Study On Preparation Of The Nanometer-size Magnetic Solid Acid Catalyst And Biodiesel

Biodiesel is a kind of engine fuel which is made from Animal and vegetable oiland modified through some reaction. Biodiesel is biodegradable, non-toxic, andenvironmentally friendly and can be extracted from renewable resources. It can benot only used as an alternative fuel directly, but also can be used as an additive forclean burning of diesel fuel.In this paper, we researched on the development of nano-magnetic solid acidcatalyst in order to make full use of high-acid value oil and further improve itsbiodiesel conversion. On the basis of catalyst preparation, we selected two (waste oilhigh acid value and stable Chinese tallow kernel oil with lower acid value)representative oil sources to fit the properties of raw material oil. We compared theresults of two different processing: making Biodiesel from Chinese tallow kernel oiland waste oil using alkaline catalyst, making biodiesel from waste oil using alkalinecatalyst and alkaline catalyst firstly, acid catalyst secondly. We found it is suitable tomake biodiesel from Chinese tallow kernel oil by alkaline catalyst, to make biodieselfrom waste oil by alkaline catalyst firstly, acid catalyst secondly. Different oilresources required different processes and different catalyst properties. In this paper,we found a reasonable and environmental friendly process of producing biodiselfrom high acid value oil.Combining solid acid SO₄^2-/M_XO_Y with magnetic materials, we got nano-magnetic solid acid catalyst which possessed both acidic and magnetic properties.We studied the effect of several important steps of the preparation process, immersedin 1.5L sulfuric acid, calcined at 500℃for 3 hours to make the best nano-magneticsolid acid catalyst. We also characterized the nano-magnetic solid acid catalysts.We characterized the nano-magnetic solid catalyst samples with surface tester,X-ray diffraction, Fourier transform infrared spectroscopy and scanning electronmicroscopy. The ration of surface to volue of nano-magnetic solid catalyst is124m²/g measured by surface tester. XRD analysis showed that after thehigh-temperature burning, catalyst ZrO₂ changed from amorphous to crystalline Quartet, formed an active site and has strong catalytic activity, and Fe₃O₄ is in thehighly fragmented state in catalyst. Solid acid catalyst can not be produced withoutburning. IR spectra show the existence of O=S=O, acid center and catalyst which iseasy-absorbent. Scanning electron microscopy analysis showed that the surface ofthe catalyst is not smooth but with very small grains which was spherical, theaverage particle size is below 100, proving its belonging to nanometer level.We prepared biodiesel from waste oil using self-made nano-magnetic solid acidcatalyst and optimized the process of Preparation, improved the preparing theprocess with quadratic regression orthogonal rotating design. The regressionequation forecast model of free fatty acid methyl ester of waste oil:Y=29.1143+0.5083x₁+0.1167x₂+1.125x₃+0.5417x₄-1.214x₁²+0.1x₂·x₁-1.239x₂²-0.0375x₃.x₁-0.125x₃·x₂-1.289x₃²-0.0375x₄·x₁-0.2x₄.x₂+0.5625x₄.x₃-2.014x₄²Optimal conditions were: reaction time, 6.4hr, dosage of catalyst, 4.0ï¼…, ratio ofmethanol to oil, 35:1, reaction temperature, 82℃, and etherifying rate, 29.49ï¼…,overall yield of the alkaline reaction 93.12ï¼….We determined the physical and chemical indicators of biodiesel made fromwaste oil and analyzed its main performance indicator (viscosity, flash point, andcetane value, acid value, Distillation, sulfur content, residual carbon, water content,machinery impurities, copper corrosion, ash content, pour point, cold filter pluggingpoint) which comply with national Light diesel standards and the United Statesbiodiesel standards.We analyzed the chemical composition of biodiesel through gaschromatography, which showed that biodiesel carbon 16 and carbon 18 fatty acidmethyl ester is its main composition, its has a similar molecular structure with thediesel substitutes. The rheological properties analysis of biodiesel showed that theviscosity of biodiesel decreased with the increase of temperature, but had nothingmuch to do with stirring time and intensity. Through the emission characteristicsstudy of the use of biodiesel in diesel engine, we got that the emission of HC and COdecreased and NOx emissions increase...