The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 09, 2000
Filed:
Sep. 17, 1997
Gregory W Sorge, Waukesha, WI (US);
Richard J Kakoczki, North Prairie, WI (US);
John E Peffer, Eagle, WI (US);
Dresser Industries, Inc., Dallas, TX (US);
Abstract
A method for calculating knock resistance ratings for various blends of non-commercial grade natural gas involves the use of a computer model derived from collecting experimental data for constituent concentration levels typical in field grade natural gas. The computer model is derived using a MN (methane number) calibration curve for various natural gas compositions typical at the wellhead. The empirically-derived computer model considers concentrations of the following molar constituents: methane (60%-100%); ethane (0%-20%); propane (0%-40%); normal butane (0%-10%); normal pentane (0%-3%); mixtures of higher order hydrocarbons (0%-2%); nitrogen (0%-15%) and carbon dioxide (0%-10%). The knock characteristics of isomers of butane and pentane are accounted for by assigning fractions of their concentrations to concentrations of modeled constituents. If the concentration levels lie outside of acceptable ranges and normalization is insufficient to correct for concentration levels, an alternative method (preferably the carbon-hydrogen ratio method) is used to calculate knock resistance rating. Excessive concentrations of inert gases such as carbon dioxide and nitrogen are accounted for separately using an empirically-based algorithm, thus the model can be extended to landfill and digester gases which typically have high concentrations of carbon dioxide.