92 research outputs found

    Thermal behavior of native, washed and steam exploded lignocellulosic biomass samples

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    The aim of this study was to evaluate the chemical changes in the main components (cellulose, hemicellulose and lignin) of various lignocellulosic biomass samples during the steam explosion pretreatment. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetry/mass spectrometry (TG/MS) measurements have been performed on different native, washed and steam exploded woody (willow and spruce) and herbaceous (hemp, wheat straw and sweet sorghum bagasse) biomass samples. The main differences between the thermal decomposition of the samples are interpreted in terms of the altered structure of the biomass samples by the effective steam explosion treatment and the different alkali ion contents which have been determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) method. In order to separate these two effects, the native biomass samples have been washed with hot water to remove the main parts of the potassium and sodium ions. The concentration of K+ and Na+ has been reduced in the treated biomass samples so the thermal decomposition mechanism has been altered due to the elimination of the catalytic effects. Principal Component Analysis (PCA) has been used to find statistical correlations between the data. The functional group compositions of the lignin molecules have been modified significantly as indicated by the pyrograms and the score plot of the PCA. The amount of hemicellulose has been reduced. On the other hand, the relative amount of the structurally modified cellulose has been increased in the samples by the steam explosion pretreatment step

    Processing sweet sorghum into bioethanol - an integrated approach

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    Numerous evidences have been provided that juice of sweet sorghum and the leftover after squeezing, the bagasse can be a proper feedstock for bioethanol production. The possibility to integrate a side stream of sweet sorghum processing into the biomass-to-ethanol process was investigated in this study. The liquid fraction, a side stream of the necessary pretreatment of the bagasse was utilized as carbon source for Trichoderma reesei RUT-C30 to produce cellulase enzymes for biomass conversion. However, to overcome the inhibitory nature of the liquid fraction, pre-adaptation of the fungus on solid media was carried out previous to submerged fermentations. The results show that with this approach the lag phase caused by the inhibitors could be markedly shortened and an enhancement of the final enzyme production could be achieved when comparing the pre-adapted strains to reference

    Rozsdából sör? – A volt Dreher sörgyár területének megújulását akadályozó tényezők

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    The development and renewal of brownfield sites have now evolved into an inevitable task in urban planning. Indeed, these areas are considered as potential and hidden reserve areas for cities due to the different urbanisation processes and urban planning trends (urban sprawl, com- pact city approach, etc.). However, the process of revitalisation is not always a ‘smooth journey.’ One reason is that merely physical regeneration is not sufficient to reintegrate the area into the urban fabric. It is essential to identify the economic, environmental, and social processes that have an impact on the area, to pinpoint the local actors/stakeholders, and to map the characte- ristics of the neighbourhood and the internal and external factors that hinder its overall rege- neration. Therefore, a detailed and in-depth study should be conducted prior to revitalisation. In this research we examined and prepared a case study of a brownfield site in Budapest (the breweries of Kőbánya in Budapest – which used to be known as the “Hungarian Munich” in the 19th century). We identified the main external and internal factors, as well as local and district particularities and obstacles to regeneration

    Biomass potential assessment for locating biorefinery plant in Hungary

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    To find a suitable site for a 150,000 metric ton dry material per year (t dm/yr) input capacity biorefinery plant in Hungary is a challenging task. Not only biomass potentials have to be assessed, competing uses, sustainability aspects, public opinion and future threats to feedstock availability should be also taken into account. As a result of our calculations, currently there is enough feedstock available for the targeted input capacity to operate in an ecologically sustainable way. However, several factors may threaten the future of feedstock availability. In the long run enhanced price competition is anticipated for biomass among biorefinery, livestock keeping, timber industry and biomass based renewable energy production. The majority of stakeholders accept in general biorefinery as a promising solution for substituting fossil based plastics, still local interests give priority to a balanced agricultural production including higher shares of husbandry

    Ethanol production from mixtures of wheat straw and wheat meal

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    Background: Bioethanol can be produced from sugar-rich, starch-rich (first generation; 1G) or lignocellulosic (second generation; 2G) raw materials. Integration of 2G ethanol with 1G could facilitate the introduction of the 2G technology. The capital cost per ton of fuel produced would be diminished and better utilization of the biomass can be achieved. It would, furthermore, decrease the energy demand of 2G ethanol production and also provide both 1G and 2G plants with heat and electricity. In the current study, steam-pretreated wheat straw (SPWS) was mixed with presaccharified wheat meal (PWM) and converted to ethanol in simultaneous saccharification and fermentation (SSF). Results: Both the ethanol concentration and the ethanol yield increased with increasing amounts of PWM in mixtures with SPWS. The maximum ethanol yield (99% of the theoretical yield, based on the available C6 sugars) was obtained with a mixture of SPWS containing 2.5% water-insoluble solids (WIS) and PWM containing 2.5% WIS, resulting in an ethanol concentration of 56.5 g/L. This yield was higher than those obtained with SSF of either SPWS (68%) or PWM alone (91%). Conclusions: Mixing wheat straw with wheat meal would be beneficial for both 1G and 2G ethanol production. However, increasing the proportion of WIS as wheat straw and the possibility of consuming the xylose fraction with a pentose-fermenting yeast should be further investigated

    Meta-analysis of gene expression profiles associated with histological classification and survival in 829 ovarian cancer samples.

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    Transcriptomic analysis of global gene expression in ovarian carcinoma can identify dysregulated genes capable to serve as molecular markers for histology subtypes and survival. The aim of our study was to validate previous candidate signatures in an independent setting and to identify single genes capable to serve as biomarkers for ovarian cancer progression. As several datasets are available in the GEO today, we were able to perform a true meta-analysis. First, 829 samples (11 datasets) were downloaded, and the predictive power of 16 previously published gene sets was assessed. Of these, eight were capable to discriminate histology subtypes, and none was capable to predict survival. To overcome the differences in previous studies, we used the 829 samples to identify new predictors. Then, we collected 64 ovarian cancer samples (median relapse-free survival 24.5 months) and performed TaqMan Real Time Polimerase Chain Reaction (RT-PCR) analysis for the best 40 genes associated with histology subtypes and survival. Over 90% of subtype-associated genes were confirmed. Overall survival was effectively predicted by hormone receptors (PGR and ESR2) and by TSPAN8. Relapse-free survival was predicted by MAPT and SNCG. In summary, we successfully validated several gene sets in a meta-analysis in large datasets of ovarian samples. Additionally, several individual genes identified were validated in a clinical cohort

    Meta-analysis of gene expression profiles associated with histological classification and survival in 829 ovarian cancer samples

    Get PDF
    Transcriptomic analysis of global gene expression in ovarian carcinoma can identify dysregulated genes capable to serve as molecular markers for histology subtypes and survival. The aim of this study was to validate previous candidate signatures in an independent setting and to identify single genes capable to serve as biomarkers for ovarian cancer progression. As several datasets are available in the GEO today, we were able to perform a true meta-analysis. First, 829 samples (11 datasets) were downloaded, and the predictive power of 16 previously published gene sets was assessed. Of these, 8 were capable to discriminate histology subtypes and none was capable to predict survival. To overcome the differences in previous studies, we used the 829 samples to identify new predictors. Then we collected 64 ovarian cancer samples (median relapse-free survival 24.5 months) and performed TaqMan RT-PCR analysis for the best 40 genes associated with histology subtypes and survival. Over 90% of subtype-associated genes were confirmed. Overall survival was effectively predicted by hormone receptors (PGR and ESR2) and by TSPAN8. Relapse-free survival was predicted by MAPT and SNCG. In summary, we successfully validated several gene sets in a meta-analysis in large datasets of ovarian samples. Additionally, several individual genes identified were validated in a clinical cohort
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