GEA, a renowned machinery and equipment manufacturer and solution provider, is supplying Mpact, a leading South African company in paper and plastic packaging production and recycling, with a new black liquor concentration and drying plant. Black liquor is a valuable by-product rich in energy and lignin, obtained from cellulose production through the sulfite process in the paper industry. It is formed when lignin is separated from pulp during the paper fiber creation process. The modernization project at the Mpact paper mill, situated in Mkhondo, Mpumalanga – a province in South Africa, incorporates advanced GEA technology, including a decanter centrifuge, a Mechanical Vapor Recompression (MVR) evaporator, and a spray dryer.
Thanks to this cutting-edge GEA plant, Mpact will be able to double its pulp capacity, increasing it from approximately 55,000 tons to 110,000 tons per year. Additionally, the GEA Spray Dryer will enable the recovery of up to 35,000 tons of sodium lignosulfonate (SLS) powder, a by-product. This SLS powder finds application as a concrete additive and is primarily intended for export.
The decision to choose GEA as the technology supplier was influenced by their impressive track record of successfully running reference plants, their stellar reputation in the industry, and their exceptional technical support. The customer was also swayed by GEA’s commitment to reducing the CO2 footprint. GEA collaborates with local producers and suppliers on-site, manufacturing locally to minimize transportation-associated CO2 emissions.
A key component of the technology used in the plant is Mechanical Vapor Recompression (MVR), which helps optimize energy consumption in evaporation processes. GEA tailors the system to suit individual customer needs, using mechanical vapor re-compressors (MVR) to recirculate the entire vapor, leading to energy efficiency. The vapor condensate’s energy is often used to preheat incoming product, further enhancing energy savings.
GEA’s decanter centrifuges play a crucial role in black liquor clarification, facilitating efficient separation of solids from liquids, thus maximizing yield in the black liquor plant and improving subsequent process steps. The use of these centrifuges aligns with sustainability objectives and reflects environmental responsibility.
Moreover, GEA employs Zero Liquid Discharge (ZLD) systems to recover marketable by-products and meet environmental regulations. These systems remove dissolved solids from wastewater, returning distilled water to the process. GEA’s ZLD technologies employ a combination of various processes such as ultrafiltration, reverse osmosis, evaporation, crystallization, desalination, separation, and drying to extract valuable salts from waste streams, generating added value. The company’s experience in handling corrosive materials ensures that each plant is designed and constructed with appropriate corrosion-resistant materials. GEA has successfully custom designed and supplied ZLD treatment systems for coal-fired power plants and waste incinerators, contributing to the precipitation of heavy metals and using evaporation with seeding as an anti-scaling measure, among other processes.
