Method For Determining Carbon Content Of A Hydrocarbon-Containing Mixture

Abstract

A method for determining a carbon content value of a hydrocarbon-containing mixture. At least one composition-dependent bulk property of the hydrocarbon-containing mixture is measured and optionally at least one non-hydrocarbon component concentration is measured with the resulting measurements used in a carbon content correlation for calculating the carbon content of the hydrocarbon-containing mixture. The carbon content may be used in a hydrogen and/or synthesis gas production process for calculating a target flow rate of steam to be combined with the hydrocarbon-containing mixture to form a mixed feed having a target steam-to-carbon ratio.

1 . A method for determining a carbon content value of a hydrocarbon-containing mixture comprising:
 containing a fixed mass of a reference gas in a fixed-volume enclosure, the reference gas having a reference gas temperature and a reference gas pressure;   measuring a density of the hydrocarbon-containing mixture to determine a density value of the hydrocarbon-containing mixture at a first temperature and a first pressure, the first temperature equal to the reference gas temperature and the first pressure equal to the reference gas pressure; and   calculating the carbon content value using at least the density value of the hydrocarbon-containing mixture in a carbon content correlation.   
     
     
         2 . The method of  claim 1  further comprising:
 measuring a concentration of at least one non-hydrocarbon component in the hydrocarbon-containing mixture to determine a non-hydrocarbon component concentration value; and   wherein the step of calculating the carbon content value further uses the non-hydrocarbon component concentration value in the carbon content correlation.   
     
     
         3 . The method of  claim 2  wherein the at least one non-hydrocarbon component is selected from the group consisting of nitrogen, carbon monoxide and carbon dioxide. 
     
     
         4 . The method of  claim 1  further comprising:
 measuring a second composition-dependent bulk property of the hydrocarbon-containing mixture to determine a second composition-dependent bulk property value; and   wherein the step of calculating the carbon content value further uses the second composition-dependent bulk property value in the carbon content correlation.   
     
     
         5 . The method of  claim 4  wherein the carbon content correlation is a multivariable function of the density and the second composition-dependent bulk property. 
     
     
         6 . The method of  claim 4  wherein the second composition-dependent bulk property is selected from the group consisting of lower heating value, higher heating value, thermal conductivity, viscosity, molecular weight, density, molar heat capacity, specific heat capacity, and sonic velocity. 
     
     
         7 . The method of  claim 4  wherein the carbon content correlation is a linear function of the density and a linear function of the second composition-dependent bulk property. 
     
     
         8 . The method of  claim 4  wherein the second composition-dependent bulk property is one of higher heating value, lower heating value and viscosity. 
     
     
         9 . The method of  claim 4  further comprising:
 measuring a third composition-dependent bulk property of the hydrocarbon-containing mixture to determine a third composition-dependent bulk property value,   wherein the step of calculating the carbon content value further uses the third composition-dependent bulk property value in the carbon content correlation.   
     
     
         10 . A method for producing a mixed feed for hydrogen or synthesis gas production comprising:
 measuring a first flow rate of a hydrocarbon-containing mixture thereby obtaining a measured flow rate value;   the method of  claim 1  for determining a carbon content value of the hydrocarbon-containing mixture;   selecting a desired steam-to-carbon ratio of the mixed feed;   calculating a target flow rate of a steam-containing feed required to obtain the desired steam-to-carbon ratio of the mixed feed using the measured flow rate value and the carbon content value, the steam-containing feed having a steam-containing feed flow rate;   regulating the steam-containing feed flow rate so that the steam-containing feed flow rate comes closer to or equal to the target flow rate, thereby obtaining a regulated flow rate; and   combining the hydrocarbon-containing mixture at the first flow rate with the steam-containing feed at the regulated flow rate to form the mixed feed.   
     
     
         11 . The method of  claim 10  further comprising:
 measuring a concentration of at least one non-hydrocarbon component in the hydrocarbon-containing mixture to determine a non-hydrocarbon component concentration value; and   wherein the step of calculating the carbon content value further uses the non-hydrocarbon component concentration value in the carbon content correlation.   
     
     
         12 . The method of  claim 10  further comprising:
 measuring a second composition-dependent bulk property of the hydrocarbon-containing mixture to determine a second composition-dependent bulk property value; and   wherein the step of calculating the carbon content value further uses the second composition-dependent bulk property value in the carbon content correlation.