Production of Gaseous Fuels Pongamia Residue - 2 P M V Subbarao Professor 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 Start of gas production Continued 1 2 3 4 5 Schedule I 2 kg pongamia oil cake with 6 kg water for 5 days 10 cm height 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 2 2

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 Biogas plant (20 m3/d) being fed with jatropha & pongamia oil seed cakes 5 5

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 % 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 6 6

Daily Biogas Production Pongamia Oil Cake KC [3.5 DR, 0 % CD] Range of ambient temperature variation 30.7 to 36.6 °C 7 7 7 7

Total Volatile Solid Mass Removal Efficiency Pongamia Oil Cake KC [3.5 DR, 0 % CD] 8 8 8 8

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

Specific Methane Yield Pongamia Oil Cake KC [3.5 DR, 0 % CD] 10 10 10 10

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 11

Other Residue: Shells

Analysis of Shells of Pongamia Fruits Entity Pongamia 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 Entity Pongamia 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 Wood Gas Shell Gas Composition CO2 CO H2 N2 CH4 Gas Sample (%) 11.46 17.03 14.95 55.55 1.02 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.

Operating parameters of gasifier: 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 wood and Pongamia shells gasifications Entity Pongamia Shells Wood gas flow rate (g/s) 9.51 9.62 N 5.46 7.30 Φ 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 25.82 ρ (kg/m3) 1.15 1.06 E (MJ/kg fuel) 10.27 15.01 Cth 0.65 0.84

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

Gasification of Pongamia Shell Pellets S. No. Gas Composition (% Volume) Pongamia shell pellets (17 mm diameter) gasification 3 nozzle opened Top opened 2 nozzle opened Top closed 1 CO 10.5 12.7 10.2 7.8 2 H2 10.3 13.4 11.5 7.1 3 CH4 1.2 1.6 1.4 4 CO2 20.7 13.5 17.9 20.4 5 N2 57.3 58.8 59.2 63.3

Engine Test Results Shell Pellets Power output 2.214 kW NOx 111 (ppm) CO 0.03(%) Exhaust Temp. 357oC De-oiled Cake Pellets Power output 2.485 kW NOx 718 (ppm) CO 0.15(%) Exhaust Temp. 360oC

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 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 CO2 16.66 24.12 18.41 5.98 7.13 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 reactor Pongamia de-oiled cake pellets were found to be not suitable for gasification in the downdraft wood gasifier.

Photograph of Engine Setup

Engine Specification Make Kirloskar Type   Type Four -stroke direct injection naturally aspirated single cylinder, C.I. engine modified to operate in SI mode Bore 87.5 mm Stroke 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 operation Loading device Electrical generator

Comparison of performance and emission characteristics of engine S No. Spark Timing (obtdc) Shell pellets(11.5 mm) Mixture pellets(11.5 mm) 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 2.466 332 442 0.07 3 30 2.538 364 289 0.09 2.982 337 764 0.03 4 35 2.975 816 2.343 342 528 5 40 2.217 359 286 ---

Tar formation inside the re-circulating duct of reactor