Systems, methods, and apparatus for optical hydrocarbon gas composition monitoring

An industrial hydrocarbon composition monitoring system providing real-time speciation and/or quantitative determination of a plurality of hydrocarbon constituents of a hydrocarbon fluid, the system comprising:

• a broadband light source;
• a gas flow cell through which the hydrocarbon fluid flows and through which or to which light from the light source passes;
• an optical detector for receiving the light after transmission through or reflection from the hydrocarbon fluid flowing through the gas flow cell and for generating a scan signal indicative of spectral information of the detected light over a continuous broadband region or over multiple discrete wavelength bands, where the scan covers a range that is equivalent to, is a subset of, or overlaps, the range from about 800 nm to about 12 μm;
• a processor;
• and
• a non-transitory computer readable medium storing instructions thereon, wherein the instructions, when executed, cause the processor to:
• identify two or more bands of spectral data from the signal corresponding to the hydrocarbon fluid in the gas flow cell, wherein the two or more bands are non-contiguous;
• combine the two or more non-contiguous bands of spectral data to form a combined spectrum of spectral data;
• and
• process data from the combined spectrum of spectral data to speciate and/or quantify in real-time two or more hydrocarbon constituents of the hydrocarbon fluid based on the combined spectrum of spectral data.