World Report. Boosting biofuel crops could threaten food security

ArticleinThe Lancet 370(9591):923-4 · October 2007with15 Reads
Impact Factor: 45.22 · DOI: 10.1016/S0140-6736(07)61427-5 · Source: PubMed
    • "It is possible to hydrolyse cellulose using chemical or biological methods, liberating the glucose monomers constituting its structure (saccharification), before fermenting into variousAbdelRahman 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. "
    [Show abstract] [Hide abstract] 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.
    Full-text · Article · Oct 2014 · Chemical Engineering Research and Design
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    • "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 [1] . Therefore, producing cellulosic bioethanol from nonedible plants is receiving increasing attention [2] . "
    [Show abstract] [Hide abstract] 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.
    Full-text · Article · May 2014 · American Journal of Plant Sciences
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    • "However, only ∼15% of the biodiesel demand could be met if all the arable land in the US were used to grow soybean for oil production [59]. Additionally, the current production of biofuels displaces croplands, previously used for food, and has been associated with increased consumer prices [73, 74]. An alternative to the soybean-derived biodiesel is algaebased systems. "
    [Show abstract] [Hide abstract] ABSTRACT: As the global atmospheric emissions of carbon dioxide (CO2) and other greenhouse gases continue to grow to record-setting levels, so do the demands for an efficient and inexpensive carbon sequestration system. Concurrently, the first-world dependence on crude oil and natural gas provokes concerns for long-term availability and emphasizes the need for alternative fuel sources. At the forefront of both of these research areas are a family of enzymes known as the carbonic anhydrases (CAs), which reversibly catalyze the hydration of CO2 into bicarbonate. CAs are among the fastest enzymes known, which have a maximum catalytic efficiency approaching the diffusion limit of 108 M−1s−1. As such, CAs are being utilized in various industrial and research settings to help lower CO2 atmospheric emissions and promote biofuel production. This review will highlight some of the recent accomplishments in these areas along with a discussion on their current limitations.
    Full-text · Article · Sep 2013 · International Journal of Chemical Engineering
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