Pressure Swing Adsorption (PSA) systems provide a well-established and reliable process for purifying hydrogen, methane and other gases from mixed gas streams. XEBEC Technologies (XEBEC) has made significant advancements in PSA technology, including the introduction of rotary valves and a much faster PSA process. For the past decade, XEBEC has been developing and selling its rotary valve PSA systems for industrial use. This case study looks at a long-term gas purification installation that includes XEBEC's rotary valve and fast-cycle PSA technology-The study covers more than five years of operating history to investigate the reliability of XEBEC's rotary valves and clearly demonstrate the costs and benefits of these advanced PSA systems.
XEBEC's fast-cycle, rotary-valve PSA system was selected because it met all customer requirements: extreme reliability, simple operation, rapid startup, minimal footprint, and the ability to produce the most cost-effective ultra-high purity
A new steam reformer and XEBEC PSA system were selected to replace an aging chemical plant that supplied high purity hydrogen to a stainless steel production facility on the remote western coast of Honshu, Japan. MKK, Ltd, (Mitsubishi Kakoki Kaisha) was awarded the project and supplied its in-house reformer design with a XEBEC fast-cycle, rotary-valve PSA.
The plant was designed to deliver 407 NCMH (normal cubic meters per hour) of hydrogen continuously with less than 1 part per million of contaminants - more than 99.999% pure hydrogen. The PSA purifies a reformate stream which consists of approximately 75% hydrogen, 20% carbon dioxide, 2.5% carbon monoxide and 2.5% methane. The reformate is produced by a steam reformer that uses liquid petroleum gas as the feedstock for producing hydrogen. Tailgas from the PSA system supplies heat for the reforming process, making an efficient method for generating hydrogen. The installation is outdoors near the coast, where the ambient temperature can range from -25°C in winter to 35°C in summer.
Result: Strong Reliability, Low Cost of Ownership
Testing revealed the annual cost to maintain the advanced XEBEC PSA was US$3,157 including regular inspections and maintenance by site personnel, repair and service work using site personnel and XEBEC factory-trained service engineers, travel and all replacement parts. (For testing procedure and details, please see page 2 of this case study.)
This study shows that XEBEC'S fast-cycle, rotary-valve PSA system is extremely reliable, with one of the highest availability figures of any gas purification technology on the market.
Maintenance and service costs are extremely low compared to all other PSA systems due to the simplicity of operation and the reliability and extended service interval of the rotary valves compared to conventional PSA systems. In addition, adsorbent materials last the life of the plant in many cases. The reduced equipment size and lower installation and operating costs are further benefits of this proven technology.
Reliability analysis of XEBEC`s fast-cycle, rotary-valve PSA systems case study