微波裂解柚子皮制备活性炭的工艺研究

通过将柚子皮微波裂解制得柚子皮炭,用化学活化法制备高品质的柚子皮活性炭。活化剂选用H3PO4,ZnCl2,KOH和NaOH,并对每种活化剂的炭剂比、活化温度、活化时间和浸渍时间进行考察,以碘吸附值为主要品质衡量指标。试验结果表明,最佳工艺条件:活化剂为KOH,炭剂比为1∶2,活化温度为800℃,活化时间为1 h,浸渍时间为36 h。制得的柚子皮活性炭碘吸附值为1 318.21 mg/g,亚甲基蓝吸附值为225 mg/g,得率为42.17%,灰分为4.96%,吸附性达到木质味精精制用颗粒活性炭国家一级品标准。     

燃料油的新型替代品——生物质裂解油

从化石能源为主向可再生能源为主过渡,是我国能源发展战略的一项重要任务,其中,燃料油将是可再生能源服务的重要对象之一。生物质裂解油以秸秆等农林废弃物为原料,其特质适于替代燃料油。国际上生物质裂解油已经迈入产业化发展的门槛,我国亦具有广阔的市场前景。当前应该抓住国际技术发展的机遇,推动该技术的研发、示范和产业化。     

微波裂解废菌袋生物油的稳定性研究

文章对废菌袋快速微波裂解制取的生物油进行了储存稳定性试验研究,对在不同存储期和不同存储条件下的生物油进行理化性质评价,并采用气质联用技术对其进行定量分析。经过储存后的生物油的水分、黏度和残渣率均有提高,酸性增强,芳香度增加。GC-MS分析表明,生物油储存过程中酚类和芳香杂环类化合物含量增加,醇类、酮类、有机酸和酯类化合物含量均有提高。     

生物质热裂解制油的动力学及技术研究

在不同升温速率下对水曲柳原料在 30 0～ 12 0 0 K范围内进行了热重分析试验 ,试验显示生物质热裂解随温度升高经历五个不同阶段。采用微商法和积分法对其主体阶段的分析得到相互一致的结果 :活化能为 10 1.4 k J/mol、指数因子为 1.2 2× 10 7s- 1 的一阶一步动力学模型。在所开发的以流化床反应器为主体的生物质热裂解制油系统上对生物质进行热裂解试验 ,得出了温度、粒径、停留时间和木种等几种最为重要的参数对热裂解制油的影响规律 ,并在 773K左右成功制取出产率高达 6 0 %的生物油 ,同时用色质联机分析 (GC- MS)技术对所制取的生物油进行了初步分析。     

稻壳连续热解特性研究

在自行研制的生物质连续热解反应装置上进行稻壳连续热解和二次裂解实验研究。随着稻壳热解温度的提高,炭产率降低,气体产率增加,液体产率先增加后减少;随着滞留时间的减少,炭产率、液体产率增加,气体产率减少。稻壳热解气以CO2和CO为主,且二者为竞争关系,热解温度提高,CO2产量降低,CH4、H2、C2H4、C2H6产量增加,CO的产率变化不大;滞留时间对热解气组分影响不大。二次裂解温度提高,裂解气中的H2、CH4、C2H4含量明显增加,二次裂解温度为800℃时,H2产率达到12%。稻壳500℃热解挥发物600℃二次裂解木醋液中醋酸含量高达49.44%,焦油中检测到的物质主要为丙酮和异丙醇。     

生物质裂解油催化裂解精制机理研究(Ⅲ)——生物质裂解油模拟物的催化裂解机理

分析生物质油6种模拟物在裂解温度500℃,不同质量空速条件下的催化裂解产物。不含芳环的生物质油模拟物(乙酸、甲醇、环戊酮和糠醛)经过HZSM-5分子筛催化剂催化裂解后的产物中,均含有苯、萘、茚和多环芳烃及其衍生物,而苯酚和间甲酚经过HZSM-5分子筛催化裂解后,产物中主要是酚类化合物。根据模拟物催化裂解产物,推测不同类型化合物的催化裂解反应途径,说明生物质裂解油催化裂解精制反应过程主要发生脱氧和芳烃化反应,为生物质油催化裂解精制机理研究提供了理论依据。     

生物质热裂解制取液体燃料的实验研究

在对生物质热裂解技术进行系统研究的基础上，率先在国内自行开发研制了以流化床反应器为主体的可连续运行的生物质热裂解制取游液体燃料系统，成功地制取出了产率高达60％的生物油。同时简要介绍了适合于生物油分析的GC－MS分析方法，得出生物油由于高水分含量和高含氧量需作进一步改性处理后才能投入实际应用。     

生物质闪速热裂解制备生物质油

生物质闪速裂解是使生物质的有机高聚物在隔绝空气、常压、快速加热到400～600℃（约104 K/s的升温速率）,超短反应时间（小于2 s）的条件下迅速断链分子键,使结炭和产气降到最小限度,从而最大限度地获得生物质油.依据这一原理,出现了涡旋反应器、烧蚀裂解、旋转锥、沸腾流化床、循环流化床等工艺.文中系统地阐述了常用的生物质闪速裂解液化的方式,介绍了生物质裂解油的特点.     

生物质裂解油催化裂解精制机理研究(Ⅰ)——生物质裂解油及其催化裂解精制油的物性及组成

通过生物质裂解油和催化裂解精制油的物性和化学分析显示催化裂解精制油的密度、粘度、水含量较生物质裂解油明显降低,而pH值和热值明显提高。催化裂解精制油的碳含量较生物裂解油增加,氧含量降低。催化裂解精制油中的酸、醛、酮、糖和醇含量明显降低,酚和芳烃含量明显增加。说明经过催化裂解精制后的精制油的品质较精制前的生物裂解油明显提高。     

催化剂对稻壳水蒸气气化特性和焦油转化的影响

使用白云石、橄榄石、菱镁矿作为催化剂,在自行搭建的小型固定床气化炉试验台上对稻壳进行高温水蒸气催化气化和焦油转化实验,研究了气化温度、催化剂种类、镍负载、表观停留时间等因素对稻壳水蒸气气化半焦产率、焦油产率、气体产率以及气体组分的影响.试验结果表明,白云石、橄榄石、菱镁矿都对焦油有一定催化裂解效果,白云石的催化活性高于...     

Optimization of fermentative hydrogen production process by response surface methodology

The effect of temperature, initial pH and glucose concentration on fermentative hydrogen production by mixed cultures was investigated in batch tests, and the optimization of fermentative hydrogen production process was conducted by response surface methodology with a central composite design. Experimental results showed that temperatures, initial pH and glucose concentrations had impact on fermentative hydrogen production individually and interactively. The maximum hydrogen yield of 289.8 mL/g glucose was estimated at the temperature of 38.6 °C, the initial pH of 7.2 and the glucose concentration of 23.9 g/L. The maximum hydrogen production rate of 28.2 mL/h was estimated at the temperature of 37.8 °C, the initial pH of 7.2 and the glucose concentration of 27.6 g/L. The maximum substrate degradation efficiency of 96.9% was estimated at the temperature of 39.3 °C, the initial pH of 7.0 and the glucose concentration of 26.8 g/L. Response surface methodology was a better method to optimize the fermentative hydrogen production process. Modified logistic model could describe the progress of cumulative hydrogen production in the batch tests of this study successfully.     

响应面法优化海带酸水解预处理工艺

采用响应面法优化酸水解海带预处理的工艺条件。在对硫酸浓度、水解时间、底物浓度、水解温度4个因素进行单因素试验基础上,以还原糖得率为响应值,以Box-Behnken中心组合设计方法,建立预处理工艺参数的回归模型,利用软件Design-Expert 7.1.6作响应曲面分析,得出海带预处理理论最佳工艺参数;对理论参数进行了平行试验验证及校正,得到最优工艺参数:酸浓度为0.48 mol/L,底物浓度为8%,水解时间为43 min,水解温度为120℃,在此条件下还原糖得率为25.47%。通过验证可知,建立的数学模型能够较好地预测试验结果。     

Optimizing thermomechanical pretreatment conditions to enhance enzymatic hydrolysis of wheat straw by response surface methodology

Wheat straw was pretreated with a thermomechanical process developed in our laboratory to improve the enzymatic hydrolysis extent of potentially fermentable sugars. This process involves subjecting the lignocellulosic biomass for a short time to saturated steam pressure, followed by an instantaneous decompression to vacuum at 5 kPa. Increasing of the heat induced by saturated steam result in intensive vapour formation in the capillary porous structure of the plant material and the subsequent release of the pressure to vacuum allows fixing the expanded structure. Response surface methodology (RSM) based on central composite design was used to optimize three independent variables of the pretreatment process: processing pressure (300-700 kPa), initial moisture contents of wheat straw (10-40%) and processing time (3-62 min). The process was optimised for hydrolysis yield and initial hydrolysis rate obtained by enzymatic hydrolysis on the pretreated solids by Celluclast (1.5 L). The analysis of variance (ANOVA) revealed that, among the process variables, processing pressure and processing time have the most significant effect on the hydrolysis yield and on initial rate of hydrolysis whereas initial moisture content observed significantly lower effect on the two responses. The predicted hydrolysis yield and in a lesser extent the predicted initial rate of hydrolysis agreed satisfactorily with the experimental values with R² of 96% and 86% respectively.     

微波预处理稻壳对纤维素酶固态发酵的影响

以稻壳为原料,通过微波预处理后用于固态发酵生产纤维素酶,研究了微波处理对后续发酵过程的影响。采用正交试验与单因素试验确定了微波处理的条件,并分析了微波功率与处理时间对发酵过程中纤维素酶活性及戊糖、还原糖含量的影响。试验结果表明,用功率为300W的微波处理稻壳7min后进行发酵,可以得到最高的纤维素酶酶活,其中滤纸酶活（干基质）可达7．09 IU／g,CMC酶活（干基质）可达87．24 IU／g,分别比未经处理的稻壳提高了21％和15％。若以单位能耗产生的酶活增加量计算,微波处理稻壳5min后发酵,可以得到最高的酶活性增加量。     

Optimization and characterization studies on bio-oil production from palm shell by pyrolysis using response surface methodology

In this work palm shell waste was pyrolyzed to produces bio-oil. The effects of several parameters on the pyrolysis efficiency were tested to identify the optimal bio-oil production conditions. The tested parameters include temperature, N₂ flow rate, feed-stock particle size, and reaction time. The experiments were conducted using a fix-bed reactor. The efficient response surface methodology (RSM), with a central composite design (CCD), were used for modeling and optimization the process parameters. The results showed that the second-order polynomial equation explains adequately the non-linear nature of the modeled response. An R² value of 0.9337 indicates a sufficient adjustment of the model with the experimental data. The optimal conditions found to be at the temperature of 500 °C, N₂ flow rate of 2 L/min, particle size of 2 mm and reaction time of 60 min and yield of bio-oil was approximately obtained 46.4 wt %. In addition, Fourier Transform infra-red (FT-IR) spectroscopy and gas chromatography/mass spectrometry (GC-MS) were used to characterize the gained bio-oil under the optimum condition.     

Box-Behnken响应面法优化粪便直接液化制取生物质油工艺条件的研究

粪便的直接液化是实现粪便无害化、减量化和资源化处理的一种新兴工艺。文章针对人粪便直接液化的工艺条件进行了探讨。以生物质油产率为指标,单因素实验结果显示,反应温度为310℃,停留时间为30min时,生物质油产率最高,为51.77%。利用Box-Benhnken响应曲面优化人粪便直接液化的工艺条件,结果显示,反应温度是影响生物质油产率的关键因素;反应温度为314℃,停留时间为43 min时,生物质油产率最高,为49.59%;生物质油热值最高可达36.59 MJ/kg。研究表明,直接液化过程是C,H元素由人粪便向生物质油中富集的过程。     

Application of response surface methodology and artificial neural network on pyrolysis of safflower seed press cake

In this study, mathematical correlation between the process variables and product yields for pyrolysis of safflower seed press cake (SPC) in fixed-bed reactor was investigated by using the response surface methodology (RSM) and artificial neural networks (ANNs). The RSM results showed that the second-order response model can be used to describe the relationship between the various factors and the response. Several feed-forward fully connected neural networks were investigated and optimal configuration of the ANN model was obtained. The results revealed that the ANN model could be considered as an alternative to RSM and practical modeling technique for the pyrolysis product yields.     

响应曲面法优化固体碱催化制备生物柴油的工艺

以固体碱硅酸钠为催化剂进行酯交换反应制备生物柴油,采用响应曲面法中的Box-Behnken模式对影响生物柴油转化率的4个主要因素(温度、催化剂用量、反应时间、醇油物质的量比)进行优化.建立生物柴油转化率的二次多项回归模型方程,并对回归方程系数进行显著性检验和方差分析.试验结果表明:当反应温度为66℃、催化剂用量为大豆油质量的2.1%、反应时间为7h、醇油物质的量比为8.6:1时,生物柴油的转化率最高,最高转化率预测值为75.78%,与实测值基本相符,优化模型有效可靠.     

基于响应面法对秸秆纤维素乙醇生产工艺参数的优化

文章在对里氏木霉T12菌株产纤维素酶的培养条件进行单因素优化的基础上,以滤纸酶活力(FPA)为响应值,通过Plackett-Burman设计法筛选出对产酶影响最显著的3个因素,依次为麦麸>温度>氯化钙。响应面优化结果为当麦麸、温度、氯化钙分别为6.27 g/L,31℃,0.709 g/L时,纤维素酶理论最大FPA酶活为62281.3 U/m L。在优化后的培养条件下纤维素酶粗酶液的实际FPA酶活为60 126.5±16.0 U/m L。将纤维素酶粗酶液以10%添加量加入秸秆一步转化乙醇的5 L发酵罐中,经过144 h的发酵,乙醇产量(v/v)可达到7.05%±0.18%。     

The pyrolysis process of biomass by two-stage chemical activation with different methodology and iodine adsorption

Current concerns with the high energy/cost nature of activated carbon production have encouraged research into alternative activated carbon production methods to reduce the environmental impact. The purpose of this study is to produce the activated carbon from biomass (carob bean seed husk, CBSH) by chemical activation with a different methodology using zinc chloride. Two different activation temperature methodologies for the preparation of activated carbons were applied at the ranges of 30–80 and 200–350°C. The effects of the pre-activation and activation temperatures, duration time, and the impregnation ratio on the surface and chemical properties of activated carbon were investigated. Studies were conducted on the adsorption of iodine from the prepared activated carbon. The highest iodine adsorption number was achieved as 874 mg/g. Langmuir surface area was 1544 m²/g. The structural morphology of activated carbons was evaluated with a scanning electron microscope. The surface chemical characteristics of activated carbons were determined by the Fourier transform infrared (FTIR) spectroscopic method.