catalyst is used which is below 300 ° C is active. 4. The method according to any one of the preceding claims, characterized in that the methanol synthesis over a Copper-containing catalyst is carried out and the Oas used contains carbon monoxide and carbon dioxide PATENT LAWYERS OR.-ING H.flNCKt DWMN *. MOHR DIK.-IM6 009823/0568