Abstract

The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated. The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated. The solid/liquid suspension is subsequently separated into a solid component comprising the bleaching earths and a liquid component comprising the digestate. The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated. The solid/liquid suspension is subsequently separated into a solid component comprising the bleaching earths and a liquid component comprising the digestate. The bleaching earths are then subjected to heat treatment, at a temperature between 400° C. and 600° C. The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated. The solid/liquid suspension is subsequently separated into a solid component comprising the bleaching earths and a liquid component comprising the digestate. The bleaching earths are then subjected to heat treatment, at a temperature between 400° C. and 600° C. Then follows a reactivation of the heat-treated bleaching earths with the aid of an acid solution and drying of the regenerated earths to render them usable in a plant for the production of biofuels.

IPC Classes  ?

• B01J 20/34 - Regenerating or reactivating
• B01D 53/14 - Separation of gases or vapoursRecovering vapours of volatile solvents from gasesChemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases or aerosols by absorption
• B01D 53/86 - Catalytic processes
• B09B 3/40 - Destroying solid waste or transforming solid waste into something useful or harmless involving thermal treatment, e.g. evaporation
• B09B 3/65 - Anaerobic treatment
• B09B 3/70 - Chemical treatment, e.g. pH adjustment or oxidation

Abstract

The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels. The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality. Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated. The solid/liquid suspension is subsequently separated into a solid component comprising the bleaching earths and a liquid component comprising the digestate. The bleaching earths are then subjected to heat treatment, at a temperature between 400°C and 600°C. Then follows a reactivation of the heat-treated bleaching earths with the aid of an acid solution and drying of the regenerated earths to render them usable in a plant for the production of biofuels.

IPC Classes  ?

• B09B 3/65 - Anaerobic treatment
• B09B 3/70 - Chemical treatment, e.g. pH adjustment or oxidation