Abstract: Carbon quantum dots having selected adsorption of carbon dioxide over nitrogen and oxygen can be prepared by amine modification or nitrogen doping of hydrocarbon-based carbon quantum dots. The carbon quantum dots can be used in various applications for the adsorption of carbon dioxide from the atmosphere and for treating industrial processes that generate carbon dioxide. The carbon quantum dots can be synthesized from lignin and can be paired with a porous activated carbon surface to create a renewable composite material with increased selective adsorption of carbon dioxide.

Abstract: A drive assembly for a progressive cavity pump includes a frame supported by the wel piping and a polish rod connected to the sucker rod. The polish rod is received by a rotary union formed by a sleeve portion rotatable with respect to a body portion with a seal structure that seals the sleeve and body portions during rotation. A mechanical drive, such as a hydraulic motor, electric motor or engine, has an output shaft that is linear with the polish rod and that has an axial passageway which receives the polish rod. A coupler mechanically couples an upper portion of the polish rod to the output shaft. The invention also includes a method of rotating a progressive cavity pump by this assembly.