CS214569B1 - Process for the production of hydrogen by low-temperature conversion of carbon monoxide from gases from steam or oxygenation of carbonaceous feedstocks - Google Patents

Abstract

The method of producing hydrogen from gases of steam or oxygen-steam oxidation of carbonaceous raw materials by converting carbon monoxide with water vapor in the presence of sulfur compounds using catalysts containing metals from groups I, II, VI, and VIII of the periodic table of elements with simultaneous conversion of undesirable substances into substances removable by absorption or adsorption methods consists in preliminary activation of the catalyst stored in at least two layers or up to three reactors connected in series by sulfurization at temperatures of 50 to 280°C for 12 hours and the actual conversion taking place at an inlet temperature on individual layers of 200 to 250°C, or 260 to 300°C, pressure of 0.1 to 10 MPa, steam to gas ratio of 0.05 to 3 and at a load of 500 to 3,000 vol. per vol. of catalyst per hour, based on dry inlet gas and total catalyst volume.

Description

SUMMARY OF THE INVENTION The present invention provides a process for the production of hydrogen from vapor or oxygen gas oxidation gases by hydrogen converting carbon monoxide by vapor in the presence of broad compounds using catalysts comprising coke I., II., VI. and VIII. groups of periodic system elements while simultaneously converting undesirable substances into substances removable by absorption or adsorption methods.

This process currently produces hydrogen by converting carbon monoxide with steam on Fe-Cr-O-S or Co-Mo-O-S catalysts, with the starting temperatures of these catalysts varying between 280 and 260 ° C, depending on the sulfur content of the gas. The efficiency of FeCr catalysts at a sulfur content of over 150- 200 ppm decreases to 50%. In the course of the carbon monoxide conversion reaction of a non-methane reaction, which would result in overheating, catalyst loss and loss of activity, the vapor / gas ratio must be above 0.6, more preferably 0.8. Since both the conversion and the methation are exothermic reactions, overheating of the catalyst can occur not only as a consequence of a slight decrease, but also an increase in the water vapor content of the gas. In the conversion of carbon monoxide in gases produced by the above-mentioned processes containing above 45% carbon monoxide, it is not possible to achieve such a desirable conversion of carbon monoxide with water vapor without the intermediate carbon dioxide, so that the methane removal of carbon monoxide can be used for hydrogen production. previous scrubbing of carbon dioxide. In addition, after achieving the desired degree of conversion of carbon monoxide after the intermediate carbon dioxide and complete scrubbing compounds to a content of less than 0.1 ppm, a low temperature copper catalyst is desirable, which, together with the high temperature catalyst, combines with a very different behavior towards the carbon dioxide. The energy efficiency of the whole line is reduced by the complete cooling of the gases from the parasitic oxidation to create conditions for partial scrubbing of the sulfur compounds and by repeated cooling to scrub carbon dioxide produced in the high-temperature conversion of carbon monoxide.

It has now been found that a satisfactory degree of conversion of carbon monoxide by water vapor contained in vapors or vapor-phase oxidation gases of carbonaceous compounds is advantageously achieved in one at least two-stage reactor or up to three sequentially coupled reactors. partial oxidation while saturating the water. by quenching and adding water between the layers or between the reactor stage, the conversion of carbon monoxide.

The nature of the process for the production of hydrogen by low temperature conversion of carbon monoxide by vapor from vapor or oxygen gas oxidation of carbonaceous materials in the presence of compounds and at the same time undesirable substances, such as carbonylsulphide, carbon disulphide, unsaturated organic compounds. Hetero compounds, more readily removable by bulk or adsorption processes in the presence of low temperature sulfur catalysts, optionally in combination with Fe-Cr or Co-Mo catalysts, according to the invention, that the conversion takes place in the catalyst in at least two layers which does not propagate and is technically activated at temperatures of 50 to 280 ° C with a gas containing at least 1 g / m 3 of sulfuric compounds after idob for at least 12 hours with a minimum throughput of 150 vol. temperature 200 to 250 ° C, 260 to 300 ° C and 20 ° C 0 to 250 ° C in the first and further conversion stages, a pressure of 0.1 to 10 MPa, preferably 1 to 6 MPa, a ratio of steam to gas in the first conversion stage of 0.05 to 3, preferably 0.1 to 1.6 and in others grades of 0.6 to 1.4 and 0.8 to 3, preferably 1.2 to 1.6, based on the total amount of water vapor added a) or water and gas at system inlet and load 500 to 3,000 v / v catalyst per hour based on dry feed gas and total catalyst volume. The low-temperature sulfur-resistant catalyst (hereinafter NSOKj is usually a Co-Mo-OS catalyst alkalized with oxides or salts of Group 1 or Group II metals) is a catalyst with multifunctional properties whose carbon conversion efficiency is specific, The hydrolysis of carbonyl sulfide, carbon disulfide, hydrogenation of unsaturated organic compounds, and hydrogenolysis of the hetero compounds can be affected, in particular, by the amount of alkali added and / or partial or total nickel cobalt substitution. transforming undesirable impurities in gases into substances removable by known procedures and / or absorption.

Since the NSOK catalysts have a starting temperature of about 200 ° C and a working temperature of 200 ° C, 490 ° C and practically no catalytic methane reaction, there is no danger of overheating of either the catalyst or the reactor material in the event of a sudden change in water vapor content in either one or the other direction and the vapor / gas ratio may vary within 0.005-3. Preferably, the catalyst operates at a ratio of 0.1: 2 of gas at a total pressure of 0.1-10 MPa, a load of 500-12,000 h -1 (relative to dry inlet gas), preferably 2,000-6,000 h -1, and sulfur content. more than 20 ppm (such as hydrogen sulfide), preferably 100 ppm. The high catalytic activity of the NSOK catalyst allows to minimize the number of conversion steps and to achieve the desirable conversion of carbon monoxide water.

Claims (1)

214569 with steam without the intervening of carbon dioxide and without the prior removal of sulfur compounds, whereby, depending on the degree of utilization, the complete removal of both the carbon monoxide and the hydrogen sulphide pre-wash as well as the hydrolysis and hydrogenolysis of the sulfur can be achieved. hydrogen sulfide compounds, optionally hydrogenation and unsaturated organic compounds. If the gas does not contain carbonyls and mechanical impurities that could clog and clog the catalyst, it is a prerequisite for the high lifetime of the NSOK catalyst because it is not only poison-sensitive, but even activated by other poisons. A disadvantage of the NSOK catalyst process is that it cannot be used for the conversion of carbon monoxide in gases free of catalytic poisons, eg for the conversion of vapor reforming gases. EXAMPLE An NSOK type catalyst was charged into three three-stage experimental reactors at 330, 1000, 1000, cc3 of catalyst. to 240 ° C. In this temperature, a gas containing 48 mol% was introduced into the first reactor. carbon monoxide and 51 mol%. hydrogen. The remainder consists of 20 to 60 ppm of hydrogen sulfide and up to 15 ppm. Subject Process for the production of hydrogen by low-temperature conversion of carbon monoxide by steam-gasification of steam or oxycarbide oxidation materials in the presence of sulfur compounds and at the same time conversion of undesirable substances into substances more readily removable by adsorption or adsorption processes. the presence of low-temperature sulfur-resistant catalysts, optionally in combination with Fe-Cr or Co-Mo catalysts, characterized in that the conversion takes place on the catalyst in at least two layers, which is soaked and technically activated at temperatures of 50 to 280 ° C with a gas containing at least 1 g / m 3 of sulfur compounds for at least 12 hours and with iron pentacarbonyl. Water was sprayed into the stream so that the vapor / gas ratio was 0.25. Under these conditions and at a load of 60% by volume on volume and on dry inlet gas, the content of carbon monoxide at the outlet of the first reactor was 25 mol%. carbon monoxide and temperature increased to 410 ° C. After spraying water behind. the first reactor, at a steam to gas ratio of 0.8 (based on dry gas entering the first reactor), the reaction mixture temperature was adjusted to 280 ° C and introduced into a second reactor where conversion of the carbon monoxide resulted in a reduction of of carbon monoxide to 2.9 mol%. (in dry gas) and increase the temperature to 410 ° C. After repeatedly injecting water at a steam to gas ratio of 1.4 (based on the total amount of water added) and dry feed gas to the first reactor, the carbon monoxide content decreased to 0.5 mol%. (in dry gas) and the temperature increased to 240 ° C. By varying the conditions on the individual reactors with a total input gas throughput of 1000 h-1 (based on the total volume of catalyst used), it was possible to achieve a carbon monoxide content in the dry gas at a system outlet below 0 after a continuous continuous run of the experimental reactors. , 4 mol%. The iron pentacarbonyl content after the first reactor was less than 0.1 ppm. of the invention at a minimum throughput of 150 vol. on the catalyst volume and 1 h on completion of the sulphurization, a gas / water vapor mixture is introduced at an inlet temperature of 200-250 ° C, 260-300 ° C and 200-250 ° C in the first and subsequent conversion steps 0.1 to 10 MPa, preferably 1 to 6 MPa, of steam to gas ratio in the first stage of 0.05 to 3, preferably 0.1 to 1.6, and in further stages of 0.6 to 1 , 4 and 0.8 to 3, preferably 1.2 to 1.6, based on the total amount of added water vapor and / or water and gas at the inlet of the system and at a load of 500 to 3,000 vol. on input dry gas and total catalyst volume. jCT, H. p., provoz 0, Jindrichuv Hradec Price: 2,40 Kčs.