1-01-2009

Well, this is not exactly a spiritual subject. Not even a fully correct title, in strict terms: the spirit is all recovered, in fact, and the power comes from what’s left after the spirit has left the  body…

Oh boy, too many drinks? What are we talking about? We are talking about a very interesting story: how to get Tartaric Acid and its salts, pure Alcohol, electric power and steam by getting rid of a mountain of residues and by-products of the wine industry. The nice story is told every day by Villapana SpA, a Company of the Giovanni Randi SpA Group – leading Italian manufacturers of Tartaric Acid and Ethyl Alcohol based in Faenza, Italy.

If you do manufacture “natural” foodstuff – wine, bread, pastries, baked products - you need to use only “natural” additives, otherwise you commit a fraud. The Randi Group supplies these “natural” products, 100% coming from grapes or wine residues, since 1969. Bono Sistemi evaluated the chemical-physical properties of the raw materials and the needs of the Villapana plant, conceived an appropriate recovery solution and submitted their thoughts for a preliminary evaluation. The proposed solution was accepted, after a constructive discussion and the relevant modifications to the project, and the contract was signed. The plant was built in less than 14 months, and is now in full operations in Faenza, the Italian town well known not only for their ceramic tiles and vases (the “Faiences”) but also because it’s Italy’s most

important district for the distillation of fruits and agricultural residuals.

What’s the matter, then? The matter of the fact is that the wet residuals of the extraction of Tartaric salts and alcohol are fed at a rate of 5 tons/hour to a customised biomass-fired

steam generator. Here they fall on a large moving grate where – using very hot combustion air – theyare fully burnt to ashes. Only in the start-up phase of each cycle the burner uses locally-produced natural bio-gas, deriving from fermentation processes run in another part of the plant, to warm up the combustion chamber: when the optimum temperature has been reached the combustion continues spontaneously using the grape’s residuals as the only fuel. The combustion generates hot fumes, which are sent through a large heat recovery boiler: here, flowing through a forest of steel pipes where pure water is recirculated, they release their heat which vaporises the water and produces steam. Lots of steam, that is sent at high pressure to a large turbine, where it produces 1.3 MW of power. Then the same saturated steam, which still has a lot of energy to give away, is sent through a well-insulated pipeline to the nearby alcohol distillery, where it is used to extract natural Ethyl Alcohol from a bland hydro-alcoholic solution coming from the marc’s washing line. The deriving alcohol, 96.5 % proof, is the basic

component of liqueurs, spirit preserves, disinfectants etc.

In figures: 36,000 tons a year of residues generate 1.3 MWe of power (used in the plant and sold to the national power grid) and 7 MWth under the form of saturated steam (used in the distillery). This means an average 70.5% of global efficiency, out of wet grape’s marcs and wine’s lees. If this looks simple, have a look at the plant’s scheme and at the pictures of this article: the supplied “complex” is 17 meter high, 17 by 29 meter wide, weighs approximately 400 tons and is fully built in anti-seismic execution. A massive furnace, nesting a burning grate exclusively designed by Bono Sistemi for this natural fuel, is covered and hidden by the ancillary equipment required to let the plant go: the heat recovery boiler, a sophisticated de-aerator for the boiler’s feed water, a large pre-heater for the combustion air, a very large flue gases treatment system to capture and separate all the solid particles contained in the  combustion flue gases. Need more satisfaction? We don’t. The statement speaks for itself.

Thank you, the “Randi family”, it was a pleasure helping you to achieve this environmentally-friendly example of clean energy production from a widely available renewable source. We hope we can repeat the same exercise in the other plants you have around the world!

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