Description
The Thermoselect process for the thermal treatment of waste was invented in the end of the 1980s. During the process organic waste is transformed into synthetic gas, and inorganic waste is transformed into mineral substances and metals. Following detailed research of the carbonisation and gasification of waste, a large pilot plant with a capacity of 30,000 t of waste per annum was built in Fondotoce near Verbania. In March 1992, the plant commenced its operations for further testing and optimisation of the process on an industrial scale. In 1999, the pilot plant in Fondotoce was closed after a new Thermoselect plant had been built in Karlsruhe. This plant is a subsidiary of Energie Baden-Württemberg (EnBW).
The first Thermoselect plant was built at the edge of a remote industrial park on an 18,000 m² site at the exit of the Toce valley. A simple factory hall houses all technical facilities. In order to display the waste disposal process, Mario Botta designed a lightweight modular trussed structure that can be extended; all of its members are load- bearing. The neutral building skin does not reveal the function of the building.
The plant is subdivided into a front building containing administrative spaces and an attached, well-lit hall. All kinds of waste are delivered by trucks at the rear of the building. The waste gets compressed, passes through a degasification channel, and enters a high-temperature reactor where organic components are gasified at a temperature of 2,000°C and inert elements are melted down. The only visible derivatives are black mineral granules and metal pellets, which can be disposed of in small trolleys. Synthetic gases that also arise can be used for the generation of heat and power after cleaning.
The waste combustion plant is a large hall with poignant arched roof girders and stepped attached wings on both sides. The pitched arched girders highlight the symmetry of the threebay building. The entire steel structure is joined precisely and the complex drainage system of the numerous roof areas shows accurate detailing. As a hint to historic industrial architecture, the roof at ridge level is a linear alignment of close-spaced gables. The pitched roof area above the machine plant is fully glazed.
The interior of the plant is reached through sliding wall elements. Inside, the roof structure is no longer visible to the visitor; only the centre span is supported by slim steel columns. Consequently, sufficient space in the middle of the hall was available to assemble the machines and systems for the waste treatment. The central disposal track subdivides the plan of the hall into three bays. It takes up little space and receives light from the generously glazed pitched roofs. The plant becomes a stage set for the visitors who can watch the different steps of the Thermoselect process through small openings and on video screens.
The plant in Fondotoce and Botta’s architecture were conceived as a prototype for further plants. The building structure can be extended by further parallel disposal tracks. The width of the middle bay can vary depending on the site and the size of the plant. In Chiba, Japan, a new plant has already been built where the Thermoselect process is being conducted within the technological envelope of Mario Botta’s outstanding architecture.
Drawings
Ground floor with surroundings
Floor plan diagram
Gable end elevation
Design sketches
Photos
General view of the Thermoselect pilot plant in its setting at the Lago Maggiore
Modular, extendable building structure with pitched arched roof girders
Originally published in: Jürgen Adam, Katharina Hausmann, Frank Jüttner, Industrial Buildings: A Design Manual, Birkhäuser, 2004.