Paper and board manufacturers need large amounts of wood. But they also need oxygen. This gas plays an important role in the paper production process, where it is used to bleach wood pulp, the main ingredient in paper. In its natural state, cooked and compressed wood pulp is much too dark to write on. The lignin in the wood pulp would also soon cause the paper to lose its strength. It therefore has to be removed in a complex production step that requires large amounts of oxygen. Pressure swing adsorption plants from Linde Engineering are an energy-efficient way to generate this oxygen on demand at the point of use.
A long-term Linde operation
Finnish forest industry company Metsä Group, is building a new large bioproduct plant in the town of Äänekoski, Finland. The company has selected Linde to supply oxygen to the new plant. To fulfil this task, Linde is installing a large vacuum pressure swing adsorption (VPSA) plant on the Metsä Group premises. Valued at around EUR 15 million, the new ADSOSS™-O plant is a key link in the production chain. Under a long-term supply agreement, Linde’s Gases Division will own and operate the plant.
Robust design, high purity level
This state-of-the-art plant will produce over 5,000 normal cubic meters (Nm3) of gaseous oxygen per hour with a purity level of 93 percent. It is extremely energy efficient and therefore cost effective, even when producing high volumes of oxygen over extended periods of time. VPSA plants from Linde are renowned for their high levels of availability. This robust design, complemented by a liquid oxygen back-up system, guarantees uninterrupted oxygen supplies to the customer – a key factor in Metsä Groups’ decision to partner with Linde. Metsä Group is investing EUR 1.2 billion in the new bioproduct plant and is determined to avoid downtime due to lack of oxygen. Once the VPSA plant goes on stream, 24x7 monitoring from Linde’s remote operating centre (ROC) in Avesta, Sweden, will further contribute to business continuity. Electricity won’t be a problem at the site in Äänekoski either. The wood pulp mill produces more energy in the pulp production process than the entire complex can use. The facility is set to go on stream in the third quarter of 2017.
On this paper mill site Linde is installing a large vacuum pressure swing adsorption (VPSA) plant for the Finnish forest industry company Metsä Group. The new mill, which is currently under construction, is integrated graphically. Source: Metsä Group.