Manufacture of gas

Title: Gas production Includes the production of gaseous fuels to supply energy through the network gas distribution system (e.g. factory gas, coal distillation gas, gasification from lignite, electrolysis or methanization; gaseous fuels with a calorific value determined, by purification, mixing and other processes from gases of various types, including natural gas or hydrogen; biogas for the purpose of gas supply, from sewage sludge, manure, waste, among others; production of gaseous biofuels for energy supply through a gas distribution network. Includes biogas purification for energy supply through a permanent network and regasification of natural gas for distribution via pipelines. Does not include:  Natural gas extraction (06200);  Production of gases from coke ovens (19100);  Production of butane, propane and other gases derived from petroleum refining (19201);  Production of liquefied petroleum gas (LPG) (19201);  Manufacturing of industrial gases (20110);  Manufacture of hydrogen, for purposes other than supplying energy through a power grid distribution by ducts (20110);  Manufacture of organic base gases (2014);  Manufacture of blast furnace gas (24100);