According to the guidelines of the European Union, Poland has adopted an act preventing the storage of municipal waste with a calorific value of more than 6 MJ/kg, ensuring instead that it must be subject to other types of treatment. To meet this requirement, a new system of municipal waste management called MWTTP – Municipal Waste Thermal Treatment Plant, has been created in the Polish city of Poznan. New Doosan branded machines are part of the operation at the new plant.
This is the first project in Poland implemented under the Public-Private Partnership contract (PPP) formula. The contract was concluded between SITA Zielona Energia, part of Suez Environnement and the City of Poznan. SITA Zielona Energia was formed by SITA Polska and Marguerite Waste Polska, a company belonging to the Marguerite Fund. The tender of SITA Zielona Energia was selected by the City of Poznan following a two-year tendering procedure. The company has designed, financed, built and, in the next 25 years will operate, the municipal waste incineration plant with a capacity of 210 thousand tonnes per year. SITA Zielona Energia selected the Hitachi Zosen Inova consortium, a world leader in the field of energy from municipal waste, and Hochtief, one of the world's largest construction companies, to build the plant. The Doosan equipment, which will support the proper functioning of the system, has been supplied by Grausch & Grausch, the authorized distributor of Doosan construction equipment in Poland. The package included two new Doosan DL350-5 wheel loaders, a Doosan DX210MH-3 material handler, two forklifts and a Bobcat T40140 telescopic handler.
Extensive cooperation is based on the assumption that each party is able to fulfill the tasks entrusted to it more efficiently than the other. In this way the parties complement each other, dealing as part of the partnership with that portion of the common tasks they do best. By dividing the tasks, responsibilities and risks under the PPP formula, the most cost-effective way to build infrastructure and provide public services is achieved. Each party derives benefits from the cooperation in proportion to its involvement in the plant.
Talks on the selection of machines began in December 2014.
“We were looking for a company which could offer equipment with the correct specifications to operate the system on our behalf. We considered a number of leading brands and we analysed every aspect carefully, including the availability of spare parts, the proximity of the supplier, the speed of response and customer references. After checking the tenders, final talks were held with Doosan and another leading manufacturer.
“In the end, Doosan offered more advantages including the price of the equipment and we thought the mode of thinking was closer to the Polish market as well. The warranty period for the loaders covers two full years of use or 4000 operating hours, and for the material handler – 60 months or 3000 operating hours,” said Szymon Cegielski, Contract Manager for the 25-year PPP contract. “I have some personal experience with Grausch & Grausch - I know they always provide high quality products. In addition, we obtained the two forklifts and the Bobcat telescopic loader in the same package. The machines will operate in dusty conditions. The DL350-5 loaders equipped with 5 m3 capacity buckets will be working very hard, moving material between the areas for evaluation, maturing and loading of slag on to trucks. An important issue forming one of the selection criteria was the height of the pin for bucket rotation ensuring that the whole of the bucket is definitely over the sides of the trucks that enter the incinerating plant.
“The DX210MH-3 material handler with a rising cab will be used in the waste unloading building. Once a week, the system will handle bulky waste, e.g. furniture and couches, which will be crushed into smaller elements with a mobile crusher, and then discharged into a bunker. The visibility from the raised cab on the material handler combined with its appropriately designed grab ensures a complete visual inspection of the feed system for the crusher, to help minimize the possibility of potentially dangerous situations. We managed to negotiate a good service package, very short response times and replacement machinery when our equipment is out of operation for an extended period of time for the purposes of repair. G&G also agreed that when we want to upgrade our machines, it will buy them back. I believe we will be very satisfied with these machines and their quality was evident as soon as they started to operate.” he added.
Operators who have already had the opportunity to sit behind the wheel of the Doosan machines have been very satisfied.
“My first impressions are very good. In general, all machines of this type are similar to one other, but the DX210MH-3 has more options than other brands. The camera installed at the rear of the machine is useful. Everything is state-of-the-art and I just need to get used to the different settings on the machine,” reports operator, Krzysztof Rykowski.
Philosophy of MWTTP
The municipal waste incineration plant was built using state-of-the-art and proven grate waste incineration technology.
“The heart of the plant is the grate system with a boiler placed over it. Waste incineration increases the temperature of the water in the pipes installed in the boiler, turning it into steam, which is pumped to the turbine connected to a generator, which converts the steam into electricity, and liquefied residual vapour in the heat exchanger heats water for central heating. Slag is a by-product. 100% of the waste fed into the plant is reduced to what constitutes 30% of residue. 25% out of this 30% can be still recovered. After proper evaluation and maturing, the slag is a high-quality admixture for aggregates used in road construction, while the ferrous and non-ferrous metals contained in it can be transferred for use in steelworks,” said Szymon Cegielski.
The process of thermal treatment in normal conditions is autothermal, which means that it does not require the use of conventional fuel, and generates heat which is turned into electricity and used to power the central heating network. An integral part of the system will be an effective multi-stage exhaust gas cleaning system, guaranteeing a reduction of emissions into the air. In addition, the actual process of thermal treatment of waste will be performed so that it generates the least pollution.
Secondary waste from the process of thermal treatment, such as fly ash from the waste heat boiler, solid waste from waste gas treatment and dust from boilers, will be managed in an environmentally sound manner, in accordance with the waste hierarchy.
Szymon Cegielski added: “The first groundbreaking at the site took place in April 2014. The facility was built within 22 months. The first incineration process took place on 11 April 2016, and the plant will be fully available to the city in November this year. Until then, tests on all devices within the system will be continued, including correlation of all the data from the sensors and logic elements, and there are 6500 of them in the whole facility. Waste management and treatment only have a decades-old tradition, so we need to correlate everything to ensure flawless operation. I’m sure that the machines provided by Grausch & Grausch will meet our expectations.”
The installation will serve 740,000 residents of Poznan and nine municipalities in the Poznan district. The thermal plant will be able to utilize up to 210,000 tonnes of municipal waste per year, working on a 24-hour cycle. The incinerating plant will also produce annually more than 100,000 MW of electricity and more than 300,000 GJ of heat energy recovered from incineration. Waste management in Poznan is truly an example of how municipal functions can be aimed at caring for the environment.