RESUMO
Biomass-derived biocrude is gaining greater recognition from people in general as an alternative fuel source to traditional fossil fuels. Worldwide, a great deal of research is being done to develop fuels made from sustainable biomass in order to replace the current conventional energy sources. Waste sludge has been thought of as a viable raw biomass source because of its accessibility, affordability, high lignin content, and higher heating value. Additionally, considering sludge contains a high proportion of moisture and water acts as a catalyst during the hydrothermal liquefaction (HTL) process, it is the best choice for thermochemical conversion. From the ultimate component value ranges obtained from elemental analysis, it can be demonstrated that the C, H, and higher heating value (HHV) of petrocrude are approximately 8.78%, 23.5%, and 10.66% higher than those of biofuel. According to the overall analysis, co-liquefaction of waste vegetable oil and swine manure can result in 87.97% bio-oil at 340 °C. The temperature, retention period, inclusion of catalysts, and use of solvents, however, can all affect this proportion. To support this illustration, it has been assessed from the study that municipal wet sewage sludge can produce an HHV of 28.52 MJ/kg when water is used as the solvent. However, 34.14 MJ/kg, or 16.5% more than the previous one, can be produced for the same amount of biomass, when the mixture of water and methanol serves as the solvents. This review article highlights an array of waste sludge categories, their chemical properties, and their conversion through the HTL process. It also features a Van Krevlen diagram with a graphical representation of essential operating parameters. This review research illustrates one of the best strategies for producing biofuel in which waste sludge can be used as raw material through the HTL conversion process, considering the prospective mass commercial production of biocrude oil.
RESUMO
The key objective of the bridge structure on a river is to confirm and assist the continual communication. On the other hand, it also has a harmful effect on the hydrological and morphological behavior of the neighboring zone as of the river width contraction. The present study assessed the Bridge construction effect on river shifting characteristics for Dharla River. For doing so, this study followed two steps. First, Landsat imageries for both pre-bridge structure period (1988, 1993 and 1998) and post-bridge structure period (2003, 2008, 2013 and 2017), has been processed and used to determine the thalweg line. Then, geo-spatial environment has been used to assess the thalweg line shifting characteristics and channel width variations. The results revealed a frequent shifting of thalweg line towards both the east and west direction at the upstream side of this Bridge and also the dominating eastwards shifting at the downstream side of the Bridge. After constructing the Dharla Bridge on Dharla River (i.e. post-bridge structure period) the movement of the channel has been changed at a significant level. Particularly, it has been found that the east side shifting is higher than the west side. Thus, the existing of Dharla Bridge has an abundant effect on the shifting characteristics of thalweg line. The study concluded that the shifting of the thalweg lines of Dharla River undergoes a drastic change of study period and the River can be treated as a very dynamic one. The results of this study might supportive for the sustainable and future development of the rivers and adjacent flood plain in Bangladesh.
