What are the processes used to produce synthetic natural gas? What are the disadvantages of each?

I don’t know what the original poster means; is it coal-to-natural gas?

Methane in coke oven gas can be separated using pressure swing adsorption units, and further processed into liquefied natural gas (LNG)

Addition to the above: Liquid fuel produced through processing at -162°C

Yes, extracting methane from coke oven gas and then producing LNG is a method with great market potential at present. Given China’s energy shortages and the global distribution of energy resources, this technology will play an important role in addressing the country’s energy crisis. Moreover, coal chemical enterprises will be able to enter the field of comprehensive utilization. Additionally, processes that combine LNG, methanol, dimethyl ether, and synthetic ammonia will be key topics in the next phase of development.

The understanding of those upstairs isn’t very comprehensive; let me add a few points. By \"alternative natural gas,\" we mean a gas whose combustion properties are similar to those of natural gas, so that cooking appliances can be used with it without any modifications. There are specific criteria for this – mainly, the calorific index and combustion value of the gas must be consistent. Therefore, LNG is not actually an alternative natural gas; it is liquefied natural gas, and its essence is still natural gas. The process of converting coal gas into natural gas does not involve separating methane from the syngas; instead, hydrogen and carbon monoxide in the syngas are converted into methane through methanation reactions, thereby increasing the methane content and making the gas’s properties as close as possible to those of true natural gas. In addition to methanation reactions, mixing liquefied gas with low-calorific urban gas can also produce alternative natural gas, provided that the above two criteria are met.

To date, the only operating SNG facility in the world is located in North Dakota, USA – namely the so-called Great Plains Facility. Its gasification, purification, sulfur recovery, methanation, and phenol recovery processes are all based on Lurgi technology, and from 1984 to 2005, its operational efficiency was 98.7%.

Will the Datang International Ketong Banner coal-to-natural gas project be the first of its kind in China? / 48 Lurgi reactors

The first is Inner Mongolia HuiNeng Coal Chemical Co., Ltd., which produces 1.6 billion cubic meters of SNG per year; the second is Datang

If natural gas is produced through gasification, the following analysis can be conducted: 1) Gasification and the hydrogenation of carbon monoxide generate a large amount of heat, which could be utilized for power generation； 2) The heat from syngas can be concentrated in the form of methane through methanation, enabling the utilization of that heat ； 3) If each type of carbon is not fixed using other chemicals, natural gas contains four hydrogen atoms, and the process generates large amounts of carbon dioxide, which is contrary to the policy trends aimed at energy conservation and emission reduction

Inner Mongolia HuiNeng Coal Chemical Co., Ltd. and the Datang International Keshiketeng Coal-to-Natural Gas Project have likely not yet received official approval

There are three routes for producing natural gas from coal as a raw material: 1. Direct production of natural gas (methane) through the hydrogenation gasification of coal under certain temperatures and pressures. The main drawback of this route is the high cost of producing the hydrogen required as a raw material, as well as the significant energy consumption associated with hydrogenation gasification. 2. Production of carbon monoxide and hydrogen through the steam gasification of coal; thereafter, the hydrogen is separated and used in combination with Process 1 to produce natural gas. 3. Production of carbon monoxide and hydrogen through steam gasification of coal, followed by the conversion of carbon monoxide and hydrogen into methane (natural gas) using a catalyst