Method for producing high-calorific-value combustible gas through in-situ catalysis of biomass pyrolysis volatile component

Abstract

The invention discloses a method for producing a high-calorific-value combustible gas through in-situ catalysis of a biomass pyrolysis volatile component to remarkably improve the content of CH4 in the gas and greatly increase the calorific value of the produced gas. The specific method is that the biomass volatile component is subjected to an isothermal synchronous in-situ catalysis methanation reaction through a perovskite catalyst in a catalyst position, the contents of CO2, CO and H2 in the combustible gas are reduced after the reaction, the content of CH4 is increased, the calorific value and the value of the produced gas are improved, and the high-calorific-value combustible gas with high quality is obtained, wherein the perovskite catalyst comprises an active ingredient and carrier ingredients in percentage by mass, the active ingredient is LaAxB(1-x)O3, A is a transition metal like Fe, Cu, Zn, Zr, Mn and Co, B is Ni, Ce, Ru and Rh, x is between 0 and 1 and is 1-15%, and the carrier ingredients are Al2O3, TiO2, ZrO2, SiO2, cordierite, honeycomb ceramics, hydrotalcite, and SBA-16 mesoporous molecular sieve. In addition, the catalyst adopted in the method further has the advantages of high activity, simple preparation, low cost, good anti-carbon property, high stability, and the like.

Description

technical field [0001] The invention relates to the field of green energy technology conversion, in particular to a method of using a perovskite catalyst to catalyze biomass pyrolysis volatiles in situ to realize the methanation reaction in the pyrolysis process to increase CH in gas production. 4 content method. Background technique [0002] Traditional non-renewable fossil energy sources such as oil and natural gas are increasingly scarce, and it is imperative to find alternative renewable energy sources. As a large traditional agricultural country, my country has abundant biomass (such as straw) energy and huge reserves. Biomass pyrolysis, as a current research hot technology, can use biomass as the basic raw material to prepare solid, liquid and gas three-state products that are widely used in industry. Efficient use of biomass energy. However, so far the dry distillation pyrolysis technology has not been fully industrialized, and the main problems are that during the r...

AI Technical Summary

Problems solved by technology

However, so far the dry distillation pyrolysis technology has not been fully industrialized, and the main problems are that during the reaction process, the high-temperature pyrolysis volatiles contain a lot of ash, which makes separation difficult, and the liquefaction of heavy tar is easy to block the reaction pipeline, and the grade of tar is not high. Solution of combustible gas calorific value is not high

For example: Chinese patent, Publication No.: CN103242922A, introduces a method for preparing fuel gas by burning biomass, which includes crushing, gasification, purification, methanation, gas upgrading and other steps, using Ni / SiO 2 -CaO-Fe 2 o 3 Combustible gas is obtained from the synthetic gas purified by methanation of the catalyst. In this method, the nickel-based catalyst is easily deactivated by carbon deposition during the reaction process, and the process operation is complicated and the energy utilization rate is not high; Chinese patent, publication number: CN105797785A, introduces a A high-temperature-resistant methanation catalyst, which is mainly composed of active component reduced nickel, carrier alumina and additives (MgO, CaO, etc.), and is produced by mixing, stirring, heating, drying, roasting and molding. catalyst, the results show that the catalyst has a better conversion rate of CO and CH 4 It has high selectivity, but the preparation method of the catalyst is complex, the cost is high, and it is easy to be sintered and deactivated, thus limiting its application in industry; Chinese patent, publication number: CN105602999A, introduces a method of using biomass to produce high A system and method for high-quality biomethane gas. In this method, biomass is first subjected to pyrolysis and gasification reaction, and then the gas raw material is mixed with a starter to carry out anaerobic fermentation to enrich methane gas and obtain CH 4 with CO 2 The mixed gas, and finally the CH 4 with CO 2 Mixed gas, external H 2 It is mixed with a starter to carry out anaerobic fermentation to enrich methane gas, and finally obtain a combustible gas with high purity, but this method has complicated operation process, long reaction cycle, high energy consumption, and the rate of methanation to generate methane is lower than that of catalytic methanation Reaction; G.Zhou et al. (Role of surface Ni and Ce species of Ni / CeO 2 catalyst in CO 2 methanation[J].Applied Surface Science,2016,383:248–252.) prepared Ni / CeO 2 methanation catalyst, resulting in higher CO 2 Conversion and CH 4 Selectivity, although the nickel-based catalyst has a high catalytic activity, the very small amount of sulfide and arsenide in the volatile matter of biomass pyrolysis will cause cumulative poisoning of the catalyst and gradually deactivate it

[0006] The high-temperature pyrolysis gas produced during the pyrolysis process of biomass contains atoms such as sulfur, phosphorus, nitrogen, and heterocyclic aromatic hydrocarbons that are not easy to crack. Inactivation, reduced useful life and poor recycling