Process for the conversion of plastics into olefins
AssigneeNextchem S.P.A.
InventorsFrancesco Micheletti, Valerio Coppini
Life of this patent
Estimating the term…
Abstract
Process for the conversion of plastics to olefins comprising the following steps: A) gasification of the plastics to synthesis gas by reaction of the plastics with pure oxygen; B) catalytic conversion of the synthesis gas produced in stage A) to methane in at least three successive stages, in each of which hydrogen is added; C) catalytic conversion of the methane produced in stage B) into olefins by the oxidative coupling reaction of methane; and D) separation of the olefins produced in stage C) from other compounds present in the reaction mixture of said stage C).
Claims20
A process converting plastics to olefins, comprising the steps of:
- a) gasifying said plastics into a synthesis gas by reacting of said plastics with pure oxygen, an amount of pure oxygen being used with an amount of oxygen from said plastics to form a combination with an amount of total oxygen ranging from 40% to 65% molar with respect to an amount of stoichiometric oxygen required for converting carbon contained in said plastics to carbon dioxide (CO2);
- b) catalytically converting said synthesis gas into methane in at least three successive stages, wherein hydrogen is added to said synthesis gas in at least first two stages of said at least three successive stages, said hydrogen having a degree of purity greater than 95%;
- c) catalytically converting said methane into olefins by oxidatively coupling said methane;
- and
- d) separating said olefins from other compounds occurring from oxidatively coupling said methane.
A process for converting plastics to olefins, comprising the steps of:
- a) selecting said plastics, said plastics comprising:
- a carbon content greater than 45% by weight;
- a hydrogen content greater than 5% by weight;
- and
- an oxygen content less than 20% by weight;
- b) gasifying said plastics into a synthesis gas by:
- reacting said plastics with pure oxygen, an amount of said pure oxygen being used with an amount of oxygen from said plastics to form a combination with an amount of total oxygen ranging from 40% to 65% molar with respect to an amount of stoichiometric oxygen required for converting carbon contained in said plastics to carbon dioxide (CO2);
- and
- introducing carbon dioxide to said plastics and reducing a quantity of air in said plastics;
- c) catalytically converting said synthesis gas into methane in at least three successive stages, wherein hydrogen is added to said synthesis gas in at least first two stages of said at least three successive stages, said hydrogen having a degree of purity greater than 95%;
- d) catalytically converting said methane into said olefins by oxidatively coupling said methane;
- and
- e) separating said olefins from other compounds occurring from oxidatively coupling said methane.
A process for converting plastics to olefins, comprising the steps of:
- a) selecting said plastics, and shredding and reducing said plastics into plastic flakes, said plastics comprising:
- a carbon content greater than 45% by weight;
- a hydrogen content greater than 5% by weight;
- an oxygen content less than 20% by weight;
- a nitrogen content, a halogen content, and a sulfur content less than 3% by weight;
- an inert content less than 20% by weight;
- and
- a moisture content less than 10% by weight;
- b) gasifying said plastics into a synthesis gas by:
- reacting said plastics with pure oxygen, an amount of said pure oxygen being used with an amount of oxygen from said plastics to form a combination with an amount of total oxygen ranging from 40% to 65% molar with respect to an amount of stoichiometric oxygen required for converting carbon contained in said plastics to carbon dioxide (CO2);
- and
- introducing carbon dioxide to said plastics and reducing a quantity of air in said plastics;
- c) catalytically converting said synthesis gas into methane in four successive stages, wherein hydrogen is added to said synthesis gas in at least first three stages of said four successive stages, said hydrogen having a degree of purity of greater than 95%;
- d) catalytically converting said methane into said olefins by oxidatively coupling said methane;
- and
- e) separating said olefins from other compounds occurring from oxidatively coupling said methane.
Dependencies are inferred from the claim text.