Increase of energy recovery from sewage sludge

The use of the pyrolysis process to obtain valuable products from biomass is amongst the technologies being investigated as a source for renewable energy. The pyrolysis process yields products such as biochar, bio-oil and non condensable gases. The main objective of this project is to increase energy recovery from sewage sludge by utilising the intermediate pyrolysis process. The intermediate pyrolysis has a residence time ranging from 5 to 10 minutes. The main product yields from sewage sludge pyrolysis are 50 wt% biochar, 40 wt% bio-oil and 10 wt% non condensable gases. The project was carried out on a pilot plant scale reactor with a load capacity of 20 kg/h. This enabled a high yield of biochar and bio-oil. The characterisation of the products indicated that the organic phase of the bio-oil had good fuel properties such as having high energy content of 39 MJ/kg, low acid number of 21.5, high flash point of 150 and viscosity of 35 cSt. An increase in pyrolysis experiments enabled large quantities of pyrolysis oil production. Co-pyrolysis of sewage sludge was carried out on laboratory scale with mixed wood, rapeseed and straw. It found that there was an increase in bio-oil quantity with rapeseed while co-pyrolysis with wood helped to mask the smell of the sludge pyrolysis oil. Engine test were successfully carried out in an old Lister engine with pyrolysis oil fractions of 30% and 50% blended with biodiesel. This indicates that these pyrolysis oil fractions can be used in similar engine types without any problems however long term effects in ordinary engines are unknown. An economic evaluation was carried out about the implementation of the intermediate pyrolysis process for electricity production in a CHP using the pyrolysis oil. The prices of electricity per kWh were found to be very high

Thermal stability of sewage sludge pyrolysis oil

The stability of the oil phase obtained from intermediate pyrolysis process was used for this investigation. The analysis was based on standard methods of determining kinematic viscosity, gas - chromatography / mass - spectrometry for compositional changes, FT-IR for functional group, Karl Fischer titration for water content and bomb calorimeter for higher heaating values. The methods were used to determine changes that occurred during ageing. The temperatures used for thermal testing were 60 °C and 80 °C for the periods of 72 and 168 h. Methanol and biodiesel were used as solvents for the analysis. The bio-oil samples contained 10 % methanol, 10 % Biodiesel, 20 % Biodiesel and unstabilised pyrolysis oil. The tests carried out at 80 °C showed drastic changes compared to those at 60 °C. The bio-oil samples containing 20 % biodiesel proved to be more stable than those with 10 % methanol. The unstabilised pyrolysis oil showed the greatest changes in viscosity, composition change and highest increase in water content. The measurement of kinematic viscosity and gas chromatograph mass spectrometry were found to be more reliable for predicting the ageing process

The Role of Probiotics in the Poultry Industry

The increase of productivity in the poultry industry has been accompanied by various impacts, including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in rearing cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in poultry, as well as demonstrating the potential role of probiotics in the growth performance and immune response of poultry, safety and wholesomeness of dressed poultry meat evidencing consumer’s protection, with a critical evaluation of results obtained to date

Morphological Changes of the Intestinal Villi in Chickens Fed the Dietary Charcoal Powder Including Wood Vinegar Compounds

To investigate the effects of dietary charcoal powder including wood vinegar compounds (4:1, CWVC) on the intestinal villus morphology, 130-d-old male Single Comb White Leghorn chickens were randomly allotted into 0, 1, 3 and 5% dietary CWVC groups of each 8 bird. Four rations were formulated by addition of each level of CWVC (CP: 2.5%) to commercial layer finisher mash diet (CP: 14.5%, ME: 2,803kcal/kg), and fed ad libitum for 28d. During the feeding experimental period, feed intake and body weight gain were measured. After the end of feeding experiments, 4 birds were randomly selected per each group, and intestinal villus height, epithelial cell area and cell mitosis in each intestinal segment were compared using a light microscope. Besides, the morphological change of villus tip surface was observed using a scanning electron microscope. Although the feed intake did not differ among each group, the body weight gain tended to be higher in 1 and 3% dietary CWVC groups than that of 0% group, resulting in the feed conversion ratio being insignificantly improved in these groups. Values of the intestinal villus height, epithelial cell area and cell mitosis were higher in 1% dietary CWVC group but lower in 5% dietary CWVC group than those of another groups in each intestinal segment. The comparatively smooth surface of the duodenal villus apex in the 0% dietary CWVC duodenum changed to the rough surface with a clear cell outline between each epithelial cell due to the conspicuous cell protuberances after feeding 1% dietary CWVC. However, such conspicuous cell protuberances disappeared and cells having no microvilli and deep cells at the sites of recently exfoliated cells were observed after feeding 3% dietary CWVC, and the latter was much increased after feeding 5% dietary CWVC. Fundamentally, the villus apex surface in the jejunum and ileum revealed an almost similar morphological alteration to that in the duodenum except that cells having no microvilli and deeper cells due to recently exfoliated cells were not seen even in 5% dietary CWVC and that the cell protuberances of 1% dietary CWVC became faint with moving caudally. The present morphological changes of intestinal villi in chickens fed the dietary CWVC diets demonstrate that the villus function could be activated also in the ileum at 1% level, and that such an activated villus function in all small intestinal segment parts might improve the feed conversion ratio