Developing A Bio-gas based Carbon Neutral Engine Systems

A Shift from Exploitation to Harvesting ….

P M V SubbaraoProfessor

Mechanical Engineering Department

Carbon Neutral Energy Systems

Bio-Diesel Seed Crops

Cake

Shell : Woody bio-mass

OilBio-Diesel

seeds

Yeild : Dry Fruits

~ 32% by mass

Energy Credits for Bio-Diesel Production

Decorticator

seeds shells

Oil Expeller

Reactor

Biodiesel

Fruits

Mechanical or ElectricalEnergy

Electrical or Mechanical Energy Oil

Electrical & Thermal Energy

Cakes

Glycerol

Pongamia Trees At IIT Delhi

Pongamia Collections

Mass Distribution of Pongamia Collections

~50%

~50%

Mass Distribution of Jatropha Collections

~40%

~60%

Mass Distribution of Pongamia Seeds

~65%

~35%

Mass Distribution of Jatropha Seeds

~65%

~35%

Energy Audit of Sub-Species of Oil Seed Collections : 1ton of Bio-Diesel

• Mass of produce: 6.3 tons.• Mass of Bio Diesel: 1 ton.• Mass of cake : 2.15 tons.• Mass of Shells : 3.15 tons.• Calorific value of Bio-diesel : 38 MJ/kg• Calorific value of cake: 19 MJ/kg.• Calorific value of shells: 15 MJ/kg. • Total Energy value of Bio-diesel: 38 GJ• Total Energy value of Cake: 40.8GJ• Total Energy value of Shells: 47.25GJ

Energy content in sub species of pongamia fruit seed as biodiesel feedstock

Mass distribution of biodiesel and by produce: Pongamia oil (17.5%); Cake (32.5%); Seed shell (50%)

Biodiesel (31%)

Cake (31%)

Shell (38%)

Decorticator

Gasifier

Crusher

Oil Heater

Biodiesel

SI Engine

Fruit

Seeds

GasShells

Oil

Power

Power

Heat

Internal Energy Generation

Internal Re-Generation of Energy Credits

Cake Extra

Indian Bio-diesel Mission

Jatropha and pongamia oils seeds.

Neither used as cattle feed nor as bio-manure.

Annual production of toxic jatropha oil cake alone is estimated to be about 60, 000 tonnes.

Non-availability of much scientific information on biomethanation of jatropha and pongamia oil seed cakes

The oil cake could be a potential source of biogas production, to supplement the petroleum demand in substantial amount.

Cake -- to -- Bio-Fuels

Biogas Generation from Non-Edible Oil Seed Cakes

Dry Pongamia Seed Cake

Dry Jatropha Seed Cake

Seed Cakes soaked in water

Proximate analysis of feed materials

Feed material

Physiochemical properties

Moisture content %

Oil content%

Total solids %

Volatile solids %

Non-volatile solids %

Cattle dung 81.6 (442.5 db) Nil 18.4 14.4 (78.8 db) 21.2

Jatropha oil seed cake 07.5 (8.1 db) 8.3 92.5 86.4 (93.0 db) 07.0

Pongamia oil seed cake

10.5 (11.7 db) 7.2 89.5 85.3 (94.8 db) 05.2

Ultimate Analysis and carbon-nitrogen ratio of feed materials

Sr. No. Feed material C (%) H (%) N (%) C/N ratio

1 Cattle Dung 35.20 4.60 1.55 22.7

2 Jatropha oil seed cake 48.80 6.20 3.85 12.7

3 Pongamia oil seed cake 47.80 6.50 5.50 8.7

The study showed that these oil cake have more than six times higher volatile solids content than that of cattle dung.

Carbon and Hydrogen contents are also higher than cattle dung.

Preliminary Batch Biomethanation Study

5 L Aspirator Bottle[DIGESTER]

5 L Aspirator BottleFilled With Water

Gas Contituents Analysis(Biogas Analyzer)

Valve Valve

Valve

Cork Cork

Cork

Gas Volume Measurement(Measuring Cylinder)

Experimental setup for batch biomethanation study

1717

Range of ambient temperature variation 24.5 to 35.1 °C

Range of substrate temperature variation 24 to 34.5 °C

Period of Experimental Study:15th March 2006 to 12th June 2006

18 Experimental Setup used for Preliminary Batch Study

1818

The Disheartening Results

• The maximum range of methane content in gas produced from biomethanation of jatropha and pongamia oil cake was found to vary from 25 to 30 % only.

• The quality of produced biogas was found very poor on oil cake substrates.

• HRT of 90 days!!!

A major challenge in biomethanation of these oil cakes is lacking of inherent bacteria like cattle dung.

Lack of these inherent bacteria demands a special attention for operation of digester with oil cake.

Other major deficiency of cake is the presence of long chain free fatty acids, which are prone to destroy the population of bacteria.

An appropriate amount of cattle dung with oil cake may stabilize the bacterial population.

Low yield and very poor quality of biogas was observed during the preliminary batch

biomethanation study.

Thus the cattle dung inoculum were not encouraging.

The substrates of jatropha and pongamia oil cakes might have created a sudden and drastic change in environment for the bacterial activity resulting in their inhibition. This shows that continuous drop in population of bacteria in the inoculum.

This is due to effect of bacterial inhibition since the substrates were new for the bacteria present in the cattle dung inoculum.

This proves that production of effective (special) inoculum in a small aspirator bottles with little amount of initial inoculum (taken from a cattle dung digester) is not feasible.

Conclusions from Characterization of Feed Materials and Preliminary Batch Biomethanation Study

2020

F

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7.523237.5All dimensions in centimetres

10 D

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B/C

EM

Pip

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10 D

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B/C

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Fou

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(1:3

:6)

Ear

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Ground Level

Gas Holder Supporting Structure

Biogas plant (20 m3/d) capacity available at IIT Delhi

21

Development of Special Inoculum

20 m3/d BGP

No feeding of CD before last 3 months

About 12 m3 CD inoculum

Feeding of pongamia oil cake in 3:1 DR for 15 days

Schedule I 2 kg pongamia oil cake with 6 kg water for 5 days

1 2 3 4 5Sta

rt of g

as

pro

du

ctio

n

Con

tinu

ed

Schedule II 5 kg pongamia oil cake with 15 kg water for 10 days

6 7 8 9 10 11 12 13 14 15

Drop in gas yield

Increase in gas yield

Constant gas yield (10-15 day) at 30 cm height

10 cm height

2222

A New Generation of Microbes

The dung based bacteria evolved into a suitable strain in order to adopt to the environment offered by new substrates.

This acclimatization is due to fact that, when the concentrations of inhibitory or toxic materials are slowly increased within the environment, many microorganisms can rearrange their metabolic resources, thus overcoming the metabolic block produced by the normally inhibitory or toxic material.

This study lead to a set of important developments, namely, an effective inoculum as a pool of new microorganisms, an optimal size of the inoculum and a mode of operation.

Sufficient time and controlled loading should be made available for this rearrangement to take place.

The slurry of the biogas plant being fed with pongamia de-oil ed cake was

used as inoculum for further studies.

BIOMETHANATION OF JATROPHA AND PONGAMIA OIL SEED CAKES AND STUDY OF REACTION KINETICS

Experimental phases of

biomethanation process

Phase Phase description Period of experimentation

I Thorough experimentation on selected batch treatments (5 L digester capacity)

60 days HRT

II Continuous feeding experimental investigation on selected treatments in digester of 300 litre capacity

30 days

III Continuous feeding experimental investigation in floating drum biogas plant of 20 m3/d capacity

30 days

Total solids and volatile solids concentration in the substrates under Phase I

Sl. No. Treatment Substrate concentration

Total solids Volatile solids

kg % kg %

Jatropha oil seed cake substrates

1 JC (4.0 DR, 0 % CD) 0.46 18.5 0.43 17.3

2 JC (4.0 DR, 50 % CD) 0.56 18.5 0.50 16.8

3 JC (10 DR, 0 % CD) 0.23 8.4 0.22 7.9

Pongamia oil seed cake substrates

4 PC (3.5 DR, 0 % CD) 0.45 19.9 0.43 19.0

5 PC (3.5 DR, 50 % CD) 0.54 19.6 0.50 18.1

6 PC (10 DR, 0 % CD) 0.22 8.1 0.21 7.8

Thorough experimentation on selected batch treatments (5 L digester capacity)

0.0025.0050.0075.00

100.00125.00150.00175.00200.00225.00250.00275.00300.00325.00350.00375.00400.00425.00450.00475.00500.00525.00550.00

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60HRT, Days

Bio

gas

Pro

duct

ion

at S

TP

, L/k

g V

S

JC[10 DR, 0%CD]

JC[4.0 DR, 0%CD]

JC[4.0 DR, 50%CD]

0.0025.0050.0075.00

100.00125.00150.00175.00200.00225.00250.00275.00300.00325.00350.00375.00400.00425.00450.00475.00500.00525.00550.00

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

HRT, Days

Bio

gas

Pro

duct

ion

at S

TP

, L/k

g V

S

KC[10 DR, 0%CD]

KC[3.5 DR, 0%CD]

KC[3.5 DR, 50%CD]

Jatropha Oil Cake Substrates

Pongamia Oil Cake Substrates

Cumulative biogas production yield based on volatile solids contents of the

substrates

Range of ambient temperature variation 25.3 to 33.2 °C.

Range of substrate temperature variation 24.3 to 31.8 °C.

Variation of methane concentration in generated biogas

0.05.0

10.015.020.025.030.035.040.045.050.055.060.065.070.075.080.085.090.095.0

100.0

0 5 10 15 20 25 30 35 40 45 50 55 60

HRT, Days

Met

hane

Con

cent

ratio

n, %

JC[10 DR, 0%CD] JC[4.0 DR, 0%CD]

JC[4.0 DR, 50%CD]

0.05.0

10.015.020.025.030.035.040.045.050.055.060.065.070.075.080.085.090.095.0

100.0

0 5 10 15 20 25 30 35 40 45 50 55 60

HRT, Days

Met

hane

Con

cent

ratio

n, %

KC[10 DR, 0%CD]

KC[3.5 DR, 0%CD]

KC[3.5 DR, 50%CD]

Jatropha Oil Cake Substrates

Pongamia Oil Cake Substrates

Variation of total volatile solid mass removal efficiencies of the substrates

05

101520253035404550556065707580859095

100

0 5 10 15 20 25 30 35 40 45 50 55 60

HRT, Days

TV

SMR

E, %

JC[10 DR, 0%CD] JC[4.0 DR, 0%CD]

JC[4.0 DR, 50%CD]

05

101520253035404550556065707580859095

100

0 5 10 15 20 25 30 35 40 45 50 55 60

HRT, Days

TV

SMR

E, %

KC[10 DR, 0%CD]

KC[3.5 DR, 0%CD]

KC[3.5 DR, 50%CD]

Jatropha Oil Cake Substrates

Pongamia Oil Cake Substrates

Specific Biogas Yield

Treatments

Phase- I

L/kg TS L/kg VS

Jatropha oil cake substrates

JC [10.0 DR, 0 % CD] 280.86 289.64

JC [4.0 DR, 0 % CD] 269.69 278.72

JC [4.0 DR, 50 % CD] 505.30 538.05

Pongamia oil cake substrates

PC [10.0 DR, 0 % CD] 347.08 351.97

PC [3.5 DR, 0 % CD] 313.32 316.99

PC [3.5 DR, 50 % CD] 470.31 493.49

Continuous Feeding Experimental Investigation on Selected Treatments in Digester of 300 Litre Capacity

To Gas Flow Meterand Gas Sampler

Slurry Level

Effluent Oulet

Influent Inlet

Valve

Partion Plate

Gas Holder

Guide Pipe to Support Gas Holder

Digester

Annular Ring for Supporting Gas Holder

5 cm 5 cm

75 cm

72.5 cm17.5 cm

61.5 cm 68.5 cm

66.25 cm

Total solids and volatile solids concentration in the substrates under Phase II

Sl. No. Treatment Substrate concentration of the daily feed material

Total solids Volatile solids

kg/d % kg/d %

1 CD [1.0 DR] 0.922 9.2 0.605 7.2

Jatropha oil seed cake substrates

2 JC (4.0 DR, 0 % CD) 0.463 18.5 0.432 17.3

3 JC (4.0 DR, 50 % CD) 0.555 18.5 0.504 16.8

Pongamia oil seed cake substrates

4 PC (3.5 DR, 0 % CD) 0.448 19.9 0.427 19.0

5 PC (3.5 DR, 50 % CD) 0.54 19.6 0.498 18.1

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

60.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

TVSM

RE,

%

CD [1.0DR]

JC[4.0DR, 0%CD]

JC[4.0DR, 50%CD]

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

60.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

TV

SMR

E, %

CD [1.0DR]

KC[3.5DR, 0%CD]

KC[3.5DR, 50%CD]

Variation of total volatile solid mass removal efficiencies of the substrates

Jatropha Oil Cake Substrates

Pongamia Oil Cake Substrates

N, P & K Contents of Biogas Spent Slurry

Sl. No. Treatment N, % P, % K, %

1 CD [1.0 DR] 1.48 0.66 1.64

Jatropha oil cake biogas spent slurry

2 JC (4.0 DR, 0 % CD) 3.60 2.20 1.72

3 JC (4.0 DR, 50 % CD) 3.30 2.10 1.69

Pongamia oil cake biogas spent slurry

4 PC (3.5 DR, 0 % CD) 5.40 1.20 1.32

5 PC (3.5 DR, 50 % CD)

5.20 1.33 1.65

Continuous Feeding Experimental Investigation in Floating Drum Biogas Plant of 20 m3/d Capacity

F

A

B1 BC

DD

30 30

15 T

hick

Par

tion

Wal

l

Cen

tral

Gui

de F

ram

e

Fla

nge

Pla

tes

30

15

7.523237.5All dimensions in centimetres

10 D

iam

ter

AS

B/C

EM

Pip

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10 D

iam

ter

AS

B/C

EM

Pip

e

CC

Fou

ndat

ion

(1:3

:6)

Ear

th F

illin

g

Ground Level

Gas Holder Supporting Structure

Biogas plant (20 m3/d) being fed with jatropha &

pongamia oil seed cakes

Total solids and volatile solids concentration in the substrates

Sl. No. Treatment Substrate concentration of the daily feed material

Total solids Volatile solids

kg/d % kg/d %

Jatropha oil seed cake substrates

1 JC (4.0 DR,0 % CD) 9.25 18.5 8.64 17.3

Pongamia oil seed cake substrates

2 PC (3.5 DR,0 % CD) 8.95 19.9 8.53 19.0

3636

37

Daily Biogas Production

0.000.501.001.502.002.503.003.504.004.505.005.506.006.507.007.508.008.509.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

Biogas

Produ

ction, m

3 /d

25.025.526.026.527.027.528.028.529.029.530.030.531.031.532.032.533.033.534.034.535.035.536.036.5

Subst

rate T

emper

ature,

°CBiogas Production

SubstrateTemperature

Range of ambient temperature variation 26 to 35 °C

37

0.000.501.001.502.002.503.003.504.004.505.005.506.006.507.007.508.008.509.009.50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

Bioga

s Prod

uctio

n m3 /d

25.026.027.028.029.030.031.032.033.034.035.036.037.038.039.040.0

Subst

rate T

empe

ratur

e, °C

Biogas Production

SubstrateTemperature

Range of ambient temperature variation 30.7 to 36.6 °C

Pongamia Oil Cake KC [3.5 DR, 0 % CD]

Jatropha Oil CakeJC [4.0 DR, 0 %

CD]

38

Specific Methane Yield

3838

Pongamia Oil Cake KC [3.5 DR, 0 % CD]

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0.550

0.600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

Speci

fic M

ethan

e Yield

, m3

Methane/kg TS

Methane/kg VS

Jatropha Oil CakeJC [4.0 DR, 0 %

CD]

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

HRT, Days

Specific

Metha

ne Yield

, m3

Methane/kg TS

Methane/kg VS

Specific Methane Yield: Phase II & III

Treatments

Phase- II Phase- III

m3/kg TS m3/kg VS m3/kg TS m3/kg VS

CD [1.0 DR] 0.055 0.070 NA NA

Jatropha oil cake substrates

JC [4.0 DR, 0 % CD] 0.172 0.184 0.394 0.422

JC [4.0 DR, 50 % CD] 0.152 0.167 NA NA

Pongamia oil cake substrates

PC [3.5 DR, 0 % CD] 0.203 0.213 0.427 0.448

PC [3.5 DR, 50 % CD] 0.181 0.196 NA NA

The maximum and minimum values of methane and carbon dioxide were found to vary from 68.0 to 60.7 % and 32.7 to 29.0 % respectively. The average values of methane and carbon dioxide contents over 30 day of HRT were found as 66.6 % and 31.3 % respectively.

Characterization of jatropha and pongamia oil cakes show that these oil cake have more than six times higher volatile solids content than that of cattle dung.

Non-volatile solids content in jatropha oil cake is marginally higher than the pongamia oil cake.

C/N ratio found to range from 8 to 12 for these two oil cakes which is comparatively too low in regard of cattle dung.

Dilution ratio of 3:1 to 4:1(water: oil cake) is essential for maintaining proper flowabilty of biogas spent slurry inside the digester of biogas plant.

It is necessary to develop a special inoculum for efficient digestion of jatropha and pongamia oil seed cakes substrates as the biomethanation process is inhibited if the substrates are seeded with normal inoculum.

Micro Model

Natural Wild Plants /Individual Plantation

Seed Collection

Oil Extraction

Transesterification

Personal Consumption / Local MarketCake Utilization Glycerol

Simple Chain

Natural Wild Plants

Seed Collection

Oil Extraction

Transestrification

Personal Consumption / Local MarketCake Utilization Glycerol

Seed Collection Seed Collection

Mini Model

Natural Wild Plants

Seed Collection

Oil Extraction

Transesterification

Industrial Consumption / Big Local MarketCake Utilization Glycerol

Seed Collection Seed Collection

44

Let’s work in coordination to

Cultivation clean and green energy ….

THANK YOU

45

Let’s work in coordination to

Cultivation clean and green energy ….

THANK YOU