【Fantasy】Is it possible to convert the heat generated by the reaction between salt and acid into steam?

If there is enough heat, it can be tried; in the sulfuric acid industry, a lot of heat used to be wasted, but now low-temperature waste heat recovery is an efficient way to save energy and generate income.

Heat recovery can be carried out to reduce production costs

Chlorine and hydrogen undergo intense combustion within the synthesis furnace, releasing a large amount of heat. According to some sources, the temperature at the peak of the flame can reach 2000°C, while the temperature inside the synthesis furnace is generally around 400°C. This temperature and this amount of heat are sufficient to boil water; therefore, most companies these days use synthesis furnaces that generate steam. The process of converting hydrogen chloride into acid salt is also an exothermic reaction. However, in order to maintain the concentration of the acid salt within the specified range (usually 31%), hydrogen chloride must be further cooled by circulating water in a graphite cooler to below 40°C. Therefore, the heat released during this conversion must be removed promptly. Recovering this heat is not very valuable or meaningful, as the costs involved exceed the benefits; this is the main reason why this heat is not currently recovered.

So that means the synthesis furnaces in many companies can generate steam, right?

But is the corrosion of the furnace tubes in the synthesis furnace very severe? Is it easy to cause a shutdown due to tube corrosion? Are there any good solutions available now?

The quality of synthesis furnaces is generally good, and the problems you mentioned usually don’t occur.

I heard that this is the case in one factory: at first, synthetic furnaces capable of producing steam were used, but after 2 years they were no longer needed. Production stops down because the furnace tubes are frequently damaged. So, what material is generally used for such furnace tubes? Is there any particular consideration? After shutting down the furnace, is it necessary to carry out some kind of displacement treatment or air purging?

The technology is now highly mature and can be fully converted into thermal energy.

“I heard that this is the case in one factory: at first, synthetic furnaces capable of producing steam were used, but after 2 years they were no longer needed. Production stops down because the furnace tubes are frequently damaged. ”-----What you say is possible; a quality issue with the graphite blocks, or debris blocking the gaps in the graphite heat exchanger, could lead to localized overheating and cracking, thereby causing the plant to shut down. Our company has experienced cases where the graphite blocks cracked due to dirt entering the cooling water. So, what material is generally used for such furnace tubes? Is there any particular consideration? ------For graphite, no research has been conducted on this material. After shutting down the furnace, is it necessary to carry out some kind of displacement treatment or air purging? -----Filling the furnace with nitrogen after listening to its operation is done to displace the hydrogen inside the furnace, as a measure to ensure safety.

Now there are synthesis furnaces that generate by-product steam. If one were to modify an existing furnace for this purpose, the costs involved would be higher than the benefits obtained, so it’s not necessary. As for using the hot water generated for heating the factory premises, I think this is something worth considering