Kaiwen Liang

Biodiesel production by in situ transesterification of municipal primary and secondary sludges

The potential of using municipal wastewater sludges as a lipid feedstock for biodiesel production was investigated. Primary and secondary sludge samples obtained from a municipal wastewater treatment plant in Tuscaloosa, AL were freeze-dried and subjected to an acid-catalyzed insitu transesterification process. Experiments were conducted to determine the effects of temperature, sulfuric acid concentration, and mass ratio of methanol to sludge on the yield of fatty acid methyl esters (FAMEs). Results indicated a significant interactive effect between temperature, acid concentration, and methanol to sludge mass ratio on the FAME yield for the insitu transesterification of primary sludge, while the FAME yield for secondary sludge was significantly affected by the independent effects of the three factors investigated. The maximum FAME yields were obtained at 75 degrees C, 5% (v/v) H(2)SO(4), and 12:1 methanol to sludge mass ratio and were 14.5% and 2.5% for primary and secondary sludge, respectively. Gas chromatography (GC) analysis of the FAMEs revealed a similar fatty acid composition for both primary and secondary sludge. An economic analysis estimated the cost of

Improved Plywood Strength and Lowered Emissions from Soybean Meal/Melamine Urea-Formaldehyde Adhesives

3.23/gallon for a neat biodiesel obtained from this process at an assumed yield of 10% FAMEs/dry weight of sludge.

Effect of sub-freezing temperatures on a PEM fuel cell performance, startup and fuel cell components

The objective of this study was to improve the wet shear strength and reduce the formaldehyde emissions for the soybean meal/melamine urea-formaldehyde (MUF) adhesive–bonded plywood by optimizing the hot pressing parameters in plywood manufacturing. An L(44) experimental design was used. A dynamic mechanical analyzer (DMA) was used to study the curing process of the adhesive during hot pressing. The DMA results showed that the storage modulus (E′) first decreased to a minimum at 72.9°C and then increased as the temperature increased to a maximum at 157.2°C. At temperatures higher than 157.2°C, the storage modulus decreased as the temperature increased. The hot press temperature had a significant effect on both the wet shear strength and the formaldehyde emissions from 120°C to 150°C, while no significant effect was found by varying the hot press time from 50 to 80 s/mm and changing the pressure from 0.8 to 1.2 MPa. The adhesive spread rate had a significant effect on the formaldehyde emissions. No signifi...