Sulfur-tolerant methanation for producing synthetic natural gas

The components of syngas are mainly hydrogen and carbon monoxide; in addition, there are also carbon dioxide and sulfur. By methods such as desulfurization conversion absorption, hydrogen and carbon monoxide can be brought to an appropriate ratio for reaction to produce methane. Coke oven gas is primarily composed of hydrogen and methane, accounting for approximately 50% and 25% respectively, with small amounts of carbon monoxide, carbon dioxide, nitrogen, oxygen, and other hydrocarbons. The amounts of carbon monoxide and carbon dioxide are very low, so there is no practical significance in methanation; although it is possible to add carbon monoxide and carbon dioxide, it is not economical to do so.

I would like to ask whether the sulfur resistance of the sulfur-resistant catalyst is good

This is the technology of the company founded by Professor Wu Diyong and others from the Dalian Institute of Chemical Physics that I have seen, which mainly deals with natural gas derived from coal and syngas. The calorific value of coke oven gas is insufficient to compare with that of natural gas; however, increasing its calorific value through methanation might indeed be a viable solution. It’s the cost issue. Introduction to M-349 Coal-to-Synthetic Natural Gas Methanation Catalyst and Technology by Dalian Preet Chemical Technology Co., Ltd.: Utilizing coal methanization technology to produce high-calorific-value gas or compressed natural gas as a substitute for gasoline represents an important way of making clean use of coal. Moreover, as the prices of liquid fuels rise, this approach is receiving increasing attention both domestically and internationally. This product is suitable for the methanation of transformed decarburized gas, featuring high catalytic activity and a high CO conversion rate; after removing H2O from the product gas, it becomes synthetic natural gas. Working principle: CO + 3H2 → CH4 + H2O; CO2 + 4H2 → CH4 + 2H2O. Key technical specifications: Product model – M-349. Physical properties: Appearance – light green spherical particles; Particle size, mm: φ3–4, φ5–6 (adjustable as required); Strength, N/particle: ≥50, 100; Crushing rate, %: ≤0.5; Bulk density, g/L: 0.95±0.05; Service life, years: ≥1. Operating conditions: Reduction temperature, °C: 400–450 (with H2 pre-reduction); Operating temperature, °C: 280–400; Operating pressure, MPa: 0.1–6.0; Operating space velocity, h^-1: 15000–6000. Performance indicators: Conversion rate of CO and CO2, %: 95–98. Application areas: This product can be used for producing synthetic natural gas from coal, as well as for removing small amounts of CO and CO2 from various gases through methanation, reducing the levels of CO and CO2 to below 10×10-6 v/v. M-348 Active Non-uniform Methanation Technology for Producing Urban Gas. Patent Number: 88105142.X. Technical Overview: This product is a proprietary methanation catalyst that features high activity, resistance to carbon deposition, resistance to temperature spikes, and dual functionality for methanation conversion. Coal gas can be produced without the need for prior conversion, and when combined with associated processes, it forms a complete technology for manufacturing urban gas through methanation. This technology has completed more than 10 sets of industrial methanation projects. Awards: This technology has received multiple awards, including the Excellence Award for Chinese Invention Patents and the **Technical Invention Award. Working principle: CO + 3H2 → CH4 + H2O; CO + H2O → CO2 + H2. Key technical specifications: Product model – M-348. Physical properties: Appearance – spherical particles; Particle size, mm: φ5–6; Strength, N/particle: ≥50; Crushing rate, %: <0.1; Bulk density, g/L: 0.95±0.05; Service life, years: ≥1. Operating conditions: Reduction temperature, °C: 400–450 (with H2 pre-reduction); Operating temperature, °C: 290–400; Operating pressure, MPa: 0.1–6.0; Operating space velocity, h^-1: 10000–3000. Performance indicators: CO conversion rate, %: 85–100. Application areas: This product can be used in the methanation of gas mixtures with a H2/CO ratio of less than 3 to produce city gas. It can also be used for carbon removal to produce synthetic natural gas and high-calorific-value gas. Additionally, it can be utilized in the methanation of various CO-containing gases to produce combustible gases.

For this project I’m working on now, the efficiency of sulfur-tolerant methanation catalysts is not as good as that of sulfur-intolerant methanation catalysts; their efficiency is low. The sulfur resistance is still very good.

Hi Haiyou on the fifth floor, do you mean that the good sulfur resistance refers to the ability to handle sulfur levels of several thousand ppm? Or what level of sulfur content.

It is possible to consider mixing coke oven gas into the raw gas; this can reduce the load on the shift reactor. Meanwhile, the high methane content reduces the heat released during the methanation process, facilitating the control of this reaction! This is my idea! Let’s discuss it together

Sulfur-tolerant methanation requires higher sulfur content to exhibit good activity; generally, a sulfur concentration of not less than 5000 ppm is needed. Below this value, sulfides usually need to be added for the sulfur-tolerant methanation reaction to proceed properly.

The conversion of coke oven gas into natural gas is currently an area of active research; depending on the composition of the gas, pressure swing adsorption can be used first for adjustment, followed by methanation

Natural gas can be produced from coke oven gas; LZ can get in touch with Sichuan Tianyi, as they have methanation catalysts for converting coke oven gas into natural gas