1
Chang Y Cha, Harry E McCarthy: Reduction of shale oil pour point. Occidental Oil Shale, Christie Parker & Hale, March 20, 1984: US04437519 (210 worldwide citation)

A portion of crude shale oil produced from an in situ oil shale retort is blended with shale oil produced from a Tosco II retorting process to produce a blended shale oil composition having a pour point lower than the pour point of the shale oil produced from the Tosco II retorting process.


2
Richard D Ridley, Chang Y Cha: Two-stage removal of sulfur dioxide from process gas using treated oil shale. Occidental Oil Shale, Christie Parker & Hale, February 20, 1979: US04140181 (207 worldwide citation)

Sulfur dioxide is removed from a process gas by passing the process gas through a first fragmented permeable mass of particles containing treated oil shale and including alkaline earth metal oxides at a sufficient temperature to remove sulfur dioxide from the process gas. Gas containing sulfur dioxi ...


3
Chang Y Cha, Michael Duc, Curtis J Hogan: Pyrolysis methods with product oil recycling. Western Research Institute & ILR Services, Browdy and Neimark, January 8, 1991: US04983278 (59 worldwide citation)

A two step retorting process for pyrolyzing a solid feed selected from the group consisting of oil shale, tar sand, waste motor oil, and scrap tires to recover valuable products therefrom comprising retorting a mixture of the solid feed in heavy oil at a relatively low temperature, recycling the oil ...


4
Suk B Cha, Chang Y Cha: Pollution arrestor. Chang Yul Cha, John O Mingle, July 16, 1996: US05536477 (59 worldwide citation)

A pollution arrestor removes various pollutants, such as soot, NO.sub.x, CO and hydrocarbons, from a gas stream. The pollution arrestor is composed in layers starting with a particulate filter to remove soot followed by various catalytic sections enhanced by radiofrequency microwave energy. The leav ...


5
Chang Y Cha, Norman W Merriam, John E Boysen: Inclined fluidized bed system for drying fine coal. Western Research Institute, John O Mingle, February 11, 1992: US05087269 (42 worldwide citation)

Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced ...


6
Chang Y Cha, John E Boysen, Jan F Branthaver: Process for removing heavy metal compounds from heavy crude oil. Western Research Institute, Browdy and Neimark, August 20, 1991: US05041209 (40 worldwide citation)

A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said hea ...


7
Chang Y Cha: In situ oil shale retort with variations in surface area corresponding to kerogen content of formation within retort site. Occidental Oil Shale, Christie Parker & Hale, April 17, 1979: US04149595 (34 worldwide citation)

An in situ oil shale retort is formed in a subterranean formation containing oil shale. The formation comprises at least one stratum of relatively higher average kerogen content which is included in formation of relatively lower average kerogen content. A void is excavated in a retort site in the fo ...


8
Chang Y Cha, Henry Plancher, Lawrence S Kraus: Process for co-recycling tires and oils. Univ of Wyoming, Amoco, John O Mingle, February 14, 1995: US05389691 (30 worldwide citation)

A thermal process co-recycles tires with oils to produce gases, liquids and solids. The letter consisting of glass and steel fibers and a carbonous residue which are separately segregated and collected. By using selected additives gas formation and hydrogen sulfide contents are reduced, light produc ...


9
Chang Y Cha: Analyzing oil shale retort off-gas for carbon dioxide to determine the combustion zone temperature. Occidental Oil Shale, Christie Parker & Hale, January 25, 1983: US04369842 (27 worldwide citation)

An in situ oil shale retort is formed in a subterranean formation containing oil shale. The retort contains a fragmented permeable mass of particles comprising kerogen and various inorganic carbonates. A processing zone is established in the fragmented mass of formation particles and advanced theret ...


10
Chang Y Cha, William J Bartel: Determining the locus of a processing zone in an in situ oil shale retort. Occidental Oil Shale, Christie Parker & Hale, August 7, 1979: US04163475 (26 worldwide citation)

A processing zone advances through a fragmented permeable mass of particles containing oil shale in an in situ oil shale retort in a subterranean formation containing oil shale. The fragmented mass has layers of formation particles of differing composition, such as kerogen content, corresponding to ...