Iwona Cybulska

Chemical characterization and hydrothermal pretreatment of Salicornia bigelovii straw for enhanced enzymatic hydrolysis and bioethanol potential.

Salicornia bigelovii straw was characterized and evaluated as a potential lignocellulosic bioethanol feedstock. S. bigelovii used in the study was grown in the United Arab Emirates using saltwater (40ppt) for irrigation. Salt removal was performed prior to pretreatment to protect the processing equipment and avoid inhibition of enzymes and yeast. Composition of the washed biomass was comparable to traditional lignocellulosic biomasses with relatively high glucan and xylan content (26 and 22g/100gDM, respectively) but with lower lignin content (7g/100gDM). The washed feedstock was subjected to hydrothermal pretreatment, producing highly digestible (up to 92% glucan-to-glucose conversion) and fermentable (up to 100% glucose-to-ethanol conversion) fiber fractions. Liquid fractions obtained in the pretreatment did not show inhibition towards Saccharomyces cerevisiae. No significant differences among the enzymatic convertibility and microbial fermentability of the fibers as well as low xylose recoveries suggest that lower severity pretreatment conditions could be exploited for S. bigelovii.

Hydrothermal Pretreatment of Lignocellulosic Biomass

As global energy demands grow and as the environmental and economic issues of fossil fuel use arise, lignocellulosic biomass is starting to attract increased attention as a potential source of energy and chemicals. Being an abundant, accessible, and cost-effective feedstock for a wide variety of products, ranging from transportation fuels to pharmaceuticals, lignocellulose shows great promise for the future. However, in order to utilize its potential, an efficient pretreatment method has to be applied. Hydrothermal pretreatment is one of the most promising and environmentally friendly biomass pretreatment methods available to make the lignocellulosic biomass vulnerable to enzymatic breakdown. This chapter describes the principle of the hydrothermal pretreatments, as well as influence of temperature and time on the effectiveness of the pretreatment and the kinetic models of the process. Various configurations of systems employing hydrothermal pretreatments have also been presented (with examples of process conditions), including hot water, steam explosion, catalyzed hydrothermal treatment, and combination with other methods.

Seawater as Alternative to Freshwater in Pretreatment of Date Palm Residues for Bioethanol Production in Coastal and/or Arid Areas

The large water consumption (1.9-5.9 m(3) water per m(3) of biofuel) required by biomass processing plants has become an emerging concern, which is particularly critical in arid/semiarid regions. Seawater, as a widely available water source, could be an interesting option. This work was to study the technical feasibility of using seawater to replace freshwater in the pretreatment of date palm leaflets, a lignocellulosic biomass from arid regions, for bioethanol production. It was shown that leaflets pretreated with seawater exhibited lower cellulose crystallinity than those pretreated with freshwater. Pretreatment with seawater produced comparably digestible and fermentable solids to those obtained with freshwater. Moreover, no significant difference of inhibition to Saccharomyces cerevisiae was observed between liquids from pretreatment with seawater and freshwater. The results showed that seawater could be a promising alternative to freshwater for lignocellulose biorefineries in coastal and/or arid/semiarid areas.

Methods for Upstream Extraction and Chemical Characterization ofSecondary Metabolites from Algae Biomass

Marine life is very rich in producing various and distinctive chemical components, both basic and complex. Due to the harsh conditions such as high salinity, deficiency of nutrients, light and space, which make the marine environment competitive, organisms adapt to the environment by producing various chemicals and metabolites to help them survive under such conditions. In many studies great emphasis has been given to the secondary metabolites produced by algae (macro and microalgae). Certain species of algae are known for their high content of fatty acids, fibers, antioxidants, carotenoids, sterols, proteins, phytocolloids, lectins, oils, amino acids, unsaturated fatty acids, and vitamins, which could be commercially utilized. Current algae studies emphasize on four main research areas: fuels, bioactive metabolites, toxins, and chemical ecology. This paper focuses on reviewing interesting biochemicals from algae biomass and their therapeutic applications. To achieve optimum extraction of high-value products, extraction methods and conditions were thoroughly presented in this review. Finally, different analytical approaches and techniques to identify the extracted chemicals were discussed.

Hydrothermal Pretreatment of Date Palm (Phoenix dactylifera L.) Leaflets and Rachis to Enhance Enzymatic Digestibility and Bioethanol Potential

Date palm residues are one of the most promising lignocellulosic biomass for bioethanol production in the Middle East. In this study, leaflets and rachis were subjected to hydrothermal pretreatment to overcome the recalcitrance of the biomass for enzymatic conversion. Evident morphological, structural, and chemical changes were observed by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy after pretreatment. High glucan (>90% for both leaflets and rachis) and xylan (>75% for leaflets and >79% for rachis) recovery were achieved. Under the optimal condition of hydrothermal pretreatment (210°C/10 min) highly digestible (glucan convertibility, 100% to leaflets, 78% to rachis) and fermentable (ethanol yield, 96% to leaflets, 80% to rachis) solid fractions were obtained. Fermentability test of the liquid fractions proved that no considerable inhibitors to Saccharomyces cerevisiae were produced in hydrothermal pretreatment. Given the high sugar recovery, enzymatic digestibility, and ethanol yield, production of bioethanol by hydrothermal pretreatment could be a promising way of valorization of date palm residues in this region.

A Novel Approach for the Identification of Economic Opportunities within the Framework of a Biorefinery

Abstract In this paper we propose a novel mathematical framework for the study of biorefinery networks. The framework is based on a natural decomposition of the biorefinery network in two sub-problems: a supply of intermediates and a demand of intermediates. The two sub-problems can be optimized independently of each other and their solutions are later coordinated to yield the optimal feasible biorefinery complex. Based on this separability, a computer aided computational environment that emulates the proposed framework is presented.

Halophytes for the Production of Liquid Biofuels

We discuss the potential of using halophytes as a source for producing liquid biofuels. We review the potential pathways for converting oilseeds into biodiesel and bio-derived synthetic paraffinic kerosene and presents some preliminary data on biomass composition and pretreatment of the halophyte Salicornia bigelovii. Six samples of S. bigelovii cultivated at three fertilizer levels (F1: 1 gN/m2, F2: 1.5 gN/m2 and F3: 2 gN/m2) and two salinity levels (S1: 10 ppt and S5: 50 ppt salt) were analyzed with regard to chemical composition and bioethanol potential. Chemical characterization showed that S. bigelovii contained, 16.31–55.67 g/100gTS (total solids) of carbohydrates, 5.42–16.60 g/100gTS of lignin, 27.85–66.37 g/100gTS of total extractives (including extractable ash), and 2.18–9.68 g/100gTS of structural ash, depending on the plant fraction and cultivation conditions. Enzymatic hydrolysis of the pretreated samples revealed high glucose recoveries of up to 90 % (of glucose in raw S. bigelovii) corresponding to ethanol yield of 111 kg ethanol/dry ton S. bigelovii.

Optimization of Lignocellulosic Waste Biorefinery using Multi-Actor Multi-Objective Mathematical Framework

Abstract Lignocellulosic biorefineries consist of multiple processing steps that can be carried out by a single or by different actors. In the latter case, biorefineries can be decomposed into suppliers of intermediates and consumers of them. Following this decomposition, a multi-actor multi-objective optimization problem can be formulated and a two-level Lagrangian approach used to find the solution that optimizes the profit of the biorefinery. This methodology is applied here to a date palm waste biorefinery in which an organosolv process is used to produce a sugar stream; and fermentation to ethanol and succinic acid are considered to compete for the utilization of it. Results shows that at selling price of

Microorganisms for Biorefining of Green Biomass

400/t ethanol and

Hydrothermal Pretreatment and Enzymatic Hydrolysis of Prairie Cord Grass

1500/t succinic acid, it is feasible to produce these products with an organosolv-sugar stream selling at