Preparation Of Solid Acid Doped With Antimony And Its Application In Catalytic Synthesis Of Biodiesel

In recent years,people are getting higher and higher the environment with the improvement of people's quality of life.People are hoping to live,study and work in low-carbon,low-polluting environment.Biodiesel is of great significance with environmental protection and resource conservation that is as an environmentally friendly,renewable biomass energy,and which replace the oil and other mineral energy directly.At present,biodiesel was synthesized by the waste oil and methanol using alkali catalysis.But the acid value of the waste oil was too high.The free fatty acid in the waste oil was easily saponified with the alkaline substance,which greatly affected the yield of biodiesel during the biodiesel was synthesized.Therefore,the problem of high acid value need to be solved.Solid acid catalyst played a huge role in the synthesis of biodiesel,and it was separated easily and the smaller degree of corrosion of the equipment than the acidic catalyst.This paper studies the preparation and characterization of solid acid,and the synthesis of esterified oil with esterification reaction and the synthesis of biodiesel transesterification reaction when high acid value of the waste oil was as raw material.The research results of this paper would help to promote the technological progress of the biodiesel industry,improve the quality of the products,and create good economic and environmental effects.The main research contents are as follows:?1?Activated carbon was as matrix,TiO₂ and La₂O₃ were as modifiers and concentrated sulfuric acid was as activator.Sulfated binary oxide rare earth solid acid SO₄^2-/C-TiO₂-La₂O₃ was prepared using high temperature sulfonation.The effects of the mass fraction of La₂O₃,sulfonation temperature and sulfonation time on the acidity of a solid acid catalyst.The results showed that the preferable preparation conditions of acid catalyst SO₄^2-/ C-TiO₂-La₂O₃: the mass fraction of La₂O₃ was 3 %,sulfonation temperature was 200?,sulfonation time was 10 h.?2?The solid acid catalysts were characterized using SEM,TEM,FT-IR,XRD,BET,EDS,DTG.The particle size of solid acid SO₄^2-/C-TiO₂-La₂O₃ was the smallest than that of SO₄^2-/C,SO₄^2-/C-TiO₂ and SO₄^2-/C-La₂O₃,the specific surface area of solid acid SO₄^2-/C-TiO₂-La₂O₃ was largest.The amount of solid acid SO₄^2-/C-TiO₂-La₂O₃ was the lost.The acid sites of solid acid SO₄^2-/C-TiO₂-La₂O₃ were the most.The optimum preparation conditions of SO₄^2-/C-TiO₂-La₂O₃ were as follows: the mass fraction of La₂O₃ was 3%,the sulfonation time was 10 h and the sulfonation temperature was 200?.Acid catalyst SO₄^2-/C-TiO₂-La₂O₃ has the largest specific surface area and the smallest particle size,they were 53.82 m2/g and 156.91 nm respectively.The O,S,Ti and La atoms in SO₄^2-/C-TiO₂-La₂O₃ were most than that of the other three solid acid catalysts.The stability of SO₄^2-/C-TiO₂-La₂O₃ was the strongest.?3?By comparing the catalytic activity of SO₄^2-/C,SO₄^2-/C-TiO₂,SO₄^2-/C-La₂O₃,SO₄^2-/C-TiO₂-La₂O₃,the catalytic activity of solid acid SO₄^2-/C-TiO₂-La₂O₃ was higher than the other three kinds of solid acid,therefore,solid acid SO₄^2-/C-TiO₂-La₂O₃ was as a catalyst.The paper studies the effect of content of the solid acid catalyst,reaction time,reaction temperature,quality ratio between waste oil and methanol on esterification rate.The results showed that the mass fraction of solid acid catalyst was 2.5%,the reaction time was 4h,the reaction temperature was65?,mass ratio between methanol and oil was 1:5,the esterification rate reached 95.64%,an acid value from 18.97mg?KOH?/g down to 1.10mg?KOH?/g,the ester oil can act as transesterification reaction directly.?4?The biodiesel was synthesized of esterification oil and methanol using catalyst NaOH,and the crude yield was used research objective.The mass fraction of catalyst NaOH,reaction time,reaction temperature,mass ratio between methanol and ester oil were influencing factors.The optimal conditions of transesterification reaction: the mass fraction of the catalyst NaOH was0.4%,the reaction time was 1h,the reaction temperature was 65?,the mass ratio between methanol and ester oil was 3:20.Under these conditions,the yield of biodiesel was 95.90%.?5?This paper tested the performance of biodiesel product concentration was-2?,kinematic viscosity was 5.0mm2/s,copper corrosion degree was 1,the density was 878 g/cm3,the closed flash point was 160?,the glue of biodiesel was 1000 mg/100 mL,acid value was 0.28mg?KOH?/g,the sulfur content was 0.02%?W/W?,the cetane number was 44,its performance was basically conformed to national standard.Therefore,biodiesel has some research value and use value.