Modeling of Technological Processes for a Rectification Plant in Second-Generation Bioethanol Production

The article deals with the recent developments in the fuel industry, considering the permanent increasing requirements for fuel quality and environmental safety. The work aims to study various technological modes at the rectification unit to produce fuel bioethanol from lignocellulosic biomass. The main goals are to solve applied scientific problems of rational designing and technological optimization to obtain boundaries of energy consumption to ensure the quality of bioethanol sufficient for a consumer. Recent approaches for numerical simulation of chemical technological processes were applied to study the operating processes and optimize technological parameters. The plant model was designed from various modules that allow us to simulate technological processes efficiently and accurately for all the primary units of the rectification equipment. The methodology based on the activity coefficient UNIFAC model of phase equilibrium was applied. As a result, a mixture with 74% of bioethanol 9% of impurities was obtained in the brew column. In the epuration column, a mixture of 46% bioethanol and 2.2% of impurities was obtained in bottoms. Finally, in the alcohol column, the mass fraction of distillate of 96.9% and impurities of 2.7% were reached. The numerical simulation results can be applied in recent fuel technologies and designing the corresponding biofuel plants.

RECONSTRUCTION OF RECTIFICATION UNIT OF ETHYLBENZENE PRODUC TION ALKYLATION OF BENZENE WITH ETHYLENE

The possibility of upgrading the unit for rectification of ethylbenzene production al kylation of benzene with ethylene. The possibility of replacing the coolant used to heat the cube of the distillation columns is shown

INCREASING THE DEGREE OF EXTRACTION OF ORGANIC IMPURITIES OF RECTIFIED ALCOHOL

Obtaining high quality rectified ethyl alcohol is a priority for the further development of the alcohol industry. The solution to this urgent problem is possible under the condition of deeper extraction and concentration of volatile alcohol impurities on the plates of the column equipment of the Distillation/Rectification Unit. In the columns of the Distillation/Rectification Unit simultaneously with the release of volatile alcohol impurities due to the esterification reaction is the formation of organic compounds that degrade its quality and reduce the yield of the final product. Thus, during the interaction of alcohols, acids, and aldehydes, the breakdown products of amino acids, sulfur compounds, and other components of the brew in the fermentation column are the formation of esters, aldehydes, and acetals of organic acids. The aim of the work was to determine the optimal technological modes of distillation of alcohol-containing intermediate products and by-products of the distillation/rectification process in the accelerating column, epuration of wash distillate in the epuration column, the concentration of rectified alcohol in the alcohol column, and its repeated epuration in the column of final clearance, under which the content of organic impurities in rectified ethyl alcohol would be the lowest. Materials and methods. Research methods were analytical, chemical, physico-chemical with the use of instruments and research methods used in the production of rectified ethyl alcohol. The concentration of volatile alcohol impurities was determined on a gas chromatograph with a column of HP FFAP 50 m × 0.32 m. It is determined that to increase the degree of extraction of organic impurities it is necessary to ensure the concentration of ethyl alcohol in the column bottom of the accelerating column, which does not exceed 4% vol.; pasteurization zone in the rectification column increase to 10 plates, reduce the concentration of ethanol in the epurate to 22-29% by hydroselection of impurities; for hydroselection in the epuration column use free of impurities bottom products of the accelerating column. To improve the quality of rectified alcohol and reduce energy consumption by extending the contact time on the plates of steam and liquid, a promising direction is the use of mass transfer equipment of cyclic mode. The proposed measures require constant monitoring of technological parameters and provide for the operation of technological equipment in an automated mode.

Comparison the Results of the Efficiency of the Simulation the Rectification Processes Using Real and Pseudocomponents

Today the stable work of a petrochemical plant and its installations, as well as its efficiency, mostly depends on the reliable and optimal operation of technological equipment. It is very common that technological equipment complexes do not work in an optimal mode, despite the fact that they are controlled by modern automated control systems. If the equipment is stopped for any reason, then no best technology or management systems can compensate for the economic costs and losses that arise in the event of equipment downtime. The solution to this problem is to create computer models that allow you to cover the technological equipment from a single point of view and conduct a number of necessary experiments without resorting to existing equipment. The computer model of the rectification unit is implemented when modeling the section of the technological scheme for the production of liquid fuel of the vacuum gasoil hydrocracking unit.

Computer model of the power system with inclusion of a heat pump in the process of separation

The results of computer simulation of industrial processes of separation of substances with the inclusion of a heat pump are presented. Designs of heat pumps of closed type, open type, like “pipe in pipe” are considered. In the simulation software Aspen HYSYS, the adequacy of the computer model of the “rectification unit – closed type heat pump” system was checked. The results of computer simulation of the “rectification unit – open-type heat pump ’pipe in pipe’” system are presented. This system allows to increase the efficiency of the unit by 9% compared with the system of separation of substances with the inclusion of an open-type heat pump and by 14% compared with a system with the inclusion of a closed-type heat pump.