Waste Mussel Shell Research Articles

Kinetic comparison of two basic heterogenous catalysts obtained from sustainable resources for transesterification of waste cooking oil

Article history: Alkaline earth metal oxides are appropriate catalysts for biodiesel production and among them, CaO and MgO are known for possessing the best efficiency. In this study, catalysts synthesized from economical and sustainable resources were used for biodiesel production. More specifically, waste mussel shells and demineralized (DM) water treatment precipitates as calcium and magnesium carbonate sources, were converted into calcium and magnesium oxides at temperatures above 900 C. Methanol and waste cooking oil were reacted in a 250 mL two-necked flask at 24:1 and 22.5:1 ratios in presence of 12 and 9.08 wt% of mussel shell-based and DM water treatment precipitates-based catalysts, respectively. The effects of temperature (328, 333, 338, 343 and 348 K) and time (1, 3, 5, 7 and 8 h) at a stirrer speed of 350 rpm on the conversion of the oil into biodiesel were investigated. The results obtained indicated a pseudo-first order kinetics for the transesterification reaction using both catalysts. The activation energies in the presence of the DM water treatment precipitates and mussel shell catalysts were measured at 77.09 and 79.83 kJ.mol -1 , respectively. Accordingly, the DM water treatment precipitates catalyst resulted in a faster reaction due to its lower activation energy value. Moreover, the catalysts were reused five times and the results obtained showed that the methanol-driven extraction of CaO contained in the DM water treatment precipitates catalyst was lower than the waste mussel shell catalyst proving the higher stability of the new heterogeneous catalyst i.e. the calcinated DM water treatment precipitates.

Optimization of biodiesel production using waste mussel shell catalyst

Calcium oxide is an appropriate catalyst for biodiesel production. In this study, an inexpensive and environment-friendly catalyst was used. The waste mussel shell collected in of Persian Gulf coast is a source of calcium carbonate which changes to calcium oxide in calcinations temperatures higher than 950°C. Transesterification reaction was done in the presence of soybean oil, methanol and mussel shell catalyst in a temperature of 60°C. Using response surface methodology (RSM) the effects of different parameters (calcination temperature, catalyst concentration and molar ratio of methanol to oil) were studied. Each parameter was set at three levels labeled as low, medium and high, respectively (calcination temperature of 950, 1000, and 1050°C; catalyst concentration of 6, 9 and 12wt.%; methanol to oil ratios of 12:1, 18:1 and 24:1). The results of the optimization implies that the calcination temperature of 1050°C, catalyst concentration of 12wt.%, and methanol to oil ratio of 24:1 provide the maximum values of purity and yield in biodiesel production. The reusability of mussel shell catalyst was studied for five times and the result showed that the catalyst re-calcination in reusability step has negative effects on the yield of biodiesel production.

Solid- Alkali Catalyst of Mussel Shell Used in Producing Biodiesel

Calcium dioxide can catalyze soybean oil to obtain biodiesel in triglyceride transesterification. Waste mussel shells were utilized as a source of calcium oxide. The shell was calcined in N2 at 1000°C with optimum time of 2 h to obtain active CaO catalysts. Parametric studies have been investigated and perfect conditions were found to be methanol/oil mole ratio, 9:1; catalyst amount, 4wt%; reaction temperature, 65°C; stirring rate of 450 round per minute; reaction time, constant 3h; methyl esters conversion above 98% . Reusability results improved that the prepared catalyst is able to be reemployed up to 9 times. These results indicate waste mussel shell combusted at high temperature can be reused in biodiesel production as a low cost catalyst.

Arsenic, chromium and mercury removal using mussel shell ash or a sludge/ashes waste mixture

Different batches of valued mussel shell and waste mussel shell ash are characterised. Shell ash has pH > 12 and high electrical conductivities (between 16.01 and 27.27 dS m(-1)), while calcined shell shows pH values up to 10.7 and electrical conductivities between 1.19 and 3.55 dS m(-1). X-ray fluorescence, nitric acid digestion and water extractions show higher concentrations in shell ash for most parameters. Calcite is the dominant crystalline compound in this ash (95.6%), followed by aragonite. Adsorption/desorption trials were performed for mussel shell ash and for a waste mixture including shell ash, sewage sludge and wood ash, showing the following percentage adsorptions: Hg(II) >94%, As(V) >96% and Cr(VI) between 11 and 30% for shell ash; Hg(II) >98%, As(V) >88% and Cr(VI) between 30 and 88% for the waste mixture. Hg and As desorption was <5% for both shell ash and the waste mixture, while Cr desorption was between 92 and 45% for shell ash, and between 19 and 0% for the mixture. In view of that, mussel shell ash and the mixture including shell ash, sewage sludge and wood ash could be useful for Hg(II) and As(V) removal.

Bio-filler from &lt;I&gt;Mussel&lt;/I&gt; Shell: Preparation and Its Effects on Polypropylene Composites Properties

Waste mussel shell stacking with a significant odor and toxicity which are hazardous to human constitutes a serious environmental hazard. For utilization of waste mussel shell resource, granule of mussel shell (YBCC) was prepared from waste mussel shell by removing cuticle, crushing, grinding and shearing emulsification and was introduced as a filler to reinforce polypropylene (PP). The characterization results of YBCC show that the mainly composition of YBCC is aragonite (CaCO3) platelets and the particle size distribution range of YBCC powder is from 40 nm to 500 nm, the proportion of organic components of YBCC is about 2.04wt% and YBCC has a good thermal stability. The mechanical behavior of PP/YBCC composite shows a higher yield strain, yield strength, tensile strength and elongation at break than traditional commercial calcium carbonate (CMCC) filled PP. Yield strength of PP/YBCC composite with 3wt% YBCC is improved by about 11.1%. A small content (about 1wt%) of YBCC can promote the heterogeneous nucleation for PP crystallization and the formation β-crystalline PP. Using mussel shell for producing bio-filler is valuable for industrial production and practical application as fillers for reinforcing polymers.