INTERGEN: COGENERATION AND EFFICIENCY PLANTS FOR THE TISSUE PAPER INDUSTRY
Cartiera Ponte d’Oro Ansalcarta has chosen the IML Group energy division for the manufacture of a 2 MW cogeneration plant
Lomagna (Lecco) March 2016 – Cartiera Ponte d’Oro Ansalcarta of Villa Basilica (Lucca) has chosen Intergen, the energy division of IML Group founded in 1987, to implement its own energy efficiency and sustainability strategy, through the installation of a 2 MW cogeneration plant.
The Ponte D’oro establishment, situated in the heart of the paper mill district of Lucca, produces rolls of white and coloured tissue paper, starting from a raw material of almost entirely recycled paper, intended for the processing and manufacture of at home and Ho.Re.Ca health and hygiene markets. Cartiera Lucchese is one of the few companies in the country that produces toilet paper and disposable rolls from recycled material, thus effectively reducing its environmental impact. The production of this type of paper, as well as the production systems of paper mills in general, requires a large amount of electric and thermal energy. A condition that finds the best solution for lowering production costs with total respect for the environment and in line with the establishment’s green vision, in Intergen cogeneration.
The rolls are manufactured in the Villa Basilica establishment using a continuous machine, which first forms the sheet, followed by pressing and finally drying. The highest consumption of electricity occurs in the realisation of the furnish and for operation of the continuous machine. Thermal consumption is instead high in the drying phase, which requires large amounts of steam.
Intergen’s driver and strong point is the capacity to recognise the needs of its partners and to study customised solutions, with the aim of guaranteeing maximum energy savings. This philosophy has also been applied to the realisation of the cogeneration unit installed at the Ponte D’Oro establishment at Villa Basilica. It is equipped with an MWM (Motoren Werke Mannheim) TCG 2020V20 gas powered endothermic engine, for which Intergen is exclusive dealer for Italy.
The electricity produced by the plant is entirely self-consumed by the establishment utilities, while the thermal energy produced by the engine is recovered and used to power various production system utilities.
Plant configuration has been studied ad hoc to make the best use of the very high temperatures of the exhaust fumes, typical of the German MWM engines, which guarantee higher efficiency (almost 25%) with respect to engines manufactured by competitors. Specifically, approximately 750 kWt are recovered from the exhaust gases, from which 1200 kg/h of steam is generated at 18 bar; used for the costly paper drying phase. Approx. 1,050 kWt are recovered from the cylinder liners and the oil cooling circuit, which feed a hot water distribution loop with a thermal gradient of 70-86°C. The heat recovery system relative to the use of hot water has also been optimised, developing thermal processes in different points of the establishment.
Continuous plant operation is envisioned for over 8250 hours annually. The cogeneration unit has been designed to recover 100% of the steam and between 75% and 100% of the hot water, with total yields of the unit expected between 74% and 80%.
The optimisation of establishment spaces was finally obtained by installing the cogeneration unit in an outdoor container with linear and compact configuration that guarantees the containment of noise emissions below 55 dB(A) at 10 m. All of the other accessories making up the plant, such as the muffler, catalyst, fumes ducts, chimney and emergency dry radiators, have been positioned on the top of the container, thus guaranteeing smaller clearance of the spaces on the ground.
