Rare earth-modified nickel-based catalyst for pressurized carbon dioxide reforming of methane to synthesis gas

Abstract

The invention discloses a rare earth modified nickel-based catalyst for pressurizing carbon dioxide to reform methane to produce syngas. A carrier of the catalyst is at least one of SiO2, Al2O3 and TiO2, an active component is Ni, Ni-Fe or Ni-Co, an auxiliary agent is at least one of rare earth oxides such as La2O3, Sm2O3, Pr6O11, Nd2O3 and Y2O3; the catalyst comprises 5% to 15% by mass of the active component, 3%-10% by mass of the auxiliary agent and balance of the carrier; the catalyst uses glycine, alanine, threonine, citric acid, oxalic acid and the like as a coordinated co-flammable agent, is prepared by a coordination-decomposition method, is simple in preparation process, relatively-low in cost, economical and environmentally friendly. The catalyst has high methane-to-carbon dioxide conversion rate for use of the carbon dioxide to reform the methane under pressurizing, exhibits high activity, high stability, high resistance to carbon deposition and high resistance to sintering.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a rare-earth modified nickel-based catalyst used for carbon dioxide reforming methane to produce synthesis gas under pressurized conditions. Background technique [0002] In recent years, with the deepening of people's understanding of the greenhouse effect, CO, one of the strongest greenhouse gases, 2 The capture of and its applications have attracted increasing attention. Carbon dioxide reforming of methane can simultaneously utilize CO 2 and CH 4 The two major greenhouse gases are of great significance to the reduction of greenhouse gas emissions, and the H of syngas 2 / CO≤1, it can be used as raw material gas for the synthesis of carbonyl and organic oxygen-containing compounds. Since Ashcroft et al. (Nat.Chem., 1991, 352:225-226) reported the research on reforming methane with carbon dioxide, reforming methane with carbon dioxide has attracted extensive att...

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Problems solved by technology

[0003] Catalyst systems for reforming methane with carbon dioxide are mainly divided into two categories, one is catalysts with noble metals (Pt, Rh, Ru, Pd, Ir) as active components, although such catalysts have high activity, selectivity and stability, but Its sources are limited, expensive, and difficult to achieve commercial application

[0005] The inventor's research group (Ind.Eng.Chem.Res.2014,53,19077-19086; Int.J.ofHydrogen Energy.2014,39,11592-11605) uses carboxylic acid or amino acid as complexing agent, adopts combustion Preparation of Ni / SiO by Decomposition 2 The catalyst is used for the pressurized carbon dioxide reforming methane reaction. When the reaction pressure is increased from 1.0atm to 10atm, after 20 hours of reaction, the carbon deposition amount of the catalyst increases from 2.0wt% to 80wt%, although the catalyst has a certain carbon capacity. However, as the surface area of ​​carbon gradually increases, once the amount of carbon deposition exceeds the carbon capacity of the catalyst, the catalyst will quickly deactivate, and the carbon deposition will block the bed layer and the reaction will have to be terminated.

[0006] It can be seen from the above that the existing carbon dioxide reforming methane reaction developed under normal pressure can run stably, and the carbon deposition is particularly serious under pressurized conditions, which makes the catalyst bed blocked by carbon deposition, making the carbon dioxide reforming methane reaction unable to continue.

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