Hydrogen recovery issues
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Is the hydrogen recovery device equipped with an online ammonia detection instrument before entering the membrane? Are the instructions accurate? How many ppm levels can it reach?
Our hydrogen recovery device does not have an online detection device. It has an on-site sampling point. Generally, the operator performs the test by himself. The normal value is 13~26ppm, and the specified maximum limit of film feed is 200ppm.
Reply 2# xnfh_wpzg "The specified maximum membrane feed limit of 200ppm" is "ammonia" or "water". Ours only requires water, and there is no requirement for ammonia content.
Ammonia content. Because ammonia destroys the permeable membrane. (General membrane materials are polyamide or polysulfone, so the imported ammonia content must be strictly controlled) I don’t know what device you are installing. We are installing the Prism® membrane recovery device of Chengdu Saipreixing Technology Co., Ltd., and the ammonia content at the membrane inlet is required to be less than 5PPM.
According to the process flow, there is no water in the membrane. Whether it is to synthesize ammonia or methanol, the ammonia-synthetic Tianbang membrane requires the content of ammonia or methanol entering the membrane to be ≤200ppm. If it is a Prism membrane, the ammonia required to enter the membrane for ammonia synthesis is ≤200ppm, while the methanol synthesis requires methanol content ≤5ppm.
Reply 1# lantian0728 Yes, currently domestic ppm level online ammonia monitors can be produced, with prices ranging from RMB 30,000 to RMB 80,000, and imported ones ranging from RMB 80,000 to RMB 220,000.； At present, it is often used in the reduction of low-pressure monoalcohol using low hydrogen temperature. However, for hydrogen recovery, it is not cost-effective to set up an online ammonia monitor.
Reply 5# xnfh_wpzg We are a hydrogen recovery company with water washing tower, from Seprexin. So there are requirements for water
This post was last edited by Chemical Gas Purification on 2010-9-24 15:18 Generally speaking, the lower the ammonia content in the membrane gas, the better. Mainly start by looking at the operating conditions of the ammonia washing tower and high-pressure water pump, combined with on-site sampling analysis to determine whether the water washing is qualified. Online analyzers also generally have biases and cannot be fully relied on. Very few domestic membrane hydrogen extraction units are equipped with online ammonia analyzers.
Hydrogen recovery devices generally do not have online ammonia detection instruments before entering the membrane. Most of them require on-site sampling and manual analysis. The general requirement is less than 100ppm.
Generally, a membrane hydrogen extraction device is equipped with a separator after the ammonia washing tower, and there is an analysis sampling point after the separator. Here, samples are taken to analyze the ammonia content in the membrane gas, which is required to be less than 200PPm. The moisture requirement is as long as the gas does not contain water.
It is of little significance to install online monitoring of the hydrogen recovery device. Our company has a separator after the ammonia washing tower. Manual analysis of the ammonia entering the membrane is <200PPm, and there is a heater for moisture removal.