“Bio-Inspired heterogeneous catalyst for sustainable biofuel production

Prof. (Dr.) Dhanapati DekaDepartment of Energy

Tezpur University, Tezpur, Assam, India

E-mail: dhanapati@tezu.ernet.inPhone: +91 3712 27 5301

Contents

1. Zoom on Energy2. Biofuel as Energy Source3. Bio-inspired Catalyst on Biofuel production4. Preparation of Bio-based CaO catalysts 5. Preparation of Carbon based catalyst6. Conclusion

Zoom on energy • High level of energy consumption in developed countries• Growth in demand in emerging economies• Impacts from production and distribution of energy on

biodiversity through• Fuelwood collection• Coal mining• Oil and gas extraction, pipelines / shipping (spills)• Dams (flooding of biodiversity reach areas)• Batteries (production and end of life / waste)

• Impacts from use of fossil energy: Climate change, which in turn, has an impact on biodiversity

Biofuels – an opportunity to reduce impacts or posing new threats??

Petroleum Fuel

Challenges

1.Energy inequality/ Energy Dependence

2.Energy Security

3. Fuels and Chemicals

4.Environmental Issues

Why biofuel ? Why now ?

9-Aug-11 Speaker- Dr. Dhanapati Deka

What are Biofuels ?

Biofuels are fossil fuel substitutes that can be made from a range of

agricultural crops and other sources of biomass. The two most

common current Biofuels are ethanol and biodiesel.

Biofuel: Liquid and gaseous fuels produced from biomass – organic matter derived from

plants or animals. (IEA)

Easy availability from biomass sources BiodegradabilitySustainabilityForeign exchange savings Energy securityOpen up a new income generating path in rural areas etc.

%

1111

21st Century: the beginning of a New Era

Challenge: TO DIVERSIFY ENERGY SOURCESChallenge: TO DIVERSIFY ENERGY SOURCESUp to 2030, the world demand for energy should increase 58%.Up to 2030, the world demand for energy should increase 58%.

Sources: Nakícenovic, Grübler and MaConald, 1998 and US Energy Information Administration Speaker- Dr. Dhanapati Deka

1.One of the main bottlenecks in manufacturing of liquid biofuels are their synthesis routes, which relies on the use of many hazardous and corrosive chemicals such as NaOH, KOH, H2SO4 as catalysts.

2.This not only causes environmental hazards but also adds to the carbon footprint and effects the overall economy of the process.

3.Use of renewables as catalysts or catalysts synthesized from renewabale precursors such as boimass and waste may address these issues.

04/21/23 12

Current Route

Major Liquid Biofuels

(Biodiesel, Bioalcohols

etc.)

Feedstocks (Renewabale

Suorces)

Catalysts/ Reagents used

for synthesis(Non-

renewabale Sources

New stratergy

Major Liquid Biofuels

(Biodiesel, Bioalcohols

etc.)

Feedstocks (Renewabale

Suorces)

Catalysts synthesized from

renewabale Sources

Goals of the study

• Our goal is to obtain a renewable multipurpose heterogeneous catalyst that is faster, active, versatile, and stable under the process conditions capable of competeing with commercialy employed catalysts in the production of major biofuels such as biodiesel and bioalchols with greater emphasis on transesterification.

• It will be capable of substituting corrosive chemicals such as H2SO4, NaOH, KOH etc in various other reactions, there by eliminating the problems associated with their use and consequent environmental hazards.

• Our proposed catalysts will make biofuel production environmentally benign and greener as it will be reusable and derived from renewable/waste materials.

Mechanism of Transesterification Reaction

CH2-OH

CH2-OH

CH2-OH

glycerol

CH2-OOC-R1

CH -OOC-R2

CH2-OOC-R3

+ 3R’OH

R1-COO-R’

R2-COO- R’

R3-COO- R’

+Catalyst

At Temp 60 to 70˚C

Triglyceride + Alcohol Esters +CH

CH2 O

CH2O C

O

C

O

R1

R3

OC

O

R2 + CH3OH

H3CO C

O

R1

H3CO C

O

R2

H3CO C

O

R3

+

++

Refined vegetable oil (Triglycerides)

CH

CH2 OH

CH2OH

HO

Glycerin FAME (biodiesel)

Scheme 1 (Reaction scheme for transesterification of lipids)

Methanol

Catalyst

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Homogeneous catalytic approach

Drawbacks of conventional heterogeneous catalysts (Alumina, Zeolites, sulfated zirconia etc.)- Expensive- Leaching- Poor activity for the price Solution: Prepare cost effective heterogeneous catalysts

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18

Heterogeneous catalytic approach

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Preparation of Bio-based CaO catalysts with improved reusability for biodiesel production

Advantages of the resources selected

Recycle the waste.

Wide source, low price & favorable biodegradability.

Environment friendly, safer & cheaper.

High active & reusable.21-Mar-2012 Speaker- Dr. Dhanapati Deka

Catalyst 1• Catalyst is prepared from waste shells of

Turbonilla striatula (mollusk)

• Ref:Boro Jutika, Thakur A. J. Deka D. Solid oxide derived from waste shells of Turbonilla striatula as a renewable catalyst for biodiesel production. Fuel Processing Technology 92 (2011) 2061–2067.

21-Mar-2012 Speaker- Dr. Dhanapati Deka

04/21/23 22

The shells were calcined at different temperatures for 4 h and catalyst characterizations were carried out by XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared spectrometer (FT-IR), thermogravimetricanalysis (TGA)/differential scanning calorimetry (DSC) and Brunauer–Emmett–Teller (BET)surface area measurements .

Formation of solid oxide i.e. CaO was confirmed at calcination temperature of 800 °C. The effect of the molar ratio of methanol to oil, the reaction temperature, catalyst calcination temperature and catalyst amount used for transesterification were studied to optimize the reaction conditions.

Biodiesel yield of 9 3. 3% was achieved when transesterification was carried out at 65±5 °C by employing 3.0 wt.% catalyst and 9:1 methanol to oil molar ratio for 6 h. BET surface area indicated that the shells calcined in the temperature range of 700 °C–900 °C exhibited enhanced surface area and higher pore volume than the shells calcined at 600 °C.

Reusability of the catalysts prepared in different temperatures was also studied

21-Mar-2012Speaker- Dr. Dhanapati Deka

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EDX analysis

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FTIR TGA

GC-MS GC analysis of the Biodiesel components

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Reusability study

XRD pattern of fresh and reused catalysts

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Fuel properties of biodiesel (in the presence of T-CaO catalyst)

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Li doped waste shell derived CaO

Catalyst 2

Ref: Boro Jutika , Konwar Lakhya Jyoti and Deka Dhanapati. Transesterification of non edible feedstock with lithium incorporated egg shell derived CaO for biodiesel production. Fuel Processing Technology 122 (2014) 72–78.

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A series of Li doped egg shell derived CaO is prepared for biodiesel production from nonedible oil feedstock. The catalyst is characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR), Brunauer– Emmett–Teller (BET) surface area measurements and their basic strengths were measured by Hammett indicators.

The feedstock for conducting experiments with Li doped waste shell derived CaO to produce biodiesel was waste cooking oil (WCO). Maximum conversion of 94% is observed with 5% of catalyst amount and 2% of Li loading is observed to be optimum for better conversions.

Though the catalyst is not reusable its catalytic activity can be improved by activating it at appropriate temperature and reloading it with Li. NMR studies showed that the final product separated after transesterification is biodiesel

04/21/23 37

XRD pattern of Li doped T-CaO catalyst

From the Figure 4.16, it is seen that peaks of lithium oxide start to appear and the peaks become more intense with higher Li loading. The peaks corresponding to 2θ= 32, 37, 54, 64, 57 corresponds to JCPDS card no. 01-078-0649 which belongs to that of calcium oxide. On the other hand the peaks which appear at 2θ = 19, 29, 30, 47, 51 belongs to lithium oxide (JCPDS file no. 01-073-1640). As the doping increases the peaks of lithium oxide are observed to dominate the XRD pattern and the peaks of CaO are reduced which indicates that the final Li doped catalyst might have overshadowed the peaks of parent catalyst due to overloading.

04/21/23 38

FTIR

Bands appear around 1400 cm-1, 1000cm-1, 850cm-1 correspond to Li=O stretching, Li-O broad band stretching and Li-O-Li group respectively

Basicity and BET analysis

Surface area decreases with increasing Li loading.

Influence of Li loading on methyl ester

transesterification was carried out with 6:1 methanol to oil ratio at 60 °C for 8 h.

1wt. % Li-doped catalyst prepared from T-CaO is considered as optimum concentration for Li

04/21/23 39

Reusability

Fuel properties of biodiesel (in the presence of Li1.0T-CaO catalyst)

04/21/23 40

04/21/23 41

Ba doped waste shell derived CaO

Catalyst 3

Ref: Boro Jutika , Konwar Lakhya Jyoti, Thakur Ashim Jyoti and Deka Dhanapati. Ba doped CaO derived from waste shell of T striatula (Ts-CaO) as heterogeneous catalyst for biodiesel production. Fuel 129 (2014) 182-187.

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XRD pattern FT-IR

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EDX analysis

Basicity and surface area

04/21/23 49

04/21/23 50

Reusability

04/21/23 51

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04/21/23 53

Preparation of Biomass/Carbon based bio-inspired catalyst

Materials and MethodsRaw material selection • The selection of raw material was based on the recent works in literature. The literature in

biomass derived catalytic materials could be classified two distinct classes:

1. Metal oxides or mixed metal oxides derived from alkali rich biomass sources (e.g. CaO prepared from waste shells of egg, shrimps, mollusk etc.). Solid Basic Catalyst.

2. Carbon materials modified with strong acidic groups (such as –SO3H) also known as sulfonated carbons prepared from biomass or products of biomass origin by carbonization

followed by subsequent sulfonation. Solid Acid Catalyst.• Precursor

Materials rich in carbon to prepare supported Active carbon catalysts namely, Turbonilla striatula (TS) shells and de-oiled cake waste from non-edible oil seeds.

04/21/23 54

CaO supported active carbon (AC) catalyst

Turbonilla striatula shells

Drying, grinding

Carbonized at 500 C, Impregnation with aq.

KOH,

Activation at 700 C

@ 10 C/min

Mixing AC and TS (1:1

w/w) followed by activation at 900 C (3 h)

Active carbon (AC)

Supported CaO catalyst (ACaO)

L J Konwar, J Boro and D Deka , Activated carbon supported CaO prepared from waste mollusk shells as heterogeneous catalyst for biodiesel production, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, (2012, In press) (doi:10.1080/15567036.2012.733483)

•The shells were crushed, dried, sieved and treated as represented below

•AC prepared by two step activation of Shells

•Active phase was formed inside the support by heat treatment of shells at 900 C

CaCO3

Chitin

04/21/23 55

L J Konwar, J Boro and D Deka , Activated carbon supported CaO prepared from waste mollusk shells as heterogeneous catalyst for biodiesel production, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, (2012, In press) (doi:10.1080/15567036.2012.733483)

Characterization results

10 20 30 40 50 60 70

inte

ns

ity

(a

.u)

2 (degree)

CaO ACaO

Fig. EDX spectrum of ACaO catalyst.

4000 3500 3000 2500 2000 1500 1000 500

50

100

150

200

250

C-Hstrech

(%)

Tra

ns

mit

tan

ce

Wavenumber (cm-1)

CaO BCh-CaO

C-O

Ca-O

O-H

Aromatic C-Hbend

C=O

Fig. XRD (top) and FT-IR (bottom) patterns of CaO in comparison to ACaO.

Fig. SEM images of AC and ACaO particles.

(a)

(b)

04/21/23 56Continued….

04/21/23 57

04/21/23 58

04/21/23 59

Basicity measurements The basicity of the CaO supported ACaO catalyst and shell derived CaO were determined using the hammett indicator tests. It was observed that the catalysts and CaO changed the colour of phenolphthalein (H_ = 8.2) from colorless to pink, the colour of indigo carmine (H_=12.2) from blue to green and the colour of 2,4-dinitroaniline (H_ = 15) from yellow to mauve but failed to change the colour of 4-nitroaniline (H_ = 18.4). Therefore, the catalyst’s basic strength was designated as 15< H_<18.4, and it was considered as a strong base for the transesterification reaction similar to pure CaO.

Optimization results

40 50 60 70 80 90 100 110 120 130 140

20

30

40

50

60

70

80

90

100

Con

vers

ion

(%)

Reaction Temperature (OC)

(a) (b)

0 2 4 6 8 10 12 14 16 18

40

50

60

70

80

90

100

Con

vers

ion

(%)

Catalyst (Wt.%)

(c)

0 1 2 3 4 5 6 7 8 90

20

40

60

80

100

Con

vers

ion

(%)

Reaction time (in h)

(d)

1

2

3

4

5

0 20 40 60 80 100

Conversion (%)

No.

of R

uns

(e)

04/21/23 60

Optimum temp 100-1200C

Optimum 40:1

Optimum 10% Optimum

8 h

No change after 5 run

04/21/23 61

Waste shells of TS were successfully utilized as a raw material for the preparation of both the support (AC) and active phase of a supported CaO catalyst (ACaO). The catalyst was prepared by physical mixing of the finely powdered TS shells with AC followed by a simple heat treatment at 900 C to generate the active CaO particles. The resulting catalyst was successfully employed in the transesterification of used cooking oil. Under optimum reaction conditions of 120 °C, 40:1 methanol to oil ratio, 10/11 wt% catalyst and 7/8 h of reaction time, methyl ester yields as high as 96% could be reached. The catalyst was reusable and it maintained its initial activity upto five cycles. Consequently the reusability issues of the ash catalysts were successfully addressed by employing ACaO catalyst.

Drawbacks and Limitations of ACaO and ash catalyst

Due to such shortcomings in the following chapters the attention of the work was shifted towards solid acid catalysts.

• -SO3H containing AC were synthesized from deoiled-cake wastes (a Lignocellulosic biomass) from non edible seeds, a by-product of biodiesel production and used as catalytic materials in the production of biodiesel and bioethanol.

1. Low surface area

2. Leaching and low stability of supported active species/phase in presence of moisture or hydrophilic molecules. As a result active sites are easily poisoned or leached during reactions.

3. Applicability restricted only to biodiesel production.

04/21/23 62

04/21/23 63

Sulfonated carbon catalysts based on de-oiled cake waste I: Synthesis and applications in biodiesel production

• A sulfonated carbon (Brønsted solid acid) catalyst exhibiting a high surface area and acidity was from de-oiled waste cake residues (DOWC) of Mesua Ferrea Linn. seeds, obtained as a byproduct from biodiesel production.

• In the first step DOWC soaked in 50% phosphoric acid were subjected to activation at 500 C under self generated atmosphere in a muffle furnace to generate the porous AC supports.

• In the 2nd step the AC was subsequently sulfonated with freshly prepared 4-benzenediazonium sulfonate (by diazotization of sulfanilic acid) to generate the catalytic materials under varying conditions.

Konwar L J, Das R, Thakur A J, Salminen E, P Mäki-Arvela, Kumar N, Mikkola J-P and Deka D. Biodiesel production from acid oils using sulfonated carbon catalyst derived from oil-cake waste, Journal of Molecular Catalysis A: Chemical 388–389 (2014) 167–176.

04/21/23 64

Fig. 12; Schematic summary of the work

Konwar L J, Mäki-Arvela P, Thakur A J, Salminen E, Kumar N, Mikkola J-P and Deka D. Towards carbon efficient biorefining: Multifunctional mesoporous solid acids obtained from biodiesel production wastes for biomass conversion. Applied Catalysis B: Environmental 176 (2015) 20–35.

A potential hazardous Waste produced by the processing of Non-edible oil seeds

Toxins includephorbol ester-Jatropha karanjin –PongamiaRicin- Castor

Disposal problems

(ultimately added to

production cost

of biodiesel)

65

Structure of activated carbon /amorphous carbon/amorphous

graphite in compassion to graphite

Graphite

OHOH

COOH

OHO

HOOC

OH

HOOC

COOH

HO

O

Sites for attaching new functional groups(-SO3H, -Ph-SO3H etc.)

Sites for attaching new functional groups(-SO3H, -Ph-SO3H etc.)

04/21/23 66

Scheme used for grafting -Ph-SO3H groups on carbon surface

OHOH

COOH

OHO

HOOC

OH

HOOC

COOH

HO

30-32%aqueous H3PO2 (Method 1)

ON2

+ Cl-HO3S

Hold in 1 M HCl for 12 h (Method 2)

OHOH

COOH

OHO

HOOC

HO3SC6H4

COOH

HO

C6H4SO3H

C6H4SO3H

C6H4SO3H

HO3SC6H4

O

HOOC

OH

Activated Carbon Sulfonated Activated Carbon

Or

4-benzenediazoniumsulfonate

+ N2

Continued….

Catalyst particles in methanol

Product (biodiesel and oil)

Fig. 13; Spontaneous separation of hydrophilic catalyst particles from non-polar product mixture (biodiesel and oil).

Fig. 14; Reaction scheme for simultaneous esterification/transesterification of acid oils using sulfonated carbons as catalysts.

Konwar L J, Das R, Thakur A J, Salminen E, P Mäki-Arvela, Kumar N, Mikkola J-P and Deka D. Biodiesel production from acid oils using sulfonated carbon catalyst derived from oil-cake waste, Journal of Molecular Catalysis A: Chemical 388–389 (2014) 167–176.)

H3PO4

Activation@500 C in air

OHOH

COOH

OHO

HOOC

OH

HOOC

COOH

HO

O

04/21/23 68

Sulfonated CarbonsCHCH2 O

CH2 O CO

CO

R1

R3

OCO

R2

+RCOOH

MeOH

H3CO CO

R2

+

Acid oils (Triglycerides + FFAs)

CHCH2 OH

CH2 OHHO

Glycerin (Trace)FAME + Triglycerides

CHCH2 O

CH2 O CO

CO

R1

R3

OCO

R2 +

+

H2O

OHOH

COOH

OHO

HOOC

HO3SC6H4

COOH

HO

C6H4SO3H

C6H4SO3H

C6H4SO3H

HO3SC6H4

O

HOOC

OH

Table 5

Surface properties of sulfonated carbons and their catalytic activitiesCatalysts Total acid

density a /(mmol g-1)

-SO3H density b (mmol g-1)

Specific Surface area(m2 g-1)

Micro Pore volume (cm3g-

1)

La c

(nm)Esterification

activityCEst

(%)k ( h-1)

MAC 2.032 - 777 0.28 5.47 11 -MAC-SO3H 2.426 0.735 556 0.20 4.89 99 0.65MAC-SO3H (spent) 2.416 0.672 - - - 90 -Starch-SO3H [1] 4.130 1.500 n.r n.r n.r ≤95 n.rOil pitch-SO3H [2] 2.040 2.210 8 n.r n.r 95 n.rCorncob-SO3H [3] n.r 0.160 80 n.r n.r n.r n.ra based on titration,b based on elemental analysis, c average size of polycyclic aromatic carbon sheets (graphitic clusters) n.r = not reported,(spent) = catalyst recovered after fifth cycle of Jatropha oil esterificationReaction conditions: 80 C, 6 h, 43:1 (methanol to oil molar ratio), esterification of crude Jatropha oil (containing 8.17 wt% FFA) Continued….

Characterization resultsTable 4

Elemental analysis of carbon materials Sample C H N Oa S O/S

Mesua ferrea L. OCW 48.63 7.38 3.65 40.34 - -MAC 70.28 2.82 3.19 23.54 - -MAC-SO3H 54. 65 3.73 4.49 34.76 2.35 14.79MAC-SO3H (spent) 55.15 2.98 4.23 35.48 2.15 16.50a by difference (ash free basis) (spent) catalyst recovered after fifth cycle of Jatropha curcas oil esterification

04/21/23 69

(a) (b)

(a)

SEM images of the carbonaceous materials (a) MAC and (b) MAC-SO3H.

The SEM pictures also show that the morphology of the carbon material remains mostly unaffected by sulfonation with 4-benzenediazoniumsulfonate

TEM image of the carbon catalyst MAC-SO3H under different magnifications (a) 100 nm (b) 20 nm. . The presence of randomly

arranged aromatic/graphitic carbon sheets is clearly visible in TEM micrographs of MAC-SO3H samples. The size of the catalyst particles in Fig. is about 348 nm.

(b)

Continued….

L J Konwar, R Das, A J Thakur, E Salminen, P Mäki-Arvela, N Kumar, J-P Mikkola and D Deka, Biodiesel production from acid oils using sulfonated carbon catalyst derived from oil-cake waste, Journal of Molecular Catalysis A: Chemical (2013, In press) (doi:10.1016/j.molcata.2013.09.031)04/21/23 70

3500 3000 2500 2000 1500 1000 500

S=O Streching (*)SO3H Streching (̂ )

^ **

^

^

^

^

% Tr

ansm

ittan

ce

Wavenumber (cm-1)

(a)

(c)(d)

^

**

**(b)

(d) MAC-SO3H(c) MAC-SO3H*(b) Spent MAC-SO3H(a) MAC

Fig. : FT-IR spectra of porous carbons.

20 30 40 50 60 70 80

Inte

nsity

(a.u

)

(c)

(a)

C (002)

C (101)

(b)

(a) MAC(b) MAC-SO3H*(c) MAC-SO3H

Fig. X-ray powder diffraction patterns of carbon materials.

0 100 200 300 400 500 60000

20

40

60

80

100

Wei

ght (

%)

Temperature (oC)

(a)

(b)

(a) MAC(b) MAC-SO3H

Fig. TGA patterns of MAC and MAC-SO3H catalysts.

High thermal stability upto 240 C

Sulfonation increases amorphous character

Presence of SO3H groups confirmed in both spent and fresh materials

Continued….71

C=O, near 1700 cm-1

1580 cm-1 incomplete carbonized ring –aromatic ring

1185 cm−1 (P=O stretching) 1075 cm-1 (P-OC stretching)

The bands appearing at 1185 cm−1 (P=O stretching) and 1075 cm-1 (P-OC stretching) in the non-sulfonated carbons were due to incorporation of H3PO4 in MAC as a result phosphoric acid activation. The appearance of additional bands at 1097 cm−1 and 1008 cm−1 (S=O stretching) and 1176 cm−1, 1171 cm−1 and 1275 cm−1 (stretching in -SO3H along with P=O stretching) in the FT-IR spectra of the sulfonated carbons were consistent with the presence of -SO3H groups .

Catalytic tests

0

20

40

60

80

100

3%

5%

0.02%

H 2SO 4

MAC

MAC-S

O 3H

MAC-S

O 3H

MAC-S

O 3H

MAC-S

O 3H

MAC-S

O 3H

MAC-S

O 3H

FFA

conv

ersio

n (%

)

2%

0%

4%

5% 6.5%

Blank

5%* ( 43.73 wt% FFA )

MAC-S

O 3H

*

MAC-S

O 3H

*

MAC-S

O 3H

*

MAC-S

O 3H

*

MAC-S

O 3H

*

Fig. 19; Effect of catalyst amount on free fatty acid (FFA) conversion. The reaction temperature was 80 °C and the reaction time was 8 hours. Methanol to acid oil molar ratio of 43:1 was applied.

0 1 2 3 4 5 6

0

20

40

60

80

100

Time (h)

FFA

conv

ersio

n (%

)

50 oC, MAC-SO3H

65 oC, MAC-SO3H

80 oC, MAC-SO3H*

80 oC, MAC-SO3H

100 oC, MAC-SO3H

Fig.20; Free fatty acid (FFA) conversion as a function of time. Effect of reaction temperature on free fatty acid (acid oil containing 8.2 wt% of FFA) conversion. The catalyst loading was 5 wt% and methanol to acid oil molar ratio was 43:1.

0 1 2 3 4 5 6

0

20

40

60

80

100

21.5:1, (43.73 wt% FFA) 10.75:1, (43.73 wt% FFA) 6:1, (43.73 wt% FFA)

Time (h)

43:1, (8.17 wt% FFA) 32.2:1, (8.17 wt% FFA) 21.5:1, (8.17 wt% FFA)

FFA

conv

ersio

n (%

)

Fig. 21; Free fatty acid (FFA) conversion as a function of time. The effect of methanol-to-acid oil molar ratio on FFA conversion. The reaction temperature was 80 °C and the catalyst (MAC-SO3H) loading was 5 wt%.

0 1 2 3 4 5 6

0

20

40

60

80

100

Time (h)

FFA

conv

ersio

n (%

) 8.17 wt% FFA (21.5:1) 14.7 wt% FFA (10.75:1) 43.73 wt% FFA (21.5:1) 43.73 wt% FFA (10.75:1)

Fig. 22; Free fatty acid (FFA) conversion as a function of time. Effect of initial FFA level on FFA conversion. The reaction temperature was 80 °C and the catalyst (MAC-SO3H) loading was 5 wt%. Cont….04/21/23 72

With the sulfonated carbon catalysts MAC-SO3H and MAC-SO3H*, the conversion of FFA in acid oils was 99 % and 97 %, respectively at 80 C within 8 h.

1ST JO5SH21-1 (JATROPHA 100).ESP

7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0Chemical Shift (ppm)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

No

rma

lize

d In

ten

sity

3RD USE JO5SH21-1.ESP

7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0Chemical Shift (ppm)

0

0.1

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0.3

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0.6

0.7

0.8

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No

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lize

d In

ten

sity

MO5SH.ESP

7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0N

orm

aliz

ed

Inte

nsi

ty

hydrogen peak of triglyceride

hydrogen peak of triglyceride

hydrogen peak of triglyceride

(a)

(b)

(c)

methyl ester peak

1ST JO5SH21-1 (JATROPHA 100).ESP

2.4 2.3 2.2Chemical Shift (ppm)

0

0.05

0.10

0.15

0.20

No

rma

lize

d In

ten

sity

Fig. 23; 1H NMR (a) Showing increased total (esterification + transesterification) yield when using AO with 43.7wt% FFA (b) Effect of reuses on transesterification (reduced yield) at fifth cycle using AO with 43.7wt% FFA (c) Showing low transesterification yield when using AO with 8.17wt% FFA, (insert shows decreased intensity of unmerged FFA triplet at 2.38 ppm); Reaction conditions: 5% MAC-SO3H catalyst, methanol-to-oil

molar ratio 43:1, T = 80 C, t = 8 h.

0102030405060708090

100

43.73 wt% FFA

43.73 wt% FFA

8.17 wt% FFA

MAC-SO3H* MAC-SO3H(5)MAC-SO3H

Met

hyl e

ster

mol

ar y

ield

(%)

Total Esterification Transesterification

MAC-SO3H

8.17 wt% FFA

Fig. 24; Comparison of esterification and transesterification activities. The reaction temperature was 80 °C and the reaction time was 8 h whereas the catalyst loading was 5 wt% and methanol to acid oil molar ratio was 43:1.

1H- NMR also confirmed the non leaching of aromatic species

80

100

FFA

conv

ersi

on (%

) 8.17 wt% FFA 43.73 wt% FFA

51 2 3 4No of Cycles

Fig. 25; Deactivation of the MAC-SO3H catalyst (FFA

conversion was illustrated for five consecutive cycles). The reaction temperature was 80 °C and the reaction time was 8 hours whereas the catalyst loading was 5 wt% and methanol to acid oil molar ratio was 43:1.

Continued….

Tranesterification activity increase with FFA amount

04/21/23 73

Sulfonated carbon catalysts based on de-oiled cake waste II: The effect of carbon source on structure and activity

• C The chapter discusses the effect of carbon source and sulfonation method on the structure and activity of the de-oiled waste cake (DOWC) residue derived sulfonated carbons, obtained from of three different non-edible oil seed wastes (Jatropha Curcas, Pongamia Pinnata and Mesua ferrea Linn), all obtained as by-products from biodiesel production.

• It presents comprehensive characterization of the said materials by means of N2-physisorption, XRD, EDX, XPS, Elemental analysis, FT-IR, Raman analysis, NH3-TPD and acid-base titrations.

• Their catalytic behavior were studied in esterification of fatty acids and saccharification of cellulosic materials, two highly contrasting and important acid catalyzed reactions associated with the production of biofuels.

Konwar L J, Mäki-Arvela P, Thakur A J, Salminen E, Kumar N, Mikkola J-P and Deka D. Towards carbon efficient biorefining: Multifunctional mesoporous solid acids obtained from biodiesel production wastes for biomass conversion. Applied Catalysis B: Environmental 176 (2015) 20–35.

74

Sulfonated Carbons+RCOOH MeOH H3CO C

OR

Fatty acid FAME

+ H2O

OHOH

COOH

OHO

HOOC

HO3SC6H4

COOH

HO

C6H4SO3H

C6H4SO3H

C6H4SO3H

HO3SC6H4

O

HOOC

OH

HOOC

Biomass (Starch, Cellulose or Lignocellulose )

Fermentable sugars

OH

HO

H

HOH

OHOHH

R

H

OH

O

HHO

H

OHH

R OH

O

HHO

H

OHH

R

O

nR= CH2OH or H

R= CH2OH (Glucose)R= H (Xylose)

H2O

OO R

Water soluble Oligomers

R= CH2OH (HMF)R= H (Furfural)

+degradation products

Sulfonated Carbons

OHOH

COOHOHO

COOH

HO3SC6H4

COOH

OH

C6H4SO3H

C6H4SO3HC6H4SO3H

HO3SC6H4

O

HOOC

OH

+H2O

Sulfonated Carbons

OHOH

COOHOHO

COOH

HO3SC6H4

COOH

OH

C6H4SO3H

C6H4SO3HC6H4SO3H

HO3SC6H4

O

HOOC

OH

Reaction scheme for Esterification of long chain fatty acids with methanol

Reaction scheme for Hydrolysis of cellulose/biomass into fermentable sugars

Thermometer

Three neck flask

Hot plate and stirrer

Condenser

Oil bath

Desired product

75

04/21/23 76Continued….

Conclusion and summary

• Three different approaches were successfully applied to transform biogenic wastes into heterogeneous catalysts (both acidic and basic)

• All the base catalysts were successfully employed in transesterification of vegetable oils to FAME (** given that the FFA content in oil was less than 1wt%).

• Highest FAME yields upto 96% was achieved under optimized reaction conditions over the ACaO catalyst.

• ACaO exhibited superior reusability under the investigated reaction conditions when compared to CaO.

• Ash (mixed alkali and alkaline oxide type catalysts) were prone to severe deactivation as the active species (K2O and CaO) were easily leached to the reaction media.

Continued….04/21/23 77

Research area developed—Biomass Conversion laboratory

a) Biodiesel production from locally available oil seeds

b) Development of heterogeneous renewable catalysts for biodiesel production and valorization of wastes.

c) Microemulsion based hybrid Biofuel using locally available vegetable oil.

d) Microbial fuel cell

Research in PlanCatalytic Transformation of microalgae into fuel and chemicals using Nano catalysts/solid acid catalyst-transesterification and hydrotreating, Green Diesel Production.

Exploring Microalgae harvesting method (RAH).

Biodiesel production Micro-emulsion based hybrid biofuel production

• Mesua ferrea (Nahar)

• Pongamia pinnata (Karanja)

• Pongamia glabra (Koroch)

• Thevetia peruviana (Karabi)

• Azadirachta indica (Neem)

• Madhuca longifolia (Mahua)

• Hevea brasiliensis (Rubber)

• Gmelina arborea (Gomari)

• Sapindus mukorossi (Reetha)

• Mesua ferrea (Nahar)

• Thevetia peruviana (Karabi)

• Gmelina arborea (Gomari)

• Acer laurinum Hasskarl (Kathbadam)

• Mimusops elengi Linn (Bokul)

• Waste Cooking Oil

• Refined Soybean Oil

Indigenous vegetable oil feedstock for

Some recent publications of Prof. D.Deka and his group (2014-2015)

1. Konwar LJ, Mäki-Arvela P, Begum P, Kumar N, Thakur AJ, Mikkola J-P, Deka R and Deka D. Shape selectivity and acidity effects in glycerol acetylation with acetic anhydride: Selective synthesis of triacetin over Y-zeolite and sulfonated mesoporous carbons. Journal of Catalysis, 329, 237–247(2015

2. Konwar LJ, Mäki-Arvela P, Salminen E, Kumar N, Thakur AJ, Mikkola J-P and Deka D. Towards carbon efficient biorefining: Multifunctional mesoporous solid acids obtained from biodiesel production wastes for biomass conversion. Applied Catalysis B: Environmental 176, 20–35 (2015).

3. Bora P, Konwar LJ , Boro J, Phukan M M , Deka D and Konwar BB. Hybrid biofuels from non-edible oils: A comparative standpoint with corresponding biodiesel. Applied Energy 135,450–460 (2014).

4. Boro J, Konwar LJ, Thakur AJ and Deka D. Ba doped CaO derived from waste shells of T striatula (TS-CaO) as heterogeneous catalyst for biodiesel production. Fuel, 129, 182–187 (2014).

5. Boro J, Konwar LJ and Deka D. Transesterification of non-edible feedstock with lithium incorporated egg shell derived CaO for biodiesel production. Fuel Processing Technology, 122, 72–78 (2014).

6. Konwar LJ, Das R, Thakur AJ, Salminen E, Mäki-Arvela P, Kumar N, Mikkola J-P and Deka D. Biodiesel production from acid oils using sulfonated carbon catalyst derived from oil-cake waste. Journal of Molecular Catalysis A: Chemical, 388-389, 167-176 (2014).

7. Konwar LJ, Boro J and Deka D. Review on latest developments in biodiesel production using carbon-based catalysts. Renewable and Sustainable Energy Reviews, 29, 546–564 (2014).

8. Das S, Thakur AJ and Deka D. Two-Stage Conversion of High Free Fatty Acid Jatropha curcas Oil to Biodiesel using Brønsted Acidic Ionic Liquid and KOH as Catalysts. The Scientific World Journal, Volume 2014, pp 1-9, Article ID 180983, http://dx.doi.org/10.1155/2014/180983 (2014).

9. Deka D, Sedai P and Chutia RS. Investigating woods and barks of some indigenous tree species in North East. Energy Sources, Part A: 36, 1913-1920 (2014) doi = {10.1080/15567036.2010.538802}.

Research group of Biomass conversion laboratory

Ph.D. Scholar1. Dr. Dipak Sarma- Ph.D. awarded2. Dr. Jutika Boro- Ph.D. awarded3. Dr. Lakhya Jyoti Konwar-Ph.D.awarded (CIMO fellowship)4. Mr. Pitambar Sedai- Ph.D, awarded.5. Mr. Plaban Bora-Ph.D. awarded6.Ms. Anuchya Devi- Ph.D. ongoing7.Ms. Velentina Das– Ph,D ongoing8. Mr. Manash Jyoti Borah-Ph.D. ongoing9. Mr. Swagat Chutia-Ph.D. ongoingM. Tech project students (ongoing)1.Minakshi Gohain2. Sikhamoni Mali3.Jery Lani4. Anjanjyoti Bharali

Contact:Professor D. DekaProfessor & HeadDepartment of EnergyTezpur UniversityTezpur-784028E-mail: dhanapati@tezu.ernet.in

Ph. D. awarded : 5Ph.D. ongoing: 4M.Tech. awarded: 26M. Tech ongoing: 4

04/21/23 82

Thank you for your attention!