Biodiesel Production by Acid Methanolysis of Slaughterhouse Sludge Cake

Abstract

Biosludge is a normal form of accumulating microbial populations inside the sewage or wastewater treatment facilities. Excessive sludge in the wastewater treatment basins has to be removed periodically to ensure good water quality of the effluent. This study aims to evaluate the feasibility of biodiesel production by transesterification of slaughterhouse sludge cake. The sludge cake was collected from a selected commercial slaughterhouse and transesterified with methanol, n-hexane, and acids (e.g., sulfuric acid or hydrochloric acid) at 55 °C. Three acid concentrations (2%, 4%, and 8%, v/v) in methanol under four reaction time periods (4, 8, 16, and 24 h) were applied. Results showed that the highest accumulated fatty acid methyl ester (FAME) yields of 2.51 ± 0.08% and 2.27 ± 0.09% were achieved when 8% (v/v) of H2SO4 or HCl were added in a 4 h reaction time, respectively. Methyl esters of palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), and oleic acid (C18:1n9c) were the major components of biodiesel from acid methanolysis of slaughterhouse sludge cake. Experimental and analytical results of acid methanolysis of slaughterhouse sludge cake showed that acid methanolysis of sludge cake was one of the feasible and practical options to recycle sludge waste and produce renewable energy.

Recovery of Copper and Zinc from Livestock Bio-Sludge with An Environmentally Friendly Organic Acid Extraction

“…The statistical analysis for this trial used SAS ® 9.4 (SAS Institute Inc., Cary, NC, USA) and then Prism 6 (GraphPad Software Inc., San Diego, CA, USA). Statistical analysis uses a 3 × 2 × 3 factorial design experimental design, similar to our previous study [28], comparing the interrelationship and sympathetic effects of three variables (acetic acid concentration, 2% hydrogen peroxide addition, and reaction time). If the results from the variance analysis are significant, Tukey's honest significant difference (HSD) test would be used to compare the difference among the various factor grades.…”

Slaughterhouse and poultry wastes: management practices, feedstocks for renewable energy production, and recovery of value added products

“…The results revealed optimal blend as 30% of CFME with 70% of diesel, which in turn lowers the carbon monoxide, hydrocarbons, and smoke emissions by 24.4%, 22.9%, and 14.4% respectively. Su and Chou [128] carried out biodiesel production from slaughterhouse sludge cake through acid methanolysis. The sludge cake was transesterified with methanol, n-hexane, and acids (using H 2 SO 4 or HCl) at varying concentrations (2%, 4%, and 8%, v/v) in different time periods (4, 8, 16, and 24 h).…”

Recent Advances in Feedstock and Lipase Research and Development towards Commercialization of Enzymatic Biodiesel

“…Pretreatment with sulfuric acid in the presence of methanol is required to esterify the FFA and reduce their content to below 1% (w/w) before the alkaline transesterification of TAG to FAME can proceed. The two-step acid-base process adds to the production cost and is considered as one of the major drawbacks of chemical biodiesel [16]. Lipases can trans/esterify both TAG and FFA in one step, hence their use on a large scale.…”

“…Vegetable oils such as sesame seed oil [12], palm oil [13], white mustard oil [14], and soybean oil [15] that consist of long chain of fatty acids have been all used for biodiesel production. In addition, waste biomass, microalgae, waste cooking oils, oily sludge, meat processing waste, and animal fat waste from slaughterhouses [16,17] are all gaining importance as inexpensive feedstock. Related information on these feedstocks is also helpful in the design of strategies for low-cost biodiesel production that can at the same time address waste disposal problems related to waste diversion, recycle and re-use [18].…”