Is it necessary to use methanol for carbon supplementation?

The reformate gas contains more hydrogen and less carbon; adding carbon helps increase methanol production and thus boosts profitability

If I’m not mistaken, what the original poster is referring to with carbon supplementation is plants that produce methanol from natural gas; the amount of carbon monoxide generated through gasification is around 25%, while that generated from the conversion of natural gas is about 12%–14%. The amount of carbon monoxide required for methanol production is approximately 19%–21%. To achieve balance, coal-based methanol production involves the generation of hydrogen through steam reforming, whereas natural gas-based methanol production requires carbon supplementation; in other words, carbon supplementation serves to turn waste into a valuable resource. Of course, if no carbon is added, the excess hydrogen produced during methanol synthesis is burned as an inert gas. So now many factories have the idea of using both natural gas and coal to produce methanol, but they aren’t approved for it.

In response to the original poster, it’s not about whether it’s necessary to use methanol for carbon supplementation; rather, it’s about whether this technology can be developed and applied in actual production. This way, waste can be turned into valuable resources, improving the overall efficiency of resource utilization and truly achieving energy savings and reduced consumption! Some methanol producers (coal-based) have invited experts to conduct investigations, with the aim of reintroducing carbon dioxide from the exhaust gases into the gasification furnace in order to adjust the combustion temperature; this allows carbon dioxide to be converted into carbon monoxide and hydrogen within the furnace. As a result, less coal needs to be burned, which increases the volume of gas produced and thus boosts methanol output! This idea is indeed great, and relevant experts have also conducted on-site inspections; I hope it can be put into practice as soon as possible! This will address the issue of methanol production companies releasing large amounts of highly concentrated carbon dioxide gas into the atmosphere, which not only causes environmental pollution but also represents a waste of resources! If this idea comes to fruition, it would be a great achievement for the chemical industry! It can save a great deal of coal resources for **and even the whole world! Once the research is successful, the production processes and operating parameters of coal chemical methanol enterprises will be improved!

Coke oven gas also requires carbon dioxide supplementation

The Texaco process involves separating the purified CO2 produced and adding it to the gasifier to participate in the reaction; this reduces CO2 emissions, is environmentally friendly, and increases the production of CO. It’s a great method, though it has not yet been put into practice. I hope it can be implemented soon! This post was last edited by ft2489244 on 2007-12-10 09:57.]

Based on the composition of your syngas, if there is less carbon and more hydrogen, adding an appropriate amount of CO2 will help balance the hydrogen-to-carbon ratio and increase the yield of methanol synthesis. The first methanol production using coke gas in Zhanhua, Yunnan was achieved by adding the exhaust gases from its fertilizer plant to the syngas in order to increase methanol production. Not all devices require carbon supplementation; it is only suitable for areas with high volatiles and high hydrogen content. This post was last edited by kaisl1314 on 2008-1-4 07:46.]

We use natural gas for the conversion to methanol; the hydrogen content is already high. Our original plant had a carbon addition process, and under normal operation we could increase production by about 30 tons per day. However, some people say that it’s completely unnecessary to use this process, and I’m not sure why. Now that we’ve switched to a new plant, there is no such carbon addition process anymore. Yet, adding carbon does indeed have a positive effect on the side reactions during synthesis and on production volume. I wonder if the investment required is simply too high

As far as I know, the hydrogen content in coke oven gas after conversion is actually quite high; in many cases it is well beyond the normal hydrogen-to-carbon ratio range. As a result, much of the hydrogen in the off-gases is wasted. Adding carbon to the conversion furnace is an effective method for improving both the conversion efficiency and production volume. . . . .

It mainly relates to the hydrogen-to-carbon ratio; in production, efforts should be made to keep (hydrogen-carbon dioxide)/(carbon dioxide+carbon monoxide) at 2.05–2.15. An appropriate amount of carbon dioxide can help prevent the occurrence of side reactions.

Our factory has installed a carbon dioxide recovery unit, and based on the results of methanol production, it is indeed effective in increasing methanol production through the use of carbon dioxide

We are a factory that produces methanol from natural gas. At first, no carbon supplementation was carried out; a large amount of unreacted hydrogen was released into the conversion system to be burned. Often, in order to ensure stable operation of the conversion process, only a small amount of this released gas was recovered, leaving most of it to be wasted. Later, a carbon supplementation system was installed, and the performance of the synthesis catalysts improved compared to before. As a result, we can produce about 60 tons more pure methanol per day. In recent years, the price of methanol has been quite good, resulting in excellent profits. It is recommended that natural gas-based methanol plants that do not use carbon supplementation consider adopting such technology; however, this is not necessary for methanol produced from coal

Returning carbon dioxide to the water-coal slurry pressurized gasification furnace has been achieved at Shanxi Fengxi, using a non-slag/slag staged gasification technology. This technology has passed a 72-hour test; relevant posts on relevant forums can be checked out.

Our factory produces methanol from natural gas; both the 100,000-ton and 300,000-ton production units are equipped with carbon supplementation systems, which helps to increase output

I think our factory has addressed your concern regarding carbon dioxide; we have installed a carbon dioxide recovery system that captures carbon dioxide from flue gas and reuses it in the conversion process, which indeed increases the production of methanol

The methanol production process using coke oven gas in our plant is equipped with a carbon supplementation unit in the conversion section. This allows for the adjustment of the hydrocarbon ratio in the reaction gas, enabling the achievement of the most optimal ratio and thus improving the efficiency of the reaction as well as increasing yield. Additionally, the gas used comes from vent gas that has been depressurized once, which constitutes a form of waste recycling; this also enhances profitability, serving two purposes at once – it is indeed a good method.

Carbon supplementation is still necessary. The natural gas in your area has a good quality, with a high methane content; after conversion, there is more hydrogen and less carbon. Carbon dioxide from the flue gases can be recovered, compressed, and fed into the inlet of the syngas compressor before entering the synthesis system. When carbon dioxide is converted into methanol, water is produced, which helps to lower the temperature and make the reaction conditions more moderate. Additionally, the heat released during the conversion of carbon dioxide to methanol is lower than that during the conversion of carbon monoxide to methanol, which also helps to prevent other side reactions from occurring. High temperatures are the main cause of such side reactions. In China, the Nanjing Chemical Engineering Design Institute is involved in the recovery of carbon dioxide from flue gas. Among the facilities in operation domestically is the 200,000-ton/year methanol plant owned by CNOOC Tianye Chemical in Inner Mongolia; those interested can learn more about this subject*.

In fact, whether it is methanol production from coke oven gas or natural gas, there is an abundance of hydrogen. To effectively utilize this excess hydrogen, it is necessary to introduce carbon, thereby improving the efficiency of gas utilization and also increasing production. Our company is currently considering the option of adding carbon, as well as process improvements – anything that is beneficial and feasible is certainly necessary

Our company produces methanol from coke oven gas; the design was carried out by the Second Chemical Engineering Institute. The designed hydrogen-to-carbon ratio is 2.67, while the actual ratio during operation is around 2.7, which is higher than the theoretical value of 2.15. The original design did not include a carbon supplementation mechanism, which is undoubtedly a significant flaw in the design. In my opinion, maintaining a reasonable hydrogen-to-carbon ratio is beneficial for increasing methanol production. Additionally, having a certain amount of CO2 in the gas flowing into the reactor facilitates the progress of the main reaction. However, if the CO2 concentration in this gas exceeds 6%, it will have an adverse effect on methanol production.

Of course carbon needs to be replenished. Carbon dioxide is indeed effective in increasing methanol levels

Our company uses a two-stage natural gas conversion process, with the second stage being conversion using pure oxygen; therefore, no additional substances are needed. It is a good process route at present, but all the burner materials are imported