Production Of Commodity Chemicals Research Articles

Simple and rapid cell growth assay using tetrazolium violet coloring method for screening of organic solvent tolerant bacteria

Tolerance to organic solvents is an important characteristic for selecting bacteria that are useful for producing commodity chemicals. An assay method for tolerance should be easy to perform and differences in tolerance should be reproducible. We propose a cell growth assay using tetrazolium violet and image analysis for assessing tolerance. When five microorganisms including Escherichia coli were tested, the organic solvent tolerance (OST) of microorganisms used was rapidly and qualitatively assessed and the degrees of OST coincided with those from the conventional method using solvent overlaid-solid medium. Moreover, the proposed method was applicable to the estimation of OST for cyclobexane resistant E. coli OST3410 using various organic solvent mixtures.

Micellar catalysis for selective epoxidations of linear alkenes

The application of surfactant systems is an excitingly new concept to perform reactive separations. One of the applications is the incorporation of homogeneous catalysts in micelles to perform reactions: micellar catalysis. Nonpolar reactants are converted into polar products, using the micelles as nano-reactors. The polar products are extracted towards the surrounding water phase, allowing for selectivity tuning. In this study, propene and 1-octene have been successfully epoxidized by hydrogen peroxide, catalysed by micelle-incorporated porphyrin catalysts. Preliminary experiments show that an ultrafiltration membrane can retain the micelles containing the homogeneous catalyst. This opens up the industrial application of homogeneous catalysis for the production of commodity chemicals.

The application of a generic feedstock from wheat for microbial fermentations.

The feasibility of a generic fermentation feedstock produced from wheat flour has been confirmed in several fermentations of yeasts, bacterium, and filamentous fungus for the production of commodity chemicals. Saccharomyces cerevisiae was incubated for the observation of yeast growth and ethanol production, Pichia farinosa for glycerol production, Monascus purpureus for fungal growth and pigment production, and Lactobacillus bulgaricus for bacteria growth and lactic acid production. The results confirmed that the feedstock contained no inhibitory components to the strains tested. Similar or higher metabolite yields were obtained in comparison with other studies carried in commonly used media.

Optimization and Control of Dynamic Bioprocesses

For many applications, such as commodity chemical production, ore leaching, waste treatment, and environmental remediation, bioprocesses can be less expensive, more energy-efficient, and more environmentally friendly than conventional processes. The key to effective implementation of bioprocesses is rational design, optimization, and process control. We are applying the tools of intelligent systems to develop supervisory systems for the optimization and control of continuous, dynamic, and uncharacterized bioprocesses. We have designed, built, and evaluated hierarchical hardware and software systems for the control of microbial oxidation of soluble iron in a continuous stirred tank reactor. The supervisory control module uses stochastic learning to determine what system parameters (i.e., pH, dilution rate, and temperature) should be, based on the state of the system. An expert-based flow-rate controller optimizes reactor performance for each set of system parameters. Theoretically, high reactor conversion ...

Synthesis of higher alcohols with cobalt and copper based model catalysts: effect of the alkaline metals

The synthesis of higher alcohols, obtained from CO hydrogenation over transition metals, is an alternative for the production of chemical commodities and less pollutant renewable fuels nowadays. In this work, the influence of different alkali metals (Li, Na, K, Cs) over the formation of active phases of supported catalysts, based on cobalt and copper, as well as the performance of these solids in the reaction of CO hydrogenation under a 50 bar pressure were studied. The solids were prepared by continuous coprecipitation of sodium carbonate with metal nitrate solutions (Al–Co, Al–Cu or Al–Co–Cu) promoted with the alkali metals with dry impregnation. Characterization studies by atomic absorption spectrophotometry, BET, XPS and also the results of catalytic tests show that physico-chemical properties of the obtained catalyst are similar to those of the industrial catalyst used as reference (I).

Heat transfer considerations in design of a batch tube reactor for biomass hydrolysis.

Biologic conversion of inexpensive and abundant sources of cellulosic biomass offers a low-cost route to production of fuels and commodity chemicals that can provide unparalleled environmental, economic, and strategic benefits. However, low-cost, high-yield technologies are needed to recover sugars from the hemicellulose fraction of biomass and to prepare the remaining cellulose fraction for subsequent hydrolysis. Uncatalyzed hemicellulose hydrolysis in flow-through systems offers a number of important advantages for removal of hemicellulose sugars, and it is believed that oligomers could play an important role in explaining why the performance of flow-through systems differs from uncatalyzed steam explosion approaches. Thus, an effort is under way to study oligomer formation kinetics, and a small batch reactor is being applied to capture these important intermediates in a closed system that facilitates material balance closure for varying reaction conditions. In this article, heat transfer for batch tubes is analyzed to derive temperature profiles for different tube diameters and assess the impact on xylan conversion. It was found that the tube diameter must be <0.5 in. for xylan hydrolysis to follow the kinetics expected for a uniform temperature system at typical operating conditions.

Multiphase reactors – revisited

Multiphase reactors are found in diverse applications such as in manufacture of petroleum-based fuels and products, in production of commodity and specialty chemicals, pharmaceuticals, herbicides and pesticides, in refining of ores, in production of polymers and other materials, and in pollution abatement. In all such applications, the knowledge of fluid dynamic and transport parameters is necessary for development of appropriate reactor models and scale-up rules. The state of the art of our understanding of the phenomena occurring in three-phase reactors such as packed beds with two-phase flow, slurry bubble columns and ebullated beds is summarized in this review.

Biotechnology for the production of commodity chemicals from biomass

Current developments, especially in fermentation technologies, membrane technologies and genetic manipulation open new possibilities for the biotechnological production of market relevant chemicals from renewable resources. This article reviews possible fermentation strategies, actual research activities and future research demands to enhance the use of renewable resources as a source of chemicals. Special focus is put on commodity chemicals, which have a considerable market volume or which are believed to be key chemicals of the future.

Bioconversion and biodegradation of aliphatic hydrocarbons

Aliphatic hydrocarbons represent a substantial energy reserve but also constitute a useful feedstock for the biotechnological production of various alkane-derived commodity chemicals. In addition, the biodegradation of aliphatic hydrocarbons continues to pose problems for fuel stocks with associated corrosion and eventual motor filter blocking. A relatively high number of yeasts and filamentous fungi have been described that degrade n-alkanes, but relatively few have received thorough investigation. Early work exploiting hydrocarbons as a potential substrate for unicellular protein production, though never commercially successful, enabled high-performance fermentation strategies to be developed that overcame many of the inherent problems caused by the use of high energy content insoluble liquid substrates. The biochemical pathways and physiological characteristics have been sufficiently established, as have the subcellular localization of the alkane-specific pathways, though many of the regulatory phenomena remain obscure. Currently, interest lies in the exploitation of such species, or their enzymes, in bioconversion processes and the unicellular yeasts, whose amenability to rational genetic engineering strategies exceeds that of filamentous species, are currently attracting renewed research interest. In view of this, the existing knowledge and potential for alkane-based biotechnology will be reviewed. Key words: alkane metabolism, bioconversion, biotechnology, aliphatic hydrocarbons, yeasts, filamentous fungi.

Interrelations of chemistry and biotechnology-VI. Microbial production of commodity chemicals (Technical Report)

Abstract

Review and analysis of renewable feedstocks for the production of commodity chemicals

Several biomass feedstocks were analyzed for their suitability in chemicals production by industry. Feedstocks included dedicated feedstock crops, industrial residuals, and conventional food crops. The factors that were examined included price of raw materials, degree of raw material preprocessing necessary, storage requirements, potential fermentable sugar yield, opportunities for waste minimization, level of technology base, crop hardiness, and land usage. The following conclusions were made: (1) the US has great potential for controlling the direction of a biomass-based chemicals industry because domestic supplies of raw feedstock materials are in excess of what is required for the production of many commodity chemicals, and (2) of the representative feedstocks that were analyzed, cellulosic industrial residuals and fermentable sugar-containing industrial residuals were the most promising prospects.

Organometallic chemistry and catalysis in industry

The keynote paper of this issue's symposium points out that the tremendous growth in the industrial usage of organometallic chemistry between 1950-1977 involved the production of commodity chemicals.

The potential for synfuels production from cellulosic papermaking wastes

Papermaking wastes, available in large quantities, have the potential for providing the raw materials for production of commodity chemicals, many of which are suitable for fuels use. A number of techniques are being developed for the recovery of these chemicals. All methods involve three stages: pretreatment, hydrolysis, then fermentation. The hydrolysis techniques include using conventional and non-conventional pulping, acid hydrolysis, high temperature and pressure, microbial digestion (fermentation), or combinations of these. Several recent advances show potential for being cost effective. Estimated production costs for ethanol so produced range as low as 22.5¢/L (85 ¢/gallon U.S.).