Synthetic ammonia to methanol

If the feed gas remains unchanged, it is more likely that the amount of methanol produced will be increased to 60,000–70,000 tons. Such a change would require significant adjustments to the processes and equipment involved

The current approach of converting ammonia into methanol involves significant efforts and is not economical; the domestic integrated methanol production route represents a good technical option, requiring only modifications in the methane processing stage to transform the purified gas into methanol product. This post was last edited by zhangchaosen on 2008-2-4 10:46]

It is recommended to use glycol instead; what Hunan Anchun produces works well. Switching everything to methanol is not cost-effective!

A new set of low-pressure methanol has been installed; the methanol exhaust gases are fed into the ammonia synthesis system for co-production of ammonia； The original ammonia synthesis system has been modified to use a fully low-temperature shift process (which can **reduce steam consumption**); the gas purification system has been changed to one that uses hydroformylation for purifying the syngas, with the syngas being further refined through a hydrocarbonation system. In this way, the product structure and system operation mode can be adjusted flexibly, thereby **reducing** the energy consumption of the ammonia synthesis system. This post was last edited by yunanshu on 2008-2-13 13:57.]

Thank you. We have several ammonia synthesis lines together; perhaps we could divert some of the syngas to build a methanol plant. It seems impossible to make all the changes, as there are too many underground pipelines. This post was last edited by yunanshu on 2008-2-13 13:58.]

If it is all changed to methanol, the investment will be high. If part of it is modified, the diol process can be used, and in the ammonia synthesis process, the refining step can be carried out before copper washing by adding diol. It not only produces some methanol but also reduces the load on copper washing, thereby **increasing production capacity**.

It’s better to use linked alcohols; they are easier to adjust and help in dealing with market risks.

It can be changed to high-pressure methanol by using the shell of the ammonia synthesis tower, adding an internal component for a methanol synthesis tower, making some adjustments to the process, and installing an additional methanol water cooler and a flash tank.

However, the production of high-pressure methanol at 30 MPa generates many by-products, poses significant operational challenges, and results in high power consumption and gas consumption. Moreover, high requirements are placed on copper catalysts; these catalysts tend to become powdered, which leads to increased resistance and other adverse effects.

It’s better to use glycol; Hunan Anchun Company in China does a good job in this area. The ratio of alcohols to ammonia can be adjusted; the product that offers better economic benefits should be chosen. The ammonia-to-alcohol ratio can reach up to 18:1.

If a synthesis tower is used, changing the inner cylinder can convert it into a methanol synthesis tower

It is easy to convert an ammonia synthesis tower into a methanol synthesis tower; the pressure in a methanol tower is lower and its internal components are simpler. It’s just a bit of overkill. It would be more economical to get rid of the ammonia synthesis tower (by selling it) and install a new methanol tower instead

First, by switching to medium-high pressure monohydrates, the equipment used in the synthesis process isn’t just something that can be updated by replacing the internals of the synthesis tower; most of the equipment in this process needs to be replaced. For example, in ammonia synthesis, an ammonia cooler is required, while for methanol synthesis, a water cooler is sufficient. Second, the heat of reaction for ammonia synthesis is lower than that for methanol synthesis; how to remove the heat generated in the methanol synthesis reaction promptly is closely related to the internal components of the synthesis tower. So sometimes, the internals of some methanol synthesis towers are not simple; of course, the isothermal type of internals appears to be simpler. Third, the idea proposed for the 6th floor is feasible: using several extraction units to serve one methanol production unit would be better than relying on a single ammonia synthesis system for methanol production.

In ammonia synthesis plants that use natural gas as raw material, the typical process flow might be as follows: desulfurization → natural gas air conversion → decarburization → methanation → ammonia synthesis. The compressor is an air, hydrogen, and nitrogen combined compressor; the specific modification suggestions are as follows: a) There is a lot of ethanol involved in the upper section of the system. In the case of the conventional natural gas process mentioned above, it is not possible to switch to using ethanol, mainly because there is hardly any excess of hydrogen produced from the conversion of air (H2+CO). Unlike fixed-bed batch vaporizers, where the hydrogen-to-nitrogen ratio can be adjusted freely, in the case of air conversion, whether it takes place in one stage or in one stage plus a second stage, the margin for adjusting the hydrogen-to-nitrogen ratio is very limited. Therefore, it is not feasible to install an ethanol processing unit! Remember! b. If converting to alcohol, the natural gas conversion furnace must be modified; switching to oxygen-enriched conversion allows for the production of alcohol. However, adjusting the alcohol-to-ammonia ratio is subject to certain limitations, and changes in the methanol market make it difficult to adjust the product structure! Suggestion: It’s best not to change the ligand! ! ! c. It is feasible to switch to high-pressure monohydric alcohols: the specific approach is as follows: ㈠ Install an air separation unit and use pure oxygen for conversion ； (ii) Retrofitting the compressor ； (III) Reform the ammonia synthesis system (reforming the ammonia synthesis system by taking into account the opinions of those above). However, methanol has high operating energy consumption, and low amounts of steam are produced as a by-product of high-pressure monohydric alcohols! Although the plan can be implemented, its operational energy consumption is high, resulting in a lack of competitiveness! This will cause businesses to die even faster! ! ! This solution is also not recommended! d. The formula with ammonia and alcohol is the best! Based on the poster’s second statement, it can be inferred that there are more than two synthetic ammonia production routes in the plant. I suggest making the following changes for reference: choose one of the synthetic ammonia routes and switch to oxygen-based gas production; all the water gas generated should be used to produce methanol, and the methane produced should then be sent to another synthetic ammonia conversion unit ； The hydrogen obtained after hydrogen extraction from the off-gases in ammonia synthesis is sent to the methanol system, while the remaining methane, nitrogen, etc. are sent to the ammonia synthesis converter. In this way, not only are the investment costs low, but it is also easy to adjust the alcohol-to-ammonia ratio; the product structure can be adjusted according to the market conditions for methanol and ammonia, and existing equipment can also be put to use! e. The specific renovation plan can be discussed further with me; only by understanding the overall situation of your factory can a conclusion be drawn! The above is for reference only! ㈣㈤㈥㈦ →→→→

Unicellulose alcohol is a suitable choice; with a capacity of 60,000 tons for total ammonia, it is possible to adjust this to 15,000–40,000 tons of unicellulose alcohol. The range of adjustment should be feasible, and there is also strong market adaptability. Our own technology allows for adjustments within roughly this range. The methanol market is not doing well right now; not much is being produced.

I agree with the opinion from floor 15; the original poster can take that into consideration

It is recommended to switch to diol, using a set of medium-pressure methanol to adjust the ammonia-to-ol ratio.

Recommended by the original poster: An article can be found in the 5th issue of the Fertilizer Design Magazine, 2005. Title: Discussion on the basic concepts and process technologies for converting an under-construction ammonia synthesis plant to produce methanol.

It seems that the benefits of using methanol these days aren’t very good, so caution is needed when considering any modifications.