Catalytic Cracking Of Waste Cooking Oil Model Compound To Produce Hydrogen And Carbon Nanotubes

As a cheap and rich resource of C and H,waste oil has broad prospects for the preparation of hydrogen and carbon nanotubes.Hydrogen has the advantages of high combustion heat value and high energy conversion rate,and is an ideal carrier of clean energy.However,there are few studies on hydrogen production from waste oil by catalytic cracking and lack of efficient catalysts.In this paper,hydrogen and carbon nanomaterials were prepared by catalytic cracking waste oil model compounds by preparing efficient catalysts.The main contents and results are as follows:（1）In view of the low catalytic activity of catalysts for hydrogen production from waste oil,30%Ni/SBA-15,1%Pt-30%Ni/SBA-15 and 2%Pt-30%Ni/SBA-15 catalysts were prepared by impregnation method.Hydrogen and carbon nanotubes（CNTs）were obtained by catalytic cracking of waste cooking oil model compound（WCOMC）.The morphology,phase,structure and reduction performance of the catalysts were characterized by ICP-OES,SEM,TEM,XRD,N₂-BET and H₂-TPR.At the same time,the effects of Pt addition and cracking temperature on hydrogen production and quality of carbon nanotubes were also studied.The results showed that 2%Pt-30%Ni/SBA-15 catalyst exhibited excellent activity at 750°C and the content of hydrogen in the gas product was up to 66.2 vol.%.After 240min of reaction,the hydrogen content in the product gas decreased from 66.2 vol.%to 38.5vol.%.XRD analysis of the catalysts collected after the reaction showed that the addition of platinum metal made the deposited carbon have higher crystallinity.TG analysis showed that the addition of Pt effectively improved the yield of CNTs.In addition,SEM,TEM,XRD,TG and Raman analysis were performed on CNTs to analyze their morphological structure,crystallinity,oxidation stability,graphitization and purity.XRD and TG results show that CNTs have high crystallinity and oxidation stability.Raman results show that CNTs have high graphitization and purity.（2）In view of the low cost and excellent catalytic activity of non-noble metals Ni and Co,Ni-Co/SBA-15 catalyst was prepared for the catalytic cracking of waste cooking oil model compound to prepare hydrogen and CNTs.The phase,structure and reduction properties of the catalyst were analyzed by ICP-OES、XRD、TEM、BET and H₂-TPR characterization methods.The effects of the nickel-cobalt metal content,the reaction temperature and the liquid feed flow rate on hydrogen production and the quality of the carbon nanotubes were investigated.The deposited carbonaceous products were characterized by SEM,TEM,TG,XRD,and Raman to analyze their appearance,internal structure,oxidation stability,purity,crystallinity and degree of graphitization.The results show that the catalyst containing 20%Ni and 30%Co shows the highest activity and stability at a feed flow rate of 0.02 m L/min.The content of hydrogen in the gas produced was close to 71.5 vol.%for a reaction temperature of 750°C.Some thinner multi-walled CNTs and some CNTs with an open-topped structure were found to be deposited on10%Ni-40%Co/SBA-15 and 30%Ni-20%Co/SBA-15,respectively.The XRD analysis of carbon indicated that the deposited carbon exhibited high crystallinity.The TGA and Raman spectroscopic analysis indicated that all CNTs showed high oxidation stability and a high degree of graphitization.After Pt was replaced by Co,the hydrogen content and the yield of carbon nanotubes increased,indicating that non-noble metals can also obtain excellent catalytic effect.