PAT Archives - Page 4 of 5 - NMR Testing Laboratory

1H NMR – 60 MHz Permanent Magnet System – Reaction Monitoring

January 18, 2012 by process nmr NMR, PAT, Process NMR

Below are a few further examples of acetylation reactions of acetic anhydride with an excess of alcohol. The alcohols include tert-butanol and isopropanol.

Reaction 1: Acetylation of t-butyl alcohol with acetic anhydride in the presence of acid.

Acetylation of t-butanol with acetic anhydride - 1H NMR Reaction Monitoring

Reaction 2: Acetylation of Isopropanol with acetic anhydride in the presence of acid.

Acetylation of isopropanol with acetic anhydride - 1H NMR Reaction Monitoring

Reaction 3: Methoxyacetone and hydroxylamine reaction in methanol to form an Oxime

Oxime Production from Ketone and Hydroxylamine - 1H NMR Reaction Monitoring

Oxime Production from Ketone and Hydroxylamine - Zoomed spectrum - 1H NMR Reaction Monitoring

Resolution of the methylenes in the methoxyacetone and the reaction product is readily observed.

Oxime from ketone and hydroxylamine - assignment - 1H NMR Reaction Monitoring

All the above experiments were performed in an NMR tube. We are currently looking at the same reactions under flow conditions utilizing a HPLC pump and PEEK tubing to transport sample to the NMR probe at 5 ml/min.

Chevron Installs Low Field NMR Application: 31P NMR Analysis of Phosphoric Acid Strength in Alkylation Process

January 2, 2012 by process nmr NMR, PAT, Process NMR

New Flash: Chevron purchases high resolution 31P NMR system for at-line analysis of a phosphoric acid catalyzed alkylation process.

The Chevron Richmond Refinery needed a simple and quick measurement of phosphoric acid strength and quality. Prior analysis procedures included transporting samples several miles from the refinery process to the technical center in order to perform the 31P NMR analysis on a high field superconducting NMR system. This process was also complicated by the fact that the process operators were not able to perform the analyses on the conventional high field NMR systems (400 MHz for 1H, 161 MHz for 31P) themselves, but had to wait for NMR technician and instrument availability. If sample analyses was required after research facility working hours the NMR lab technicians were required to come in and run the NMR for the process operators.

A simple permanent magnet bench-top NMR system has now been placed in the existing process lab adjacent to the process unit control room. The NMR samples are placed in specially designed 9 mm (diameter) x 50 mm (length) sample tubes in order to accommodate sample handling issues (high viscosity sample with no solvents being added) and are place easily into the NMR probe. Sample preparation is essentially non-existent and sample waste is minimal. The 31P NMR analysis itself takes around 3 minutes to perform.

The “at-line” NMR system is a high resolution Qualion permanent magnet system operating at 58.3 MHz for 1H and 24.2 MHz for 31P. The system is located on a lab bench in the process lab building. Some examples of the system performance are shown along with the comparison with high field NMR results. It can be seen that the lower field instrument provides more than adequate resolution to perform the acid strength analysis.

31P NMR - Orthophosphoric Acid

Figure 1: 31P NMR of 85% Phosphoric Acid

Figures 1 and 2 show quantitative 31P NMR spectra of different phosphoric acid concentrations dissolved in water. The NMR analysis is found to be fully quantitative.

31P NMR of Different Concentrations of H3PO4 in Water - At-Line NMR

Figure 2: 31P NMR signal acquired at 24.2 MHz on several concentrations of phosphoric acid in water.

Figure 3 shows the 31P NMR data obtained at 7 Tesla (121 MHz) and 1.4 Tesla (24.2 MHz) of actual process samples. The peak at 0 ppm corresponds to orthophosphoric acid, the peak at -15 ppm corresponds to the terminal P atoms of a polyphosphoric acid chain, and the peak at -30 ppm corresponds to internal P atoms in the middle of polyphosphoric acid chains. Relative areas of these peaks are used to calculate the acid strength.

31P NMR - Phosphoric Acid Strength - At-Line Assay

Figure 3: High field and low field 31P NMR spectra of Used Phosphoric Acid from Alkylation Process

Used Phosphoric Acid - At-Line 31P NMR Analysis

Figure 4: 31P NMR spectra and calculated acid strengths obtained on 3 different used phosphoric acid samples

Used Phosphoric Acid - At-Line 31P NMR - Acid Strength Assay

Figure 5: Another comparison of 7 Tesla laboratory acquired NMR data compared to rapid at-line 1.4 Tesla NMR assay of phosphoric acid strength.

The NMR system being utilized at the Chevron Richmond refinery is a Qualion 60 MHz NMR system utilizing a 31P probe.

For further details or to discuss your own NMR applications please contact Paul Giammatteo (Tel: +1 203-744-5905)

Reaction Monitoring Using NMR and Vibrational Spectroscopy – RSC Conference

March 7, 2011 by process nmr IR-ATR, NMR, PAT, Process NMR

Dr. John Edwards of Process NMR Associates will be attending an RSC sponsored one day symposium on “Reaction Monitoring Using NMR and Vibrational spectroscopy – An Industrial Perspective”. The meeting will be held at the Pfizer Research Center in Sandwich, Kent, UK on March 22, 2011. Dr Edwards will be presenting a poster entitled “Practical Applications of Compact High-Resolution 60 MHz Permanent Magnet NMR Systems for Reaction Monitoring and Online Process Control”. The abstract of the talk is presented below:

For the past two decades high resolution 1H NMR at 60 MHz has been utilized to monitor the chemical physical properties of refinery and petrochemical feed-streams and products. These approaches involve the use of partial least squares regression modeling to correlate NMR spectral variability with ASTM and other official test methods, allowing the NMR to predict results of physical property tests or GC analysis. The analysis is performed in a stop flow environment where solenoid valves are closed at the beginning of the NMR experiment. This approach allows up to 5 or 6 different sample streams to be sent to the sample in order to maximize the impact of the instrument. The current work with these permanent magnet NMR systems is to utilize them as chemistry detectors for bench-top reaction monitoring, mixing monitoring, dilution monitoring, or conversion monitoring. In the past use of NMR for these applications has been limited by the need to bring the “reaction” to the typical “superconducting” NMR lab. A compact high resolution NMR system will be described that can be situated on the bench-top or in the fume hood to be used as a continuous or stop-flow detector and/or an “in-situ” reaction monitoring system. The system uses a unique 1.5 Tesla permanent magnet with a simple flow cell and total system volumes of 2 to 5 ml depending on the length and diameter of the transfer tubing. Further, detection limits of analytes in the 200+ ppm range are possible without the use of typical deuterated NMR solvents. Analysis times of 5 to 20 seconds are also possible at flow rates of 5 to 20+ ml/minute. Reaction monitoring directly in standard 5 mm NMR tubes again using conventional (non-deuterated) reactants, solvents and analytes will also be described.

Details of the symposium and registration information can be found at the RSC website.

IFPAC Conference: Process NMR Associates and University of California, Davis to Present Process NMR and MRI Short Course Prior to Meeting

November 24, 2010 by process nmr NMR, PAT, Process NMR, TD-NMR Tagged: NMR, Process Analytical

Short Course on Process NMR and MRI to be presented at the IFPAC Meeting (http://www.ifpac.com/)
When: Monday, January17, 1:00pm to 5:00pm, and continues on Tuesday January 18, 8:00AM to 12 noon
Location: Baltimore Marriott Waterfront
Instructors: Michael J. McCarthy, Professor of Engineering, University of California, Davis, CA
Paul J. Giammatteo, Ph.D., Process NMR Associates LLC, Danbury, CT

The course is specifically designed and organized for industry professionals who want to add to their knowledge-base on magnetic resonance and process analytical technology. Topics include compositional analysis, rheological characterization, measurement of the state of mixing, visualizing transport and product stability as well as recent advances in process magnetic resonance sensors. This course will bring you up-to-date on the latest information concerning the applications and state-of-the art instrumentation for process magnetic resonance.
Outline:
* Introduction to Process NMR Magnetic resonance theory
– Time-domain, High resolution, Diffusion, Imaging
* Hardware
– Spectrometers, magnets, probes
* Coupling the sensor to the process
* Applications will include:
– Composition measurement
– Property measurement
– Rheology measurement
– Product structure
For Details contact Paul Giammatteo Tel: (203) 744-5905 or Michael McCarthy Tel: (530) 752 8921

Process NMR Spectroscopy Chapter to Appear in Wiley Publication

March 22, 2010 by process nmr NMR, PAT, Process NMR, TD-NMR

John Edwards and Paul Giammatteo of Process NMR Associates have written a chapter “Process NMR Spectroscopy: Technology and On-Line Applications” to appear in the 2nd Edition of “Process Analytical Technology” published by Wiley and Sons and Edited by Katherine Bakeev. The book will be published in May 2010 and is available for pre-order.

Process Analytical Technology - 2nd Ed. - Wiley