Abstract: A process is disclosed in which the overhead vapor stream of a fractionation column is utilized as the working fluid which is depressurized to drive a turbine. The turbine may be used to generate electricity which is then used within the fractionation process or in another process, with a preferred use of the electricity being to supply heat to the bottom of the fractionation zone. The turbine is integrated into the overhead system of the column and the turbine effluent enters the overhead condenser to form liquid which may be used as reflux to the column.

Abstract: Heat is recovered from the flue gas stream discharged from a power plant combustion zone by heat exchange of the flue gas stream against the air stream which enters the combustion zone. Each gas stream flows through two rotating air preheaters, with a first preheater rotating at a constant rate and a second preheater rotating at a variable rate. The rate of rotation of the second preheater is varied to adjust the temperature of either the heated air stream or the temperature of the flue gas stream after passage through the preheaters.

Abstract: A mixture of a hydrocarbon-selective solvent -- e.g. isobutane -- and deasphalted oil is separated in a two-stage hot-separator system at progressively higher temperatures and substantially the same pressure. Resulting vaporous phases are subjected to a cold-flash separation at a lower pressure and a considerably lower temperature. The initial hot separation, in the two-stage system, is effected at a temperature from about 1.0.degree. F. to about 25.degree. F. above the critical temperature of the solvent; the second is conducted at a temperature about 30.degree. F. to about 130.degree. F. above that in the initial hot-separation. This technique is especially advantageous when integrated into a catalytic slurry process for the conversion of metal- and asphaltene-containing hydrocarbonaceous black oils.

Abstract: Anhydrous liquid sulfur dioxide is recovered from environmentally unsuitable vapor or liquid streams comprising water, sulfur dioxide and carbon dioxide. The vapor streams are fed into an absorption zone and contacted with a lean liquid water stream. A resulting sulfur dioxide rich water stream is passed into a first fractionation column utilized in part as the stripper column which produces the lean water stream. A sidecut stream removed above the feed point is passed into a second fractionation column, and the overhead vapor of the first column is subjected to two stages of partial condensation to aid carbon dioxide rejection. Anhydrous sulfur dioxide is removed as a liquid sidecut of the second column, and the net overhead vapor of the second column is preferably passed into the overhead system of the first column after a partial condensation.

Abstract: Contaminants, such as water and hydrogen sulfide, are removed from hydrocarbon streams by the use of beds of solid adsorbents including molecular sieves. The adsorbents are regenerated by heating, with the heating being performed in a closed-loop operation wherein a small quantity of the hydrocarbon being treated is recycled in a closed-loop recirculation system comprising the adsorbent and a heater until the adsorbent reaches an effective regeneration temperature. Closed-loop operation is then terminated, and a regeneration gas is passed into the system and the adsorbent on a once-through basis.

Abstract: A process for the fractionation of hydrocarbons which includes the steps of extracting heat from a liquid sidecut stream, splitting the sidecut stream into two portions, splitting the liquid stream formed by condensing the overhead vapor stream into two portions, admixing one of the portions of the sidecut stream with one of the portions of the overhead liquid stream to form the reflux to the fractionation column, and admixing the other portion of each stream to form a product stream.