1.Introduction

  Carbon molecular sieve (CMS) is a new kind of adsorbent and an excellent non-polar carbon adsorbent material, which belongs to the category of porous carbon. The main component of CMS is elemental carbon, which appears as a black columnar solid.

  The pore size of carbon molecular sieve is mainly composed of micro pores below 1nm and a few large pores, which are evenly distributed and have high chemical stability and gas selectivity.  Therefore, using carbon molecular sieves as adsorbent with high pressure adsorption technology for gas separation is the main application field.  

2.Operating principle

  Carbon molecular sieve contains a large number of diameter of 4 angstrom micro pores, which  have a strong affinity for oxygen molecules (oxygen diffusion rate is much higher than nitrogen), can be used to separate oxygen and nitrogen in the air. In industry, pressure swing adsorption device (PSA) is used to make nitrogen.

  Nitrogen generated by PSA air separation is that when compressed air enters the CMS adsorption tower, with the increasing of reaction pressure, the adsorption rate of O2 is much higher than that of N2 in a short period of time after the adsorption starts due to the different diffusion rates of O2 and N2. Therefore, the CMS has different adsorption capacity for O2 and N2 in a certain period of time, and the cyclic process of pressure adsorption and decompression resolution is controlled by the program controller to complete the separation of O2 and N2.  

3.Application

  Carbon molecular sieve (CMS) is used to separate air and generate nitrogen. It adopts the low pressure nitrogen process at room temperature. Compared with the traditional cryogenic high pressure nitrogen process, CMS has the advantages of less investment cost, fast nitrogen generation rate and low cost of nitrogen. Therefore, it is the preferred PSA air separation nitrogen-rich adsorbent in the engineering field. The nitrogen is widely used in chemical industry, oil and gas industry, electronics industry, food industry, coal industry, pharmaceutical industry, cable industry, metal heat treatment, transportation and storage. With the increasing pressure of global environmental protection, the expansion of the application field of air separation equipment, the start of shale gas exploitation and other projects, the demand for carbon molecular sieve is increasing.