Search results for "fuel"
showing 10 items of 986 documents
Effect of Tire-Char Ash on the Extent of Synergy during CO2 Cogasification with Hydrochar from Potassium-Rich Coconut Fiber
2020
The influence of inherent tire char ash during co-gasification with coconut hydrochar prepared at different intensities was investigated by thermogravimetric analysis to ascertain the extent to which synergistic interaction, reactivity, and activation energy reduction were altered. High-ash tire tread (TT) and low-ash sidewall (SW) both exhibited enhanced synergy, reactivity, and activation reduction upon co-gasification with hydrochars; however, the extent of promotion was more pronounced in SW-hydrochar blends. This difference was caused by the inhibiting nature of TT inherent ash, particularly the role of Si-containing compounds. Inhibition in TT-hydrochar blends was mainly due to the pr…
Terpenoid composition and chemotaxonomic aspects of Miocene amber from the Koroglu Mountains, Turkey
2014
Abstract A recently discovered fossil resin from Koroglu Mountain in Turkey has been analyzed by gas chromatography–mass spectrometry and pyrolysis gas chromatography–mass spectrometry to determine its structural class and botanical origin. The sesqui- and diterpenoids contained in the amber extract were used as chemosystematic markers when compared with terpenoids in extant conifers. The pyrolysis products were dominated by labdanoid derived bicyclic products together with succinic acid indicating Class Ia type amber. The biomarker compositions of the resin comprise mainly sesqui- and diterpenoids, and lack triterpenoids. This distribution suggests a gymnosperm, and more specifically a con…
Bacterial Bioconversion of Primary Aliphatic and Aromatic Alcohols into Acids: Effects of Molecular Structure and Physico-chemical Conditions
1997
The biotransformation of four alcohol substrates (butanol, 2-methylbutanol, 3-methylbutanol and 2-phenylethanol) into their acids was studied using a strain of Acetobacter aceti. Bioconversion yields depended on the molecular structure of the alcohol. Biotransformation of high concentrations of alcohols was possible until the precursor reached an inhibiting concentration (3.8 g dm -3 for butanol and 3-methylbutanol, 4.2 g dm -3 for 2-methylbutanol). In contrast, biotransformation of 2-phenylethanol decreased when alcohol concentration was higher than 0.3 g dm -3 . Dissolved oxygen concentrations and pH conditions of the medium were important factors in improving bioconversion. Transformatio…
Optimization of alkali pretreatment to enhance rice straw conversion to butanol
2021
Abstract The use of rice straw (RS) was enhanced to produce biobutanol as biofuel, for which the NaOH pretreatment was optimized by considering the butanol-biomass ratio that quantify the mass balance efficiency of the three sequential stages of the process: pretreatment, enzymatic hydrolysis and fermentation by Clostridium beijerinckii. The optimum point (solid loading of 5% w/v with 0.75% w/v NaOH at 134 °C for 20 min) of the best cost-wise option yielded an enhanced biomass use of 77.6 g kg RS−1. A maximum butanol titer of 10.1 g L−1 was reached after 72 h of fermentation with the complete uptake of glucose and nearly complete uptake of xylose. The NaOH concentration was the most influen…
Thermophilic hydrogen production from cellulose with rumen fluid enrichment cultures: Effects of different heat treatments
2011
Elevated temperatures (52, 60 and 65 °C) were used to enrich hydrogen producers on cellulose from cow rumen fluid. Methanogens were inhibited with two different heat treatments. Hydrogen production was considerable at 60 °C with the highest H2 yield of 0.44 mol-H2 mol-hexose -1 (1.93 mol-H2 mol-hexose-degraded-1) as obtained without heat treatment and with acetate and ethanol as the main fermentation products. H2 production rates and yields were controlled by cellulose degradation that was at the highest 21%. The optimum temperature and pH for H2 production of the rumen fluid enrichment culture were 62 °C and 7.3, respectively. The enrichments at 52 and 60 °C contained mainly bacteria from …
On the fermentative behavior of auxotrophic strains of Saccharomyces cerevisiae
2014
Background: The selection of new yeast strains could lead to improvements in bioethanol production. Here, we have studied the fermentative capacity of different auxotrophic mutants of Saccharomyces cerevisiae, which are routinely used as hosts for the production of heterologous proteins. It has recently been found that these strains exhibit physiological alterations and peculiar sensitivities with respect to the parental prototrophic strains from which they derive. In this work the performance of auxotrophic S. cerevisiae CEN.PK strains was compared to the corresponding prototrophic strain, to S. cerevisiae T5bV, a strain isolated from grape must and to another auxotrophic strain, S. cerevi…
Grape pulp, grape pips and their mixture: Novel substrates or supports for solid state fermentation
1997
Grape marc, comprising of grape pulp and grape pips, is generated in high quantities during ethanol production, but has no significant commercial value. The components of the grape marc, individually or in combination, can serve as substrate or support in solid state fermentation. The potential benefits of sieved fractions (800-3150 µm particle size) was, therefore, evaluated using Trichoderma viride, with or whithout enrichment. Based on sorption isotherm profiles, grape pulp showed the best performance, though its ability to promote biomass formation was the lowest. The latter could be improved by enrichment with glucose. It, thus, offers potential as a reusable support. Grape pips promot…
Researches on the Advantages for the Environment of Using Bio-Fuels to Vehicles
2011
The paper presents researches on the possibilities and advantages for the environment of using bio-fuels , especially bio-ethanol and bio-gas. The international context is favorable to using bio-fuels, considering that a direction of European Union establishes that in 2020, 20% of the energy consumption of Romania must be provided by rechargeable energy. One source for producing bio-fuels, not so much used until now is sugar beet. Sugar beet wastes are estimated as 1.22 times sugar production, since the total dry matter of processing wastes and field wastes exceed the weight of sugar in the ratio of 55:45. The novelty of the present paper approach is the fact that sugar beet is less used fo…
Indoor air pollution in extremely poor Colombian households
2013
Objetivo Caracterizar la exposición a la contaminación del aire interior por uso de combustibles sólidos en hogares en situación de pobreza extrema en Colombia. Métodos A partir de la información gubernamental oficial de hogares en situación de pobreza extrema (encuesta Red Unidos de septiembre 2012, n=1,3 millones de hogares y >5 millones de individuos) se estructuraron dos modelos de regresión logística: (i) Factores asociados al uso de combustibles sólidos para cocinar a nivel hogar, (ii) Asociación entre el uso de combustibles sólidos en el hogar y prevalencia de limitaciones de la salud a nivel individuo. Resultados Un total de 530 mil hogares en situación de pobreza extrema donde habi…
Agroecological potential and prospects of alternative use of natural feed resources for bioenergetics
2018
Produkcja biomasy dla biogazu, paliw stałych i ciekłych jest ważna w szerokim zakresie zastosowań niekonwencjonalnych źródeł energii. Jednakże produkcja i wykorzystanie biomasy do celów energetycznych również wymaga kosztów finansowych i prowadzi do zmian w strukturze obszarów upraw w produkcji rolnej. Czynniki te powodują wzrost cen produktów rolnych. Zmiana klimatu i wysokie koszty zasobów mineralnych przyczyniają się do poszukiwania i rozwoju nowych sposobów pozyskiwania zasobów energetycznych. Badania nad produkcją biomasy z użytków zielonych w celach energetycznych są w Europie istotne i priorytetowe, a ich wyniki mają ogromną wartość praktyczną. Dlatego konieczne jest rozwiązanie prob…