Aerodyne Research, Inc.

David D Nelson, Jr

Joseph R Roscioli

Scott Christopher Herndon

Joanne H Shorter

Mark Stuart Zahniser

Charles E Kolb

Scott C Herndon

J Barry McManus

John Barry McManus

In various embodiments, rapid, sensitive detection of molecular hydrogen is achieved by in a detector that divides sample gas into two flows by dividing the sample gas before dampening variation and converting hydrogen to water vapor at two different points. For example, a detector may receive sample gas that includes ambient water vapor and hydrogen, divide the sample gas into a chemical conversion flow and bypass flow, perform a first chemical conversion of hydrogen in the chemical conversion flow to water vapor, alternate between drying the converted chemical conversion flow or the bypass flow to produce a modulated flow, perform a second chemical conversion of hydrogen in the modulated flow to water vapor, measure water vapor in the converted modulated flow to produce a water vapor signal, separate the water vapor signal in the time domain to extract a hydrogen-derived water vapor signal, and output a hydrogen signal based thereon.

Rapid, sensitive hydrogen detector with flow path difference compensation

In various embodiments, rapid, sensitive detection of molecular hydrogen is achieved by chemically converting hydrogen to water vapor and then detecting the water vapor as a surrogate for the hydrogen. Detection may be enhanced by dampening variation in ambient water vapor and rapidly actively modulating a hydrogen-derived water vapor component. For example, the detector may receive sample gas that includes ambient water vapor and hydrogen, dry the sample gas to dampen variation in the ambient water vapor, divide the sample gas into a chemical conversion flow and a bypass flow, chemically convert hydrogen in the chemical conversion flow to water vapor, alternate between measuring water vapor in the converted chemical conversion flow or the bypass flow to produce a water vapor signal, separate the water vapor signal in the time domain to extract a hydrogen-derived water vapor signal, and output a hydrogen signal based on the hydrogen-derived water vapor signal.

Rapid, sensitive hydrogen detector with active hydrogen-derived water vapor signal modulation

In various embodiments, rapid, sensitive detection of molecular hydrogen is achieved by receiving sample gas that includes ambient water vapor and hydrogen, passing the sample gas through a gas dryer, chemically converting hydrogen in the sample gas to water vapor to produce converted sample gas, measuring water vapor in the converted sample gas to produce a water vapor signal, separating the water vapor signal in the time domain into an ambient water vapor signal and a hydrogen-derived water vapor signal, wherein the gas dryer dampens variation in the ambient water vapor signal, and outputting a hydrogen signal that describes molecular hydrogen in the sample gas that is based on the hydrogen-derived water vapor signal.

Rapid, sensitive hydrogen detector

In one embodiment, a COleak detection instrument detects leaks from a site (e.g., a COsequestration facility) using rapid concentration measurements of CO, Oand optionally water concentration that are achieved, for example, using laser spectroscopy (e.g. direct absorption laser spectroscopy). Water vapor in the sample gas may not be removed, or only partially removed. The sample gas may be collected using a multiplexed inlet assembly from a plurality of locations. COand Oconcentrations may be corrected based on the water concentration. A resulting dataset of the COand Oconcentrations is analyzed over time intervals to detect any changes in COconcentration that are not anti-correlated with Oconcentration, and to identify a potential COleak in response thereto. The analysis may include determining eddy covariance flux measurements of sub-surface potential carbon.

Methods and apparatus for measuring small leaks from carbon dioxide sequestration facilities

In one embodiment, active (continuous or intermittent) passivation may be employed to prevent interaction of sticky molecules with interfaces inside of an instrument (e.g., an infrared absorption spectrometer) and thereby improve response time. A passivation species may be continuously or intermittently applied to an inlet of the instrument while a sample gas stream is being applied. The passivation species may have a highly polar functional group that strongly binds to either water or polar groups of the interfaces, and once bound presents a non-polar group to the gas phase in order to prevent further binding of polar molecules. The instrument may be actively used to detect the sticky molecules while the passivation species is being applied.

Techniques for active passivation

In one embodiment, an apparent equilibrium constant involving a clumped isotope in a gaseous sample is measured by acquiring sample spectra of portions of the gaseous sample at different pressures. An external bulb coupled to a sample cell is filled with the gaseous sample. A first portion of the gaseous sample is transferred from the external bulb to the sample cell, where it is at a first pressure. A first sample spectrum is obtained. Then, a second portion of the gaseous sample is transferred from the external bulb to the sample cell, where it is at a second, different pressure. A second sample spectrum is obtained. An apparent equilibrium constant for the clumped isotope is calculated by determining a first isotopic ratio at the first pressure, determining a second isotopic ratio at the second pressure, and taking a product of the first isotopic ratio and the second isotopic ratio.

Laser absorption measurement for clumped isotopes

A non-contact, extractive sampling system and method is provided for measuring the exhaust gas composition and fine particle composition of exhaust emissions of various types of vehicles under actual operating conditions. A portion (or sample) of an exhaust plume of a vehicle is pulled or extracted through an extraction sampling tube, via a vacuum pump, to a remote trace gas detection system where the concentration of one or more constituents present in the sample of exhaust plume may be measured. In this regard, the invention enables vehicle emissions measurements to be made at a location remote from roadway, rather than using known, 'cross-path' remote emissions sensing systems.

Extractive sampling system and method for measuring one or more molecular species

A cross-road motor vehicle exhaust gas analyzer uses tunable infrared laser differential absorption spectroscopy incorporating photon infrared detection to determine the absolute fractional absorption of a laser by the gaseous medium. Spectroscopic constants of the gaseous species of interest are applied to the absolute fractional absorption to calculate the pertinent absolute column densities. In addition to a laser that sweeps across one or more absorption line of an component of interest, the system of the invention includes a laser source tunable over an absorption line of a reference species; the calculated column density of the reference species is used to normalize the concentration of the component of interest to the fuel consumption rate of the motor vehicle.

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N. Chelmsford, MA, United States of America

David D Nelson, Jr