Systems and methods are provided for using differential scanning calorimetry (DSC) to predict properties of fuel compositions, such as marine fuel oils. It has been discovered that various features of the data plots generated by DSC can be correlated with properties of interest for marine fuel oil compositions. The fuel composition properties that can be predicted based on DSC include, but are not limited to, density; micro carbon residue; pour point; and estimated cetane number (ECN). This can include prediction of ECN for resid-containing fuel compositions. Using DSC to predict ECN can reduce or minimize the number of resid-containing fuel oil samples that require testing using the limited availability equipment required for the IP 541 method.

Fuel compositions that are low sulfur and have adequate combustion quality are disclosed. An example fuel composition that is low sulfur may have the following enumerated properties: a sulfur content of about 0.50% or less by weight of the fuel composition; a calculated carbon aromaticity index of about 870 or less; a density at 15 C. of about 900 kg/m.sup.3 to about 1,010 kg/m.sup.3; a kinematic viscosity at 50 C. of about 100 centistokes to about 700 centistokes; and an estimated cetane number of about 7 or greater.

To characterize hydrocarbon contamination, a container, an ultraviolet laser source and a detector are spatially positioned relative to each other. The container carries a hydrocarbon sample including a first hydrocarbon and a second hydrocarbon. The ultraviolet laser source is configured to emit an ultraviolet laser at a wavelength to irradiate the hydrocarbon sample in the container. The wavelength is configured to induce fluorescence in the hydrocarbon sample. The detector is configured to detect the induced fluorescence. The hydrocarbon sample in the container is irradiated with the ultraviolet laser at multiple locations within the container at respective multiple distances from the detector. The multiple locations are arranged in a straight line normal to the detector. A volume of the first hydrocarbon in the hydrocarbon sample is determined based on induced fluorescence detected by the detector at each of the multiple locations arranged in the straight line normal to the detector

The invention relates to a method for investigating process streams comprising five or more different hydrocarbon-containing components. In the method at least one process flow line (35) is in operative connection with an online IR spectrometer (2) and an online gas chromatograph (1). The process stream passed through the process stream conduit (35) is subjected to an online characterization which comprises measurements both with the online IR spectrometer and with an online gas chromatograph. The spectral data and the chromatography data are mathematically related to one another by suitable statistical models, thus allowing training of a model used for evaluating the analytical data and for characterizing the process streams. The method according to the invention is characterized by short measurement times in the range of seconds and milliseconds and a high accuracy. The method according to the invention for investigating process streams preferably relates to investigation of process streams deriving from processes proceeding in parallel, the process streams preferably deriving from reaction spaces arranged in parallel.

A fuel quality sensor can include a pump with a suction side and a pressure side for pumping fuel along a fuel flow path between an underground reservoir and a nozzle of a fuel dispensing unit; a first transmitter disposed at the suction side of the pump on a first side of a bypass plenum in fluid communication with the fuel flow path, the first transmitter configured to transmit a first light signal at a first predetermined frequency in the bypass plenum; a receiver disposed at the suction side of the pump on a second side of the bypass plenum and configured to receive the first light signal; and a control unit electrically connected to the first transmitter and the receiver and configured to determine at least one parameter of the fuel present in the fuel flow path based on the received first light signal at the first predetermined frequency.

A system and computer program product are provided for calculating one or more indicative properties, e.g., one or more of the cetane number, octane number, pour point, cloud point and aniline point of oil fractions, from the density and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) of a sample of an oil sample.

Systems and methods for monitoring a crude oil blending process use nuclear magnetic resonance (NMR) sensors which investigate properties of a plurality of crude oil streams that are mixed together to form a crude oil blend. An NMR sensor is also used to investigate the properties of the crude oil blend. The investigated properties may include viscosity. Resulting determinations may be used to control the input streams so that the output stream meets desired criteria. Additional sensors such as spectroscopy sensors, viscometers, and densitometers may be used in conjunction with the NMR sensors.

A system and method are provided for in-line processes of separating and blending transmix, gasoline and diesel fuel from a refined petroleum product within a pipeline using optical properties.

A detonation pickup testing system, comprising: (i) apparatus for coupling to at least one terminal of a detonation pickup; and (ii) a computational system, for communicating with the pickup via with the apparatus, to test at least one characteristic, excluding or in addition to DC resistance, of the detonation pickup.

The present disclosure provides a method for predicting a fluid type, comprising sensing, by a first sensor, mass flow data of a fluid in an engine, wherein the first sensor operates based on a first fluid property; sensing, by a second sensor, mass flow data of the fluid, wherein the second sensor operates based on a second fluid property; and detecting, by a logic circuit of a controller, a percent difference in the mass flow data provided by the first and second sensors, the percent difference indicating that the fluid is comprised of at least a first fluid type.