A method of removing impurities from a gas including the steps of removing impurities from biogas comprising at least one adsorbents via a process vessel or reactor, directing the purified gas to an device to generate power and/or heat, regenerating the saturated adsorption media with the waste heat recovered from the engine exhaust and directing the regeneration gas (hot air or engine exhaust) to flare, engine exhaust stack, or atmosphere.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.

A system includes a passive NOx adsorber (PNA) for receiving and treating exhaust gas generated by an engine and a controller. The controller is configured to: while exhaust gas is received by the PNA, detect a torque demand that is greater than a threshold value; responsive to detecting that the torque demand is greater than the threshold value, engage a motor, coupled with a battery system, with a drive shaft of the system to meet at least a portion of the torque demand; and in response to the engagement of the motor with the drive shaft not meeting all of the torque demand, engage the engine with the drive shaft to meet a remainder of the torque demand.

A method of predicting the temperature of a resistive heating element in a heating system is provided. The method includes obtaining resistance characteristics of resistive heating elements and compensating for variations in the resistance characteristics over a temperature regime. The resistance characteristics of the resistive heating element include, but are not limited to, inaccuracies in resistance measurements due to strain-induced resistance variations, variations in resistance due to the rate of cooling, shifts in power output due to exposure to temperature, resistance to temperature relationships, non-monotonic resistance to temperature relationships, system measurement errors, and combinations of resistance characteristics. The method includes interpreting and calibrating resistance characteristics based on a priori measurements and in situ measurements.

An exhaust system is provided that includes at least one exhaust aftertreatment unit provided in an exhaust fluid flow pathway and a thermal storage device disposed upstream from the exhaust aftertreatment unit. The thermal storage device is operable to store thermal mass and provide thermal insulation to enable a catalyst to maintain a minimum predetermined temperature for a minimum predetermined time. In one form, a heater is also provided proximate the thermal storage device, along with variations that include a secondary flow pathway for the thermal storage device.

A susceptor for use in a heated fluid flow system is provided. In one form, a susceptor is arranged within a conduit and adapted to absorb radiant energy from at least one heating element and inhibit the radiant energy from being absorbed by the at least one wall of the conduit and/or other components. In another form, the susceptor absorbs and inhibits the radiant energy from being absorbed by the outer wall of the conduit.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

A fluid control system is provided that in one form includes a first flow channel, a second flow channel, a heater disposed in the second flow channel, and a fluid control device disposed upstream from the first and second flow channels. When the heater is turned on, the fluid control device changes a fluid flow rate through at least one of the first flow channel and the second flow channel. In another form, the fluid control system includes a bypass conduit, a heater disposed within the bypass conduit, and a fluid control device disposed near the inlet and outlet of the bypass conduit. In still another form, the fluid control system includes a regeneration device disposed downstream from at least one exhaust aftertreatment system and closes an outlet of the exhaust pipe.

A control system for use in a fluid flow application is provided. The control system includes a heater having at least one resistive heating element. The heater is adapted to heat the fluid flow. The control system further includes a control device that uses heat loss from at least one resistive heating element to determine flow characteristics of the fluid flow.

A control system for a heating system of an exhaust system is provided. The control system includes at least one electric heater disposed within an exhaust fluid flow pathway, and a control device adapted to receive at least one input selected from the group consisting of mass flow rate of an exhaust fluid flow, mass velocity of an exhaust fluid flow, flow temperature upstream of the at least one electric heater, flow temperature downstream of the at least one electric heater, power input to the at least one electric heater, parameters derived from physical characteristics of the heating system, and combinations thereof. The control device is operable to modulate power to the at least one electric heater based on at least one input.