Co-pyrolysis Of Sargassum Horueri And Polypropylene For Liquid Hydrocarbon Fuels

The increasing human activities demand a large number of energy.The excessive consumption of fossil fuels not only leads to the shortage of energy but also makes the environment pollution becoming more and more serious.Under the double pressures of energy and environment crisis,biomass is paid close attention to by researchers due to its renewability,low pollution,wide distribution and abundant resources.Biomass energy is considered to have the potential to replace traditional fossil fuels,using biomass to produce liquid and gaseous fuels is attracting more and more attentions of researchers.The research conducted elemental analysis,composition analysis,industry analysis,metal content analysis and thermal gravimetric analysis on Sargassum horueri,Sargassum fusiforme(Harv.)Setch.(macro algae),Triticum aestivuml(herb),bamboo and Cunninghamia Lanceolata(woody plants),in order to found a solid basis for their further utilization in the future.The results showed that macro algae,such as Sargassum horueri and Sargassum fusiforme(Harv.)Setch.,contained higher content of nitrogen and sulfur than the other three.The contents of N and S in Sargassum horueri were 2.10% and 1.39%,respectively,while in bamboo were only 0.29% and0.11%.The woody biomass obtained higher lignin conent than herbaceous plants and marine plants.In general,the highe content of metal elements would lead to highe ash content,a negative correlation consist between the ash content and carbon content,the higher carbon content would cause the lower ash content,while volatile content and ash content had the same correlation,the higher ash content was the lower volatile content was.TG and DTG results indicated that high volatile content resulted in remarkable pyrolysis rate and high weight loss after pyrolysis.The pyrolysis experiment of the mixture of Sargassum horueri and polypropylene was conducted in a small sealed reactor with the volume is 0.2L.The effects ofcracking temperature,mixture ratio and residence time of pyrolysis gas on the yield and distribution of products.The experimental results showed that the mixture ratio had the greatest effect on the reaction,followed by the pyrolysis temperature and residence time.When the content of polypropylene in the mixture decreased from90% to 10%,the liquid yield decreased from 57.11% to 9.56%,the gas yield increased from 38.34% to 64.47% and then decreased to 55.28%.When the ratio of polypropylene to Sargassum horueri are 3: 7 and 9: 1,the content of oxygen compounds and nitrogen heterocyclic compounds in the liquid increased abruptly while the content of alkanes and olefins were low.By analying the yield and contribution of products the optimum experiment conditions were obtained,the appropriate pyrolysis temperature is 375?,the mass ratio of polypropylene to Sargassum horueri was 9:1,the residence time of gas was 30 min.Under the optimum reaction conditions,the liquid yield was up to 64.79%,the gas yield was 30.69%,and the solid yield was 4.52%.Gas chromatographic(GC)and gas chromatographic-mass spectrometry(GC-MS)were respectively used to analyze the gas and liquid products.The components of bio oil were mainly alkanes,alkenes,aromatic hydrocarbons and a small amount of alcohol,aldehyde,ether,ketone,carboxylic acid,lipid compounds;incoagulable gas was mainly composed of CO,CO2,H2,CH4,C2 ~ C5 and small molecule hydrocarbons(C2H4,C2H6,C3H6,C3H8).The results showed that a synergistic effect exist in the co-pyrolysis of polypropylene and Sargassum horueri.The addition of polypropylene can improve the oil yield and reduce the content of oxygen containing compounds.The reaction mechanism of the reaction is that the polypropylene generates a large number of free radicals which could react with the oxygen compounds produced by the decomposition of the Sargassum horueri.