Nickel-Based Composite Catalyst for Pressurized Carbon Dioxide Reforming of Methane to Syngas

Abstract

The invention discloses a nickel-based composite catalyst for methane reforming with carbon dioxide to produce a synthesis gas under pressurization. A carrier of the catalyst is at least one selectedfrom SiO2, Al2O3 and TiO2, an active component is Ni, Ni-Fe or Ni-Co, and an auxiliary agent is one selected from composite oxides such as CeO2-La2O3, CeO2-Sm2O3, CeO2-Pr6O11, CeO2-Nd2O3 and CeO2-Y2O3; based on a mass of the catalyst of 100%, the catalyst comprises 5%-15% of the active component, 3%-15% of the auxiliary agent, and the balance of the carrier; and the catalyst is prepared by adopting a coordination-decomposition method with glycine, alanine, threonine, citric acid and oxalic acid as a coordination-combustion improver. The catalyst disclosed by the invention has a simple preparation process and lower costs, and is economic and environmentally friendly; and the catalyst has a higher methane and carbon dioxide conversion rate for methane reforming with the carbon dioxide underthe pressurization, exhibits high activity, high stability and extremely high resistance to carbon deposition and sintering.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a nickel-based composite 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 attention of ...

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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) used carboxylic acid or amino acid as complexing agent, and used combustion decomposition Ni / SiO 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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