THT eNewsletter
6
Offices in ENGLAND, USA, CHINA, INDIA Representation Worldwide
description
October 2014 edition of our Newsletter for Chemical Applicaitons
Transcript of THT eNewsletter
Offices in ENGLAND, USA, CHINA, INDIARepresentation Worldwide
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Battery Safety and Battery PerformanceStudiesProcess Safety & Optimisation Calorimetry
Welcome to THT’s latest newsletter! As well asupdates from our international offices, we arepleased to include a selection of latestdevelopments and application notes from our testlaboratory.
ChinaEarlier in the month,Danny Montgomeryvisited the NanjingUniversity of Scienceand Technology.NUST have a largesafety lab with manycalorimeters includinga THT ARC, RSD and
uRC. Danny gave a talk on the application of THTinstruments to process safety at a process safetyconference hosted by Professor Chen. Two daysof training on THT was carried out at the NUSTprocess safety lab.
We welcome Mr. Hengwei Liu to ourChina Office as Battery ApplicationsSpecialist. Previously Hengwei was aTHT ARC user at Tsinghua University,Beijing.
IndiaIn India, demand for the RSD Rapid ScreeningDevice is strong. Since the last eNewletter, ourrepresentatives KAN-THT have sold six newsystems to academic and pharmaceuticallaboratories across India.
In response to the increased demandMr Rao Mallikharjaun has joined thesales team as South RegionalManager.
KAN-THT will be exhibiting at P-MEC / CPhIMumbai, India. 2-4 December. Booth number O32
Ben Watson joins THT to continueour success in providing innovativeinstruments and software to gainquantitative heat and pressure datafrom the widest range of reactive
chemicals and materials. Ben joins as asElectronics and Manufacturing ProductionTeam Manager and comes with a wealth ofexperience within the Industry. We welcomeBen’s appointment and are confident he will playa key role in providing and implementing highquality solutions for our clients.
UK
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October 2014 Newsletter
ARCDetection of Exothermic Reactions:Onset and SensitivityThe ARC combines the best of both, but haslimitations. With step heating onset isdetermined after multiple isothermal periods,sensitivity is ‘high’ due to the large sample mass;heat release is quantified by extent oftemperature rise. However the features arecombined to give technology that replicatespotential runaway reaction safely in a lab. Highsensitivity is not a major feature; classic ARCtests are carried out overnight and in this timeperiod quality temperature and pressure datathat mimics a runaway reaction in real life isobtained. Onset is classically determined whenthe temperature rise rate measured in the ARCis greater than 0.02°C/min. From onset, the rateincreases as the temperature rises. Typically if
a lower rate (eg 0.005°C/min) is selected as thecriterion for onset, not much more informationmay be obtained but the test would take a muchlonger time (perhaps an additional 24 hours).However, there are times (eg onset of explosivematerials, evaluation of additives, quantifyingminor low temperature impurity reactions) whendetection at low heat release rate is useful.Onset at 0.005°C/min can easily beaccomplished, but the THT esARC system canbe used to determine and quantify heat releaseat rates of 0.002°C/min and even 0.001°C/min.This has been achieved by improved controlalgorithms and makes the THT ARC systemunique and has higher sensitivity than othercommercial adiabatic calorimeters. The databelow illustrates THT esARC calorimeterstability and onset detection.
In the data shown, an esARC was calibrated at 0.005°C/min and this was followed by a driftcheck; all rates were below 0.005°C/min and, as illustrated, where most challenging (highertemperatures) the rate is typically near 0.001°C/min. Onset is seen in the graphs where detectionat 0.002°C/min is simply achieved. Such performance has never been published by anycompetitor calorimeter, and it is suggested the stability of the esARC allows it to have a level ofdetection which provides 10 to 50 times greater sensitivity. Contact THT for full details of theperformance of the esARC system in sensitivity and other aspects.
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October 2014 Newsletter
Solid AdditionAccurate measurements of the enthalpy ofdissolution of solid compounds is an area ofincreasing interest. In response, THT has madea major improvement to the design of the solidaddition accessory. During development wefound that immersing the tube in water is notnecessary for isothermal equilibrium – andsuffers from issues such as possible wateringress and potential of interference of the stirrer.
The new solid addition accessory consists ofStainless Steel Sample Delivery Tube (5mm ID,30mm length); Modified PTFE & Stainless SteelShunt; Reusable Teflon plug; Teflon Plunger;Standard Glass Vial and Standard Vial Lid.
The design allows for up to 400mg of powder tobe manually added to the µRC sample vial. Moredetails are given in our Technical ApplicationsNote. The uRC brochure can also be viewed infull online.
HydrogenationMany chemical processes, particularly in industry,require substrates which exist in the gas phaseunder typical reaction conditions. Furthermore,the transformations discovered in recent yearsare almost ubiquitous in requiring catalysts. Whilemany novel systems are homogeneus, a solidsupport will promote high turnover numbers andimproved recyclability.
for exploring kinetics and determining thereaction enthalpies of these processes. In ourmost recent Technical Applications Note thehydrogenation enthalpy of Octene to Octane hasbeen studied at ambient pressure with apalladium catalyst.
µRC
Teflon Plunger
PTFEShunt/Cap
DeliveryTube
Vial Lid
Vial
TeflonPlug
StainlessSteel Shunt
RSDNew Applications: Quality Control / Rapid ScreeningRapid screening and quality control are at theheart of key applications for the RSD. This isbecause the RSD has the ability to measure up to6 sample simultaneously, to carry out a test in 1hour.
Application 1: Highest SensitivityWaste streams; recycling of solvents.Solvent recovery, waste recycling… importantaspects of Eco-friendliness as well as economy.Consider a solvent to be distilled for re-use. In apharmaceutical manufacturing process thesolvent may carry over 1-2% of a reactiveingredient. How much? Determining a smallquantity presents challenges to mostcalorimeters as the 98-99% solvent acts toabsorb heat in any analysis. Rapid RSDscanning is the answer. See the real raw RSDdata below with 3 samples of DTBP in toluene at1%, 2% and 3% level.
Request THT RSD Technical Application Notes
Results from 1% (top) 2% (middle) and 3% (bottom)
October 2014 Newsletter
RSDApplication 2: ResinsQuality control of resins is of importance firstly tofully characterise the recipe and then todetermine batch variations Curing prior torelease from the reactor can lead to a solid and alarge cost! To develop new formulations,understanding the amount of additives, manytests are likely to be required and these carriedout under isothermal conditions. The keyparameter to determine is onset temperature andtime prior to exothermic reaction; an inductiontime. Because tests could take hours or evendays the use of multiple samples per test is ofgreat value. The results shown below for a testwith three samples and the data is imported intoARCCal for convenience and to extend theanalysis ability (for example to determine time tofull curing). Repeatability is shown in the table.
Temperature as a Function of Time
Temp°C
Time1
(min)
Time2
(min)
Time3
(min)70 600 550 56580 30 310 32590 180 190 205
100 120 130 145120 45 45 60
Improved Software: Thermokinetic AnalysisThe RSD is designed as a screening tool but, withgood thermal control and heat measurement, theRSD allows repeatability of data and the ability tomeasure heat of reaction. Any calorimeter similar tothe RSD (multipurpose, thermal ramping, largesample, lower cost) is not designed for qualityquantitative measurements. However measurementof Heat of Reaction is possible to a reliability of5-10% within a range of heat release amounts and
Temperature as a Function of Time
Predicted Time to Max Rate
rates. Firstly by the ‘classical’ method ofmeasuring peak area and by use of acalibration derived from a prior test with aknown heat release to scale the heat axis.Secondly by theoretical calculation basedupon knowledge of heat exchange and heattransfer and model development.
The data above show a series of RSD tests,repeated at differing heat release values andat differing ramp rates. A prior calibrationconstant was used. Heat releases for 5%,10% and 15% peroxide are near 60 J/g, 120J/g and 180 J/g. In house testing has shownthat the method is most reliable when the totalheat release is 100-1000J, released on a timeperiod of 0.5 - 15 minutes. Best results areobtained when calibration is done with asample where the known heat release issimilar to that being measured. Neverthelessthe new RSD software enhances thequantitative nature of the RSD.
Four tests with 5%, 10% and 15% DTBP. Method used: calibration with 10% DTBP Standard Sample(triplicate prior test). Calibration constant = 7.2. And below tests at differing heat rate.
0
50
100
150
200
250
5% DTBP 10% DTBP 15% DTBP
1
2
3
4
0
50
100
150
200
250
5% DTBP 10% DTBP 15% DTBP
2.5°C/min
4°C/min
6°C/min
Hea
t (J/
g)H
eat (
J/g)
© Thermal Hazard Technology 2014 All rights reserved.
Offices in ENGLAND, USA, CHINA, INDIARepresentation Worldwide
HEAD OFFICE1 North House, Bond Avenue,Bletchley, MK1 1SW, England.
Tel: +44 1908 646800Fax: +44 1908 645209Email: [email protected]: www.thtuk.com
US OFFICETel: +1 317 222 1904Fax: +1 317 660 2092
Email: [email protected]: www.thtusa.com
CHINA OFFICETel: +86 21 5836 2582Fax: +86 21 5836 2581
Email: [email protected]: www.thtchina.com
INDIA OFFICETel: +91 9560 655 626
Email: [email protected]: www.thtindia.com
