水相循环对乙醇-水体系液化蜈蚣草产油特性和砷富集影响  

Effects of aqueous phase recycling on the bio-oil characteristics and arsenic enrichment during hydrothermal liquefaction of Pteris vittata L.in ethanol-water system

作　　者：蒋海伟 艾仙斌 阙志刚 文震林[1,2] 邹武 付尹宣 黄蓉[1,2] 石金明 JIANG Haiwei;AI Xianbin;QUE Zhigang;WEN Zhenlin;ZOU Wu;FU Yinxuan;HUANG Rong;SHI Jinming(Institute of Energy,Jiangxi Academy of Sciences,Nanchang 330096,China;Carbon Neutrality Research Center of Jiangxi Province,Nanchang 330096,China)

机构地区：[1]江西省科学院能源研究所,南昌330096 [2]江西省碳中和研究中心,南昌330096

出　　处：《农业工程学报》2024年第17期244-249,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(22308136);江西省自然科学基金资助项目(20232BAB214063);江西省科学院包干制试点示范项目重点研发计划项目(2022YSBG21011);江西省碳中和研究中心新型研发机构创新平台能力提升项目(江西省科技创新基地建设S20231A0002);江西省科学院引进博士项目(2023YYB05)。

摘　　要：砷富集植物的生态友好处置是实现植物修复产业化发展的关键环节,对土壤重金属污染治理高质量发展起到了制约作用。该研究以蜈蚣草为原料,采用乙醇-水作为反应共溶剂体系,考察了乙醇占比和水相循环次数对蜈蚣草水热产油及重金属砷分布的影响。研究结果显示:在乙醇浓度60%、水相循环3次的条件下,蜈蚣草液化生物油产率最高可达51.08%,其热值为29.15 MJ/kg。生物油主要由酯(>80%)、酚、醇、酮、烃等组成。随水相循环次数的增加,生物油中的酯类和酚类物质增加,高沸点化合物会减少,生物油产率和能量回收率分别提高了58%和32.23%;经过水相循环液化后,超过80%的重金属砷主要分布在水相,且砷的浓度增加至215.05 mg/kg,该结果可为砷富集植物无害化后处置提供参考。因此,水相循环利用是砷富集植物液化处置制取高产率生物油与砷富集的有效途径,为富集植物生态友好处置提供了新的思路。The ecologically friendly disposal of arsenic-enriched plants is the key link to achieve the industrial development of phytoremediation,and plays a restricting role in the high-quality development of soil heavy metal pollution control.Conventional treatment methods of hyperaccumulators mainly include incineration and landfill,but these methods may lead to secondary pollution of heavy metals.Hydrothermal liquefaction can transform agricultural and forestry waste with low energy density into liquid biofuel with high energy density.It has the advantages of low reaction temperature,low energy consumption,water as solvent and no need for drying as raw material.As a typical representative of arsenic contaminated soil phytoremediation,the effects of ethanol ratio and water cycle times on hydrothermal oil production and heavy metal arsenic distribution of centipede grass were investigated in this study using Pteris vittata L.as raw material and ethanol-water reaction co-solvent system.The results showed that under the conditions of 60%ethanol concentration and 3 cycles of aqueous phase,the highest yield of liquefied bio-oil was 51.08%,and its calorific value was 29.15 MJ/kg.The reasons for the increase of bio-oil after water phase circulation in the co-solvent system are as follows:1)the organic acids(acetic acid,etc.)in the recycled water phase have an acid catalytic effect to promote biomass liquefaction;2)Compared with pure water,ethanol in cosolvent has lower liquefaction critical point and dielectric constant,which promotes biomass degradation and hydrolysis;3)Ethanol can esterify the acid in the aqueous phase to improve the yield of bio-oil.Bio-oil is mainly composed of esters(>80%),phenols,alcohols,ketones,hydrocarbons,etc.With the increase of water cycle times,the esters and phenols in bio-oil increased and the high boiling point compounds decreased,the bio-oil yield and energy recovery increased by 58%and 32.23%,respectively.This may be affected by esterification of ethanol with fatty acids.Moreover,aqueous cycl

关 键 词：水热液化 生物油 蜈蚣草 水相循环 乙醇-水共溶剂 

分 类 号：TK6[动力工程及工程热物理—生物能] TQ519[化学工程]