Study On Manufacturing High-purity Nitrogen By Carton Molecular Sieve Pressure Swing Adsorption Process

An improved nitrogen manufacturing technique of carbon molecular sieve pressure swing adsorption process is proposed. The purity of nitrogen product, nitrogen productivity of plant and nitrogen recovery rate are improved remarkably by designing of the asymmetric middle uniform pressure piping and adding the product nitrogen pressurizing, purging and other steps. As results, the production capacity and efficiency the existing carbon molecular sieve are brought into full play and the equipment investment and the long-term operation cost of the plant are reduced. On the base of the above mention, process parameter optimization of the plant is carried out. The optimized design process parameter abtained are as follow:hen air pressure is 0.8 MPa, purity of nitrogen manufactured is 99.99%, nitrogen purging rate is 10% and Type CMS-220 adsorbent is used, the nitrogen productivity is 89.3 L/Kg-h and nitrogen recovery reaches 23%.All these provide valuable basic data for scale-up of industrial plant design.NGN-700E industrial nitrogen production plant has been designed and set up by adopting the middle uniform pressure equalization process with a capacity of 700 Nm3/h. The results of continuance running at full load for one year show that for manufacturing 99.99% nitrogen, the nitrogen productivity and recovery of the NGN-700E pressure swing adsorption plant adopting middle uniform pressure equalization process are increased by 10% nd 3% respectively as compared with the one using conventional process,and the plant is characterized with easy operation, low energy consumption and stable production cost, about 9 million yuan RMB can be saved per year, the economic benefit is obvious.Asper the rate of return on investment, the period of investment return of the plant is 6 months.