Process for purifying a pyrolysis oil

Abstract

The present invention relates to a process for purifying a pyrolysis oil comprising providing a stream S0 comprising a pyrolysis oil, the pyrolysis oil comprising one or more halogenated organic compounds and one or more organic compounds comprising conjugated double bonds; subjecting the stream S0 to hydrogenation in at least one reaction zone Z1 containing a heterogeneous hydrogenation catalyst, obtaining a stream S1 being depleted, compared to S0, in the one or more organic compounds comprising conjugated double bonds; subjecting the stream S1 to dehalogenation in at least one dehalogenation zone Z2 down-stream of Z1, obtaining a stream S2 being depleted, compared to S1, in the one or more halogenated organic compounds.

1 - 17 . (canceled) 
     
     
         18 . A process for purifying a pyrolysis oil, the process comprising:
 (i) providing a stream S0 comprising a pyrolysis oil, the pyrolysis oil comprising one or more halogenated organic compounds and one or more organic compounds comprising conjugated double bonds;   (ii) subjecting the stream S0 provided in (i) to hydrogenation in at least one reaction zone Z1 containing a heterogeneous hydrogenation catalyst, obtaining a stream S1 being depleted, compared to S0, in the one or more organic compounds comprising conjugated double bonds;   (iii) subjecting the stream S1 obtained from (ii) to dehalogenation in at least one dehalogenation zone Z2 downstream of Z1, obtaining a stream S2 being depleted, compared to S1, in the one or more halogenated organic compounds.   
     
     
         19 . The process of  claim 18 , wherein the pyrolysis oil according to (i) comprises the one or more organic compounds comprising conjugated double bonds in a total amount in the range of from 0.1 to 75 g(l2)/100 g of the pyrolysis oil. 
     
     
         20 . The process of  claim 18 , wherein the one or more organic compounds comprising conjugated double bonds comprise one or more organic compounds according to formula (I)
   R 1 R 2 C 1 ═C 2 R 3 -C 3 R 4 ═X   (I)
   
       wherein ═X is ═O, ═S, ═NR 5 , or ═C 4 R 6 R 7 ; 
       wherein R 1 , R 2 , R 3 , R 4 , R 5  are, independently of each other, H, alkyl having from 1 to 6 carbon atoms, alkenyl having from 1 to 6 carbon atoms, or aryl having from 5 to 10 carbon atoms; 
       wherein R 6  and R 7  are, independently of each other, H, alkyl having from 1 to 6 carbon atoms, alkenyl having from 1 to 6 carbon atoms, or aryl having from 5 to 10 carbon atoms; 
       or wherein either R 4  and R 6  or R 4  and R 7  are linked together, thus forming, together with C 3 =C 4 , an aromatic ring. 
     
     
         21 . The process of  claim 18 , wherein the heterogeneous hydrogenation catalyst according to (ii) comprises an element of the groups 8 to 12 of the periodic table of elements. 
     
     
         22 . The process of  claim 18 , wherein (ii) comprises
 (ii.1) introducing a gas stream G0 into Z1, the gas stream comprising H 2 ;   (ii.2) introducing the stream S0 into Z1;   (ii.3) bringing S0 in contact with G0 and the heterogeneous hydrogenation catalyst comprised in Z1, obtaining a stream S1 being depleted, compared to S0, in the one or more organic compounds comprising conjugated double bonds;   (ii.4) removing S1 from Z1.   
     
     
         23 . The process of  claim 22 , wherein the gas stream G0 has a temperature in the range of 100 to 250° C. 
     
     
         24 . The process of  claim 18 , wherein the stream S1 obtained from (ii) and subjected to dehalogenation in (iii) comprises the one or more organic compounds comprising conjugated double bonds in a total amount in the range of from 0 to 3 g(l2)/100 g of the stream S1. 
     
     
         25 . The process of  claim 18 , wherein the stream S1 subjected to dehalogenation in (iii) has a temperature in the range of from 150 to 450° C. 
     
     
         26 . The process of  claim 18 , wherein (iii) comprises
 (iii.1) introducing a gas stream G1 into Z2;   (iii.2) introducing the stream S1 obtained from (ii) into Z2;   (iii.3) bringing S1 in contact with G1 and a heterogeneous adsorbent material suitable for adsorbing halide comprised in at least one of the one or more halogenated organic compounds comprised in Z2, obtaining a stream S2 being depleted, compared to S1, in the one or more halogenated organic compounds;   (iii.4) removing S2 from Z2.   
     
     
         27 . The process of  claim 26 , wherein the gas stream G1 has a temperature in the range of 250 to 500° C. 
     
     
         28 . The process of  claim 18 , wherein the dehalogenation zone Z2 according to (iii) comprises a catalytic zone. 
     
     
         29 . The process of  claim 18 , wherein the stream S2 obtained from (iii) has a total chlorine content in the range of from 0 to 200 wppm (ppm by weight). 
     
     
         30 . The process of  claim 18 , further comprising
 (iv) subjecting the stream S2 obtained from (iii) to hydroprocessing in at least one reaction zone Z3 downstream of Z2, Z3 comprising a heterogeneous hydroprocessing catalyst;   obtaining a stream S3;   wherein the stream S2 subjected to (iv) has a temperature in the range of from 150 to 400° C.   
     
     
         31 . The process of  claim 30 , wherein (iv) comprises
 (iv.1) introducing a gas stream G2 into Z3, G2 comprising H 2 ;   (iv.2) introducing the stream S2 obtained from (iii) into Z3;   (iv.3) bringing S2 in contact with G2 and a heterogeneous hydroprocessing catalyst comprised in Z3, obtaining a stream S3;   (iv.4) removing S3 obtained in (iv.3) from Z3.   
     
     
         32 . The process of  claim 18 , being a continuous or semi-continuous process. 
     
     
         33 . A production unit for carrying out the process for purifying a pyrolysis oil according to  claim 18 , the unit comprising
 at least one reaction zone Z1, Z1 comprising a heterogeneous hydrogenation catalyst;   an inlet means for introducing S0 into Z1;   an outlet means for removing S1 from Z1;   at least one dehalogenation zone Z2;   an inlet means for introducing S1 into Z2;   an outlet means for removing S2 from Z2;   wherein Z1 is located upstream of Z2.   
     
     
         34 . A purified pyrolysis oil, obtained by the process according to  claim 18 .