Pyrolysis gas treatment including caustic scrubber
AssigneeEastman Chemical Company
InventorsDavid Eugene Slivensky, Daryl Bitting, Michael Gary Polasek, Xianchun Wu
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Abstract
Processes and facilities for recovering and purifying a pyrolysis gas formed by pyrolyzing waste plastic are provided. The purification process may comprise one or more treatment processes, including a caustic scrubber process, which may be included in a cracker facility or separate from the cracker facility. The resulting gas effluent stream from the caustic scrubber is particularly useful for recovering recycled chemical products and co-products from a downstream cryogenic separation process.
Claims20
A process for purifying pyrolysis gas (pygas), the process comprising:
- (a) providing a pygas by:
- (i) pyrolyzing a waste plastic to provide a pyrolysis effluent stream;
- (ii) cooling and at least partially condensing at least a portion of the pyrolysis effluent stream;
- and
- (iii) separating the cooled and at least partially condensed pyrolysis effluent stream to thereby provide at least a pygas stream and a pyrolysis oil (pyoil) stream,
- wherein the pygas stream comprises one or more of:
- (i) greater than 1 ppm of hydrochloric acid (HCl);
- (ii) greater than 1 ppm of carbon dioxide (CO2);
- and/or
- (iii) greater than 1 ppm of hydrogen sulfide (H2S);
- and
- (b) feeding a gas stream comprising at least a portion of the pygas and a pyoil stream comprising at least a portion of the pyoil to a cracker facility that comprises a cracker furnace and a caustic scrubber process downstream of the cracker furnace,
- (c) introducing the gas stream into the caustic scrubber process, and
- (d) introducing at least a portion of the pyoil stream as a feedstock to the cracker furnace.
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Dependencies are inferred from the claim text.