The aim was to obtain extracts with high anthocyanin content and stability during storage for potential use in commercial applications as natural colorants. Single-step batch extractions were performed with ethanol, ethyl-acetate and acetone in different ratios with water as well as two-step extractions, combining SFE and conventional batch extractions. The most efficient conventional solvents in single-step extractions were mixtures of organic solvent and water at 60 °C. Pre-treatment of natural material with supercritical CO2 improved the extraction of polyphenols.
Continuous adsorption measurements show that silica aerogels are excellent adsorbents of BTEX vapours from waste gas stream. Aerogels exhibit adsorption capacities which enormously exceed that of commonly used adsorbents such as active carbon and silica gel. Silica monolith aerogels with different degrees of hydrophobicity by incorporating methyltrimethoxysilane (MTMS) or trimethylethoxysilane (TMES) in standard sol-gel synthesis were prepared. Excellent properties of aerogels, obtained with the sol-gel synthesis, were preserved with supercritical drying with CO2.
The developments on applications of supercritical fluids as alternative solvents for biocatalytic processes that have taken place over the past two decades have been reviewed. An overview of process parameters influencing enzyme activity and stability, reaction rates and productivity are presented as well as applications of various types of reactors for enzymatic reaction in dense fluids, limitations of using enzymes as biocatalyst in supercritical fluids and future trends.
The monograph gives an overview of engineering physics with an emphasis on energy–saving houses in context of sustainable development and building design. The various energy-saving houses (low energy house, three litre house, passive house, zero house, energy self–sufficient house and plus house) and installation of heat–insulated windows, which significantly contribute to less energy losses and consequently to reduced environmental pollution with greenhouse gases are presented. The following are guidelines for effective choice of heat insulation and comfortable feeling in the living space.
In this paper, the optimisation of pipe network with hot water is presented. The mathematical model, consisting of the nonlinear objective function and system of nonlinear equations for the hydraulics limitations is developed. On its basis, the computer program for determination optimal tree path with the use of simplex method was solved. For economic estimation the capitalised value method, which consider all costs of investment and operation was used. The results are presented for real case study network with 24 nodes and 33 pipe sectors.