Oxygen generation. By Vacuum Pressure Swing Adsorption. Vacuum Pressure Swing Adsorption (VPSA) plant in Italy. Oxygen generation 03 Sulfur recovery plants have increased capacity The steelmaking process requires oxygen. through oxygen enrichment. Proven technology – tailored to your needs. Fast, cost-effective oxygen on demand Advantages. Balancing performance needs with cost constraints. Demand for on-site oxygen generation solutions continues to rise across a number of industries. Vacuum Pressure Swing Adsorption Our entire VPSA offering is geared towards ensuring the perfect fit for (VPSA) technology is an increasingly popular way ofmeeting this individual application needs. You can rely on our VPSA specialists to demand. VPSA involves separating air into its constituent components recommend the configuration that strikes the best balance between by means of adsorption. In other words, the gas molecules bind with your performance needs and investment constraints. With a VPSA adsorbent material at different rates depending on the pressure. This system from Linde, you can look forward to the following benefits: allows operators to single out one particular gas from air. The growth in demand for VPSAtechnology is largely attributable to its simplicity, Right volume and purity on demand reliability and low operating costs. Scaling from 50 to 10,000 Nm³/h (2 to 342 tpd) with purity levels of up to 95 vol.% our plants deliver the precise volume and purity you need – on demand. Experience counts Outstanding availability World leader in adsorption technology, Linde has designed and Offering exceptional availability rates of almost 100%, all of our supplied more than 700 adsorption plants worldwide – including the plants are engineered for excellence, featuring premium components world‘s largest units. We also offer the highest availability levels in the to ensure maximum operational uptime. industry. Our adsorption systems are therefore the solution of choice where performance, flexibility, availability and reliability are key Low operating costs success factors. High quality and easy accessibility to all components Our VPSA units are designed for the highest levels of energy efficiency, also ensure ease of maintenance. making them a cost-effective option. Ease of maintenance and automated operations further reduce operating costs. A PLC-based control system dynamically adjusts the VPSA process to meet changing Adsorption applications purity and flow needs. Major applications include the recovery of high purity hydrogen, Advanced flexibility methane and carbon dioxide as well as the generation of oxygen and Operational capacity can be easily adjusted to the required levels – nitrogen. Linde oxygen VPSA systems are successfully deployed in anything from 0% to 100% is possible. Our plants also start up at the industries as diverse as iron and steel, metals, mining, chemicals, pulp push of a button and are operational within a few minutes. Shut-down and paper, water treatment, glass, food and fish farming. is also completed within minutes. Remote control Large portfolio for all capacity needs To increase manageability even further, our VPSA systems come with an optional dedicated port that can be connected to a plant-wide Our VPSA units for oxygen generation come in multiple sizes and control system (DCS) and/or a communication board for remote control. shapes to suit individual needs. All systems support on-stream applications requiring gaseous oxygen with purity levels of up to 95%. Modular design and prefabricated equipment Capacities scale up to 10,000 Nm³/h (342 tpd) – with one single train. Prefabrication of VPSA modules accelerates deployment, reduces installation effort and saves costs. For instance, our valve skids – In addition, we have developed a fully containerised C-series containing switching and control valves, instrumentation and piping – supporting oxygen streams of up to 2,000 Nm³/h (68 tpd). are preassembled and tested prior to delivery. Our specially designed This C-series is ideal for customers looking to combine the containerised C-series takes mobility, time efficiencies and cost benefits of rapid deployment with maximum cost efficiencies. savings to the next level. 04 Oxygen generation VPSA in detail. How Vacuum Pressure Swing Adsorption works. Process description Each adsorber undergoes a cyclic process, Before the adsorbent is fully saturated with consisting of: nitrogen, the system switches over to the Use of adsorption to recover gases is based → Adsorption (O₂ production) other bed in order to regenerate the saturated on the ability of certain porous materials → Desorption (evacuation) adsorber. to adsorb gases through their large surface → Re-pressurisation (pressure build-up) areas. Individual gases are adsorbed to Desorption different extents depending on the pressure While the first adsorber is in adsorption stage, and temperature of the feed gas and the Adsorption and regeneration cycles the second bed (B) is regenerated by opening selectivity of the adsorbent (see figure 1). the residual gas valve, which is connected to a A VPSA plant is often designed as “2-bed vacuum pump. This pump draws out moisture, Adsorptive air separation is a periodic system”. One bed is in the adsorption stage carbon dioxide and nitrogen in the opposite batch process, in which adsorbent material and the other in the regeneration stage direction to the gas flow in adsorption mode. is alternately (see figure 2). This residual gas is vented to the atmosphere. 1. fed with pressurised air to produce the Adsorption Re-pressurisation required product, and The vessel (A) in the adsorption phase is fed In order to reduce energy consumption during 2. regenerated by vacuum to remove the with compressed process air through an open pressurisation of the regenerated adsorber, residual gases from the adsorbent. air valve. dry gas from the pressurised adsorber (A) flows to the evacuated adsorber (B). To During the generation of oxygen, a cyclic Moisture and carbon dioxide are captured at increase pressure further, the process air swing between overpressure and vacuum the entrance zone of the adsorber. Nitrogen blower pressurises ambient air and feeds it occurs (Vacuum Pressure Swing Adsorption). molecules are continuously adsorbed, thus into the adsorber (B). To reduce energy consumption, the pressure separating oxygen molecules from nitrogen is equalised between the production molecules. At the discharge side of the And so the cycle continues. (overpressure) and regeneration (vacuum) adsorber, the dry oxygen flows into the buffer steps. vessel. Figure 1: Ranking of adsorption forces Figure 2: Typical process flow diagram of a Linde oxygen VPSA plant Compressed air Oxygen Residual gas Hydrogen weak Oxygen Argon Nitrogen VPSA O2 buffer Carbon monoxide Methane Oxygen Carbon dioxide Adsorber A Residual gas Ethane to atmosphere Ethylene Propane Butane Adsorber B Propylene Air Silencer Ammonia compressor Air Hydrogen sulfide Mercaptanes BTX Water strong Vacuum pump Oxygen generation 05 Containerised VPSA. A prefabricated solution for accelerated deployment and reduced costs. Figure 3: 3D graphic of a containerised VPSA plant 7 7 5 1 3 6 2 4 3 8 1 Machinery container 2 Valve skid container 3 Adsorption vessels 4 Interconnecting piping 5 Electrical container 6 Oxygen product gas compressor package (optional) 7 Utility container (optional) 8 Buffer vessel Our C-series “containerised” VPSA plants 4 Interconnecting piping “Understanding our are designed as highly prefabricated, The interconnecting piping between customers' needs, offering modularised and cost-effective facilities. the machinery container, adsorber a value-creating solution The main equipment of the VPSA plant, i.e. vessels, valve skid container and oxygen the air blower and vacuum pump package, compressor is delivered prefabricated for and executing are the valve skid and the electrical system, are the installation on site. key capabilities at supplied fully assembled inside hoods or Linde Engineering.” tailor-made containers. Expenses for erection 5 Electrical container and commissioning of the highly modularised Including PLC control system, electrical Jürgen Nowicki C-series VPSA plant are significantly reduced switchgears and Motor Control Centre Managing Director Member of the Board of Directors with this solution. Due to the containerised (MCC). Linde Engineering Division design of the C-series, a separate machinery building is not required. 6 Oxygen product gas compressor package (optional) 1 Machinery container Including motor, coolers, pulsation Including rotary-lobe-type air blower unit dampers, valves and instrumentation. and vacuum pump unit with motors, cooler, It is skid-mounted and designed as an oil- silencers, valves and instrumentation. free, dry-running compressor, driven by an electric motor. 2 Valve skid container Including process piping, switching and 7 Utility container (optional) control valves, O₂ analyser and field Including the instrument air station and instrumentation. the closed-loop cooling water system. 3 Adsorption vessels 8 Buffer vessel The system consists of two vertical-type The buffer vessel downstream of the adsorber vessels where the adsorption adsorbers ensures a continuous supply process takes place. The vessels are of oxygen. Read more: designed for outdoor installation. linde-engineering.com/adsorption 06 Oxygen generation Linde’s VPSA and PSA solutions. A large portfolio to suit individual needs. To ensure the perfect fit for