Parameter Estimation for Simultaneous Saccharification and Fermentation of Food Waste Into Ethanol Using Matlab Simulink

The increase in waste disposal and energy costs has provided an incentive to convert carbohydrate-rich food waste streams into fuel. For example, dining halls and restaurants discard foods that require tipping fees for removal. An effective use of food waste may be the enzymatic hydrolysis of the waste to simple sugars and fermentation of the sugars to ethanol. As these wastes have complex compositions which may change day-to-day, experiments were carried out to test fermentability of two different types of food waste at 27 degrees C using Saccharomyces cerevisiae yeast (ATCC4124) and Genencor's STARGEN enzyme in batch simultaneous saccharification and fermentation (SSF) experiments. A mathematical model of SSF based on experimentally matched rate equations for enzyme hydrolysis and yeast fermentation was developed in Matlab Simulink. Using Simulink parameter estimation 1.1.3, parameters for hydrolysis and fermentation were estimated through modified Michaelis-Menten and Monod-type equations with the aim of predicting changes in the levels of ethanol and glycerol from different initial concentrations of glucose, fructose, maltose, and starch. The model predictions and experimental observations agree reasonably well for the two food waste streams and a third validation dataset. The approach of using Simulink as a dynamic visual model for SSF represents a simple method which can be applied to a variety of biological pathways and may be very useful for systems approaches in metabolic engineering in the future.     

Efficient Production of Ethanol from Empty Palm Fruit Bunch Fibers by Fed-Batch Simultaneous Saccharification and Fermentation Using Saccharomyces cerevisiae

The concentration of ethanol produced from lignocellulosic biomass should be at least 40 g l^?1 [about 5 % (v/v)] to minimize the cost of distillation process. In this study, the conditions for the simultaneous saccharification and fermentation (SSF) at fed-batch mode for the production of ethanol from alkali-pretreated empty palm fruit bunch fibers (EFB) were investigated. Optimal conditions for the production of ethanol were identified as temperature, 30 °C; enzyme loading, 15 filter paper unit g^?1 biomass; and yeast (Saccharomyces cerevisiae) loading, 5 g l^?1 of dry cell weight. Under these conditions, an economical ethanol concentration was achieved within 17 h, which further increased up to 62.5 g l^?1 after 95 h with 70.6 % of the theoretical yield. To our knowledge, this is the first report to evaluate the economic ethanol production from alkali-pretreated EFB in fed-batch SSF using S. cerevisiae.     

Aqueous Ammonia Soaking of Switchgrass Followed by Simultaneous Saccharification and Fermentation

Simultaneous saccharification and fermentation (SSF) of switchgrass was performed following aqueous ammonia pretreatment. Switchgrass was soaked in aqueous ammonium hydroxide (30%) with different liquid–solid ratios (5 and 10 ml/g) for either 5 or 10 days. The pretreatment was carried out at atmospheric conditions without agitation. A 40–50% delignification (Klason lignin basis) was achieved, whereas cellulose content remained unchanged and hemicellulose content decreased by approximately 50%. The Sacccharomyces cerevisiae (D₅A)-mediated SSF of ammonia-treated switchgrass was investigated at two glucan loadings (3 and 6%) and three enzyme loadings (26, 38.5, and 77 FPU/g cellulose), using Spezyme CP. The percentage of maximum theoretical ethanol yield achieved was 72. Liquid–solid ratio and steeping time affected lignin removal slightly, but did not cause a significant change in overall ethanol conversion yields at sufficiently high enzyme loadings. These results suggest that ammonia steeping may be an effective method of pretreatment for lignocellulosic feedstocks.     

Biodiesel Production from Alkali-Catalyzed Transesterification of Tamarindus indica Seed Oil and Optimization of Process Conditions

Biodiesel is considered a sustainable alternative to petro-diesel owing to several favorable characteristics. However, higher production costs, primarily due to the use of costly edible oils as raw materials, are a chief impediment to its pecuniary feasibility. Exploring non-edible oils as raw material for biodiesel is an attractive strategy that would address the economic constraints associated with biodiesel production. This research aims to optimize the reaction conditions for the production of biodiesel through an alkali-catalyzed transesterification of Tamarindus indica seed oil. The Taguchi method was applied to optimize performance parameters such as alcohol-to-oil molar ratio, catalyst amount, and reaction time. The fatty acid content of both oil and biodiesel was determined using gas chromatography. The optimized conditions of alcohol-to-oil molar ratio (6:1), catalyst (1.5% w/w), and reaction time 1 h afforded biodiesel with 93.5% yield. The most considerable contribution came from the molar ratio of alcohol to oil (75.9%) followed by the amount of catalyst (20.7%). In another case, alcohol to oil molar ratio (9:1), catalyst (1.5% w/w) and reaction time 1.5 h afforded biodiesel 82.5% yield. The fuel properties of Tamarindus indica methyl esters produced under ideal conditions were within ASTM D6751 biodiesel specified limits. Findings of the study indicate that Tamarindus indica may be chosen as a prospective and viable option for large-scale production of biodiesel, making it a substitute for petro-diesel.     

Multivariate Determination of Total Sugar Content and Ethanol in Bioethanol Production Using Carbon Electrodes Modified with MWCNT/MeOOH and Chemometric Data Treatment

This work reports the characterization and application of a voltammetric electronic tongue using an array of glassy carbon electrodes modified with multi‐walled carbon nanotubes containing metal (Pd, Au, Cu) and oxy‐hydroxide nanoparticles (MetalsOOH of Ni, Co) towards the determination of total sugar content in products related with sugarcane‐bioethanol production. The prediction model based on Artificial Neural Networks (ANN) has given satisfactory results for the carbohydrate sum and the obtained response had shown an adequate accuracy. Voltammetric data was first adapted for the computation using the Fast Fourier transform, and results from the electronic tongue approach were compared with use of different electrodes alone. Final performance was better using uniquely the Ni oxy‐hydroxide modified electrode, especially in the quantification of ethanol, a side‐effect of counter‐balancing its interference.     

高效液相色谱法定量测定采油微生物发酵菌液中的有机酸

采用反相高效液相色谱法(RP-HPLC)在Kromasil C18分析柱上,以0.015 mol/L磷酸二氢钠缓冲液(pH=2.3)和乙腈(体积比为96∶4)的二元流动相分离测定了采油微生物发酵液中的有机酸,流动相的流速为1.0mL/min,采用紫外检测器在210 nm处对有机酸进行测定.结果表明有机酸浓度在0.05～1.5 g/L时其峰面积与相应的质量浓度有良好的线性关系,其r大小等于0.9990,测定结果的RSD都小于4.0%(n=8),平均回收率均为100±4%以内.该方法具有测定结果准确可靠,操作简便快速,重现性好等特点.     

Evaluation and Optimization of the Oxidation efficiency of a UV-Persulphate-Oxidation Toc-Analyzer for the Determination of Oil Contamination from Forestry in Ground Water

Different chain oils (tall, rape seed and mineral oils) have been used as model compounds to evaluate and optimize the applicability of UV-persulphate TOC-analyzer for quantitative determination of forestry oils and to follow the progress of their biodegradability. It was shown, that K 2 S 2 O 8 -UV-oxidation method is not sufficient to oxidize chain oils completely. There were differences in oxidation efficiency between different oils, changing from about 46% measured for tall oil to about 25% observed for rape seed chain oil. The addition of Triton X-100 surfactant up to 2% (w/w) was observed to increase the oxidation efficiency, e.g. to 75% for tall oil. The observations can be explained by assuming that in the presence of surfactant the emulsions are more homogeneous and stable. Optimization using two-level full factorial design (temperature of the oxidation chamber and the amount of persulphate) was studied. The results show that the UV-persulphate-oxidation TOC-analyzer is not suitable method to monitor biodegradability of chain oils.     

废动植物油脂制备烷醇酰胺的研究

以废动植物油脂为原料,在自制DYD催化剂作用下制得脂肪酸甲酯,再以氢氧化钾为催化剂,与二乙醇胺合成烷醇酰胺。考察了反应温度、反应时间、催化剂用量、真空度等因素对反应的影响,通过单因素实验和析因实验确定最佳工艺条件为:甲酯/二乙醇胺物质的量比1∶1.55,反应温度110℃,反应时间2.5 h,真空度0.08 MPa,催化剂用量0.65%(相对于脂肪酸甲酯的质量),烷醇酰胺的收率达96.3%。通过红外光谱对产物结构进行了表征,并对界面张力进行了测定。结果表明,产物具有较好的界面活性。     

钐钆富集物中钐、钆的同时测定

本文初步探讨了稀土的DBC偶氮刖络合物与CyDTA取代反应机理。对于不同显色剂和取代剂进行了选择，建立了测量钐、钆的最佳反应体系，用速差动力分析法进行了钐钆富集物中钐、钆的同时测定。速差动力分析结果与ICP发射光谱法结果相符。本法测定钐、钆相对含量在1：2－4：1范围，误差约为10％。     

Optimization Studies of Porous Carbon Preparation from Oil Shale Using Response Surface Methodology and Its Application for Phenol Adsorption

This paper discusses the elaboration of adsorbents from oil shale. The experimental designs a response surface methodology(RSM), which has been applied to optimize the significant preparation factors, such as temperature, time, and the activating agent percentage. The results obtained from central composite design(CCD) revealed that the interaction between the factors was significant for the maximum quantity of adsorption(response). Planned results have shown that a maximum quantity of adsorption for methylene blue is 65 mg/g, which could be achieved with a temperature of 275℃ over 2 h and a percentage of the activating agent of 45%. The predicted values agreed with the experimental finding, with a determination coefficient(R²) of 0.96. The model has been validated by experiments after conditions optimization. The new material(RHO) was characterized by cation exchange capacity, zero charge pH, surface functions, X-ray fluorescence, specific surface area, and electron microscopy analysis. Phenol adsorption was determined using Langmuir, Freundlich and Temkin, which were used to describe the adsorption isotherms. The adsorption capacity of the material was about 263 mg/g, and the kinetic studies showed rapid adsorption.     

SAPO-11的绿色制备及在棕榈油催化加氢制备生物航煤方面的应用

通过加入晶种的方法降低在合成SAPO-11分子筛过程中有机胺类模板剂的含量从而减少对环境的污染。通过调节晶种及模板剂的含量,得到加入4%晶种、模板剂与Al2O3物质的量比值(ntemplate/nAl2O3)为0.6的条件下得到的晶体的形貌、结晶度等最好。分子筛负载Ni-Mo金属合成催化剂,以棕榈油加氢脱氧产物(HDO)为原料,在623 K下测得对生物航煤的选择性为66.1%,转化率为79.8%。     

Continuous Production of Ethanol from Starch Using Glucoamylase and Yeast Co-Immobilized in Pectin Gel

This work presents a continuous simultaneous saccharification and fermentation (SSF) process to produce ethanol from starch using glucoamylase and Saccharomyces cerevisiae co-immobilized in pectin gel. The enzyme was immobilized on macroporous silica, after silanization and activation of the support with glutaraldehyde. The silica–enzyme derivative was co-immobilized with yeast in pectin gel. This biocatalyst was used to produce ethanol from liquefied manioc root flour syrup, in three fixed bed reactors. The initial reactor yeast load was 0.05 g wet yeast/ml of reactor (0.1 g wet yeast/g gel), used in all SSF experiments. The enzyme concentration in the reactor was defined by running SSF batch assays, using different amount of silica–enzyme derivative, co-immobilized with yeast in pectin gel. The chosen reactor enzyme concentration, 3.77 U/ml, allowed fermentation to be the rate-limiting step in the batch experiment. In this condition, using initial substrate concentration of 166.0 g/l of total reducing sugars (TRS), 1 ml gel/1 ml of medium, ethanol productivity of 8.3 g/l/h was achieved, for total conversion of starch to ethanol and 91% of the theoretical yield. In the continuous runs, feeding 163.0 g/l of TRS and using the same enzyme and yeast concentrations used in the batch run, ethanol productivity was 5.9 g ethanol/l/h, with 97% of substrate conversion and 81% of the ethanol theoretical yield. Diffusion effects in the extra-biocatalyst film seemed to be reduced when operating at superficial velocities above 3.7 × 10⁻⁴ cm/s.     

高效液相色谱法测定油脂中抗氧化剂BHA、TBHQ

采用乙腈浸提油脂中抗氧化剂叔丁基羟基茴香醚(BHA)和特丁基对苯二酚(TBHQ)，用以乙腈-水淋洗的反相高效液相色谱法测定提取液中BHA，TBHQ，回收率为92.42％～96．69％，变异系数为2．26％～2．88％，方法简便、快速、准确，已用于油脂中抗氧化剂BHA、TBHQ的测定。     

Production of 5-Hydroxymethylfurfural and Furfural from Lignocellulosic Biomass in Water-Tetrahydrofuran Media with Sodium Bisulfate

5-Hydroxymethylfurfural (HMF) and furfural (FF), two bio-based platform chemicals, were produced from various raw lignocellulosic materials (corncob, corn stover, wheat straw, rice straw and sugarcane bagasse) in a water-tetrahydrofuran media by using NaHSO₄ as catalyst. The in fluences of reaction temperature (160-200 oC), reaction time (30-120 min), solvent volume ratio, feedstock concentration (2.4wt%-11.1wt%) and catalyst dosage were studied. The highest HMF and FF yields obtained from corncob were 47mol% and 56mol% under condition of 190 oC, 90 min, 10/1 of THF/H₂O. Besides, the lignin in the raw biomass wasalso depolymerized into organosolv lignin.     

Production of acetone-butanol-ethanol from corn mash and molasses in batch fermentation

The production of solvents from corn mash and molasses in batch fermentation usingClostridium acetobutylicum P 262 was examined. The content of saccharose of beet molasses used in experiments is determined by using the gravimetric method (52.45% saccharose). The quantities of molasses that are used in the nutrient medium are calculated after doing the above determination. The samples of fermentation liquid are taken within a certain time, the determination of saccharose is done by using the same method, and all the saccharose is converted by the microorganism to organic end products. The quantitative and qualitative determination of acetone-butanol has been made by using gas chromatography. On the other hand, using the three isolation way, three different cultures are obtained, and with microscopic observations, the cultures obtained are of the C.acetobutylicum genus. According to the literature values, the concentration of maximum mixed solvent formed during fermentation is about 2%. This is seen in this experiment. There is only a slight difference from this value. This difference is caused by another organic product that is formed during fermentation.     

HCO_3~-浓度对油气田中CO_2腐蚀的影响

应用动电位扫描和失重法研究HCO3-对油气田CO2腐蚀的影响.实验表明,当HCO3-浓度低于0.042 mol/L时,随着HCO3-浓度的增加,溶液pH升高,H+的还原速率(阴极电流密度)下降;HCO3-浓度增至0.126 mol/L时,溶液中的H2CO3、HCO3-的直接还原占主导地位,故阴极过程随HCO3-浓度的上升而加速,对阳极过程,在HCO3-浓度低于0.042 mol/L下,主要为活化过程,而且其阳极溶解电流(密度)随HCO3-浓度的增加而下降;HCO3-浓度增至0.126 mol/L时,阳极过程出现明显的活化-钝化行为.高温高压腐蚀试验显示,材料的腐蚀速率随介质HCO3-浓度的增加而下降.SEM、EDS、XRD分析表明,在较低的HCO3-浓度下,腐蚀产物膜的主要成分为FeCO3晶体,HCO3-浓度较高时,则腐蚀产物主要为Ca、Mg的化合物,并形成Ca(Fe,Mg)(CO3)2复盐.在高pH值下,Ca2+、Mg2+比Fe2+更容易沉积.     

油气化探样品芳烃分析中干扰因素的识别

通过对全国各大油田典型油气的分析,提出各种油气的三维荧光光谱和固定波长同步荧光光谱特征峰和共性峰。利用三维荧光光谱可以判断油气的属性,油气性质的精细分析尚要依靠同步荧光光谱。钻井过程常常加入磺化沥青或原油,三维荧光光谱可以进行很好的干扰识别;钻遇煤层或含煤层段,根据煤的三维荧光等值线图加以判断。人类活动、化石燃料的不完全燃烧均能造成芳烃的污染,在取样和处理分析数据时应该进行校正。湖相和海相沉积物含有丰富的多环芳烃,采用固定能量同步荧光光谱分析效果更佳。     

Synthesis of Biodiesel from Palm Oil in Capillary Millichannel Reactor: Effect of Temperature,Methanol to Oil Molar Ratio,and KOH Concentration on FAME Yield

Application of microtube reactor for the continuous synthesis of biodiesel has been widely studied due to excellent performance in liquid-liquid phase reaction. In order to commercialize biodiesel production, integration of microtube reactor is highly recommended. Therefore, in this study, synthesis of biodiesel was carried out in capillary millichannel reactor with inner diameter of 1.59 mm using methanol and potassium hydroxide (KOH) as base catalyst with palm oil as a feedstock. The influences of reaction temperature, methanol to oil molar ratio, and KOH concentration on the production of fatty acid methyl ester (FAME) were examined. The highest FAME yield was achieved at 60 ˚C with 23:1 methanol to oil molar ratio and 5 wt% of KOH concentration.     

石英Al2O3 PLOT柱在油气化探中的应用

报导了采用石英Ａｌ２Ｏ３ＰＬＯＴ柱分析油气化探样品的组成，在同一色谱条件下，该柱既能用于野外采样后现场直接分析游离烃，又能在室内分析酸解烃。具有分析周期短，重复性好，柱寿命长等优点，为石油勘探取样迅速准确的分析发挥了重要作用。