A system for on-site solid to liquid phase transformation and in-line delivery of a chemical into oilfield fluid streams comprising: i) a receptacle, the receptacle including: a) an inlet; b) an outlet; and c) a wall extending between the inlet and outlet and defining an open interior volume, the open interior volume being in fluid communication with the inlet and outlet and comprising a first volume and a second volume, wherein the second volume is between the outlet and the first volume; ii) a heating component adapted to emit heat, positioned adjacent to the outlet and separated from a majority volume of the open interior volume and a majority portion of the wall, wherein the majority volume and majority portion extend away from the heating component, such that only a portion of the majority volume and a portion of the majority portion are oriented toward the heating component; iii) an outlet conduit connected to the outlet at a first end and being adapted for operable connection to an injection port of the oilfield fluid stream at a second end; iv) a pressure component, the pressure component operably connected to the receptacle and adapted to apply pressure on at least a portion of the chemical in the open interior volume; and v) a valve adapted for enabling discharge of liquid phase chemical into the oilfield fluid stream in predetermined doses, wherein, in operation with solid chemical loaded in the open interior volume, actuation of the heating component heats the second volume to a temperature above the melting point of the solid chemical, thereby transforming solid chemical positioned in the second volume into liquid phase without substantive phase transformation of solid chemical positioned in the first volume, the pressure component applies pressure on at least a portion of chemical in the receptacle and liquid phase chemical flows from the receptacle, through the outlet conduit and the injection port, and into the oilfield fluid stream, allowing solid chemical in the first volume to move toward the second volume, and wherein, at a point in time during discharging, the portion of the liquid phase chemical represents less than 90% of total chemical in the receptacle. i) a receptacle, the receptacle including: a) an inlet; b) an outlet; and c) a wall extending between the inlet and outlet and defining an open interior volume, the open interior volume being in fluid communication with the inlet and outlet and comprising a first volume and a second volume, wherein the second volume is between the outlet and the first volume; a) an inlet; b) an outlet; and c) a wall extending between the inlet and outlet and defining an open interior volume, the open interior volume being in fluid communication with the inlet and outlet and comprising a first volume and a second volume, wherein the second volume is between the outlet and the first volume; ii) a heating component adapted to emit heat, positioned adjacent to the outlet and separated from a majority volume of the open interior volume and a majority portion of the wall, wherein the majority volume and majority portion extend away from the heating component, such that only a portion of the majority volume and a portion of the majority portion are oriented toward the heating component; iii) an outlet conduit connected to the outlet at a first end and being adapted for operable connection to an injection port of the oilfield fluid stream at a second end; iv) a pressure component, the pressure component operably connected to the receptacle and adapted to apply pressure on at least a portion of the chemical in the open interior volume; and v) a valve adapted for enabling discharge of liquid phase chemical into the oilfield fluid stream in predetermined doses, wherein, in operation with solid chemical loaded in the open interior volume, actuation of the heating component heats the second volume to a temperature above the melting point of the solid chemical, thereby transforming solid chemical positioned in the second volume into liquid phase without substantive phase transformation of solid chemical positioned in the first volume, the pressure component applies pressure on at least a portion of chemical in the receptacle and liquid phase chemical flows from the receptacle, through the outlet conduit and the injection port, and into the oilfield fluid stream, allowing solid chemical in the first volume to move toward the second volume, and wherein, at a point in time during discharging, the portion of the liquid phase chemical represents less than 90% of total chemical in the receptacle.