Low Temperature Co-pyrolysis Of Eichhornia Crassipes And Low Rank Coal

With the increasing scarcity of fossil fuels and seriousness of environmental issues, lookingfor clean alternative energy is more and more pressing. Recently, co-pyrolysis of biomass andcoal has attracted much attention for its low prices of feedstock, wide variety of sources, mildoperating conditions, efficient cascade utilization of raw materials, less CO2emission and so on.In this paper, low-temperature co-pyrolysis of wild eichhornia crassipes (EC) and Hongyingmixing coal (MC), a kind of low rank coal which is not suitable for traditional utilization isundertaken in a special fixed bed reactor to investigate the influence of EC dosage (0,10%,20%,30%,40%,100%) for the distribution of co-pyrolysis products, and optimize the pyrolysisconditions based on the orthogonal experiment (L934). The pure ingredients and the best ratioblends are thermal gravimetric analyzed in order to discuss the interactions between rawmaterials from the aspect of pyrolysis characteristics and dynamics, and their oils are analyzedby GC-MS respectively. In addition, detect the pyrolysis oil and semi-coke with elemental andcalorific value analysis, which is attributing to their following use. Studies indicate that:1) With the increasing of biomass content, the tar yield increase gradually and decrease later.The pyrolysis oil yield rise to11.32%with the EC ratio of30%, which increased by24.81%and5.11%respectively compared with MC and calculated value from the additive model.2) From TGA experiments, additional weight loss is observed at300-700℃, which revelsthe existence of synergistic effect. The activation energy and pre-exponential factor ofco-pyrolysis are smaller than the separate pyrolysis at main temperature ranges. It shows thatthere is compensating effect between Ea and A, leading to the raise of pyrolysis activity anddiminish of reaction rate. The promoter action is mainly for enlarging the pyrolysis activity.3) According to the orthogonal experiments, the logical progression of factors are as follows:final temperature＞proportion＞particle diameter＞heat preservation time. The maximum yieldof pyrolysis oil is11.70%when the EC ratio is35%, the final temperature is550℃, the particlediameter of EC is0.355-0.500mm and the heat preservation time is25min, which increases by3.36%compared with before.4) The content of alkanes rise by34.46%and organic acid descend to zero compared withseparate pyrolysis supported by GC-MS, which conducive to replacing partial petroleum and thestability of oil. The H/C of co-pyrolysis oil rise by8.72%compared with coal tar. The heat valueis36.96MJ/kg, which is slightly lower than diesel oil and petroleum. After optimization, thecontent of benzene reaches63.17%, which rise by81.99%. At the same time, the content ofphenol and other aromatic compounds increase. Ultimate analysis and heat value analysisindicates that there is little or no variation in H/C, N, S and heat value of pyrolysis oil. The yieldof pyrolysis oil has been increased without impairing the quality.