Integrated process for the production of biofuels from solid urban waste

Abstract

Integrated process for the production of biofuels from solid urban waste which comprises: subjecting said waste to liquefaction obtaining a mixture comprising an oily phase consisting of bio-oil, a solid phase and an aqueous phase; subjecting the mixture obtained from said liquefaction to separation obtaining an oily phase consisting of bio-oil, a solid phase and an aqueous phase; subjecting the oily phase consisting of bio-oil, obtained from said separation to hydroconversion in slurry phase, in the presence of at least one nanodispersed hydrogenation catalyst; wherein said liquefaction is carried out at a temperature ranging from 150° C. to 350° C., preferably ranging from 200° C. to 320° C., at a pressure ranging from 5 bar to 170 bar, preferably ranging from 15 to 115 bar and for a time ranging from 5 minutes to 240 minutes, preferably ranging from 15 to 90 minutes. The biofuels thus obtained can be used as such, or in a mixture with other fuels, for automotive.

1 . An integrated process for the production of biofuels from solid urban waste which comprises:
 subjecting said waste to liquefaction obtaining a mixture comprising an oily phase consisting of bio-oil, a solid phase and an aqueous phase;   subjecting the mixture obtained from said liquefaction to separation obtaining an oily phase consisting of bio-oil, a solid phase and an aqueous phase; and   subjecting the oily phase consisting of bio-oil obtained from said separation to hydroconversion in slurry phase, in the presence of at least one nanodispersed hydrogenation catalyst;   wherein said liquefaction is carried out at a temperature ranging from 150° C. to 350° C., at a pressure ranging from 5 bar to 170 bar, and for a time ranging from 5 minutes to 240 minutes.   
     
     
         2 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said solid urban waste is selected from:
 the organic fraction of solid urban waste deriving from selected collection;   prunings deriving from the maintenance of public parks;   agribusiness waste products and waste products of large retailers;   primary and/or biological sludges produced by urban water treatment plants;   or mixtures thereof.   
     
     
         3 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said solid urban waste is treated by subjecting it to a preliminary grinding or sizing process before being subjected to said liquefaction. 
     
     
         4 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said solid urban waste is wet. 
     
     
         5 . The integrated process for the production of biofuels from solid urban waste according to  claim 4 , wherein said solid urban waste has a water content higher than or equal to 50% by weight with respect to the total weight of said solid urban waste. 
     
     
         6 . The integrated process for the production of biofuels from solid urban waste according to  claim 5 , wherein said solid urban waste has a water content ranging from 55% by weight to 80% by weight with respect to the total weight of said solid urban waste. 
     
     
         7 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said oily phase consisting of bio-oil is subjected to hydroconversion together with heavy oils of a fossil origin such as heavy crude oils, bitumens deriving from tar sands, distillation residues, heavy residues deriving from thermal treatment processes, oils deriving from coal, oil shales. 
     
     
         8 . The integrated process for the production of biofuels from solid urban waste according to  claim 7 , wherein said oily phase consisting of bio-oil and said heavy oils of a fossil origin are used in a weight ratio ranging from 0.01 to 50. 
     
     
         9 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said hydroconversion is carried out in the presence of a stream of hydrogen or of a stream consisting of a mixture of hydrogen/hydrogen sulfide (H 2 S). 
     
     
         10 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said nanodispersed hydrogenation catalyst is selected from sulfides of transition metals, or an oil-soluble precursor of the same. 
     
     
         11 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said hydrogenation catalyst is used in such a quantity that the concentration of transition metal present in the oily phase consisting of bio-oil, or in the oily phase consisting of bio-oil together with heavy oils of a fossil origin, ranges from 50 wppm to 50000 wppm. 
     
     
         12 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said hydroconversion is carried out at a temperature ranging from 350° C. to 480° C. 
     
     
         13 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said hydroconversion is carried out at a pressure ranging from 100 bar to 200 bar. 
     
     
         14 . The integrated process for the production of biofuels from solid urban waste according to  claim 1 , wherein said hydroconversion is carried out with an average residence time ranging from 2 hours to 8 hours.