Abstract: Nitrogen oxides are effectively removed from a gaseous mixture comprising the same and oxygen by adding ammonia thereto and contacting with a suitable catalyst for the nitrogen oxide-ammonia reaction. While the presence of sulfur dioxide is not essential to such removal, best results are achieved when sulfur dioxide is also present in the gaseous mixture. When sulfur dioxide is present, and particularly when the same is present in a concentration in excess of that required for most effective nitrogen oxide conversion, the excess sulfur dioxide may be separated prior to the nitrogen oxide conversion, simultaneously therewith or subsequent thereto.

Abstract: Materials consisting essentially of hydrocarbons with at least two straight chain alkyl groups are useful as wax crystal modifiers in petroleum oils, particularly middle distillate fuel oils such as heating oils and diesel fuels. These materials can be prepared by dimerizing .alpha.-olefins, which dimers can be used per se, or can be further derivatized, e.g. polymerized, alkylated on to an aromatic molecule, etc.