Potential bioethanol and biogas production using lignocellulosic biomass from winter rye, oilseed rape and faba bean

To meet the increasing need for bioenergy several raw materials have to be considered for the production of e.g. bioethanol and biogas.In this study, three lignocellulosic raw materials were studied, i.e. (1) winter rye straw (Secale cereale L), (2) oilseed rape straw (Brassica napus L.) and (3) faba bean straw (Viciafaba L.). Their composition with regard to cellulose, hemicellulose, lignin, extractives and ash was evaluated, as well as their potential as raw materials for ethanol and biogas production. The materials were pretreated by wet oxidation using parameters previously found to be optimal for pretreatment of corn stover (195 1C, 15 min, 2 g l_1 Na2CO3 and 12 bar oxygen). It was shown that pretreatment was necessary for ethanol production from all raw materials and gave increased biogas yield from winter rye straw. Neither biogas productivity nor yield from oilseed rape straw or faba bean straw was significantly affected by pretreatment. Ethanol was produced by the yeast Saccharomyces cerevisiae during simultaneous enzymatic hydrolysis of the solid material after wet oxidation with yields of 66%, 70% and 52% of theoretical for winter rye, oilseed rape and faba bean straw, respectively. Methane was produced with yields of 0.36, 0.42 and 0.44 l g_1 volatile solids for winter rye, oilseed rape and faba bean straw, respectively, without pretreatment of the materials. However, biogas productivity was low and it took over 50 days to reach the final yield. It could be concluded that all three materials are possible raw materials for either biogas or ethanol production; however, improvement of biogas productivity or ethanol yield is necessary before an economical process can be achieved. 2007 Elsevier Ltd. All rights reserved

Higgsless electroweak symmetry breaking at the LHC

While the Higgs model is the best studied scenario of electroweak symmetry breaking, a number strongly-coupled models exist, predicting new signatures. Recent studies of WW and WZ final states at the ATLAS and CMS experiments are summarized and expected sensitivities are presented within the frameworks of the technicolor straw-man model and the electroweak chiral Lagrangian.Comment: Proceedings for the EPS HEP 2007 conference, Manchester, U.K., on behalf of the ATLAS and CMS Collaboration

The Effect of Supplementing Mannan Oligosaccharide or Finely Ground Fiber, during the Summer on Body Temperature, Performance, and Blood Metabolites of Finishing Steers

Crossbred beef steers (12 pens, n=96) were used to determine the effect of adding Agrimos or 5% ground (1 in.) wheat straw compared to a control on body temperature, panting score and performance. Th ere were no differences in final BW, ADG, and DMI among treatments. Feed conversion was increased for cattle fed 5% additional ground straw when compared to control and Agrimos. Hot carcass weight, dressing %, LM area, and marbling score were not different among treatments. Cattle fed the control had greater 12th rib fat depth and USDA yield grade than cattle fed straw or Agrimos. Both average and maximum body temperatures were slightly greater for cattle fed Agrimos than for cattle fed control or added straw. Panting scores were decreased slightly for cattle fed the extra straw when compared to control and Agrimos. The addition of Agrimos or wheat straw to the diet had minimal effects on heat stress measures

Solid State Fermentation Of Rice Straw For Production Of Cellulases By Selected Fungi

The production of cellulases from rice straw (RS) by four fungi: Trichoderma harzianum (SCahmT105), Trichoderma spp.(1) (STP101), Trichoderma spp.(3) (STP103) and Phanerochaete chrysosporium was investigated. The microbial treatment using solid state fermentation was conducted in 250 ml Erlenmeyer flasks considering rice straw as a major solid substrate. The highest cellulase activities such as 25.53 U/g of rice straw due to filter paper activity and 42.86 U/g of rice straw due to carboxymethyl cellulose activity were obtained at day 4 of cultivation using Phanerochaete chrysosporium for the purpose of selecting the best fungus among these four strains. Glucosamine for growth and reducing sugar as substrate utilization indicator were observed to evaluate the fermentation of rice straw in the experiment and pH values were recorded as well. Four process parameters of the solid state fermentation namely moisture content, mineral content, co-substratre and inoculum size with three levels of each parameter were used to optimize the production of cellulases by Plackett-Burman technique under factorial design. The results for first phase of optimization showed that the production of cellulases were higher i.e. 26.43 U/g of rice straw due to filter paper of activity and 46.25 U/g of rice straw due to carboxymethyl cellulose activity compared to the production obtained during the earlier study of selecting best strain among four fungi but the optimum regions of the surfaces was not found. Second phase of optimization was conducted to determine the actual optimum conditions within the ranges of variables tested. The experimental data were used to develop second order polynomial models considering linear, quadratic and interaction effects of the variables (factors). The optimum values obtained at second phase of optimization for moisture content, inoculum size, co-substrate and mineral content were 50% (v/w), 10% (v/w), 1% (w/w) and 5% (v/w) respectively. Using the final model equations the process factors/variables were tested by increasing or decreasing the values within the ranges of parameters tested and optimum production of cellulases were obtained to be 30.18 U/g of rice straw (FPU) and 53.93 U/g of rice straw (CMCase) for Phanerochaete chrysosporium with the optimum process conditions. A final experiment with these optimum process parameters of SSF was conducted to evaluate the production of cellulases as well as the validation of the models which indicated the production of 29.46 U/g of rice straw due to filter paper activity and 54.83 U/g of rice straw due to carboxymethyl cellulose activity in the laboratory which approved the optimum production obtained with 2.4% and 1.6% error, respectively

Anaerobic co-digestion of microalgal biomass and wheat straw with and without thermo-alkaline pretreatment

This study aimed at analyzing the anaerobic co-digestion of microalgal biomass grown in wastewater and wheat straw. To this end, Biochemical Methane Potential (BMP) tests were carried out testing different substrate proportions (20–80, 50–50 and 80–20%, on a volatile solid basis). In order to improve their biodegradability, the co-digestion of both substrates was also evaluated after applying a thermo-alkaline pretreatment (10% CaO at 75 °C for 24 h). The highest synergies in degradation rates were observed by adding at least 50% of wheat straw. Therefore, the co-digestion of 50% microalgae – 50% wheat straw was investigated in mesophilic lab-scale reactors. The results showed that the methane yield was increased by 77% with the co-digestion as compared to microalgae mono-digestion, while the pretreatment only increased the methane yield by 15% compared to the untreated mixture. Thus, the anaerobic co-digestion of microalgae and wheat straw was successful even without applying a thermo-alkaline pretreatment.Peer ReviewedPostprint (author's final draft

Performance of the AMS-02 Transition Radiation Detector

For cosmic particle spectroscopy on the International Space Station the AMS experiment will be equipped with a Transition Radiation Detector (TRD) to improve particle identification. The TRD has 20 layers of fleece radiator with Xe/CO2 proportional mode straw tube chambers. They are supported in a conically shaped octagon structure made of CFC-Al-honeycomb. For low power consumption VA analog multiplexers are used as front-end readout. A 20 layer prototype built from final design components has achieved proton rejections from 100 to 2000 at 90% electron efficiency for proton beam energies up to 250 GeV with cluster counting, likelihood and neural net selection algorithms.Comment: 11 pages, 25 figures, espcrc2.sty (elsevier 2-column

Sugarcane Straw Blanket Management Effects on Plant Growth, Development, and Yield in Southeastern Brazil

In Brazilian sugarcane (Saccharum spp.) production systems, the practice of moving harvesting residue from row to inter-row positions (i.e., raking) has increased in response to producer concerns over the potential negative effects of sugarcane straw on crop establishment and stalk yield. Despite increasing adoption among sugarcane farmers, the impacts of straw raking practices on plant growth and yield remain unclear. A 2-yr experiment that included both dry and wet seasons was conducted at two sites in southeastern Brazil to evaluate straw management strategy effects on plant tillering, phytomass accumulation, plant nutritional status, and stalk yield. The experiments were established at the Bom Retiro mill and the Univalem mill. Experimental treatments included raking straw to inter-rows (raked), total straw removal (bare soil), and no straw removal (straw cover). Raked and bare soil treatments improved plant tillering but did not influence final plant population. Straw management had a slight effect on phytomass accumulation. Reduction of phytomass yield was observed from the first to the second ratoon during both seasons at both sites. At Bom Retiro, phytomass yield decreased 37% for stands established during the dry season and 19% for stands established during the wet season. At Univalem, phytomass yield decreased 20% for stands established during the dry season and 30% for stands established during the wet season. Retaining straw in the field (regardless of treatment) increased leaf tissue P content but not stalk yield. Raking straw from row to interrow positions at these locations in southeastern Brazil had no benefit on sugarcane yield but may result in soil compaction and higher production costs over time

Ensiling of wheat straw decreases the required temperature in hydrothermal pretreatment

BACKGROUND: Ensiling is a well-known method for preserving green biomasses through anaerobic production of organic acids by lactic acid bacteria. In this study, wheat straw is subjected to ensiling in combination with hydrothermal treatment as a combined pretreatment method, taking advantage of the produced organic acids. RESULTS: Ensiling for 4 weeks was accomplished in a vacuum bag system after addition of an inoculum of Lactobacillus buchneri and 7% w/w xylose to wheat straw biomass at 35% final dry matter. Both glucan and xylan were preserved, and the DM loss after ensiling was less than 0.5%. When comparing hydrothermally treated wheat straw (170, 180 and 190°C) with hydrothermally treated ensiled wheat straw (same temperatures), several positive effects of ensiling were revealed. Glucan was up-concentrated in the solid fraction and the solubilisation of hemicellulose was significantly increased. Subsequent enzymatic hydrolysis of the solid fractions showed that ensiling significantly improved the effect of pretreatment, especially at the lower temperatures of 170 and 180°C. The overall glucose yields after pretreatments of ensiled wheat straw were higher than for non-ensiled wheat straw hydrothermally treated at 190°C, namely 74-81% of the theoretical maximum glucose in the raw material, which was ~1.8 times better than the corresponding yields for the non-ensiled straw pretreated at 170 or 180°C. The highest overall conversion of combined glucose and xylose was achieved for ensiled wheat straw hydrothermally treated at 180°C, with overall glucose yield of 78% and overall conversion yield of xylose of 87%. CONCLUSIONS: Ensiling of wheat straw is shown to be an effective pre-step to hydrothermal treatment, and can give rise to a welcomed decrease of process temperature in hydrothermal treatments, thereby potentially having a positive effect on large scale pretreatment costs