Method for Improving Liquid Yield During Thermal Cracking of Hydrocarbons

A method for improving liquid yield during thermal cracking of a refinery hydrocarbon comprising:

• introducing a metal additive and a dispersant to a refinery hydrocarbon feed stream, where the metal additive is selected from the group consisting of a metal overbase and a metal dispersion, where the metal in the metal additive is selected from the group consisting of:
• magnesium alone or magnesium together with a second component selected from the group consisting of barium, strontium, aluminum, boron, silicon, cerium, titanium, zirconium, and platinum, and
• two metals selected from the group consisting of calcium, barium, strontium, zinc, silicon, and cerium;
• where the metal additive contains at least about 1 wt % metal;
• heating the refinery hydrocarbon feed stream to a thermal cracking temperature;
• and
• recovering a hydrocarbon liquid product;
• where the amount of hydrocarbon liquid product is increased as compared with an identical method absent the overbase additive.

A refinery process comprising a coking operation further comprising:

• introducing a metal additive and a dispersant to a coker feed stream, where the metal additive is selected from the group consisting of:
• magnesium alone or magnesium together with a second component selected from the group consisting of calcium, barium, strontium, boron, zinc, silicon, cerium, titanium, zirconium, chromium, molybdenum, tungsten and platinum;
• and
• two metals selected from the group consisting of calcium, barium, strontium, zinc, silicon, and cerium;
• heating the coker feed stream to a thermal cracking temperature;
• and
• recovering a hydrocarbon liquid product.