There are known methods and plants for obtaining alcohols, such as ethanol, from the fermentation and distillation of green corn.

The main drawback of the known methods and plants consists in that they produce, as alcohol by-product, big amount of a liquid containing, in solution and/or in suspension, at least vegetable fibers, proteins, oils and yeasts, whose extraction would require a lot of energy and further complex and uneconomic processing phases ; therefore such liquid is intended to disposal, causing cost increases and ecological problems.

Further drawback consists in that such known methods and plants require a constant and conspicuous supply of new water and of energy necessary to the heating the water, provoking an increase of costs and of quantity of polluting products to be disposed or dispersed in the environment.

DISCLOSURE OF THE INVENTION The main object of the present invention is to propose a plant and a method for converting vegetables for separately providing at least alcohol, fibers and an aqueous liquid practically without fiber, proteins and related by-products and, thus, recyclable guaranteeing an efficient utilization of green vegetable, reduction of energetic costs and reduction of residual and polluting by-products.

Other object is to propose a method fit for providing oils, proteins and cellulose obtained from the green vegetable.

BRIEF DESCRIPTION OF THE DRAWINGS The characteristics of the present invention are underlined in the following with particular reference to the attached drawings, in which: - figure 1 shows a schematic view of the plant object of the present invention in which the initial, intermediate and final products are represented by circles; - figures from 2 to 4 show schematic views of respective details of figure 1 plant; - figure 5 shows a partial schematic view of a variant of figure 1 plant.

BEST MODE OF CARRYING OUT THE INVENTION With reference to figures from 1 to 4, numeral 100 indicates the plant for converting vegetables which provides utilizing green vegetable such us corn, soy, sunflower, legumes and cereals not completely ripe, or combinations of portions thereof such as stem, foliage and fruits.

The plant 100 includes container means 1 for the shredded vegetables A to feed grinder means 2 connected to a first separating station 3.

The latter has an outlet for a fraction including at least wet fiber B and an outlet for a liquid fraction P, containing at least sugars and proteins, connected to the inlet of a second separating station 5.

The last station 5 has an outlet for a solution containing starch G and an outlet for a solution containing sugars and proteins C that is connected, through a solution concentrator 36, to a proteins separator 7 provided with separate outlets for proteins L and for sugars I. This last outlet is connected to the inlet of fermentation station 8, which converts fermentable sugars in alcohol that is separated by the distillation station 9 providing, in correspondence of respective outlets, alcohol E and an aqueous liquid F nearly without solid and polluting substances, in suspension or in solution.

The outlet for the fraction including at least fiber B of the first separating station 3 is connected to a third separating station 4 provided with separate outlets for cellulose pulp M and for a proteins and glucose solution N.

The outlet of the separating station 5 for the solution containing starch G is connected to a hydrolysis station 6 fit to convert starch G in sugars I and whose outlet, corresponding to these last, is connected to the inlet of fermentation station 8.

The container means 1 includes a receiving tank 10 for the vegetables A charged with a liquid V and connected in cascade to store means 11 and silo means 12, for feeding the grinder means 2.

The first separating station 3 includes first drainer means 13 a wet solid residual product outlet of which is connected to the inlet of washing means 14, a wet solid residual product outlet of which is connected to the outlet of second drainer means 15, a wet solid residual product outlet of which is connected to the outlet of press means 16, a wet solid residual product outlet of which provides the fraction including at least fiber B at the inlet of third separating station 4.

Each of drainer means 13,15, washing means 14 and press means 16, is provided with a respective outlet for the liquid fraction P, almost without solid residual products, connected to the inlet of the second separating station 5, substantially consisting of a thickener means of two separate outlets type.

The third separating station 4 includes, cascade connected, first mixer means 17, second mixer means 19, heating means 35 of the fraction including fiber B and fiber refiner means 21. The outlet for fiber B of the first separating station 3 flows into first mixer means 17 which have additive proportioner means 18; the second mixer means 19 are provided with soda mixer means 20.

The fiber refiner means 21 has a solid fraction outlet connected to the inlet of revolving screen means 22 whose solid fraction outlet is connected to the inlet of a band press means 23 whose solid fraction outlet provides the cellulose pulp M.

Each fiber refiner means 21, revolving screen means 22 and band press means 23 has respective liquid fraction outlet flowing into an inlet of forced separator means 24, an outlet of which provides the proteins and glucose solution N, the other outlet providing water nearly without impurities and fit for feeding the first mixer means 17.

The hydrolysis station 6 includes a first hydrolysis device 25, whose inlet is connected to the outlet for the solution containing starch G of the second separating station 5, and whose outlet is

connected to the inlet of a second hydrolysis device 26.

Each hydrolysis device, first 25 and second 26, includes a thermoregulated enzymatic room 28, into which respective enzyme delivering means 27 and additive delivering means 29 flow.

Respective store means 62 are positioned upstream and downstream the enzymatic room 59 of each hydrolysis device, first 25 and second 26.

Hydration and store means 31 are positioned upstream the first hydrolysis device 25 for charging the solution containing starch G with liquid V.

The plant 100 includes heat exchanger means 32 inserted in the inlet and outlet connections of the first hydrolysis device 25 and fit for thermal regeneration.

It is also provided that the hydrolysis devices 25,26 can be integrated in a single hydrolysis station.

The outlet for the proteins L of proteins separator 7 is cascade colmected to drier means 43 and rotary feeder means 44 to provide proteins L in dehydrated form.

The plant 100 is provided with connections including pipes, valve means and store means for the interconnections and with liquid delivering means V for means and devices requiring liquid supply.

The liquid delivering means V consist of connections to the waterworks and/or connections to the outlet of the aqueous liquid F of the distillation station 9.

A possible operation of plant 100 corresponds to the method object of the present invention providing: - to grind the vegetables A; - to separate said vegetables in a fraction including at least fiber B and a liquid fraction P containing at least sugars, proteins and starches by at least one among draining, washing and filter-pressing; - to separate liquid fraction P in a solution containing sugars and proteins C and a solution containing starch G by thickening;

- to separate proteins L and sugars I of the solution containing sugars and proteins C; - to convert the starch G in sugars I by at least an enzymatic hydrolysis; - to ferment sugars I by means of yeasts - to distill fermented sugars I separately obtaining alcohol E and an aqueous liquid F practically without solid and polluting products, in suspension or in solution.

Moreover the method provides: - to mix the fraction including at least fiber B with additive and soda; - to heat the fraction including at least fiber B; - to refine, to screen and to press the fraction including at least fiber B in order to separate the last in liquor R and rough cellulose pulp M; - to subject the liquor R to separation obtaining a protein and glucose solution N and water practically without impurities fit at least for mixing the fraction including fiber B with additive and soda.

The method also provides: - to add a liquid V at least in correspondence of one among grinding, separations, conversion and fermentation; - to take the liquid V from the waterworks and/or from the outlet of the aqueous liquid F, obtained from distillation of sugars I.

In the variant of figure 5, the container means 1 include shredder means 30 for vegetable A not shredded and flowing into the receiving tank 10.

Particularly for vegetable A consisting of panicles having husks, grains and cob and similar, the container means 1 also include husk separator means 31, having an outlet for the husks T which flows into the shredder means 30 and of an outlet for the grains and the cob of the vegetables A without husks, cascade connected to treatment means 32, including a fine grinding means and a liquid mixer V, and to separating means 33.

The separating means 33 are provided with an outlet for a fraction including fiber B connected to a drier 34 and provided with an outlet for the liquid fraction P, practically without solid residual products, connected to the inlet of the second separating station 5.

The separating means 33 include a set of press means 16 and washing means 14, each one

provided with an outlet for the liquid fraction P practically without solid residual products and an outlet for the wet solid residual product. These last outlets are cascade connected to the inlets of said means 14,16 in order to provide, in correspondence of the downstream outlet of the others, the fraction including at least fiber B. The outlets for the liquid fraction P convey the latter into the second separating station 5.

The main advantage of the present invention is to provide a plant and a method for converting vegetables fit for separately providing at least alcohol, fibers and an aqueous liquid practically without fiber, proteins and related by-products, and thus recyclable, so guaranteeing efficient utilization of the vegetable or vegetable parts, reduction of energetic costs and reduction of residual and polluting by-products.

Other advantage is to provide a method fit for providing oils, proteins and cellulose obtained from the vegetable.