**2.3. Feedstock combustion for gasifier**

as biogas production and second purpose may be as a fertilizer. The seed cake of jatropha can be used as organic fertilizer because it still has nutrients and mineral needed by the plant. Jatropha seed cake could be used in combustion process but considering air emission pro-

In this section, use of jatropha as a fertilizer or green manure has been presented. Green manure can reduce loss of nutrients from soil and give sustainable nutrient supply for long period as compared to chemical fertilizer. Chemical fertilizers can get solubilize in water and will drift together with water especially during the rainy seasons. Patolia et al. [10] reported after 2 years

also reported that dry matter of sandy loam soil could be increased upto 120% by adding 3 tons

Biogas (methane) is produced by anaerobic digestion. Biogas has wide utilities as it can be applied directly for cooking, heating and stationary engine operation in dual fuel mode. The biogas is purified, compressed and stored in cylinder as CNG (Compressed Natural Gas) for automotive transport purposes, power generation as well as in agricultural unit operation. Jatropha seed cake has good potential as biogas feedstock due to confer 60% higher biogas and also better calorific value than the cattle dung [11]. Chandra et al. [11] reported jatropha seed cakes have biogas generation potential in the range of 220–250 and 240–265 L/kg of cake respectively (under mesophilic temperature range of anaerobic digestion). C, H, and N composition was 48.8; 6.20 and 3.85% with C/N ratio of 12.70. The methane content of biogas derived from non-edible oil seed cakes has been found to range between 65 and 70% against 55% from the cattle dung. The best dilution ratio of cake is at 1:4 (cake:water) for *J. curcas* seed cakes. Production of biogas from *J. curcas* seed cakes is one of easy ways for waste management. It can also be used to fulfill energy need for rural areas. According to Kumar [12], in India ~2550 million cubic meters of biogas has been produced from 10.2 lakh metric tons of *J. curcas* seed cakes. Visser and Adriaans [13] studied anaerobic digestion of *J. curcas* press cake. The cake was from cold pressing jatropha seed including the husk. Digestion was carried out at temperature 20°C, pressure 1 bar during 60 days. Jatropha cake that pressed with nozzle (aperture size

application. Ghosh et al. [6]

O.

/kg dry matter, with

and 1.4% K<sup>2</sup>

O5

duced by burning, its use as a fertilizer would be a better choice.

that N45 application could increase the dry matter compared to N<sup>o</sup>

of seedcake/ha as manure. *J. curcas* L. seedcake contain 2% N, 1.2% P2

of 7 mm) contain 33% hull produced a cumulative biogas yield of 0.95 m<sup>3</sup>

mesh. Other parts of *J. curcas* plant as a biogas feedstock is presented in **Figure 3**.

0.23 L/g VS added, it shows oil has potential with 0.739 L/g Volatile Solid added.

85% carbon conversion. Gunaseelan [8] reported energy biomass from part of fresh *J. curcas*. The feedstocks were dried at 60°C before use and subsequently grained to become 2 mm

**Figure 3** suggests not only jatropha cake, but also all parts of the jatropha plant could be utilized for producing biogas (methane). The highest yield was achieved from seed kernel 0.969 L/g Volatile Solid added. If compared to the yield from de-oiled cake, which is just

**2.1. Jatropha as a fertilizer (green manure)**

**2.2. Biogas production**

276 Advances in Biofuels and Bioenergy

Vyas and Singh [14] reported that jatropha seed husk could be used successfully as feedstock for open core down draft gasifier, although the gasifier has to be induced by 1 kg charcoal and 3.2 kg wood. Jatropha seed husk analysis contains 3.97% dry basis ash, 71.04% dry basis volatile matter and 24.99% dry basis fixed carbon. Gasifier was able to run on jatropha seed husk for 340 minute at 2 flow rates (4.5 and 5.5 m<sup>3</sup> /h) without any problems. Gasification efficiency of 68.31% was achieved at gas flow rate of 5.5 m<sup>3</sup> /h and biomass consumption rate of 2.2 kg/h. Gasification efficiency can possibly be increased 2.35% by increasing 1 m<sup>3</sup> /h of gas flow rate and by adding 0.4 kg/h biomass consumption rate.

#### **2.4. Bioactive compost production**

Bioactive compost can be produced from *J. curcas* hull. Sharma et al. [15] produced bioactive compost from jatropha hull biomass by using lingocellulolytic fungi. Bioactive compost is for increasing the added value compared to ordinary manure. Within 1 month, carbon to nitrogen (C/N) ratio of hull decreases from 66.93 to 12–16. From C/N ratio point of view, composting of jatropha hull in 1 month has indicated a better composition of bioactive compost. However, it takes nearly 4 months for complete compost maturation. After 4 months, phytotoxicity of compost can be reduced, thus compost will be ready to use. Bioactive compost from jatropha hull is alkaline, so it is suitable for acidic soil. It can balance the pH of the acidic soil.
