Abstract: To improve environmental protection from hydrocarbon emissions particularly from vehicles a heater for fluids comprising heating elements of an electrically conductive monolith, wherein the heater comprises a passageway for the fluid to be heated with a defined flow direction of the fluid during heating operation, the heater comprising at least two heating elements arranged side by side inside the passageway, so that they are arranged in parallel with respect to the fluid flow, is proposed improved in that one of the at least two heating elements is a controlled heating element, which has a slightly larger heating power, and a temperature sensor is provided at or close to the downstream end of the controlled heating element, and wherein the temperature sensor is connected to a control means for temperature control during heating operation of the heater; and a method of operating such

Abstract: A fuel vapor storage and recovery apparatus includes a fuel vapor storage canister, said fuel vapor storage canister comprising at least first and second vapor storage compartments filled with an absorbent material, for instance filled with activated carbon, at least a vapor inlet port, an atmospheric vent port and a purge port. Said fuel vapor storage canister defines an air flow path between said vapor inlet port and said atmospheric vent port during shut-off of the internal combustion engine of the vehicle. During purging cycles there is defined an air flow path between said atmospheric vent port and said purge port wherein said first and second vapor storage compartments are arranged in concentric relationship and wherein said first and second vapor storage compartments in flow direction are separated from each other by an air gap diffusion barrier.