Patents by Inventor Madhava Malladi

Madhava Malladi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4892644
    Abstract: A solvent extract obtained from a conventional hydrocarbon oil solvent extraction process, e.g., one employing furfural as the extraction solvent, is cooled to a temperature providing, following a secondary decantation of the cooled extract, a pseudo raffinate containing most of the non-aromatics and a pseudo extract possessing a hydro-aromatic content of H.sub.alpha hydrogen of at least 20 percent of the total hydrogen content. The pseudo extract is ideally suited as a hydrogen-donor for a variety of refinery operations such as visbreaking. The pseudo raffinate is suitable as a co-feed for such catalytic cracking operations as fluidized catalytic cracking (FCC) and thermofor catalytic cracking (TCC) and can be recycled to the extraction unit to produce more lube oil.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: January 9, 1990
    Assignee: Mobil Oil Corporation
    Inventors: Byung Choi, Grant G. Karsner, Chang-Kuei Lee, Madhava Malladi, Donald Milstein
  • Patent number: 4661241
    Abstract: A delayed coking process having improved liquid yield and liquid product distribution relative to coke yield is characterized by the absence of heavy recycle. The coker feedstock is heated in the coker furnace and led to the coker drums where coking takes place and the vaporous effluence are passed to a fractionator from which the heavy gas oil fraction is removed as product. Process heat is conserved by indirect heat exchange of the feedstock with the coking products prior to the feedstock entering the coking furnace. A further improvement in liquid yield and selectivity is obtained by adding a solvent or diluent to the feedstock and this may be either a hydrocarbon fraction such as a coker distillate, a light gas oil or another fraction having an end point below 450.degree. C.; in addition, it may be used in conjunction with a reactive or nonreactive gas such as nitrogen, steam, hydrogen or hydrogen sulfide.
    Type: Grant
    Filed: April 1, 1985
    Date of Patent: April 28, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Michael J. Dabkowski, Madhava Malladi
  • Patent number: 4615791
    Abstract: Heavy petroleum oils such as resids are subjected to visbreaking in the presence of a hydroaromatic hydrogen donor solvent having an aromatic and alpha-to-aromatic proton content each of at least 20 percent of the total solvent hydrogen. The amount of donor solvent is from 0.1 to 50, preferably 0.1 to 20, weight percent of the heavy oil feed. The visbreaking may be carried out at relatively high severities as the use of the donor solvent reduces coke formation as well as producing a product of reduced viscosity, pour point and sedimentation characteristics. Reaction severity is usually in the range of 250 to 1500 seconds ERT at 800.degree. F. (427.degree. C.) but may range up to 15000 seconds ERT. Suitable solvents may be obtained from catalytic cracking process, for example, FCC cycle oils, slurry oils and main column bottoms.
    Type: Grant
    Filed: September 3, 1985
    Date of Patent: October 7, 1986
    Assignee: Mobil Oil Corporation
    Inventors: Byung C. Choi, Benjamin Gross, Madhava Malladi
  • Patent number: 4541921
    Abstract: A fast fluidized bed regenerator of an FCC apparatus is improved by incorporating into the regenerator an internal riser, for more complete combustion of coke, and by providing a means of preventing catalyst flow reversals between the spent and regenerated beds of the catalyst.
    Type: Grant
    Filed: January 5, 1984
    Date of Patent: September 17, 1985
    Assignee: Mobil Oil Corporation
    Inventors: Benjamin Gross, James H. Haddad, Madhava Malladi
  • Patent number: 4448753
    Abstract: A fast fluidized bed regenerator of an FCC apparatus is improved by incorporating into the regenerator an internal riser, for more complete combustion of coke, and by providing a means of preventing catalyst flow reversals between the spent and regenerated beds of the catalyst.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: May 15, 1984
    Assignee: Mobil Oil Corporation
    Inventors: Benjamin Gross, James H. Haddad, Madhava Malladi
  • Patent number: 4428824
    Abstract: A process is described for visbreaking a deasphalted hydrocarbon oil and subsequently reblending the recovered asphaltene fraction to produce a product of low viscosity and pour point and requiring less cutter stock oil as compared to conventional visbreaking processes.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: January 31, 1984
    Assignee: Mobil Oil Corporation
    Inventors: Byung C. Choi, Benjamin Gross, Madhava Malladi