Abstract: A process for upgrading petroleum residuums by hydrogen diluent donor visbreaking employs coking of a higher boiling fraction of the visbreaker effluent wherein the hydrogen donor is also supplied to the coker feed either by excess feed to the visbreaker or by mixing a portion with the coker feed. Controlling the quantity of hydrogen donor in the visbreaker and coker feed proportionally controls the quantity of coke produced.

Abstract: Nitrogen and methane are separated in a nitrogen-methane cryogenic fractionator operating at a temperature between the boiling points of nitrogen and methane. A distillative aid or absorbent is injected into the nitrogen-methane cryogenic fractionator for enhancing separation, for enabling an increase in operating pressure, and for enabling a high separation rate at relatively high temperature.

Abstract: Disclosed is a method and apparatus for refrigeration utilizing a combined mechanical and absorption cycle. Two immiscible or only partly miscible refrigerants are mixed and evaporated in an evaporator to cool a process stream. The refrigerants are separated in an absorber which absorbs one of the refrigerants from the vapor mixture. The non-absorbed refrigerant vapor is compressed and condensed, while the absorbed refrigerant is desorbed and condensed to produce respective liquid refrigerant streams to the evaporator. Optionally the vapor mixture from the evaporator is compressed in a first stage of compression prior to passing to the absorber.

Abstract: Disclosed is a method and apparatus for separating and purifying carbon dioxide and natural gas contained in the associated gas of an oil well. Feed containing hydrocarbons, carbon dioxide, water and hydrogen sulfide, is fed to a stabilizer column where heavy hydrocarbons and water are removed. Hydrogen sulfide is then stripped from the gas in a carbon dioxide fractionator using a solvent which absorbs H.sub.2 S and increases the relative volatility of carbon dioxide to hydrogen sulfide. Overhead from the CO.sub.2 fractionator contains carbon dioxide and light hydrocarbons, which are then separated in a demethanizer column which produces liquid carbon dioxide as a bottoms product. The invention is particularly useful in recovering carbon dioxide from the associated gas of oil produced from enhanced oil recovery processes using carbon dioxide injection.

Abstract: A process for continuously gasifying wood, wood chips, wood charcoal, or other low-ash biomass material in a mechanically-ashed gasifier using a fixed bed gasification system to obtain a gaseous product relatively rich in carbon monoxide and hydrogen. Product gas comprising carbon monoxide, hydrogen, and carbon dioxide, together with methane and other diluents, is withdrawn from the gasification chamber. Sufficient noncombustible, particulate, refractory material is fed to the gasifier to provide an adequately deep layer of noncombustible solids on a moveable grate which supports the fuel bed, the object being to prevent damage to the grate and the grate-actuating mechanism caused by overheating, when the ash bed becomes too thin. The product gases from the gasification chamber may be used as raw synthesis gas for the production of, for example, methanol or as furnace heating gases.