Processes and systems for removing coke particles from a pyrolysis effluent

A hydrocarbon pyrolysis process, comprising:

• introducing a hydrocarbon feed into a pyrolysis furnace comprising a first radiant coil and a second radiant coil, wherein the hydrocarbon feed comprises ethane, propane, naphtha, gas oil, vacuum gas oil, waxy residues, atmospheric residues, residue admixtures, crude oil, or a mixture thereof;
• pyrolysing at least a portion of a first quantity of the hydrocarbon feed in the first radiant coil to produce a first hydrocarbon effluent and to deposit coke on an inner surface of the first radiant coil;
• pyrolysing at least a portion of a second quantity of the hydrocarbon feed in the second radiant coil to produce a second hydrocarbon effluent and to deposit coke on an inner surface of the second radiant coil;
• decreasing a flow rate of the hydrocarbon feed into the first radiant coil while maintaining a flow rate of the hydrocarbon feed into the second radiant coil;
• introducing a decoking feed comprising steam or a mixture of steam and air into the first radiant coil of the pyrolysis furnace to remove at least a portion of the coke deposited on the inner surface of the first radiant coil and to produce a de-coking effluent comprising steam and a plurality of coke particles;
• indirectly exchanging heat from the second hydrocarbon effluent to water, steam, or a mixture thereof to produce a cooled second hydrocarbon effluent;
• indirectly exchanging heat from the de-coking effluent to water, steam, or a mixture thereof to produce a cooled de-coking effluent;
• mixing the cooled second hydrocarbon effluent and the cooled de-coking effluent to produce a combined effluent;
• introducing the combined effluent into an inlet conduit of a separator under conditions that provide ≥80 wt. % of the plurality of coke particles with a Stokes number of ≥10 to about 20,000;
• removing ≥70 wt. % of the plurality of coke particles in the combined effluent from a first exit conduit of the separator, and
• removing a coke-lean hydrocarbon effluent comprising ≤30 wt. % of the plurality of coke particles in the combined effluent from a second exit conduit of the separator, wherein:
• the first exit conduit is coupled to the inlet conduit,
• the second exit conduit is coupled to the inlet conduit,
• a longitudinal axis of the first exit conduit is substantially aligned with a longitudinal axis of the inlet conduit,
• the second exit conduit is angled with respect to the inlet conduit and the first exit conduit to provide an angle of about 45° to about 90° between a longitudinal axis of the second exit conduit and the longitudinal axis of the inlet conduit and an angle of about 90° to about 135° between the longitudinal axis of the second exit conduit and the longitudinal axis of the first exit conduit,
• the plurality of coke particles is introduced into a coke catch apparatus,
• a flow control device couples the first exit conduit to the coke catch apparatus, and
• a total length of the first exit conduit and the flow control device is <8 times an inner diameter of the first exit conduit.

A process for separating particles from a fluid, comprising:

• introducing a mixture comprising a gaseous hydrocarbon and a plurality of particles into an inlet conduit under conditions that provide ≥80 wt. % of the plurality of particles with a Stokes number of ≥10,
• recovering ≥55 wt. % of the plurality of particles in the mixture from a first exit conduit coupled to the inlet conduit, wherein:
• the plurality of particles recovered from the first exit conduit is introduced into a particle receiving apparatus,
• a flow control device couples the first exit conduit to the particle receiving apparatus, and
• a total length of the first exit conduit and the flow control device is ≤8 times an inner diameter of the first exit conduit;
• and
• recovering a particle-lean gaseous hydrocarbon comprising ≤45 wt. % of the plurality of particles present in the mixture from a second exit conduit coupled to the inlet conduit.

A separator for separating particles from a fluid, comprising:

• an inlet conduit configured to receive an effluent comprising hydrocarbons, steam, and a plurality of coke particles, wherein the inlet conduit is further configured to provide ≥80 wt. % of the plurality of coke particles with a Stokes number of ≥10;
• a first exit conduit coupled to the inlet conduit;
• a second exit conduit coupled to the inlet conduit;
• a particle receiving apparatus in fluid communication with the first exit conduit, the particle receiving apparatus configured to receive coke particles;
• and
• a flow control device that couples the first exit conduit to the particle receiving apparatus, wherein:
• a longitudinal axis of the first exit conduit is substantially aligned with a longitudinal axis of the inlet conduit,
• the second exit conduit is angled with respect to the inlet conduit and the first exit conduit to provide an angle of about 20° to about 90° between a longitudinal axis of the second exit conduit and the longitudinal axis of the inlet conduit and an angle of about 90° to about 160° between the longitudinal axis of the second exit conduit and the longitudinal axis of the first exit conduit, and
• a total length of the first exit conduit and the flow control device is <8 times an inner diameter of the first exit conduit.