A process for producing syngas starting from pretreated recovery plastic polymers

A process for producing syngas from pre-treated recovery plastic polymers comprising: a) gasifying said recovery pre-treated polymers according to the following reaction scheme R1: R1 : [-CH2-] + H20 = CO + 2H2 b) hydrogenating said pre-treated polymers to higher hydrocarbons and methane by using hydrogen produced in Rl, according to the following reaction scheme R3 R3: [-CH2-] n + H2 = Cn H(2n+2); wherein n is an integer of from 1 to 3, said reaction being optionally combined with oligomers and olefin formation reactions; c) steam reforming of methane according to the following reaction scheme: R4: CH4 + H20 = CO + 3H2 and optionally d) reforming reaction of methane according to the following reaction scheme R5: R5: CH4 + C02 = 2CO + 2H2 said process being carried out in a plant (10), (20), (30), (40), (50) comprising a gasification section (11), (21), (31), (41), (51) and a reforming section (12), (22), (32), (42), (52) comprising a tube bundle (13), (23), (33), (43), (53) provided with a catalyst wherein, i) said gasification (11), (21), (31) and reforming sections (12), (22), (32) are part of a sole reactive unit (10), (20), (30), or said gasification (41), (51) and reforming section (42), (52) are two physically distinct reactive units (40), (50). ii) the gasification section (11), (21) or the reactive unit (41) provides respectively the energetical support to the reforming section (12), (22) or to the reforming reactive unit (42), thanks to the exothermic combustion reaction scheme R2 R2: [-CH2-] + 1.502 = C02 + H20 or in alternative: the reforming section (32) or the reforming reactive unit (52) provides energetic support to the corresponding gasification section (31) or gasification reactive unit (51), thanks to the exothermic combustion reaction scheme R6: R6: CH4 + 202 = C02 + 2H20,