Low-temperature methanation catalyst and preparation method thereof

Abstract

The invention discloses a low-temperature methanation catalyst and a preparation method thereof. The low-temperature methanation catalyst comprises an active component, a surfactant, a structural auxiliary agent and a cocatalyst, wherein the active component is Ni; the structure auxiliary agent is a composite structure auxiliary agent composed of Al2O3 and diatomite; the cocatalyst is one or two of La2O3, MgO, CuO and MnO; the content of the active component accounts for 50%-75% of the total mass of the low-temperature methanation catalyst, and the content of the cocatalyst accounts for 0.4%-0.8% of the total mass of the low-temperature methanation catalyst. The method is lower in reaction temperature, lower in energy consumption and simple to operate, has high catalytic activity and longservice life in a low-temperature environment, and can realize efficient catalytic conversion of CO and CO2.

Description

technical field [0001] The invention relates to the field of methanation catalysts, in particular to a low-temperature methanation catalyst and a preparation method thereof. Background technique [0002] Crude hydrogen gas in ethylene industrial plants and ammonia plants inevitably contains CO and CO 2 Components whose presence can be toxic to downstream devices must be cleaned. At present, the most economical and efficient method of purifying hydrogen is methanation, that is, through CO, CO 2 React with a small amount of hydrogen to form inert CH 4 to remove CO and CO from the gas 2 . [0003] CO and CO are inevitably contained in the hydrogen-rich gas separated from the hydrogen / methane separation tank in the hydrogen / methane separation tank of the ethylene production plant by cracking naphtha and light hydrocarbons 2 , and this part H 2 It is the raw material for the downstream hydrogenation process, and if the CO is not removed, it will cause catalyst poisoning and...

AI Technical Summary

Problems solved by technology

[0005] At present, domestic low-temperature methanation technology is not mature enough, so it is necessary to develop a low-temperature methanation catalyst

Chinese patent application CN108479844A discloses a nickel-based catalyst for CO low-temperature selective methanation and its preparation method and application. The catalyst uses metal Ni as the active component and Zr-doped mesoporous molecular sieve Zr#SBA#16 as the carrier Supported catalyst, although the invented nickel-based catalyst can deeply remove CO in hydrogen-rich reformed gas to below 10ppm at a relatively low temperature (180-230°C), and at the same time, the selectivity of CO methanation reaction is higher than 50% , but the cost of mesoporous molecular sieves is high, the stability is insufficient, and the catalyst activity is slightly low

Chinese patent application CN107376925B provides a low-temperature high-activity carbon dioxide methanation catalyst and its preparation method, using CO(NH 2 ) 2 instead of NaOH and Na 2 CO, through slow hydrolysis at 90-120°C, provides OH needed for precipitation - and CO 2- Generate a uniform [Ni 1-x 2+ Al x 3+ (OH) 2 ] x+ (CO 3 ) x/2 2- Precipitation, the cataly