US 11,613,623 B2Granted

Catalytic pyrolysis of polystyrene into aromatic rich liquid product using spherical catalyst

AssigneeIndian Oil Corporation Limited

InventorsBineesh Vijayan Kanattukara, Gurmeet Singh, Dheer Singh, Gurpreet Singh Kapur, Sankara Sri Venkata Ramakumar

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Abstract

The present invention provides a process of catalytic depolymerization of polystyrene involving a spherical catalyst, an apparatus for carrying out the depolymerization, recovering the aromatic rich liquid product and recycling the catalyst without any decrease in the catalytic performance. Further, the present invention provides that the aromatic rich liquid product includes styrene, xylene, benzene, ethyl benzene, with styrene content greater than 65%. Additionally, the catalyst involved in the depolymerization process is a spherical catalyst that is easily recovered from coke/char formed during the process and is recycled and reused without any decrease in the catalytic performance.

Claims15

Dependent claims

A process of catalytic depolymerization of polystyrene, the process comprising:

(a) adding a polystyrene feed and a catalyst into a reactor, wherein the catalyst and the feed are added together, or the feed is added first followed by the catalyst, or the feed is added into the reactor containing the catalyst;
wherein the catalyst is a spherical catalyst;
(b) mixing the feed with the catalyst in the reactor to obtain a mixture and heating the mixture at a rate ranging from 3 to 20° C./min in an inert atmosphere for generating a vapor;
(c) passing the vapor from the reactor to a condenser to obtain a condensate, wherein a heating tape is connected to a temperature controller to prevent condensation of the vapor before entering the condenser;
and
(d) routing the condensate from the condenser to a liquid product collection flask to collect a liquid product, and passing non-condensable gases from the condenser through a scrubber;
wherein the liquid product is present in an amount ranging from 85% to 90% by weight of a total weight of a solid, a liquid and a gas exiting the reactor, and wherein the liquid product comprises styrene in an amount ranging from 65% to 71% by weight of the liquid product.

4 more elements

An apparatus for depolymerization of polystyrene, the apparatus comprising:

(a) a stainless steel cylindrical or tubular reactor equipped with a mass flow meter to control the flow of an inert gas, wherein the stainless steel cylindrical or tubular reactor is configured to polystyrene feed and a spherical catalyst;
(b) a split type single zone electrical furnace with a programmable digital temperature controller for heating the reactor using an electrical or a thermal fluid system, wherein the reactor is heated at a rate ranging from 3 to 20° C./min;
(c) a K-type thermocouple connected to the programmable digital temperature controller to measure a temperature of the reactor;
(d) an opening provided at a top of the reactor for routing vapors generated in the reactor during depolymerization of the polystyrene feed into a condenser;
(e) a heating tape connected to the programmable digital temperature controller to prevent condensation of the vapors before entering the condenser;
(f) a chiller connected to the condenser for maintaining a temperature of the condenser;
(g) a liquid product collection flask for collecting a condensate from the condenser, wherein the condensate is a liquid product and is present in an amount ranging from 85% to 90% by weight of a total weight of a solid, a liquid and a gas exiting the reactor, and wherein the liquid product comprises styrene in an amount ranging from 65% to 71% by weight of the liquid product;
and
(h) a scrubber for passing un-condensable gases from the condenser.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/481,050Filed 21 Sep 2021
Priority: IN 20202104081921 Sep 2020
Published: US 2022/0089831 A124 Mar 2022
Granted: 28 Mar 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification44 codes

C08J 11/16
By chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation: by treatment with inorganic material
C10B 53/07
Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form: of solid raw materials…
B01J 8/0221
The fluid flow within the bed being predominantly horizontal: in a cylindrical shaped bed
B01J 8/0403
The fluid passing successively through two or more beds: the fluid flow within the beds being predominantly horizontal