World Report. Boosting biofuel crops could threaten food security
(Impact Factor: 45.22).
10/2007; 370(9591):923-4. DOI: 10.1016/S0140-6736(07)61427-5
Available from: Adam P. Harvey
- "useful chemicals including ethanol and lactic acid (Abdel- Rahman et al., 2011; Sarkar et al., 2012). Utilisation of crop wastes, including straws and stover, avoids conflict between human food and industrial use (Boddiger, 2007). An estimated worldwide production of lignocellulosic biomass from seven major crops including rice straw and corn stover is 1.5 petagrams (Pg) per year (Kim and Dale, 2004) offering great potential. "
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ABSTRACT: Enzymatic saccharification of pure α-cellulose was conducted in, oscillatory baffled (OBR) and stirred tank (STR) reactors over a range of, mixing intensities requiring power densities (P/V) from 0 to 250 Watts, per cubic metre (W/m3). Both reactor designs produced similar, saccharification conversion rates at zero mixing. Conversion increased, with increasing mixing intensity. The maximum conversion rate occurred at, an oscillatory Reynolds number (Reo) of 600 in the OBR and at an impeller, speed of between 185 and 350 rpm in the STR. The OBR was able to achieve, a maximum conversion rate at a much lower power density (2.36 W/m3) than, the STR (37.2 to 250 W/m3). The OBR demonstrated a 94 to 99% decrease in, the required power density to achieve maximum conversion rates and showed, a 12% increase in glucose production after 24 hours at 2.36 W/m3.
Available from: Jun Abe
- "Bioethanol is a promising alternative to fossil fuels and is viewed as a potential countermeasure to global warming. However, there are concerns that the cultivation of food crops for consumption is sacrificed for bioethanol production, leading to global food insecurity . Therefore, producing cellulosic bioethanol from nonedible plants is receiving increasing attention . "
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ABSTRACT: The production of cellulosic bioethanol from non-edible plants is drawing increasing attention, as it potentially avoids food-fuel competition. Because growing such plants on farmland indirectly reduces food availability, the plants should be grown on marginal, non-arable lands. In this study, we evaluated the growth of cellulosic energy crops at a former mining site in Indonesia. This mine was abandoned because it contained few mineral deposits, and exposed subsoils rather than toxic soils prevented revegetation. In the first trial, growths of two energy plant species Erianthus spp. and Napier grass (Pennisetum purpureum) were compared with that of maize (Zea mays) at the mine site and a nearby degraded farm. Erianthus and Napier grass produced 11.7 and 22.5 t·ha −1 of shoot dry matter at 8 months after planting (MAP) in the farm respectively while maize plants failed to establish, but none of the three species grew at the mine. In the second trial, two-week-old seedlings of Erianthus and Napier grass rather than stem cuttings as used in the first trial were planted at the mine site. Erianthus and Napier grass produced 16.3 and 24.0 t·ha −1 of shoot dry matter over the course of 18 months, respectively. Application of organic fertilizer significantly increased shoot dry matter to 18.9 and 39.6 t·ha −1 in Erianthus and Napier grass, respectively. During the 18-month growth period, both of the energy plants significantly increased soil carbon at the 0 -0.3 m depth from 0.33% to 1.15% -1.23% when chemical fertilizer was applied and to 0.67% -0.69% when both chemical and organic fertilizers were applied. From 0 -5 MAP, soil sur-face level dropped by 28.0 -34.7 mm in plots without plants due to soil erosion. In contrast, both of the energy plants significantly reduced the drop of soil surface level to 16.0 -19.3 mm in plots with chemical fertilizer alone and to 18.0 -20.7 mm in plots with chemical and organic fertilizers. * Corresponding author. N. Sekiya et al. 1712 Proportions of small soil particles, that would be easily detached and transported by water flow compared with large particles, were larger in the planted plots than the no-plant plots at 16 MAP. The results suggest that successful cultivation of energy plants on abandoned mine sites is possi-ble, particularly if seedlings are transplanted and the crops are fertilized with organic fertilizer. In addition, the cultivation of Erianthus and Napier grass has positive impacts on soil quality that may contribute to their sustainability as crops and to the conservation of the local ecosystem.
Available from: Keitha Dunstan
- "Imperative to biofuels' socio-economic sustainability is transparency, between participating stakeholders to whom costs and benefits are attributed, who decide on the distribution of costs and benefits, and how they are dispersed (von Maltitz et al., 2009). Contentious land-ownership issues owing to the form of (or lack of) property rights in many developing countries (especially in sub-Saharan Africa) cause uncertainties for land tenure, population marginalisation, project security and livelihoods (Boddiger, 2007). Land deals are often performed without the commitment of investors to show transparency or regard for indigenous property and cultural rights. "
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ABSTRACT: Considerable effort has been put into developing sustainability assessment frameworks for biofuel production in developing countries. Nevertheless, their successful implementation remains problematic in sub-Saharan Africa. To address this challenge in this paper, through a thorough examination of academic and grey literature, repeatedly occurring sustainability aspects/issues were drawn from internationally recognised biofuel assessment frameworks. Theoretical framings that corresponded with the interlinking socio-environmental-economic qualities and issues for achieving sustainability through ethical implementation conformity (political ecology, development economics, social capital and institutional economics) were then used to inform development of a conceptual framework that could guide biofuel project implementation in sub-Saharan Africa to address complex sustainability issues. The supporting theories pursue sustainable development through, amongst others, an emphasis on the more equitable dispersal of costs and benefits through transparent networking in rural settings and the integration of contrasting viewpoints of diverse stakeholders in emerging economies.
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