Feasibility of Batch Reactive Distillation with Equilibrium-Limited Consecutive Reactions in Rectifier, Stripper, or Middle-Vessel Column.

A general overall feasibility methodology of batch reactive distillation of multireaction systems is developed to study all the possible configurations of batch reactive distillation. The general model equations are derived for multireaction system with any number of chemical equilibrium-limited reactions and for any number of components. The present methodology is demonstrated with the detailed study of the transesterification of dimethyl carbonate in two reversible cascade reactions in batch reactive distillation process. Pure methanol is produced as distillate, and pure diethyl carbonate is produced at the bottom simultaneously in middle-vessel column; in each section, continuous feeding of ethanol is necessary. The results of feasibility study are successfully validated by rigorous simulations

CURRENT AFFORESTATION PRACTICE AND EXPECTED TRENDS ON FAMILY FARMS IN WEST HUNGARY

The primary aim of the National Forest Strategy and National Development Plan in Hungary is to increase the ratio of forest cover from the current level of 19,7% to 26-28%. This means planting 700,000 ha of new forest plantation in Hungary between now and 2035. Around 90% of the afforestation1 will occur on private land. So the simultaneous improvement of farming and forestry is critical. Our survey sought to capture the current situation in western Hungary. Our aim was to research the possibilities for complimentary development of agriculture and forestry on family owned farms. Relatedly, we wanted to know about the motivations of farmers regarding afforestation. We established that forestry does not have a favorable effect on the labour effi ciency of agriculture and does not reduce the seasonality of agriculture. Most of the farmers consider afforestation could be a good investment or a potential source of better profi t. However, the level of support available is what mainly motivates willingness to plant tree crops. They believe that the government should compensate short-term profi t loss (due to land set aside for tree crops) with longer-term subsidies (according to established EU support practices

CURRENT AFFORESTATION PRACTICE AND EXPECTED TRENDS ON FAMILY FARMS IN WEST HUNGARY

The primary aim of the National Forest Strategy and National Development Plan in Hungary is to increase the ratio of forest cover from the current level of 19,7% to 26-28%. This means planting 700,000 ha of new forest plantation in Hungary between now and 2035. Around 90% of the afforestation1 will occur on private land. So the simultaneous improvement of farming and forestry is critical. Our survey sought to capture the current situation in western Hungary. Our aim was to research the possibilities for complimentary development of agriculture and forestry on family owned farms. Relatedly, we wanted to know about the motivations of farmers regarding afforestation. We established that forestry does not have a favorable effect on the labour effi ciency of agriculture and does not reduce the seasonality of agriculture. Most of the farmers consider afforestation could be a good investment or a potential source of better profi t. However, the level of support available is what mainly motivates willingness to plant tree crops. They believe that the government should compensate short-term profi t loss (due to land set aside for tree crops) with longer-term subsidies (according to established EU support practices

New extractive configuration separating azeotropic mixture in semi-batch way

A new variant of batch extractive distillation, the so-called inverse-fed batch extractive distillation is presented. The total amount of the entrainer is pre-loaded to the boiler, and the mixture charge to be separated is continuously fed to the column in this novel configuration. The feasibility study of conventional extractive distillation was extended and a thorough study was performed to separate a maximum boiling azeotrope with intermediate boiling entrainer. The new configuration was found more efficient than the conventional one. The results of the feasibility study was validated and completed with a sensitivity analysis performed with commercial simulator software

Batch Extractive Distillation with Light Entrainer

Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol/water (minimum boiling azeotrope) with methanol, water/ethylene diamine (maximum boiling azeotrope) with methanol, and chlorobenzene/ethylbenzene (close boiling mixture) with 4-methylheptane. Feasibility, operating steps, limiting entrainer flows, limiting reflux ratios, and limiting number of theoretical stages are determined by parametric study on profiles maps, and verified by rigorous simulation. The effects of reflux ratio, feed ratio, feed stage, number of stages, and thermodynamic state of the entrainer are also examined. It can be established, as a result, that processes separating either minimum or maximum boiling azeotropes, or close boiling mixtures, in batch extractive distillation using a light entrainer are feasible

Etude de faisabilité de la séparation éthylenediamine – eau avec méthanol dans un stripper extractif batch

En présence d’eau (W), l’éthylène diamine (EDA) forme un mélange azéotropique de point de bulle maximum dont séparation est impossible par distillation conventionnelle. Elle peut être réalisée dans une colonne de distillation extractive inverse discontinue (BES) alimentée en continue par un solvant (méthanol (MeOH)). Le mélange à séparer est introduit dans le bac de tête permettant alors de soutirer le produit au bouilleur. Une étude de faisabilité basée sur l’analyse des diagrammes de composition de colonne montre que le procédé permet d’obtenir un produit pur à 95% en EDA si le tiers corps est alimenté à un point intermédiaire de la colonne. Les étapes opératoires de la séparation sont : 1/ remplissage (F/L’=0 ; s=∞); 2/ nettoyage (F/L’>0 ; s=∞); 3/ production EDA (F/L’>0 ; s<∞) ; 4/ coupe intermédiaire ; production W et régénération MeOH (F/L’=0 ; s<∞). Un bon rendement (~80% en EDA) est atteint par simulation rigoureuse, ProsimBatc

Feasibility of extractive distillation process variants in batch rectifier column

A systematic comparison is presented about the separation tasks of azeotropic and close-boiling mixtures applying batch extractive distillation (BED) in rectifier. All the eight possible mixture types with at most a single azeotrope (minimum and maximum boiling azeotropes with heavy, light, and intermediate boiling entrainers; and close boiling mixtures with heavy and light entrainers) are compared. The main results of the feasibility studies on the hitherto unpublished cases are presented. All the cases are feasible in batch rectifier, applying BED. The operation steps are determined by the relative position of the azeotropic composition and entrainer in bubble point ranking. The main limiting parameters (F/V, N, Epremix) are also determined by the mentioned relative position; only the existence of maximum number of stages in the rectifying section is determined by the type of the azeotrope. Use of residue curves maps (RCMs) for predicting feasibility is not generally satisfactory, but profiles maps can be used instead. Studying only the total reflux case can be misleading, and should be treated with great care. The theoretical results of separation variants applying intermediate boiling entrainer were proved experimentally