Feedstock Components Research Articles

Direct Infusion Electrospray Ionization – Ion Mobility – High Resolution Mass Spectrometry (DIESI-IM-HRMS) for Rapid Characterization of Potential Bioprocess Streams

Direct infusion electrospray ionization - ion mobility - high resolution mass spectrometry (DIESI-IM-HRMS) has been utilized as a rapid technique for the characterization of total molecular composition in "whole-sample" biomass hydrolysates and extracts. IM-HRMS data reveal a broad molecular weight distribution of sample components (up to 1100 m/z) and provide trendline isolation of feedstock components from those introduced "in process." Chemical formulas were obtained from HRMS exact mass measurements (with typical mass error less than 5 ppm) and were consistent with structural carbohydrates and other lignocellulosic degradation products. Analyte assignments are supported via IM-MS collision-cross-section measurements and trendline analysis (e.g., all carbohydrate oligomers identified in a corn stover hydrolysate were found to fall within 6% of an average trendline). These data represent the first report of collision cross sections for several negatively charged carbohydrates and other acidic species occurring natively in biomass hydrolysates.

Improvements in ethanol production from xylose by mating recombinant xylose-fermenting Saccharomyces cerevisiae strains

To improve the ability of recombinant Saccharomyces cerevisiae strains to utilize the hemicellulose components of lignocellulosic feedstocks, the efficiency of xylose conversion to ethanol needs to be increased. In the present study, xylose-fermenting, haploid, yeast cells of the opposite mating type were hybridized to produce a diploid strain harboring two sets of xylose-assimilating genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase. The hybrid strain MN8140XX showed a 1.3- and 1.9-fold improvement in ethanol production compared to its parent strains MT8-1X405 and NBRC1440X, respectively. The rate of xylose consumption and ethanol production was also improved by the hybridization. This study revealed that the resulting improvements in fermentation ability arose due to chromosome doubling as well as the increase in the copy number of xylose assimilation genes. Moreover, compared to the parent strain, the MN8140XX strain exhibited higher ethanol production under elevated temperatures (38 °C) and acidic conditions (pH 3.8). Thus, the simple hybridization technique facilitated an increase in the xylose fermentation activity.

Comparison of Feedstock Pretreatment Performance and Its Effect on Soluble Sugar Availability

Cellulosic feedstocks for bioenergy differ in composition and processing requirements for efficient conversion to chemicals and fuels. This study discusses and compares the processing requirements for three lignocellulosic feedstocks—soybean hulls, wheat straw, and de-starched wheat bran. They were ground with a hammer mill to investigate how differences in composition and particle size affect the hydrolysis process. Enzyme hydrolysis was conducted using cellulase from Trichoderma reesei at 50°C and pH 5. Ground fractions were also subjected to dilute sulfuric acid treatment at 125°C, 15 psi for 30 min prior to cellulase treatment. Reducing particle size of biomass resulted in segregated components of feedstock. Grinding wheat straw to particle size <132 μm resulted in measured lignin content from 20% to ≈5% and reduced hemicellulose content. Reducing lignin content increased the effectiveness of enzyme hydrolysis of wheat straw. Particles sized <132 μm exhibited the highest soluble sugar release upon hydrolysis for all three feedstocks studied. Hemicellulose digestion improved with dilute sulfuric acid treatment with residual hemicellulose content <5% in all three feedstocks after acid treatment. This enhanced the cellulase action and resulted in approximately 1.6-fold increase in sugar availability in de-starched wheat bran and ≈1.5-fold for wheat straw and soybean hulls. Higher sugar availability in wheat bran after acid-mediated enzyme treatment correlated to higher ethanol yields during yeast fermentation compared with soybean hulls and wheat straw.

End product yields from the extraruminal fermentation of various polysaccharide, protein and nucleic acid components of biofuels feedstocks

"Extraruminal" fermentations employing in vitro incubation of mixed ruminal bacterial consortia, are capable of converting a complex array of biomass materials to mixtures of volatile fatty acids (VFA), methane, and carbon dioxide. Most of the potential energy in the biomass feedstock is retained in the VFA products, which are potential reactants for electrochemical conversion to hydrocarbon fuels. Quantitative data on VFA yields and proportions from biomass components are necessary for determining industrial feasibility, but such measurements have not been systematically reported. VFA yields and proportions were determined for a variety of carbohydrates, proteins and nucleic acids. Carbohydrates yielded primarily acetic and propionic acids, while proteins also yielded a more favorable product mix (longer average chain length and branched chain VFAs). Addition of certain co-substrates (e.g., glycerol) favorably improved the VFA product mix. The results have implications for hydrocarbon fuel generation from biomass materials by hybrid fermentation/chemical processes.

The materials characteristic and the efficiency degradation of solar cells from solar grade silicon from a metallurgical process route

The rising conventional energy prices have opened up the market for photovoltaic, but the lack of polycrystalline silicon from the chemical route restricts the growth of crystalline silicon solar cells. Recently there is a trend that produces solar cells by using the newly developed solar grade silicon feedstock from a metallurgical process route. In this article, the chemical components of solar grade silicon feedstock are analyzed. The single crystalline silicon solar cells from 100% solar grade silicon feedstock from a metallurgical process route are investigated. The outdoor performance of solar modules encapsulated by such cells is reported. The experimental evidence suggests that such solar cells can achieve the average efficiency higher than 14% on single crystalline silicon wafers. However, the efficiency degradation of solar cells under natural sunlight is significant, and the electrical uniformity of small cells diced from the whole cell is too bad. The metal impurities, oxygen, carbon, and their complexes influence the performance stabilization. The article proves that the module made by such cells has a big cell mismatch loss than normal cells made by electronic grade silicon, even if these cells come from the same sort. And the operating temperature of the cells of the modules is 15–22 °C higher than normal modules under the same conditions. The solar grade silicon feedstock from a metallurgical process route has to be improved farther in order to be used in photovoltaic industry.

Compositional Analysis of Lignocellulosic Feedstocks. 2. Method Uncertainties

The most common procedures for characterizing the chemical components of lignocellulosic feedstocks use a two-stage sulfuric acid hydrolysis to fractionate biomass for gravimetric and instrumental analyses. The uncertainty (i.e., dispersion of values from repeated measurement) in the primary data is of general interest to those with technical or financial interests in biomass conversion technology. The composition of a homogenized corn stover feedstock (154 replicate samples in 13 batches, by 7 analysts in 2 laboratories) was measured along with a National Institute of Standards and Technology (NIST) reference sugar cane bagasse, as a control, using this laboratory's suite of laboratory analytical procedures (LAPs). The uncertainty was evaluated by the statistical analysis of these data and is reported as the standard deviation of each component measurement. Censored and uncensored versions of these data sets are reported, as evidence was found for intermittent instrumental and equipment problems. The censored data are believed to represent the “best case” results of these analyses, whereas the uncensored data show how small method changes can strongly affect the uncertainties of these empirical methods. Relative standard deviations (RSD) of 1−3% are reported for glucan, xylan, lignin, extractives, and total component closure with the other minor components showing 4−10% RSD. The standard deviations seen with the corn stover and NIST bagasse materials were similar, which suggests that the uncertainties reported here are due more to the analytical method used than to the specific feedstock type being analyzed.

Effect of NiCr Clad BaF2·CaF2 Addition on Wear Performance of Plasma Sprayed Chromium Carbide-Nichrome Coating

NiCr clad BaF2 center dot CaF2 fluoride eutectic powders were added into chromium carbide-nichrome feedstock to improve the tribological properties of NiCr-Cr3C2 coating, and the structures, mechanical, and ball-on-disk sliding wear performance of the coating were characterized. The results show that NiCr cladding can effectively decrease the density and thermophysical difference between the feedstock components, while alleviate the decarburization and oxidization of the constituent phases, and form the coating with a uniform and dense microstructure. However, the addition of BaF2 center dot CaF2 has a negative effect on mechanical properties of the coating. When the temperature reaches 500 A degrees C, the BaF2 center dot CaF2 eutectic is soften by the heat and smeared by the counterpart, thus the low shear stress lubricating film forms between the contact surface, that improves the tribological properties dramatically. At this temperature, the dominant wear mechanisms also change from splats spallation and abrasive wear at room temperature to plastic deformation and plawing by the counterpart. Within the temperature range from 600 to 800 A degrees C, the friction coefficient, the wear rates of NiCr/Cr3C2-10% BaF2 center dot CaF2 coating and its coupled Si3N4 ball are 20%, 40%, and 75% lower than those of the NiCr/Cr3C2 coating, respectively. The NiCr/Cr3C2-BaF2 center dot CaF2 coating shows superior wear performance to the NiCr/Cr3C2 coating without lubricant additive.

Synthesis of phenolic resol resins using cornstalk-derived bio-oil produced by direct liquefaction in hot-compressed phenol–water

For the synthesis of biomass-based resol resins, cornstalk powders were liquefied in a hot-compressed phenol–water (1:4, wt./wt.) medium at 300–350 °C. It was observed that essentially no phenol was reacted with the cornstalk degradation intermediates during the liquefaction process. The cornstalk-derived bio-oils contained oligomers of phenol and substituted phenols, originated primarily from the lignin component of the cornstalk feedstock. Using the cornstalk-derived bio-oils, resol resins were readily synthesized under the catalysis of sodium hydroxide. The biomass-derived resol resins were brown viscous liquids, possessing broad molecular weight distributions. In comparison with those of a conventional phenol resol resin, the properties of the bio-based resins were characterized by GPC, FTIR, DSC and TGA. The as-synthesized bio-oil resol resin exhibited typical properties of a thermosetting phenol–formaldehyde resin, e.g., exothermic curing temperatures at about 150–160 °C, and an acceptable residual carbon yield of ca 56% at 700 °C for the cured material.

Developing Optimal Combination of Bulking Agents in an In‐Vessel Composting of Vegetable Waste

The objective of the study is to determine the optimum combination of feed stock components for composting the organic solid waste, a prerequisite for effective microbial degradation and for obtaining quality compost. Combination of dry leaves with locally available bulking agents like sawdust, wood shavings, paddy straw, sugarcane bagasse and rice husk are composted along with vegetable waste in a laboratory scale reactor for the study. The central core of composting process is replicated in controlled conditions in the in‐vessel by keeping initial feed stock C/N ratio fixed between 30 and 35. The study is monitored for 14 days for the variations in temperature, pH, moisture and macronutrients C and N of the compost. It is found that composting vegetable waste with the combination of paddy straw and dry leaves provided best results of C/N ratio of 17.58 confirming that, if right feedstock components are provided, an effective environment for the growth of microorganisms is achieved to accelerate the process to produce a resultant C/N ratio acceptable to be used as compost.

Biomanufacturing process analytical technology (PAT) application for downstream processing: Using dissolved oxygen as an indicator of product quality for a protein refolding reaction

Process analytical technology (PAT) is an initiative from the US FDA combining analytical and statistical tools to improve manufacturing operations and ensure regulatory compliance. This work describes the use of a continuous monitoring system for a protein refolding reaction to provide consistency in product quality and process performance across batches. A small-scale bioreactor (3 L) is used to understand the impact of aeration for refolding recombinant human vascular endothelial growth factor (rhVEGF) in a reducing environment. A reverse-phase HPLC assay is used to assess product quality. The goal in understanding the oxygen needs of the reaction and its impact to quality, is to make a product that is efficiently refolded to its native and active form with minimum oxidative degradation from batch to batch. Because this refolding process is heavily dependent on oxygen, the % dissolved oxygen (DO) profile is explored as a PAT tool to regulate process performance at commercial manufacturing scale. A dynamic gassing out approach using constant mass transfer (k(L)a) is used for scale-up of the aeration parameters to manufacturing scale tanks (2,000 L, 15,000 L). The resulting DO profiles of the refolding reaction show similar trends across scales and these are analyzed using rpHPLC. The desired product quality attributes are then achieved through alternating air and nitrogen sparging triggered by changes in the monitored DO profile. This approach mitigates the impact of differences in equipment or feedstock components between runs, and is directly inline with the key goal of PAT to "actively manage process variability using a knowledge-based approach."

Comprehensive analysis of diesel hydrotreating feedstock

Comprehensive analysis of the physicochemical properties of petroleum fractions, components of hydrotreater feedstock for manufacturing diesel fuel, was performed. Twenty two fractions, of which 14 are straight-run oil distillates, six are products of thermal and thermocatalytic processes, and two fractions represent mixed hydrogen-treatment feedstock, were studied. The fractional composition, the density, the refractive index, the sulfur content, the total concentration of aromatic hydrocarbons, and the amounts of sulfonatable compounds and aromatic hydrocarbons of different classes were determined. The group composition of sulfur compounds in feedstock sources and in the mixed hydrotreater feedstock was determined. The influence of the quality of hydrotreating feedstock on the residual sulfur content in the hydrogenation product was shown for industrial conditions.

Tribological behavior of NiCr-base blended and nanostructured composite APS coatings by rig test

In the present paper, a nanostructured composite powder containing nano-sized Cr 2O 3 (<100 nm) is manufactured by spray drying and heat treatment. By wear and rig test at room temperature (RT), 200 °C, and 350 °C, respectively, the mechanical and tribological properties of atmospheric plasma spray (APS) blended (PS304) and composite coatings with same composition (60NiCr–20Cr 2O 3–10Ag–10BaF 2/CaF 2, wt.%) are compared. The results show that uniform microstructure of the composite coating could be obtained by eliminating the difference in physical and thermophysical properties of components in feedstock, which leads to the non-uniformity of blended coating due to their different in-flight trajectories of components in APS process. Therefore, the excellent wear resistance of composite coating benefits from its uniform and fine microstructure. Also, the wide and uniform distribution of plastic Ag lubricant could result in the formation of surface localized tribofilm as lubricant film to protect the coating from fracture and spallation.

Effects of the reaction atmosphere composition on the synthesis of single and multiwalled nitrogen-doped nanotubes

Single and multiwalled nitrogen-doped carbon nanotubes were grown by chemical vapor deposition varying the feedstock composition between pure acetonitrile and ethanol/acetonitrile mixtures. The advantage of using CN sources that develop close vapor pressure values has been used in order to elucidate the effects of the reaction atmosphere in the synthesis of N-doped nanotubes. Our findings show that the morphology of the nanotube material depends strongly on the composition of the reaction atmosphere. When carrying out the experiments in an atmosphere solely determined by the vapor pressure of the feedstock components, improved homogeneity is achieved with pure CN sources or low concentration of the foreign solute. Under these conditions the temperature has strong influence in the diameter distribution.

Molecular Composition of the High-Boiling Components of Needle Coke Feedstocks and Mesophase Development

Mesophase development during the carbonization of needle coke feedstocks in delayed coking affects the microstructural anisotropy (or graphitizability) of the resulting coke. Previous work has employed gas chromatography/mass spectrometry (GC/MS) to study the relationships between the molecular composition of the fluid catalytic cracking decant oil (FCC DO) and mesophase development. In this study, the principal emphasis was placed on analyzing the non-GC amenable fraction of DO samples using a combination of analytical techniques, including high pressure liquid chromatography with photodiode array (PDA) and mass spectrometer detectors in tandem (HPLC/PDA and HPLC/MS/MS), and laser desorption mass spectrometry (LD/MS). The experimental data showed that major molecular species in DO samples consist of 3–6 ring multimethyl-substituted polyaromatic hydrocarbons (PAHs), including phenanthrenes, pyrenes, chrysenes, benzopyrenes, perylenes, and benzo[g,h,i]perylenes. Large differences were observed in the molec...

Effect of pre-composting and vermicomposting on compost characteristics

The aim of this study was to determine the effect of thermophilic pre-composting followed by vermicomposting on compost characteristics compared with thermophilic pre-composting and windrow composting. Source segregated household waste was thermophilically composted (14 days) to sanitise the waste. Organic matter and nitrogen losses were 9% and 5% respectively. The waste was then matured (84 days) using either vermicomposting beds ( n = 5) or composting windrows ( n = 5). At the end of the 98 days processing there was a significantly greater mass ( P < 0.01) of fine particles (<10 mm) in the vermicomposting beds (65.3% m:m) compared with the compost windrows (36.9% m:m) suggesting enhanced fragmentation of the paper-based feedstock components by the earthworms. When screened, the windrow compost (<10 mm) contained significantly higher ( P < 0.01) concentrations of total N, P and K and total Cu ( P < 0.01), Pb ( P < 0.001), Ni ( P < 0.05) and Cd ( P < 0.01). Significantly higher levels of electrical conductivity (EC) 3.08 mS.cm ( P < 0.001) and water-soluble K 6366 mg kg −1 ( P < 0.01) were recorded for the windrow compost compared with the vermicompost (1.78 mS.cm; 3328 mg kg −1). The vermicompost NO 3 concentration (2660 mg kg −1) was significantly higher ( P < 0.05) than for the windrow compost (1531 mg kg −1). In a programme of plant response tests based on B.S.I. PAS 100 (2005), the screened (<10 mm) vermicompost and windrow compost performed comparably when formulated into growing media based on equalising EC levels.

Dark H 2 fermentation from sucrose and xylose using H 2-producing indigenous bacteria: Feasibility and kinetic studies

Cellulosic materials are the major components in biomass feedstock used for bioenergy production. Hydrolytic products of cellulosic substances consist primarily of hexose (e.g., glucose) and pentose (e.g., xylose). In this study, the efficiency of fermentative conversion of sucrose (representing hexose) and xylose into H 2 was examined with seven H 2-producing pure strains isolated from a high-rate H 2-producing system in our recent work. The isolates were identified as Clostridium butyricum (strains CGS2 and CGS5), Clostridium pasteurianum (strains CH1, CH4, CH5, and CH7), and Klebsiella sp. Batch H 2 fermentation shows that only Cl. butyricum and Klebsiella sp. strains could utilize xylose for H 2 production, while all of them can grow and produce H 2 on sucrose. Among all strains examined, Cl. butyricum CGS5 was the best H 2 producer on xylose with the highest H 2 production rate and yield of 212.5 ml/h/l and 0.73 mol H 2/mol xylose, respectively, taking place at 20 g COD/l of xylose. In contrast, Cl. pasteurianum CH4 was most efficient in converting sucrose to H 2; the highest H 2 production rate (569 ml/h/l) and yield (2.07 mol H 2/mol hexose) were obtained at a sucrose concentration of 40 g COD/l. The substrate preference of the H 2-producing isolates was consistent with the bacterial community structure that existed in the bioreactor, showing that Cl. butyricum and Cl. pasteurianum were predominant in the cultures grown on xylose and sucrose, respectively. Irrespective of the carbon substrate used, butyrate and acetate were the predominant soluble metabolites. Shake-flask cultures displayed higher H 2 productivity over static ones, indicating the importance of efficient mass transfer for H 2 production. The dependence of cell growth and H 2 production on carbon substrate concentration could be described by the proposed kinetic models with good agreements.

Determination of Synthesis Conditions of Medium, High, and Overbased Alkali Calcium Sulfonate

This review covers a method for preparing an overbased detergent−dispersion additive called overbased calcium sulfonate solution (OBCSS) containing 38.9% (w/w) CaCO3, with a total base number (TBN) value of 436 mg KOH, starting from neutral calcium sulfonate solution (NCSS).1,2 After the column conditions were optimized, the reaction parameters (PCO2 and the amounts of Ca(OH)2, water, and monoethanolamine (MEA)) were examined throughout the tests. The first product medium alkali calcium sulfonate solution (MACSS) with 8.5% (w/w) CaCO3 (TBN = 95 mg KOH/g) is obtained, but higher base values could not be reached. In the second stage, monoethanolamine is added to the feed as a promoter and high alkali calcium sulfonate solution (HACSS) containing 30.4% (w/w) CaCO3 with the value of TBN = 274 mg KOH/g is obtained. In the third stage of the study, targeted product OBCSS is obtained by using HACSS as a feedstock component instead of NCSS.

Molecular reconstruction of naphtha steam cracking feedstocks based on commercial indices

A new method for feedstock reconstruction of industrially important hydrocarbon fractions is developed using as input the analytically determined commercial indices such as the average molecular weight, the specific density, the H/ C-ratio, the paraffin, isoparaffin, olefins, naphthenes, aromatics (PIONA) weight fractions and a set of ASTM boiling points. The method is based on Shannon's entropy criterion and allows generating a molecular composition of a naphtha fraction that meets all the boundary conditions set by the industrially available commercial indices. The most important components present in a naphtha fraction are selected as possible feedstock components. This approach is very fast because the optimization function can be transformed from a nonlinear equation in the N mole fractions ( N ∼ 10 2) into a nonlinear equation in maximally 14 parameters, making it very attractive for the petrochemical industry. A good correspondence exists between the simulated weight fractions and the actual analytically determined ones provided that the specified commercial indices are sufficiently accurate. The feedstock module is implemented in a simulation package for steam cracking but can be used as a stand-alone tool too. The combination of these two simulation tools makes it possible to obtain a good agreement between the simulated and experimentally determined product yields for a set of 50 pilot plant experiments with different naphtha feedstocks under widely varying operating conditions.

Modeling and optimization for the secondary reaction of FCC gasoline based on the fuzzy neural network and genetic algorithm

The secondary reaction of fluidized-bed catalytically cracked gasoline (FCC gasoline) was investigated experimentally with a riser reactor using an improved Y zeolite catalyst in different operating conditions. The product distributions were predicted using a new black-box model based on fuzzy neural network (FNN) combined with genetic algorithm (GA) named FNN–GA method. In this new approach, the fuzzy neural network model is constructed for correlating the values of input, namely feedstock components, operating variables with output, namely the yields of upgraded gasoline and the olefin fraction in it. And then, the inputs of operating variables are optimized using genetic algorithm with a view to maximize yields of upgraded gasoline and the restricting of olefin in the product gasoline. This new FNN–GA modeling and optimization can be conducted completely from the experimental data wherein the complicated knowledge of the reaction mechanisms, kinetics, mass and heat transfer are not required. Using artificial neural network (ANN)–GA strategy, a set of optimized operation conditions leading to maximized yields upgraded gasoline with olefin restrict for different feedstock were obtained. The experimental results agreed well with the predicted ones and a significant improvement in the upgraded gasoline product were gained under the optimized operating conditions.

Preparation and purification of synthetic protein nanoparticulates

The protein nanostructure used in this study (bovine serum albumin; BSA nanoparticles) were fabricated with an average nanoparticle diameter 150 nm based on the principle of coacervation. Practical recovery of nanoparticulate mimics, of products such as plasmid DNA and viruses as putative gene therapy vectors from model systems, has been studied. The adsorbents employed in this study for the recovery of nanoparticles had one of four discrete designs i.e. microporous (pore size <0.2 microm), macroporous (pore size >0.8 microm), solid phase (nonporous) and pellicular (pore size <0.5 microm). Soluble protein was included in the study to represent cellular components of complex feedstocks and the separation of assemblies from components, while particulate protein served as surrogate size and charge mimics of less easily sourced viral and plasmid gene therapy vectors. Candidate adsorbents were physically characterised to assess their suitability for fluidised-bed operation, biochemically characterised exploiting batch-binding experimentation and laser scanning confocal microscopy. The adsorptive capacity of nanoparticulate products was strongly influenced by the physical design of the adsorbents, and microporous adsorbents appeared to be less suited for the recovery of nanoparticulate products. The generic application of such adsorbents for the recovery of nanoparticulate bioproducts is discussed.