INSPIRING IMAGINATION FOR MATERIAL SCIENCE

Energy related applications of calorimetry

Rémi ANDRE – SETARAM Instrumentation

ECN / ExperTA Technology day

Petten, The Netherlands, Thursday, February 5th

Definition of DSC

� Differential Scanning

Calorimetry (DSC) :

� A technique in which the heat

flux (thermal power) to (or

from) a sample is measured

versus time or temperature

while the temperature of the

sample is programmed, in a

controlled atmosphere.

� The difference of heat flux

between a crucible containing

the sample and a reference

crucible (empty or not) is

measured

International

Confederation for Thermal

Analysis and Calorimetry

www.ictac.org

Differential Scanning Calorimetry

� Plate shaped differential

thermocouples (Standard DSC)

� Contact with the sensor through

the bottom area of the crucibles

� Up to very high temperature

(1600°C)

� Thermopile composed of multiple

thermocouples (Calvet DSC)

� Contact with the sensor all around

the crucible

� Very high sensitivity and accuracy

Metal 2

Metal 1Metal 1

U = f (q1-q2)

T1 T2

q1 q2

C80

Calorimetric cavity

Insulation : Vermiculite

Sample thermocouple

Heating element

Cell support

Insulated cover

Calvet Calorimetry

Sample vessels

Peltier

Elements

Reference

vessels

Microcalorimetry

� Peltier elements (networks of semiconductors)

� µDSC Peltier elements are used both ways

� To heat up or cool down the calorimetric block

� To collect heat from the sides of the cells

7

� Large number of cells available means a wide range of applications

�Standard cells : transitions, isothermal stability, Cp

of solid or powders,…

• Fields of application : chemical compatibility, stability of

hazardous materials, phase diagrams,…

�Mixing cells : heats of mixing, of wetting

(immersion), of dissolution, of adsorption,…

• Fields of application : cement setting, chemical reactions,

polymerizations, surface properties (adsorption, wetting),…

Cells

8

High Pressure cells

� Stainless Steel

� Temperature range : -40°C / 120°C

� Max pressure : 400 or 1000 bars

� 1 gas input

� Used under isothermal or scanning mode

� Max available volume : 0.33mL or 0.19mL

� Connection to gas panels

Injection from HP gas panel

Solid or liquid sample

Solid or liquid sample

Injection from HP gas panel

Batteries

� Self discharge of batteries

� Temperature : 30°C

� Sample : AA type lithium battery

� Reference : equivalent mass of

alumina

� Insertion of sample and reference

cell at t = 0

� After 5 hours, the cells are

swapped, leading to a new

equilibrium

� Self discharge power is equal to

half of the difference in terms of

equilibrium levels, i.e. 228.2 / 2 =

114.1µW

Time (h)87.576.565.554.543.53

Hea

tFlo

w (m

W)

0.15

0.1

0.05

0

-0.05

-0.1

-0.15

-0.2

Exo

t : 4.1 and 7.1 (h) ∆ : 228.2 (µW)

cells swapped

Thermal Energy Storage (TES)

Related to the heat that a

compound is able

accumulate (heat capacity)

∆Q=m.CP.∆T

Related to the heat

absorbed or released

during a phase change

∆Q=∆Ht

Use of a (preferably)

reversible endo /

exothermic reaction

∆Q=∆Hr

Sensible heat measurements

� Heat capacity of Propylene Glycol

Aqueous solution

� 750mg of 40wt% PPG in water

� Continuous method

� Tested between 0°C and 40°C at

0.1K/min

� Blank: empty cells same conditions

� The experimental data are within

+/-1% of literature values

� The total heat stored can be

obtained by integration over the

tested temperature range

� Q=∫CpdT Furnace Temperature (°C)403530252015105

Cp

cont

inuo

us (

J.g^

-1.K

^-1)

43.953.9

3.853.8

3.753.7

3.653.6

3.553.5

3.453.4

3.35

PPG µDSC7 EvoPPG µSCLitt. (Curme and Johnston, 1952)

Latent heat measurements

� Commercially available PCM

� Blend of paraffins, specifications:

mp = 27°C, ΔH = 184 J.g-1

� 50 mg samples fresh and aged

� Test conditions

� Heating from -5°C to 35°C at

0.05°C.min-1

� After accelerated ageing (100

heating / cooling cycles at 5°C/min):

� The storage capacity is not affected, the

latent heat of melting still being 158 J.g-1

� The shift of melting temperature is

significant (0.7°C)

Furnace Temperature (°C)302520151050

Hea

tFlo

w (f

resh

sam

ple)

(mW

)

0

-1

-2

-3

-4

-5

Hea

tFlo

w (a

ged

sam

ple)

(mW

)

0-0.5-1-1.5-2-2.5-3-3.5-4-4.5

HeatFlow (fresh sample)HeatFlow (aged sample)

Exo

Heat : 22.0 (J/g) Onset : 2.0 (°C)

Heat : 158.0 (J/g) Onset : 27.1 (°C)

Exo

Heat : 21.7 (J/g) Onset : 1.7 (°C)

Heat : 158.0 (J/g) Onset : 26.4 (°C)

Oil&Gas - Flow assurance

� Flow assurance

� Refers to the control of hydrocarbon flow from the

reservoir to the delivery point

� Topics

� Wax, asphaltene crystallization, gas hydrates

formation

� 51 serious problems linked with wax deposition

in the Gulf of Mexico between 1992 and 2002

� The cost for repair can reach à $1 million/mile in

subsea pipelines (400m)

� Revenue losses can reach $3 million/day for

deep wells

Wax Buildup in Production Piping

Flow Assurance - Waxes

� Technique: DSC

� Experiment� Crude oil samples (40mg) in aluminum

crucibles

� Temperature profile

� Heating from 25°C up to 80°C at 5°C/min

� Cooling down to 10°C at 2°C/min

� Results

� Exothermic crystallization of the waxes

contained in the oili. Onset temperature = WAT

ii. The amount of waxes precipitated vs.

Temperature data can be obtained by partial

integration and estimation of the heat of

crystallization of « pure » paraffin

Sample Temperature (°C)70605040302010

% P

reci

pita

ted

wax

es (

J/g)

12

10

8

6

4

2

0

Crude Oil 1Crude Oil 3

Sample Temperature (°C)70605040302010

Hea

tFlo

w (

mW

)

Heat : -23.2 (J/g) WAT : 54.2 (°C)

Heat : -7.7 (J/g) WAT : 35.4 (°C)

0.5

Cooling

(i)

(ii)

Flow Assurance - Waxes

Lenise C. Vieira, Maria B. Buchuid, Elizabete F. Lucas, Effect of Pressure on the Crystallization of Crude Oil Waxes. II. Evaluation

of Crude Oils and Condensate, Energy & Fuels (2009)

WAT vs nitrogen pressure

WAT vs methane pressure

� Technique: µDSC + HP

� Experiment� Crude oil samples (100mg) in HP cells with

high (A) and low (C) wax content

� At a given N2 or CH4 pressure:

� heating to 80°C and isotherm of 180

minutes at this temperature,

� cooling at 1°C/min until reaching a

temperature of -10°C

� Results

� Nitrogen: WAT increases with P

� Methane: WAT decreases with P

� CH4, unlike N2, plays a role in

improving the solubilization of waxes.

Hydrogen Storage

� Fuel cell applications :� Stationary

� Safety power (hospital, networks, defense…)

� Electricity for isolated sites

� Power for industrial processes

� Portable� Laptop

� Mobile phones

� Digital equipments

� Portable electrical tools

� Automotive � Transportation

� Defense

� Bike, scooter, boat

� Car

DaimlerChrysler

Angstrom

Axane

Volumetry / Manometry

� Gas is injected in a reservoir

� Of known volume

� At a controlled Temperature

� At a set pressure

� Quantity of gas in the reservoir is

known from these three

parameters and its equation of

state (EOS)

� Sample is contained in a reservoir

� At a set temperature

� Whose free volume is determined

Vent

Test gas

Vacuum

ExpansionReservoir

Sam

ple

Reservo

ir

Pressure measurement

Volumetry / Manometry

� Isolation valve is opened

� The gas expands in the new volume

(reservoir volume + free volume above

the sample)

� The pressure is measured in this

new volume until equilibrium

� The theoretical equilibrium pressure

(that correspond to zero adsorption)

can be calculated by the EOS

� The real equilibrium pressure and the

EOS allows calculating the adsorbed

quantity

Vent

Test gas

Vacuum

ExpansionReservoir

Sam

ple

Reservo

ir

Pressure measurement

RT

VPVP

RT

VVPn cell

icellref

irefcellreff

gas

+−

+=∆

)(

PCTPro-E&E Features

� Instrument flexibility� Wide temperature and pressure ranges

� Vacuum to 200 bar

� -269°C to 500°C

� External sample holder� Wide range of sample sizes

� Easy airless sample handling

� Fully automated computer control

� 5 calibrated volumes (5 to 1,200ml)� Experiment can be optimized for sample and

type of measurement

� Multiple pressure aliquot settings

Hydrogen - Kinetics

� Destabilization of the Mg/MgH2

system by transition metals, their

oxides, and carbon

� Sample (0.5g) directly activated in

the HP cell of a Sensys at 350 °C

by hydrogen cycles between 15

bar and 1 bar

� Very good kinetic behaviors:

� 1.5 min/1.7 min to absorb / desorb 6

wt % H2

C. Milanese et al, International Journal of Hydrogen Energy 35 (2010) 9027-9037

Mg 94wt% - C 1wt% - Nb2O5 5wt%

milled during 1h

Hydrogen - Thermodynamics

*Lynch J. F., J. Chem. Soc., Faraday Trans. 1, (1974) 70 814-824

� PCT Mode� Palladium 880mg at 170°C

� Injections of H2 1 bar in a

volume of 5.78mL

� Heat release per dose increases

during the alpha -> beta

transition of Pd

� The average differential heat of

adsorption in the alpha phase is

found equal to 23.2kJ/molH2

(litt*: 23.32 kJ/molH2–1)

Hydrogen - Thermodynamics

� Hydrogen adsorption on MOF-

5 (BASF Basolite Z100H)� 180mg Sample

� Degasing at 130°C, 3 hours, 10-2mbar

� Isotherm at -186°C (BT2.15)

� Sorption isotherm and differential

heat of adsorption are measured

� The integral heat of adsoprtion (-

4.19kJ/mol) can be compared to the

value detemrined by B. Schmitz et al*:

-4.0kJ/mol

Pressure (bar) (h)

35302520151050

H2

wt%

|c

(-)

3.5

3

2.5

2

1.5

1

0.5

Dif

f. H

ea

t (k

J/m

ol)

(-)

-1

-2

-3

-4

B. Schmitz et al, ChemPhysChem, Volume 9, Issue 15, pages 2181–2184 (2008)

Biomass

� Biodiesel production from vegetable oil

� Biodiesels are synthesized from a transesterification reaction of triglycerides by low molecular weight alcohols leading to the formation of fatty acid alkyl esters.

� This reaction requires the use of a catalyst:� liquid (KOH, NaOH, H2SO4…)

� solid catalyst (zinc aluminates, zeolites, silica mesostructured materials or immobilized enzymes)

Transesterification:

� Conditions� Apparatus: C80

� cells: batch mixing with membrane

� Sample masses:

� Temperature: 30°C, 40°C and 50°C

� Stirring: 20 min

Biomass

Sample Mass (mg)

Colza oil 1300

NaOH in EtOH 450

Biomass

Time (h)302520151050

Hea

tFlo

w (

mW

)

Con

vers

ion

(%)

100

80

60

40

20

0

Colza Oil + NaOH / EtOH 50°CColza Oil + NaOH / EtOH 40°CColza Oil + NaOH / EtOH 30°C

0.5

Reaction

Temp (°C)

Enthalpy

(J/g EtONa)

Time to 98%

conversion (h)

Max heat release

(mW/g)

30 -10.3 20.0 0.69

40 -10.9 11.7 0.89

50 -11.5 10.8 1.37

CO2 Capture and sequestration

� Mainly on Power generation unit,

but also in industries

� Technologies

� Solvent scrubbing (amine solution)

� Post- or Pre-combustion capture

� Cryogenic separation

� Energy cost is high due to refrigeration needed

� Membranes

� Separation of CO2 from gas flow through

porous membranes

� Adsorption

� Activated carbon, zeolites

� MOFs, carbonates

CO2 Capture and sequestration

� High pressure continuous flow

mixing cell

� Fluids (CO2 and amine solution)

introduced at the upper part

� Preheating of the fluids before

entering the calorimetric zone

� Mixing at the bottom part of the

cell

� Resulting mixture extracted from

the cell through the oulet tube.

� Reaction heat is exchanged with

the thermopile through the rolled

tube

Outlet A+B

Preheater

Fluid A

Fluid B

Mixing

device

Thermopile

surrounding

the cell

CO2 Capture and sequestration

2000 4000 6000 8000 100000

0.5

0.0

1.0

1.5

2.0

2.5

3.0

Hea

t fl

ow

(mW

)

Adsorption time (s)

1. Amine

solution

2. CO2

mixing

CO2 Capture and sequestration

� Solubility limit in water + NaCl

� ΔHmix (kJ.mol−1 salt

free solution)

� mNaCl = 1

� T = 323.1 K

� p = 5 MPa

Solubility limit

No additional CO2 dissolved; Total

mixing enthalpy unchangedTotal mixing enthalpy increases

D. Koschel et al. Fluid Phase Equilibria 247 (2006) 107

CO2 Capture and sequestration

� Enthalpies of mixing in water + NaCl at high pressure

D. Koschel, L. Rodier, J-Y. Coxam, V. Majer, Fluid Phase Equilibria 247 (2006) 107

5MPa

10MPa

323 K

Solubility increases with P

14MPa

20MPa

Thanks for your attention!

Energy related applications of calorimetry

Rémi ANDRE – SETARAM Instrumentation

ECN / ExperTA Technology day

Petten, The Netherlands, Thursday, February 5th