Jatropha curcas oil (JCO) is considered a future feedstock for biodiesel production because it is easily grown in harsh environments and is a non-edible crop that is not in demand as a food source. Three basic methods are used to produce biodiesel from oils/fats, namely the base-catalyzed transesterification, acid-catalyzed transesterification, and enzymatic catalysis. However, heterogeneous transesterification using a solid catalyst rather than a liquid acid or base catalyst is a more environmentally responsible way to utilize crude Jatropha oil for biodiesel production. The use of a heterogeneous catalyst also avoids neutralization and washing steps, thereby leading to a simpler and more efficient process. This paper presents an overview of the production of biodiesel from Jatropha Curcas Linnaeus (JCL) using a heterogeneous catalyst. This review also includes the current economic trend of biofuel production particularly on the production of biodiesel. Different types of conventional and advanced methods like ultrasound, microwave, membrane reactor, supercritical methanol, etc., using several types of heterogeneous catalysts like calcium oxide (CaO), sulfanated zirconia alumina (SZA) and others in the JCO biodiesel transesterification process are discussed in detail. The system design of the transesterification process via process simulation and optimization are also presented. Finally, the persistent challenges facing this process are discussed. (c) 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Together with 106 farmers who started growing Jatropha (Jatropha curcas L.) in 20042006, this research sought to increase the knowledge around the real-life experience of Jatropha farming in the southern India states of Tamil Nadu and Andhra Pradesh. Launched as an alternative for diesel in India, Jatropha has been promoted as a non-edible plant that could grow on poor soils, yield oil-rich seeds for production of bio-diesel, and not compete directly with food production. Through interviews with the farmers, information was gathered regarding their socio-economic situation, the implementation and performance of their Jatropha plantations, and their reasons for continuing or discontinuing Jatropha cultivation. Results reveal that 82% of the farmers had substituted former cropland for their Jatropha cultivation. By 2010, 85% (n = 90) of the farmers who cultivated Jatropha in 2004 had stopped. Cultivating the crop did not give the economic returns the farmers anticipated, mainly due to a lack of information about the crop and its maintenance during cultivation and due to water scarcity. A majority of the farmers irrigated and applied fertilizer, and even pesticides. Many problems experienced by the farmers were due to limited knowledge about cultivating Jatropha caused by poor planning and implementation of the national Jatropha program. Extension services, subsidies, and other support were not provided as promised. The farmers who continued cultivation had means of income other than Jatropha and held hopes of a future Jatropha market. The lack of market structures, such as purchase agreements and buyers, as well as a low retail price for the seeds, were frequently stated as barriers to Jatropha cultivation. For Jatropha biodiesel to perform well, efforts are needed to improve yield levels and stability through genetic improvements and drought tolerance, as well as agriculture extension services to support adoption of the crop. Government programs will -probably be more effective if implementing biodiesel production is conjoined with stimulating the demand for Jatropha biodiesel. To avoid food-biofuel competition, additional measures may be needed such as land-use restrictions for Jatropha producers and taxes on biofuels or biofuel feedstocks to improve the competitiveness of the food sector compared to the bioenergy sector. (c) 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Duckweed is a promising feedstock for the production of biofuels. Advantageous characteristics include rapid, clonal growth as small free-floating plants on nutrient-rich water; global adaptability across a broad range of climates; naturally high protein content; and inducible high starch content with low or no lignin, which enables other value-added products. The objective of this article is to review the published research on duckweed cultivation in nutrient-rich wastewaters, starch enrichment in duckweed plants and conversion of high-starch duckweed to biofuels. Duckweed yields of 39.1–105.9 t ha-1 year-1 have been achieved using wastewater as the nutrient source, which are much higher than the yields of most other potential energy crops. Duckweed starch contents of 31.0–45.8% dry weight have been achieved after it has been subjected to nutrient starvation for 5–10 days, and up to 94.7% of the starch could be converted to ethanol using the existing technologies for corn starch conversion. Future research objectives include selecting high-performance duckweed strains, improving starch enrichment and conversion, and developing technologies for large-scale operations.