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Sweet sorghum juice extraction, sterilisation and concentration

Objective

To built and test a complete innovative pilot scale unit for the treatment of Sweet Sorghum fresh matter for ethanol production. Then to participate at an EC network, dealing in the matter, aimed at optimising the complete cycle from Sweet Sorghum's seed selection to final anhydrous ethanol.
An innovative method has been developed for high speed juice extraction of sweet sorghum. The chopped stalks of sorghum are treated in mill then homogenised in a special olive paste equipment (glamoratrice). The homogenised sweet sorghum paste is then centrifuged by a special centrifugal decanter machine fed by a volumetric pump. The decanter extracts the juice and separates the bagasse.

Several trials were carried out with a pilot unit also utilising frozen sweet sorghum. The unit power is 40 kW. The decanter speed is 3.5 revolutions per minute. The delivery of the unit is about 100 tons per hour of sweet sorghum chops. The juice can be fermented and distilled to ethanol. The bagasse, after solar passive drying, can be used in various ways such as energy; paper pulp; animal fodder; and compost. All the units were built in real scale.
The production and processing of sweet sorghum can be an interesting way to obtain ethanol. Sweet Sorghum is a crop recently introduced in the European agriculture. Its characteristics are fast growth (about 110 days in Mediterranean climate), the large yield (100 tons of dry material per hectare), the high content of sugar (about 10%), the suitability in several pedo-climatic conditions, the favourable environmental impact. The process for its production and ethanol conversion includes several steps.

The Rapanelli Fioravante firm is a world leader in the field of the olive oil machinery, that have been built over several years with many advanced units. The Rapanelli's project is related at the realisation of an innovative for the treatment of the Sweet Sorghum raw matter extracting the sugar juice. Until now the juice extraction methods were based on the extraction by pressure or by dilution (or both). The Rapanelli Firm studied the possibility to realise the extraction by horizontal centrifuges utilising the technology of the olive oil. The forecast unit includes several apparatuses to built specifically for the application. The process includes:

- milling of Sweet Sorghum chops by a special hammer mill;
- homogenisation and heating of the obtained paste;
- Centrifugal extraction of sugar juice;
- separation of dry bagasse;
- pre-treatment of the juice.

The horizontal centrifuge (40 kW of power, 3.500 revs/min.) is the heart of the unit. It is an innovative project of the Rapanelli Firm, specially designed and built for this application. It includes several new apparatus covered by patents.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Rapanelli Fioravante SpA
Address
Via Umbria 14
06034 Foligno Perugia
Italy