Hydrogen recovery from methanol off-gas

Membrane recovery requires a certain pressure to achieve optimal results; the pressure of the off-gas is usually not sufficient, so additional pressure is needed. If the volume of gas is low, recovery may not be feasible.

Hydrogen recovery is possible, but pressure swing adsorption can also be used.

Membrane separation can be used, as well as pressure swing adsorption. Membrane separation requires less investment; pressure swing adsorption involves higher investment, but it offers a higher recovery rate and a higher hydrogen concentration. If membrane separation is used, domestic ones can be employed; of course, imported ones are also an option, offering a better cost-performance ratio.

It mainly depends on the pressure and volume of the released gas, as well as whether there are requirements regarding the yield and purity of the recovered gas, etc. If the gas volume is too small, it’s better to send it directly to the combustion pipeline network. Membrane separation and PSA are used for passage. Membrane separation generally yields relatively lower yields and purities, around 90% typically. The operating pressure is generally around 10 MPa or more; pressure requirements for pressure swing adsorption are lower, with a few MPa or just a few kilograms of pressure being sufficient. The initial investment is higher, but the recovery rate and purity can be achieved at higher levels. The key components for membrane separation include domestic Dalian Tianbang membranes, as well as Prisen membranes imported from the United States, which are more expensive. Whether it is PSA or membrane separation, our company has extensive experience in such projects; those interested can add me on QQ at 123807447 for further discussion.

Using membrane separation for hydrogen recovery will suffice; a very high purity level isn’t required, as the recovered hydrogen is meant to be returned to the system. The pressure is sufficient – the pressure in the synthesis system is around 5 MPa+, while the pressure of the product hydrogen is about 2 MPa. A pressure difference of 3 MPa should be enough, right? Moreover, membrane separation requires less investment, is easy to operate, and occupies little space. There’s no need to use pressure swing adsorption; why go to the trouble of producing such highly pure hydrogen?

It mainly depends on the purity required for the hydrogen you intend to recover; membrane separation and pressure swing adsorption are commonly used. When it comes to membrane separation, of course, domestic solutions should be given strong support!

This depends on pressure and flow rate; if the pressure is low and the flow rate is high, pressure swing adsorption is a better option, while membrane separation is suitable for low flow rates. If the pressure is high, membrane technology should be used. In the case of membrane technology, Dalian Tianbang’s products are a good recommendation

Whether to use membrane separation or PSA depends mainly on the actual conditions and requirements, followed by an economic analysis – regardless of which method is chosen The main consideration is still cost-effectiveness. Calculate it carefully

For methanol plants, membrane recovery is a suitable method for hydrogen recovery for the following reasons: 1. Cryogenic methods yield the best results, but they require high investment and consume a lot of energy； Pressure swing adsorption requires a large footprint and experiences high pressure losses ； As long as the quality of the incoming air is ensured, membrane separation methods also allow for a longer service life of the membranes. 2. The purity requirement for the recovered hydrogen is not high, and the membrane separation process is fully capable of meeting the process requirements. 3. The pressure of the bleed gas is relatively high, providing sufficient power to meet the requirements of membrane separation.

Reply to 1# gsyybb: Our company uses hollow fiber membranes, and their performance is average; they can recover around 50-60% of the hydrogen