we used it to determine the degree of hydrogenation in a food process. continuous monitoring was not a requirement.
the on-line application of the measurement is a new one to me.
a variation of nmr is used in down-hole oil exploration.
the usual focus of lab-nmr is on the molecular environment of the hydrogen atoms in the material.
Online NMR is used for the determination of both RON (Research Octane Number) and MON (Motor Octane Number) for gasoline blending stocks. This online measurement is used to allow a refinery to blend different stocks of gasoline in real time to meet an export RON or MON.
it was a determination of the ratio of two types of edible oils. the degree of hydrog. was the only way to quantify it, other than a series of testing by individuals.
As for lab testing I've seen it being used to determine oil content in paraffin waxes, with a high degree of correlation with other specific tests such as ASTM D 721 and IP 158.
We use process NMR to control on-line and off-line (lab)polymer production with over 40 production lines worldwide.
Low field NMR is also used in a number of other industries:
- Food - moisture, fat and oil content, droplet size, composition of dairy, oils, starches, rice, fruits, vegetables, etc.
- Agriculture - moisture and oil content, composition of soil, seeds and feeds.
- Petroleum - oil content, octane numbers, free/bound components, viscosity, porosity, pore size in coals, waxes and rocks, crude oil blending.
- Chemicals - free/bound moisture, viscosity, activity, loading efficiency in powders, catalysts, liquids, detergents, and pigments.
- Cosmetics - moisture and oils in powders and pigments.
- Pharmaceuticals - (moisture / oil contents, coatings, composition in capsules and tablets.
- Polymers - density, crystallinity, rubber content, dispersion of fillers, copolymer content, solubles, melt properties, extent of cure, moisture and plasticizer content, polymer mixing, crosslinking, finish content, tensile strength, etc.
There are a number of companies which offer this service to get you started
- Progression, Inc (formerly Oxford)
- Process NMR Associates (great web site with details)
- Bruker MiniSpec
- Process Control Technology
- Resonance Instruments
- Foxboro
Most systems are low field NMRs 10-30 MHz though processes that examine mobile liquids can use higher magnetic fields to improve results (50-100 MHz). Most low field NMRs are lab units to my knowledge with only some petroleum and polymer applications actually using on-line systems to control the process directly.
online NMR analyzers are gaining further penetration in controlling refining processes. Online applications include:
- measure composition of reformer product (reformate) to fine tune reformer serverity and light/heavy reformate split.
-measure aromaticity of gasoil feed to FCC to tie into DMC controller or just to monitor process health.
In the mid 1980's there was a published study using nmr for flow measurement in coal slurry. I may still have something at home. A web search would be better for current applications.
