Feedback control for reducing flaring process smoke and noise

A system for reducing emissions at a processing plant, comprising:

• a plurality of sensors for sensing flare-related parameters including a sensor for sensing at least one of a smoke count and a flare count and a sensor for sensing a noise level emitted from a flare stack during operation of a flaring process at said processing plant;
• a model predictive control (MPC) model for controlling said flaring process including an assist gas comprising a plurality of identified one-to-one models between controlled variables (CVs) including (i) at least one of said smoke count and said flare count (CV1) and (ii) said noise level (CV2), and a flow of said assist gas as a manipulated variable (MV) and at least one other process gas flow as a disturbance variable (DV);
• a control system including a processor receiving said flare-related parameters from said plurality of sensors during operation of said flaring process including a measure of said CV1 (CV1*) and said CV2 (CV2*), said processor implementing said MPC model;
• wherein provided said CV1* is above a predetermined minimum setpoint for said CV1 (CV1 setpoint) and said CV2* is above a predetermined setpoint for said CV2 (CV2 setpoint), automatically controlling said flaring process using said MPC model implemented by said processor which automatically determines an updated flow setpoint for said MV based on (i) said CV1* and said CV2*, (ii) a difference between said CV1 setpoint and said CV1* and a difference between said CV2 setpoint and said CV2*, and (iii) said identified one-to-one models, and
• a process controller coupled to receive said updated flow setpoint for said MV from said control system which is coupled to an actuator that controls a valve position to provide said updated flow setpoint for said MV that implements said updated flow setpoint for said MV.

A computer program product, comprising:

• a non-transitory data storage medium that includes program instructions executable by a processor to enable said processor to execute a method of reducing emissions at a processing plant, said program instructions including:
• code for said processor implementing a model predictive control (MPC) model for a flaring process run at said processing plant including an assist gas comprising a plurality of identified one-to-one models between controlled variables (CVs) including (i) at least one of a smoke count and a flare count (CV1) and (ii) a noise level (CV2), and a flow of said assist gas as a manipulated variable (MV) and at least one other process gas flow as a disturbance variable (DV);
• wherein said processor receives sensed flare-related parameters during operation of said flaring process including a measure of said CV1 (CV1*) and said CV2 (CV2*), and
• code for checking that said CV1* is above a predetermined minimum setpoint for said CV1 (CV1 setpoint) and said CV2* is above a predetermined setpoint for said CV2 (CV2 setpoint), and
• code for automatically controlling said flaring process using said MPC model provided said CV1* is above said CV1 setpoint and said CV2* is above said CV2 setpoint based on i) said CV1* and said CV2*, (ii) a difference between said CV1 setpoint and said CV1* and a difference between said CV2 setpoint and said CV2*, and (iii) said identified one-to-one models.