Patents by Inventor Stephen A. Leng

Stephen A. Leng 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: 5481052
    Abstract: This invention relates to a process for cracking waste polymers in a fluidized bed reactor to produce vaporous products comprising primary products which can be further processed, eg in a steam cracker to produce olefins, characterized in that the vaporous products are treated to generate a primary product substantially free of a high molecular weight tail having molecular weights >700 prior to further processing. The removal of the high molecular weight tail minimizes fouling and prolongs the lifetime of the reactors used for further processing.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: January 2, 1996
    Assignee: BP Chemicals Limited
    Inventors: Stephen Hardman, Stephen A. Leng, David C. Wilson
  • Patent number: 5364995
    Abstract: This invention relates to a process for the conversion of waste and/or fresh polymers, especially polyolefins, into lower hydrocarbons by vaporizing them in a fluidized bed of particulate material in the presence of a fluidizing gas at a temperature from 300.degree.-690.degree. C. The lower hydrocarbons can be further converted to useful olefins, paraffins or waxes by steam cracking the lower hydrocarbons, preferably in the absence of any catalyst. This is an effective and efficient method of recycling waste polymers.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: November 15, 1994
    Assignee: BP Chemicals Limited
    Inventors: Kenneth C. Kirkwood, Stephen A. Leng, David W. Sims