1,721,482 research outputs found
Techno-economic analysis of levoglucosan production via fast pyrolysis of cotton straw in China
Full text linkPyrolysis of cotton straw is a promising technology because of the large variety of chemical species that can be produced. A more promising chemical-levoglucosan, is the subject of this study. The techno-economic feasibility of producing levoglucosan via fast pyrolysis and extraction was evaluated by modeling a 200,000 dry ton cotton straw/year facility. Experimental and modeling data were gathered from recent publications and used for analysis. For the modeled feedstock handling capacity, the results indicated that levoglucosan production could reach around 18,000 ton/year. The estimated levoglucosan production cost, including byproduct credits, was $3.3 per kg. Additionally, sensitivity analysis was performed to determine the effect of variability in different system parameters on the levoglucosan production cost
Upgrading effluent from anaerobic digestion of dairy manure through hydrothermal carbonization
Full text linkThe coupling of hydrothermal carbonization (HTC) and anaerobic digestion (AD) is investigated in this paper. Effluent from AD of dairy manure was collected as feedstock for the HTC process. Three parameters, temperature, reaction time and pH, were investigated. Central composite design (CCD) and response surface methodology (RSM) were applied for the optimization of hydrochar production. Mass balance was performed for the HTC process. The results showed that temperature was the most significant parameter for hydrochar production. With the increase of temperature and time, the energy and mass yields of hydrochar decreased, while the high heating value (HHV) increased. Optimization models set up for hydrochar production showed that 260oC, 70 min with AD effluent of pH 6 was the best option. Hydrochar with HHV of about 20.18 MJ/kg could be achieved with mass and energy yields of 49.09% and 62.99%, respectively. Chemical oxygen demand (COD) of resulting HTC process water was analyzed. More than 30% COD remained in the liquid, which showed that HTC processed water could have a potential to be recirculated back to the AD system. HTC of the AD effluent could greatly reduce odor issues caused by AD processes, and the hydrochar had good dewatering and drying properties. Consequently, integrating HTC after AD promises to be a way to deal with various wastes in an environmental friendly way
Fungal pretreatment of miscanthus for fermentable sugar production: experimental and techno-economic evaluation
Full text linkLignocellulosic biomass is an abundant, renewable feedstock for biorefineries, but pretreatment is usually required to overcome its high recalcitrance to biodegradation. Fungal pretreatment, an alternative process to traditional pretreatments, can enhance the enzymatic digestibility of the lignocellulosic biomass. Fungal pretreatment can be performed at low temperature, without added chemicals, and no wastewater generation. However, in comparison with traditional pretreatments, longer residence times, lower yields, and feedstock sterilization requirements make it challenging to implement. This work investigated the fungal pretreatment of the dedicated energy crop Miscanthus × giganteus with the white rot fungus Ceriporiopsis subvermispora. Fungal pretreatment of non-sterile miscanthus was performed in batch using miscanthus previously colonized with the fungus as inoculum. The process enhanced the enzymatic digestibility of miscanthus by 2-fold over that of untreated miscanthus, and was comparable to the pretreatment of sterilized miscanthus inoculated with a pure culture of the white rot fungus. The finished material from the unsterilized pretreatment was used as inoculum for two more generations in a sequential fungal pretreatment process, where no increase in enzymatic digestibility was observed. A propagation of indigenous fungi that out-colonized C. subvermispora was observed through the generations, showing that sterilization is a required step for the stability and reproducibility of fungal pretreatment. A techno-economic analysis of the production of fermentable sugars from miscanthus using fungal pretreatment showed that the process was not feasible at full biorefinery scale due to the high capital cost caused by long residence time, low feedstock bulk density, and low sugar yields
Response by Sag et al to Letter Regarding Article, “Distinct Regulatory Effects of Myeloid Cell and Endothelial Cell NAPDH Oxidase 2 on Blood Pressure”
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Effects of pre- and post-extraction autoclaving on the nutritional value of rapeseed meal for broiler chicks
No full textAn experiment was conducted to study the influence of autoclaving for different length of times before and after extraction of oil on the nutritional value of rapeseed meal for broiler chicks. Seeds of HG-rapeseed variety Pakcheen (glucosinolates 60.8 mu mol/g in fat free meal) were subjected to autoclaving treatments for 15 and 30 minutes. Alternatively the oil was extracted from the seeds and the resultant meal was given the autoclaving treatments. These meals were incorporated into the diet of broiler chicks at a level of 10%. The experiment lasted for five weeks. Data was recorded for feed intake and weight gain of the chicks. Results indicated that different dietary treatments did not significantly influence the bird's performance. It was, however, observed that feed intake in general was better in the case of pre-extraction autoclaving. Maximum total weight gain per chick (952.3 g), was recorded with seed autoclaved for 30 minutes, followed by control (950 g). Feed to gain ratio obtained by different groups ranged from 1.94 (untreated control) to 2.08 (Seed Autoclaved -30 minutes). Dressing percentage of different groups ranged from 51.4 (standard) to 53.49 (MA-30) (see table 2), and the differences again were not significant. It can be concluded that this rapeseed meal at a level of 10% inclusion in a diet containing several supplementary protein sources of animal and plant origin, was safe and did not adversely affect the bird's growth performance
Angiotensin II regulates cardiac L-type Ca channels and ryanodine receptors via NADPH oxidase 2-dependent activation of protein kinase A and CaMKII
No full textEffects of dehulling and dry heating on the nutritional value of rapeseed meal for broiler chicks
No full textA five weeks feeding experiment was conducted to study the effect of including rapeseed meal (processed in different ways) in the diet of broiler chicks on their biological performance. Rapeseed meal was prepared in three different ways: 1) Normal procedure was adopted; 2) Seeds were given dry heat (80 degreesC) treatment and were then extracted in the normal way; 3) Seeds were dehulled and the remaining cotyledon part of the seeds was extracted. These meals were included in the diet of broiler chicks at a level so as to provide 25% of the total dietary protein from rapeseed meal. Data on feed consumption and weight gain were recorded weekly. Results showed no significant effects of different treatments. However among the groups, heat treatment resulted (although not significantly) in the highest feed intake (2081 g/chick) followed by control (1940 g/chick) and dehulled rapeseed meal (1915 g/chick). This trend was paralleled by gain in weight and maximum gain was recorded in the case of heat treated rapeseed meal fed group (788 g/chick). Feed to gain ratio ranged from 2.49 (dehulling group) to 2.72 (control group)
ECHOCARDIOGRAPHIC ESTIMATION OF MEAN PULMONARY ARTERY PRESSURE: A COMPARISON OF DIFFERENT APPROACHES TO PREDICT PULMONARY HYPERTENSION
No full textEffects of feeding increased levels of heat processed rapeseed meal on performance of broiler chicks
No full textA six week feeding trial was conducted involving day-old male broiler chicks to study the effect of increased levels of untreated and heat (105 degreesC/15 minutes) treated RSM (variety Pak-cheen, glucosinolate content 60.85 mug/g) on growth performance of these chicks. Chicks were divided. into seven groups, each replicated three times, with 8 chicks in a replication. One group was fed on standard commercial diet without rapeseed meal, three groups were given diets containing 15, 20 and 25% rapeseed meal, while another three groups were fed on diets containing 151, 20 and 25% heat treated rapeseed. All dietary treatments did not effect significantly feed consumption (45.1 to 61.6 g/chick/day). Effect on weight gain was significant (P < 0.01). Highest average daily weight gain (30.91 g/chick) was recorded in the standard diet group. This however, was not significantly different from average daily weight gain in 15% untreated RSM fed group (29.7 g/chick). All other RSM groups showed significantly (P < 0.01) lower weight gain values than the standard diet group. Feed to gain ratio ranged from 1.70 to 2.24 among various dietary treatments. The feed economy was highest in 20% treated RSM diet group which consumed 1.70 kg of feed per kg of weight gain. This was followed by the 15% treated RSM fed group (1.71). Dressing percentage was not influenced by different treatments. Similarly, differences in liver, gizzard and heart weights were statistically non-significant. Heat processing of rapeseed prior to oil extraction may result in the inactivation of myrosinases, leading to reduction in the anti-nutritional effects of glucosinolates. This effect may not have been important in the present study, because initial glucosinolate content of the feed was 9.12 mug/g in 15% RSM diet which was below the threshold. On the other hand damage to protein, in terms of loss of amino acids due to heating, seems to have led to the inferior nutritional quality of the feed
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