Chi Fei and Chen Hongzhang.

Bioresource technology, Vol. 100, No. 3, Feb 2009, pp. 1315-1318.

The aim of this work is to study the feasibility of using a low-cost biomass absorbent steam-exploded corn stalk (SECS) to absorb ethanol in its production by fermentation. Measurement of many the physical properties of SECS showed its specific surface area was about 214 m super(2)/g and it had a good structure for absorption. Some influencing parameters of using SECS to absorb ethanol in water were studied. Second-order and parabolic diffusion equations excellently described the kinetics of absorption for ethanol. Its absorption isotherm was well described by an improved BET equation, indicating that it was a process of polymolecular layer absorption and had phenomena similar to capillary coacervation. Mesh size did not significantly affect absorptivity, but absorbency decreased with temperature. Absorptivity of SECS for ethanol was compared to that of other absorbents: at 30 degree C and 5% initial ethanol, the absorptivity of SECS for ethanol at 5 h was 92 mg/g. When inactivated through use, SECS can continue to be used as an substrate to produce more ethanol, thus avoiding pollution through discarding.

H. Noureddini, M. Malik, J. Byun and A. J. Ankeny.

Bioresource technology, Vol. 100, No. 2, Jan. 2009, pp. 731-736.

Distillers dried grains with solubles (DDGS) and corn gluten feed (CGF) are major coproducts of ethanol production from corn dry grind and wet milling facilities, respectively. These coproducts contain important nutrients, nevertheless, high levels of phosphorus (P). About 50-80% of the P in these products is in an organically bound form known as phytate. The phytate P in these products cannot be digested by nonruminant animals. Consequently, large quantities of phytate are deposited into the soil with the animal wastes which potentially could cause P pollution in soil and underground water resources. As regulations on the concentration of P material in ethanol production coproducts become more restrictive, measures need to be taken for effective extraction of phytate P from the coproducts to make these processes more environmentally compatible. Proper marketing of coproducts is critical to the overall economy of ethanol production facilities. In this study, distribution of P compounds in different streams of dry grind and wet milling operations was determined. In the dry grind process, the highest P concentration was found to be in the condensed distillers solubles (CDS) at about 1.34 wt.% (db). About 59% of P in this stream was in phosphates form. The highest concentration of P in the wet milling process was found in the light steep water at about 3.4 wt.% (db). In this stream, about 22% of P was attributed to phosphates.

Q. Yang, B. Chen, Xi Ji, Y. F. He and G. Q. Chen.

Communications in Nonlinear Science & Numerical Simulation, Vol. 14, No. 5, May 2009, pp. 2450-2461.

The cumulative exergetic method is used in this study to identify the renewability of the total corn-ethanol production in China when capturing all natural nonrenewable resources consumed in the integrated process including agricultural crop production, corn transportation, industrial conversion and waste treatment. A modified exergy-based indicator is thereby proposed to quantify the renewability of corn-ethanol production process. For the conditions prevailing in China, the renewability indicator as suggested by Berthiaume et al. is calculated to be -4.58, denoting the production process is highly nonrenewable. In addition, a novel indicator is also presented to reveal the environmental cost-effectiveness of the corn-ethanol process as supplement to the renewability indicator. Finally, the sensitivity analysis shows that the defined system boundaries, electricity-generation structure of the country, and technological constraints and choices of production process influence the renewability evaluation results.

Ben Brehmer, Bryan Bals, Johan Sanders and Bruce Dale.

Biotechnology and bioengineering, Vol. 101, No. 1, 1 Sept. 2008, pp. 49-61.

Currently in America the biofuel ethanol is primarily being produced by the dry grind technique to obtain the starch contained in the corn grains and subsequently subjected to fermentation. This so-called 1st generation technology has two setbacks; first the lingering debate whether its life cycle contributes to a reduction of fossil fuels and the animal feed sectors future supply/demand imbalance caused by the co-product dry distillers grains (DDGS). Additional utilization of the cellulosic components and separation of the proteins for use as chemical precursors have the potential to alleviate both setbacks. Several different corn feedstock layouts were treated with 2nd generation ammonia fiber expansion (AFEX) pre-treatment technology and tested for protein separation options (protease solubilization). The resulting system has the potential to greatly improve ethanol yields with lower bioprocessing energy costs and satisfy a significant portion of the organic chemical industry. Biotechnol. Biotechnol. Bioeng. 2008;101: 49-61.

Anonymous

MRS Bulletin, Vol. 33, No. 2, Feb. 2008, pp. 81, 82.

If projected increases in the use of corn for ethanol production occur, the harm to water quality could be considerable, and water supply problems at the regional and local levels could also arise, according to a report from the National Research Council. The committee that wrote the report examined policy options and identified opportunities for new agricultural techniques and technologies to help minimize effects of biofuel production on water resources.