Using Hydrogen and CO2

1. A Presentation by:
DEBAJYOTI BOSE
M Tech- REE, UPES

2. NECESSITY
 Growing concerns about global climate change have increased
attention on various approaches to reduce emissions of CO2 and
other GHGs
 Several relatively small-scale carbon capture and sequestration
(CCS) approaches are currently in development and
demonstration stages.
 Technologies being developed today to capture and sequester
CO2 require the isolation, compression, and transport of the
CO2 to a sequestration site

3. THE BETTER ALTERNATIVE
 Converting CO2 to a useful product involves reaction with H2
(hydrogen) over a metal catalyst to produce methane
 This methanation process, also called the Sabatier reaction has
been studied extensively
 This same process is effective in converting carbon monoxide
(CO) to methane
 Methanation of both CO and CO2 are highly exothermic reactions

4. RESEARCH FINDINGS
 Bugante et.al, 1989 conducted experiments on methane
production from hydrogen with a gas mixture of CO and CO2
 All chemicals used were of commercial grades
 Measurement of CO2, CO, CH4 and H2 were done by the
process of Gas chromatography
 Nitrogen quantity is measured by Micro Kjeldahl method
 Involved a two stage process

5. PROCESS BASICS
 Thermophilic methanogens were used in a bioreactor
 Preparation of methane sludge:
 Acclimatized at 55°C for at least 6 months to establish
methanogenic fermentation
 A portion of the sludge was inoculated in S medium as
described by Schauer et. Al, 1980
 It is also incubated with gas mixture of 80% H2 and 20% CO2
“Gas recirculation at 55°C at pH 7.4”

6. SYSTEM COMPONENTS
Taken from Bugante et.al, 1989

7. SYSTEM ESSENTIALS
 Reactor volume = 500 ml
 2 liter (each) rubber balloon at top
 Gas recirculation pump is used (Max
capacity 6L/minute)
 A gas filter (2.5 cm dia) at bottom
inside of column for gas recirculation
 100 ml media used for cultivation of
methanogens
 Thermo-regulator and pH regulator
 Baked clay, gravel balls and cristobalite
PQ 10 no 1 and no 2 were tested for
supporters

8. PROCESS PARAMETERS (REACTANTS)
 Reactant Gas Mixture: N2 + CO2 + CO
Consumption rate of CO = 480 mmol/l-d
CH4 production = 120 mmol/l-d
Gas recirculation speed = 18 l/hr
 Second reactant is Hydrogen gas obtained from
renewable electrolysis
 Rate of Hydrogen Consumption = 1380 mmol/l-d
Conditions:
T = 55°C
pH = 7.4

9. The S Medium
 As additives the following were present:
0.05% Trypticase
0.05% yeast extraction
 Cultivation was done for ten days with repeated supply of gas
 Gas mixture (80% H2 + 20% CO2)
 Recirculation speed 18l/hr at 55°C
“pH at 7.4 maintained by adding 10% HCl or NaoH solution”
When turbidity of the medium reaches 0.5, medium was removed (OD660)
100 ml of S medium was newly supplied to the column for a methane
production test

10. BASIC CHEMISTRY
50% N2 50% N2
25% CO → 2% CO
25% CO2 48% CH4
Reactant Product Gas
Gas
+ H2
Calorific Value
of Product gas = 4621 Kcal/m³

11. STEPS INVOLVED
 First step of the conversion
Hydrogen used = 2.24 l
 Second step of conversion
Hydrogen used = 4.02 l
A Gas Balloon was used to achieve
the second step of conversion of CO2
to CH4
Starting Gas at second step:
17.9% N2
15.7% CO2
2.2% CH4
64.2% H2
Calorific Value = 2250 Kcal/m³

12. OTHER PROMISING PROCESSES
 Sabatier Process
 Nickel was the first catalyst used (P. Sabatier, 1897)
 Further research (Ru, Rh, Co)
 To minimize cost and increase efficiency oxide (TiO2, MgO, Al2O3)
supports were used
“Ru-TiO2 being most stable & effective”
 Sabatier Process with Bio-digester
 Utilizing CO2 in biogas to effectively to produce bio methane
 This has the potential to replace expensive industrial operation

14. LIMITATIONS
 The source of the reactants is a significant barrier to
commercial use of Sabatier Process
 Until the value of methane is greater than the value
of hydrogen there is unlikely to be any market for CH4
created from hydrogen, regardless of the source of
hydrogen

15. REFERENCES
 Bugante, E. Shimomura, Y. Tanaka, T. Taniguchi, M Oi,
S.: Methane production from hydrogen and carbon di
oxide in a column bio reactor of thermophilic
methanogen by gas recirculation. J. Ferment and
Bioeng., 67, 419-421 (1989).
 Schauer, N.L. and Ferry, J.: Metabolism of formate in
Methanobacterium formicicum. J. Bacteriol,, 142, 800-
807 (1980).
 http://www.pennenergy.com/articles/pennenergy/20
10/03/the-sabatier-reaction.html

16. THANK YOU !!!
A PRESENTATION BY
DEBAJYOTI BOSE
M TECH REE, UPES