Production of Gaseous Fuels Pongamia Residue - 2

P M V SubbaraoProfessor

Mechanical Engineering Department Indian Institute of Technology Delhi, New Delhi

Enhance the value of Fuel Energy ….

Development of Special Inoculum

20 m3/d BGP

About 12 m3 CD inoculum

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

No feeding of CD before last 3 months

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

1 2 3 4 5

Sta

rt of g

as

pro

du

ctio

n

Con

tinu

ed

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

Schedule II

Drop in gas yield

6 7 8 9 10 11 12 13 14 15

Increase in gas yield

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

10 cm height

22

Biogas Plant After Feeding of Oil Cake Slurry

Evolution of Microbes

This shows the adaptation of bacteria to the environment offered by new substrates possibly by developing into a suitable strain.

This acclimatization is due to fact that, when the concentrations of inhibitory or toxic materials were

slowly increased within the environment, many microorganisms could rearrange their metabolic

resources, thus overcoming the metabolic blockage produced by the normally inhibitory or toxic material.

However, sufficient time should be made available for this rearrangement to take place, whenever there is drastic change in environment (feed material).

The slurry of the biogas plant stabilized with pongamia oil seed cake was used as inoculum for further studies.

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

e

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

55

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

66

7

Daily Biogas Production

77

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

Biog

as P

rodu

ctio

n m

3 /d

25.026.027.028.029.030.031.032.033.034.035.036.037.038.039.040.0

Subs

trat

e Tem

pera

ture

, °C

Biogas Production

SubstrateTemperature

Range of ambient temperature variation 30.7 to 36.6 °C

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

8

Total Volatile Solid Mass Removal Efficiency

88

0.05.0

10.015.0

20.025.0

30.035.0

40.045.0

50.055.0

60.065.0

70.075.0

80.085.0

90.095.0

100.0

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,

%

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

Variation of methane and carbon dioxide content in produced biogas from pongamia oil seed cake substrate

10

Specific Methane Yield

1010

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

Spec

ific M

ethan

e Yiel

d, m

3

Methane/kg TS

Methane/kg VS

Specific Methane Yield

Treatments m3/kg TS m3/kg VS

Jatropha oil cake substrates

JC [4.0 DR, 0 % CD] 0.394 0.422

Pongamia oil cake substrates

PC [3.5 DR, 0 % CD] 0.427 0.448

Other Residue: Shells

Analysis of Shells of Pongamia Fruits

EntityPongamia

Shell (%)Wood (%)

Ash 4.09 1-3

Volatile matter 66.99 70-80

Fixed carbon 18.95 15-20

Moisture content of Pongamia Shells : 10.6%

Ultimate Analysis of Shells

EntityPongamia

Shell (%)Wood (%)

Ash 4.09 1-3

Carbon 44.3 44-52

Hydrogen 7.45 5-7

Nitrogen 1.73 0.5-0.9

Sulfur 0.3 Negligible

Oxygen 42.13 40-48

Shells -- Biomass

• Micro Construction basic chains:– Cellulose

– Hemi-cellulose

– Lignin

• All these are long-chain organic molecules with C, H, O as main constituent elements

• Cellulose (generic chemical formula (C6H10O5)n) is the carbohydrate that makes up the main structure of plants.

• It is also referred to as "fibre" and is indigestible by humans.

• Cotton fibre is almost pure cellulose.

Typical Composition of Shelly Wood

Thermal Decomposition of Pongamia Shell at Various Heating Rates(HR)

Learning from TGA study

Maximum mass loss take place in first stage of pyrolysis (TR 165-485 oC)

Mass loss rate(%/oC) of shell is high and suitable for thermo-chemical gasification.

Heating rate 10 oC/min. is good for gasification. This is easy to achieve. The apparent activation energy of shell is comparable with

that of rice husk, corn straw The shells are having good energy potential for

exploitation through thermochemical gasification in a gasifier.

Biomass Gasification

Gasifier at IIT Delhi

Gasifier with I.C. Engine

Gas Composition

Composition CO2 CO H2 N2 CH4

Gas Sample (%) 11.46 17.03 14.95 55.55 1.02

Wood Gas

Shell Gas

Gas CO2 CO H2 N2 CH4

Sample (%) 9.47 9.71 5.29 74.56 0.96

Performance Analysis of Gasifier

• Energy content of gas produced per heating value of one unit of shells.

• Depends on

• Amount of Hydrogen produced per unit mass of shells.

• Amount of CO produced per unit mass of shells.

• Measure flow rate of gas and composition of gas.

• Maximize specific gas energy.

•Gas flow rate = 9.51 g/s

•Air-Fuel ratio = 4.97

• Calorific value of producer gas = 2.29 MJ/m3

•Mass of producer gas generated per kg of shell = 5.14 kg of gas/kg of shell

Operating parameters of gasifier:

EntityPongamia

ShellsWood

gas flow rate (g/s) 9.51 9.62N 5.46 7.30Φ 3.62 2.01(A/F)m 4.97 2.77

CVg (MJ/m3) 2.29 4.48

mg (kg of gas/kg fuel) 5.14 3.54

MWg (kg/kmol) 28.02 25.82ρ (kg/m3) 1.15 1.06E (MJ/kg fuel) 10.27 15.01

Cth 0.65 0.84

Operating parameters of wood and Pongamia shells gasifications

Pongamia residue

Peculiarity of Pongamia shell high lignin content(40.5wt%) Irregular shape of shells low bulk density

Pelletizatin

Pelletization Using Briquetting Machine

•

Photograph of Pongamia shell pellets

17 mm diameter

Bulk density 460 kg/m3

S. No.Gas

Composition(% Volume)

Pongamia shell pellets (17 mm diameter) gasification3 nozzle openedTop opened

2 nozzle openedTop opened

3 nozzle openedTop closed

2 nozzle openedTop closed

1 CO 10.5 12.7 10.2 7.82 H2 10.3 13.4 11.5 7.13 CH4 1.2 1.6 1.2 1.44 CO2 20.7 13.5 17.9 20.45 N2 57.3 58.8 59.2 63.3

Gasification of Pongamia Shell Pellets

Engine Test Results

Over all conclusions from Pongamia residue pellets

• Tavg.)oxidation 861oC

• Tmax.)oxidation 983oC

• Tavg.)reduction 741oC

• η gasification 72.5%

• Power output 2.214 kW

• Nox (ppm) 111

Photograph of Pongamia shell pellets

11.5 mm diameter

Bulk density 469 kg/m3

Variation of Producer gas composition

 S.No.

 Gas

Composition (%)

Gas composition for various samples(from 11.5 mm shell pellets)

Sample 1 Sample 2 Sample 3 Sample 4

Sample 5

1 H2 14.46 10.45 10.55 14.03 13.87

2 CO 13.48 12.20 15.52 19.46 15.61

3 CH4 1.71 1.73 1.11 0.98 1.04

4 CO2 16.66 24.12 18.41 5.98 7.13

5 N2 53.96 51.49 54.39 59.53 62.35

Conclusions from gasification of Pongamia pellets(11.5 mm dia.)

• Tavg.)oxidation 831oC

• Tmax.)oxidation 1047oC

• Tavg.)reduction 700oC

• η gasification 87.1%

• ΔP)overall 98 to 111 mm H2O It was observed that gasification efficiency was high for 11.5 mm diameter pellets as compared to 17 mm diameter pellets.It was found that there was an agglomeration of cake pellets with 11.5 mm diameter and these chunks were choking the gasifier reactorPongamia de-oiled cake pellets were found to be not suitable for gasification in the downdraft wood gasifier.

Photograph of Engine Setup

Make Kirloskar        

TypeFour -stroke direct injection naturally aspirated single cylinder,C.I. engine modified to operate in SI mode

Bore 87.5 mmStroke 110 mm

Cylinder capacity 661.5 cc

Compression ratio 10 (after modification)Power output 4.4 kW at 1500 rev/min for diesel operation

3.12 kW at 1450 rev/min

Maximum torque 30 Nm at full load at 1500 rev/min for diesel operationLoading device Electrical generator        

Engine Specification

S No. SparkTiming (obtdc)

Shell pellets(11.5 mm) Mixture pellets(11.5 mm)

Power output(kW)

EGT(oC)

NOx(ppm)

CO(%vol)

Power output(kW)

EGT(oC)

NOx(ppm)

CO(%vol)

1 20 2.296 387 248 0.10 2.489 338 426 0.06

2 25 2.320 325 266 0.10 2.466 332 442 0.07

3 30 2.538 364 289 0.09 2.982 337 764 0.03

4 35 2.975 332 816 0.06 2.343 342 528 0.09

5 40 2.217 359 286 0.10 --- --- --- ---

Comparison of performance and emission characteristics of engine

Tar formation inside the re-circulating duct of reactor