农业工程学报
農業工程學報
농업공정학보
2014年
5期
262-269
,共8页
蒋恩臣%赵晨希%秦丽元%陈爱慧
蔣恩臣%趙晨希%秦麗元%陳愛慧
장은신%조신희%진려원%진애혜
热解%生物质%化学分析%松子壳%木醋液%成分
熱解%生物質%化學分析%鬆子殼%木醋液%成分
열해%생물질%화학분석%송자각%목작액%성분
pyrolysis%biomass%chemical analysis%pine nut shell%wood vinegar%components
木醋液的应用十分广泛,但其成分较复杂。该文研究了松子壳热解过程中不同反应温度和时间对制备木醋液产物的影响,并对木醋液成分和性质进行了分析。结果表明随着反应温度的升高,木醋液产率先升高,在500℃左右时达到最大,然后迅速降低;含水率由94%左右降至85%左右;黏度降低,流动性变强;pH值由3.2左右降至2.6左右。随着处理时间的增加,木醋液产率、含水率、黏度、流动性和pH值变化的趋势均不明显。优化工艺(500℃、8 min)下热解制备的木醋液,其成分主要包括酚类、酮类、醚类、酯类、醛类、酸类、醇类和胺类,其中酚类和酮类物质的含量较高,质量分数分别为53.88%和20.93%,所以其抗氧化性较强,并且尽管其pH值较低,但腐蚀性较同pH值甲酸弱。
木醋液的應用十分廣汎,但其成分較複雜。該文研究瞭鬆子殼熱解過程中不同反應溫度和時間對製備木醋液產物的影響,併對木醋液成分和性質進行瞭分析。結果錶明隨著反應溫度的升高,木醋液產率先升高,在500℃左右時達到最大,然後迅速降低;含水率由94%左右降至85%左右;黏度降低,流動性變彊;pH值由3.2左右降至2.6左右。隨著處理時間的增加,木醋液產率、含水率、黏度、流動性和pH值變化的趨勢均不明顯。優化工藝(500℃、8 min)下熱解製備的木醋液,其成分主要包括酚類、酮類、醚類、酯類、醛類、痠類、醇類和胺類,其中酚類和酮類物質的含量較高,質量分數分彆為53.88%和20.93%,所以其抗氧化性較彊,併且儘管其pH值較低,但腐蝕性較同pH值甲痠弱。
목작액적응용십분엄범,단기성분교복잡。해문연구료송자각열해과정중불동반응온도화시간대제비목작액산물적영향,병대목작액성분화성질진행료분석。결과표명수착반응온도적승고,목작액산솔선승고,재500℃좌우시체도최대,연후신속강저;함수솔유94%좌우강지85%좌우;점도강저,류동성변강;pH치유3.2좌우강지2.6좌우。수착처리시간적증가,목작액산솔、함수솔、점도、류동성화pH치변화적추세균불명현。우화공예(500℃、8 min)하열해제비적목작액,기성분주요포괄분류、동류、미류、지류、철류、산류、순류화알류,기중분류화동류물질적함량교고,질량분수분별위53.88%화20.93%,소이기항양화성교강,병차진관기pH치교저,단부식성교동pH치갑산약。
With China’s growing energy problems, biomass conversion technologies have attracted considerable attention for converting biomass into energy products. These technologies can be divided into four main categories: direct-combustion processes, thermochemical conversion, biochemistry and liquefaction technology, respectively. Of the variety of technologies, thermochemical conversion and, particularly, pyrolysis have aroused great attention all over the world in recent years. Biomass as a renewable energy source has significant potential to transform into high-value and high-grade charcoal, bio-oil and combustible gas by the pyrolysis process. The wood vinegar refined from pyrolysis bio-oil can be used as insect repellents, plant growth-promoting liquid fertilizer, and as a soil improver after appropriate treatment, which has a very broad market prospects. The use of wood vinegar presents some problems due to its complex ingredients and big quality differences obtained by different materials and process conditions. However, there are very limited studies on the produced conditions and properties of biomass pyrolysis wood vinegar. <br> In this paper, red pine nut shell, which is a specialty in the northeast of China, was pyrolysed as raw material. The characteristics of wood vinegar have been investigated, including proximate analysis, elemental analysis, composition analysis, heating value analysis and thermo-gravimetric analysis (TGA). The experiments were conducted on the biomass continuous pyrolysis reaction device with a variable pitch spiral conveyor to obtain wood vinegar at different reaction temperatures (300℃,400℃, 500℃600℃and 700℃) and different reaction times (4min、6min、8min、10min and 12min). The characteristics of wood vinegar consisting of water content, viscosity, pH value, chemical compositions, the antioxidant activity and corrosion properties were determined by the Karl Fischer method, viscometer, acidity meter, gas chromatography and mass spectrometry (GC-MS), ultraviolet spectrophotometer, and scanning electron microscope (SEM), respectively, which provided a scientific basis for the study of the pine nut shell pyrolysis process. <br> The results were as follows:with pyrolysis temperature increasing, the yield of wood vinegar increased gradually until the temperature reached 500 ℃, which provided the maximum yield, then reduced quickly. The moisture content of wood vinegar gradually decreased from about 94% to 85%; the viscosity decreased gradually; the liquidity became stronger; and the pH showed a slow decreasing trend, from 3.2 down to about 2.6. With increased pyrolysis time, the yield of wood vinegar had no significant change, water content basically appeared as an inconspicuous trend, the viscosity showed almost no obvious trend, the liquidity also almost had no significant change, and the pH ranging of wood vinegar made little change by contrast. In addition, the main ingredients of wood vinegar were phenols, ketones, ethers, esters, aldehydes, acids, alcohols and amines at a pyrolysis temperature of 500℃and a pyrolysis time of 8min, in which the contents of phenols and ketones were 53.88%and 20.93%, respectively. Under the same pyrolysis conditions, the hydroxyl radical scavenging rate of wood vinegar was 66.63%, equivalent to 3μmol/L of ascorbic acid. SEM images showed that wood vinegar had a significant role in scavenging hydroxyl free radicals, which had a strong antioxidant activity. Wood vinegar gained under the condition of 500℃and 8min had weak corrosion, despite the low pH value of 3.1. All of the above results provided a theoretical basis for experimental study of wood vinegar prepared from pine nut shell continuous pyrolysis.