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The destructive effects of burning conventional fossil fuels on the environment have created the realisation of the significance of using alternative fuels as a mitigating measure to reduce greenhouse gas emissions. One of the most promising and environmentally friendly substitutes for petroleumbased gasoline fuel is bioethanol. This study uses agricultural residue (bagasse), halophytes and non-edible biomass as feedstocks to produce bioethanol, through lignin content extraction from Panicum antidotale, Phragmites karka, Sugarcane bagasse, Jatropha curcas husk and Conocarpus erectus leaves and then cellulose reduced by acid pretreatment followed by hydrolysis. The cellulose content was found higher in Panicum antidotale (43.39 percent) and lowest in Jatropha curcas husk (35.10 percent), while moderate values of (42.81 percent) in Sugarcane bagasse, Phragmites karka (37.48 percent), and Conocarpus erectus (38.53 percent). At the beginning and end of the fermentation process, the total carbohydrate contents of the hydrolysed biomass were analysed, and their bioethanol yields were measured. Maximum reducing sugar was found 19 gm/L (1.186 lb/ft3 ) in Panicum antidotale followed by Phragmites karka, sugarcane bagasse, Jatropha curcas husk, and Conocarpus erectus leaves as 15.89 gm/L (0.991 lb/ft³ ) and 12.09 gm/L (0.754 lb/ft3 ), 10.52 gm/L (0.656 lb/ft3 ), 4.51 gm/L (0.281 lb/ft3 ), respectively. Bioethanol percentage yield by volume was found as 4.36 percent (Panicum antidotale), 3.93 percent (Phragmites karka), 2.87 percent (Jatropha curcas husk), 2.52 percent (sugarcane bagasse) and 1.64 percent (Conocarpus erectus leaves), respectively. The results showed the potential of producing eco-friendly bioethanol as biofuels from halophytes that will help ease the strain on food crops by providing inexpensive and abundant feedstock. [ABSTRACT FROM AUTHOR]

This paper presents the production of biodiesel from indigenous species of Jatropha curcas and Neem (Azadirachta indica) oils, then its engine performance and emission characteristics of B10 blends measured at 1000 rpm. Biodiesel production yields were found 90% and 68% by weight from Jatropha curcas and Neem (Azadirachta indica), respectively. Three prepared biodiesel blends were 10% Neem biodiesel (NB10), 10% Jatropha biodiesel (JB10) and 5% Jatropha + 5% Neem biodiesels (NJB10). The engine emission test showed less carbon monoxide production from NB10 (94 ± 2.15 ppm), followed by JB10 (100 ± 2.44ppm) and NJB10 (121 ± 3.65ppm) as compared to diesel (135 ± 2.18ppm). However, the carbon dioxide emissions were found higher due to the better combustion characteristics of biodiesel blends as NB10 (3.21%), JB10 (3.06%) and NJB10 (2.53%) than diesel (2.13%) by volume. The reduced amounts of sulphur dioxide (SO2) emissions were found with blended biodiesel fuel in comparison to mineral diesel. Nitrogen dioxide (NO2) emissions were 5 ppm from diesel at 73ffiC exhaust temperature, while it was increased by using blended biodiesel, to 8 ppm with NB10 due to higher exhaust temperatures 85;33ffiC. The measured engine power and torque produced from the blended biodiesel samples were slightly lower than the conventional diesel by 12% and 7.7%, respectively. The experimental results showed that an engine performance and emission characteristic of Neem biodiesel (NB10) was better as compared to other biodiesel blends. [ABSTRACT FROM AUTHOR]

The conventional jar test was used to evaluate the % mixed microalgae harvesting efficiency from domestic wastewater by using different natural coagulants such as de-oiled Jatropha curcas cake, Moringa oleifera, Conocarpus erectus and neem (Azadirachta indica) seeds compared to alum as a chemical coagulant. The highest microalgae removal efficiency (97.91%) was achieved with powdered neem (A. indica) seeds at 100 mg/L dosing, mixing speed 100 rpm, with 10 min agitation time and pH 9. Interestingly, it was observed that % removal of microalgae was found above 94% in all cases with neem (A. indica) seeds as compared to other coagulants. Then, the % removal is followed by C. erectus with 93.44 % and alum 91.62%. However, the consumption of alum was very high (200 mg/L) to achieve higher % removal efficiency making it uneconomical. Statistically, it was found that both coagulants neem (A. indica) and de-oiled cake of J. curcas seeds were having a percentage contribution of coagulant dosing on the harvesting results. The techno-economic analysis showed that the powdered neem (A. indica) and M. oleifera seeds were found the most economical in terms of mixed microalgae harvesting cost per litre of wastewater, i.e. (US$ 0.0068/L) and (US$ 0.0052/L), respectively. De-oiled cake of J. curcas seeds can effectively remove microalgae with % removal 84.98 %, but the cost analysis revealed that de-oiled cake of J. curcas seeds has higher harvesting cost per litre (US$ 0.0103/L) compared to neem (A. indica) and M. oleifera seeds. Thus, it is suggested to use the neem (A. indica) as coagulants for mixed microalgae removal from domestic wastewater with effective % microalgae removal in a cost-effective manner for biodiesel production. [ABSTRACT FROM AUTHOR]

Abstract: Performance of biodiesel in engines is well established and biodiesel is currently adjudged as a low carbon fuel with the most potential of replacing fossil fuels. The fossil fuel sources are dwindling in Pakistan resulting in importation of about 8.1 million tonnes at approximately US$ 9.4 billion per annum. In the ambit of this justification, augmenting the energy scarce resources in Pakistan through intense harnessing of the varied biodiesel sources can adequately address the deficiency and can ensure energy security. Towards this end, the progress attained in biodiesel related researches in Pakistan are evaluated and presented with the view of highlighting ways of achieving the target set by the Government. A feedstock that drew less attention is spent triglycerides, and the little work reported by some organizations appeared promising. Now the onus is upon organizations such as the Alternative Energy Development Board and Pakistan State Oil to harness the research results from several indigenous Universities and develop a full-scale biodiesel economy in Pakistan. [Copyright &y& Elsevier]