Economic and environmental impacts of the energy source for the utility production system in the HDA process

The well-known benchmark process for hydrodealkylation of toluene (HDA) to produce benzene is revisited in a multi-objective approach for identifying environmentally friendly and cost-effective operation solutions. The paper begins with the presentation of the numerical tools used in this work, i.e., a multi-objective genetic algorithm and a Multiple Choice Decision Making procedure. Then, two studies related to the energy source involved in the utility production system (UPS), either fuel oil or natural gas, of the HDA process are carried out. In each case, a multi-objective optimization problem based on the minimization of the total annual cost of the process and of five environmental burdens, that are Global Warming Potential, Acidification Potential, Photochemical Ozone Creation Potential, Human Toxicity Potential and Eutrophication Potential, is solved and the best solution is identified by use of Multiple Choice Decision Making procedures. An assessment of the respective contribution of the HDA process and the UPS towards environmental impacts on the one hand, and of the environmental impacts generated by the main equipment items of the HDA process on the other hand is then performed to compare both solutions. This ‘‘gate-to-gate’’ environmental study is then enlarged by implementing a ‘‘cradle-togate’’ Life Cycle Assessment (LCA), for accounting of emission inventory and extraction. The use of a natural gas turbine, less economically efficient, turns out to be a more attractive alternative to meet the societal expectations concerning environment preservation and sustainable development

Méthodologie d'éco-conception de procédés par optimisation multiobjectif et aide à la décision multicritère

Ce travail a pour objectif le développement d’une méthodologie de conception de procédés éco-efficaces, avec prise en compte simultanée de considérations écologiques et économiques lors de la phase de conception préliminaire de procédés chimiques. L’aspect environnemental est quantifié à travers l’utilisation d’un ensemble d’indicateurs selon les lignes directrices de concepts de développement durable. Le cadre conceptuel est basé sur une modélisation du procédé et de l’unité de production d’utilités, car l’impact environnemental d’un procédé est lié non seulement aux effluents directs du procédé, mais également à la consommation énergétique, l’effet du recyclage, de la conversion des matières premières … Dans ce but, le logiciel d’aide à la décision ARIANETM dédié à la gestion des utilités des unités de production (vapeur, électricité, eau …) et des effluents (CO2, SO2, NOx, etc..) a été couplé au modèle d’un procédé pour déterminer les besoins en énergies primaires et quantifier les émissions polluantes. Ces modèles ont ensuite été intégrés au sein d’une boucle d’optimisation multiobjectif, basée sur une variante d’un algorithme génétique multiobjectif de type NSGA-II (Non Sorted Genetic Algorithm). Le compromis entre les objectifs économiques et écologiques est illustré à travers la génération de fronts de Pareto. La sélection des meilleures solutions parmi cet ensemble est effectuée par utilisation de techniques d’analyse multicritère. L’exemple test bien connu du procédé de production de benzène par hydrodésalkylation du toluène (HDA) est revisité ici dans un mode multiobjectif pour illustrer l’utilité de l’approche pour trouver des solutions de conception économiques et écologiques. ABSTRACT : This study aims at the development of a design methodology for eco-efficient processes, meaning that ecological and economic considerations are taken into account simultaneously at the preliminary design phase of chemical processes. The environmental aspect is quantified by using of a set of indicators following the guidelines of sustainability concepts. The design framework is based on a modelling approach considering both process and utility production units, since the environmental impact of a chemical process not only contains the material involved in the process but also the energy consumption, the effect of flow recycle, material conversion and so on... For this purpose, a decision support tool dedicated to the management of plant utilities (steam, electricity, water...) and pollutants (CO2, SO2, NOx, etc..), (ARIANETM package) was coupled to process modelling and used here both to compute the primary energy requirements of the process and to quantify its pollutant emissions. Both models were thus integrated in an outer multiobjective optimization loop, based on a variant of the so-called NSGA-II (Non Sorted Genetic Algorithm) multiobjective genetic algorithm. The trade-off between economic and environmental objectives is illustrated through the generation of Pareto fronts. The selection of the best design alternatives is performed through the use of multicriteria analysis. The well-known benchmark process for hydrodealkylation (HDA) of toluene to produce benzene, revisited here in a multi-objective mode, is used to illustrate the usefulness of the approach in finding environmentally friendly and cost-effective designs

Effets Antihypertensifs Des Extraits Aqueux Et Éthanolique Des Graines Fermentées De Parkia Biglobosa (Mimosaceae) Chez Les Rats

High blood pressure is a major cardiovascular risk factor in the occurrence of stroke, heart failure, kidney failure, and coronary heart disease. They are regarded as the leading causes of death worldwide. The aim of this study was to provide a scientific and pharmacological basis for the traditional use of Parkia biglobosa in the traditional treatment of arterial hypertension. Here, we first looked for certain mineral elements in the fermented seeds of P. biglobosa "soumara". Subsequently, we evaluated the hypotensive and antihypertensive effects of the aqueous and ethanolic extracts from these fermented seeds of P. biglobosa in normotensive and hypertensive rats. The cardiovascular parameters studied were systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). The results showed that "soumara" is rich in calcium, potassium and magnesium, but low in sodium. Also, plant extracts at doses between 1000 and 2000 mg / kg bw induced a dose-dependent decrease in cardiovascular parameters in healthy rats. The treatment of rats made hypertensive with adrenaline by the ethanolic extract at a dose of 1500 mg / kg bw induced a dose-dependent decrease in cardiovascular parameters until normalization. The aqueous and ethanolic extracts of “soumara” acted in the same way as Nifédipine®, which is a calcium channel blocker

Floristic Diversity and Conservation Value of Tanoe-Ehy Forest in South-Eastern (Cote d’Ivoire)

The Tanoe-Ehy Forest, located in the South-Eastern of the Côte d’Ivoire is one of the rare forest cover of this type that still exists in the Country. These Forest was identified as a top priority site for conservation in West Africa. However, this important forest is subject to strong anthropogenic pressures which through poaching, uncontrolled takeoffs of natural resources and some agricultural clearing. A Botanical study based on plots, itinerant and linear inventory conducted in this forest intends to assess the plant species diversity and the conservation value for biodiversity of this forest. At the end of the study, 432 plant species were recorded. Among them, 14 are listed on endemic of Upper Guinea and 16 threatened and endangered list of species. Concerning the species threatened and endangering, 3 species are really in endangering (Hemandradenia chevalieri, Tieghemella heckelii, Irvingia gabonensis) and 13 others are a category of vulnerable species. A Sassandrian species of type II (Piptostigma fugax) was also observed. The dominant species of the forest are Symphonia globulifera and Uapaca paludosa. Concerning the vegetation condition, the swamp forest, the dry land forest and the raphiale vegetation have a high conservation value

Economic and environmental strategies for process design

This paper first addresses the definition of various objectives involved in eco-efficient processes, taking simultaneously into account ecological and economic considerations. The environmental aspect at the preliminary design phase of chemical processes is quantified by using a set of metrics or indicators following the guidelines of sustainability concepts proposed by . The resulting multiobjective problem is solved by a genetic algorithm following an improved variant of the so-called NSGA II algorithm. A key point for evaluating environmental burdens is the use of the package ARIANE™, a decision support tool dedicated to the management of plants utilities (steam, electricity, hot water, etc.) and pollutants (CO2, SO2, NO, etc.), implemented here both to compute the primary energy requirements of the process and to quantify its pollutant emissions. The well-known benchmark process for hydrodealkylation (HDA) of toluene to produce benzene, revisited here in a multiobjective optimization way, is used to illustrate the approach for finding eco-friendly and cost-effective designs. Preliminary biobjective studies are carried out for eliminating redundant environmental objectives. The trade-off between economic and environmental objectives is illustrated through Pareto curves. In order to aid decision making among the various alternatives that can be generated after this step, a synthetic evaluation method, based on the so-called Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) (), has been first used. Another simple procedure named FUCA has also been implemented and shown its efficiency vs. TOPSIS. Two scenarios are studied; in the former, the goal is to find the best trade-off between economic and ecological aspects while the latter case aims at defining the best compromise between economic and more strict environmental impact

Antibacterial Activity of 04 Medicinal Plant on the IN VITRO Growth of Multi-Resistant Strains Involved in Diarrhea in the Department of Kouto (Ivory Coast)

This work aims at evaluating in vitro the antibacterial effects of aqueous and hydroethanolic extracts of leaf macerates, Manilkara multinervis, Waltheria indica root bark, Securrinega virosa, and Anogeissus leiocarpa stem bark. These four medicinal plants are traditionally used to treat diarrhea in the canton of North-Niéné (Department of Kouto, Côte d'Ivoire). The antibacterial activities of the various extracts from these plants were carried out on multi-resistant strains (Escherichia coli BLSE, Shigella flexneri BLSE, Staphylococcus aureus meti-R). The methodology consisted of extracting the drugs with a 70% hydroalcoholic solvent and distilled water. Agar diffusion and dilution methods were used for susceptibility testing and determination of CMI and CMB parameters. Agar diffusion and dilution methods were used. By the diffusion method, all four plants were found to be active on at least one of the bacteria tested. The ethanolic extract of M. Multinervis was the most active by inducing a diameter of 15 mm on the growth of S. aureus meti-R. As for the dilution method, the ethanolic extracts of W. indica and M. Multinervis showed bactericidal effects on both S. aureus at 6.25 mg/mL and 3.125 mg/mLrespectively as well as on all other 100 mg/mL germs. Only M. Multinervis recorded the highest activity. This important activity was demonstrated on S. aureus meti-R with a minimum bactericidal concentration of 3.125 mg/mL. These results confirm the traditional use of these plants in the management of diarrheal diseases in the Department of Kouto

Antibacterial Activity of 04 Medicinal Plant on the IN VITRO Growth of Multi-Resistant Strains Involved in Diarrhea in the Department of Kouto (Ivory Coast)

This work aims at evaluating in vitro the antibacterial effects of aqueous and hydroethanolic extracts of leaf macerates, Manilkara multinervis, Waltheria indica root bark, Securrinega virosa, and Anogeissus leiocarpa stem bark. These four medicinal plants are traditionally used to treat diarrhea in the canton of North-Niéné (Department of Kouto, Côte d'Ivoire). The antibacterial activities of the various extracts from these plants were carried out on multi-resistant strains (Escherichia coli BLSE, Shigella flexneri BLSE, Staphylococcus aureus meti-R). The methodology consisted of extracting the drugs with a 70% hydroalcoholic solvent and distilled water. Agar diffusion and dilution methods were used for susceptibility testing and determination of CMI and CMB parameters. Agar diffusion and dilution methods were used. By the diffusion method, all four plants were found to be active on at least one of the bacteria tested. The ethanolic extract of M. Multinervis was the most active by inducing a diameter of 15 mm on the growth of S. aureus meti-R. As for the dilution method, the ethanolic extracts of W. indica and M. Multinervis showed bactericidal effects on both S. aureus at 6.25 mg/mL and 3.125 mg/mLrespectively as well as on all other 100 mg/mL germs. Only M. Multinervis recorded the highest activity. This important activity was demonstrated on S. aureus meti-R with a minimum bactericidal concentration of 3.125 mg/mL. These results confirm the traditional use of these plants in the management of diarrheal diseases in the Department of Kouto

Analyse de la Diversité Floristique de Quelques îles Aménagées du Barrage de Buyo (Côte d’Ivoire)

This paper focuses on analyzing the floristic composition of islands of Buyo’s dam after strong anthropization. Using surfaces surveys, linear surveys and itinerant surveys, the floristic composition and diversity were determined. Seven hundred and twenty-three plants species belonging to 353 genera and 99 families were recorded. The ecological importance of the species has been assessed from the Value of Significance. The study showed that for tree species with diameter ≥ 10 cm, the species Alchornea cordifolia, Ceiba pentandra, Theobroma cacao, and Lannea welwitschii were the richest and had the highest Indices of Value Importance. The mean richness of species showed a significant difference (p≤ 0. 03797) among the Islands of Buyo’s dam. Island D which is close to the Park with the presence of animals isrich in species(101 ± 10 74). Apolinaire and Laminebougou Islands farthest to the Park with strong agricultural activity are poor in species (51 ± 11. 14; 50 ± 6. 29). Floristic diversity and evenness do not vary statistically from one site to another.La présente étude se propose d’analyser la composition et la diversité floristique des îles du barrage de Buyo après forte anthropisation. À l’aide de relevé de surface, de relevé linéaire et de relevé itinérant, la composition et la diversité floristique de onze îles ont été déterminées. L’inventaire a permis de noter 723 espèces de plantes reparties entre 353 genres et 99 familles. L’importance écologique des espèces a été appréciée à partir de l’Indice de Valeur d’Importance. L’étude a montré que pour les arbres de diamètre ≥ 10 cm, les espèces Alchornea cordifolia, Ceiba pentandra, Theobroma cacao, Lannea welwitschii sont celles qui ont les plus forts indices de valeur d’importance des espèces. La moyenne de la richesse spécifique montre une différence significative (p≤ 0,03797) entre les différentes îles du barrage de Buyo. L’île D, proche de la forêt du Parc, avec une présence moyenne de mammifères, est la plus riche en espèces (101 ± 10, 74). Les îles Apollinaire et Laminebougou, plus éloignées de la forêt mère et avec une intense activité, sont les plus pauvres en espèces (51 ± 11,14 ; 50 ± 6, 29). La diversité floristique et l’équitabilité ne varient pas statistiquement entre les îles

Former Botanical Garden of ORSTOM (Côte d’Ivoire): What Remain after Thirty Years of Abandonment and Forest Restoration

Botanical gardens represent important places for ex situ conservation. One of these botanical gardens has been abandoned in Côte d’Ivoire for 30 years. This is the former botanical garden of ORSTOM. This study was conducted to determine the level of diversity of this former garden in order to assess the opportunity for its rehabilitation. The authors carried out inventories in 18 quadrats of 500 m2 through the vegetation to collect woody species. Dendrometric measurements (height, diameter) were also recorded to assess the structure of the site. A total of 190 species have been identified. They belong to 141 genera and 47 families. This former botanical garden contains important species because of their origin, status or particularity (threatened, endemic, rarity, etc.). A total of 19 threatened species including 2 endangered and west African endemic (Chrysophyllum azaguieanum J. Miège, Placodiscus pseudostipularis) were found at the site. Also, Chrysophyllum azaguieanum is declared extinct from Côte d’Ivoire. Four species are rare in the flora of Côte d’Ivoire: Balanites wilsoniana, Chrysophyllum azaguieanum, Gilletiodendron kisantuense and Loesenera kalantha. The most abundant species is Hopea odorata. Although this introduced species is considered globally vulnerable, it presents a risk of invasion in the forest of Côte d’Ivoire. The diameter and height structures show that all the stages of development are presented indicating a good regeneration on the site. Ultimately, this botanical garden deserves to be rehabilitated and especially urgent management of Hopea odorata is needed to prevent an invasion of this species

Diversité Floristique, Croissance et Qualité du Bois de Cedrela odorata L. (Meliaceae) et Gmelina arborea Roxb (Verbenaceae) dans Différents Systèmes de Reboisement dans la Forêt Classée de la Besso (Sud-Est de la Côte d’Ivoire)

La couverture forestière de la Côte d’Ivoire estimée à environ 16 millions d’hectares dans les années 1900 a connu une importante régression et elle est passée de nos jours à moins de 3 millions d’hectares. Cette réduction résulte de l’effet conjugué de l’urbanisation galopante, de l’agriculture et de l’exploitation des massifs forestiers en bois d’œuvre. Cette diminution a conduit à la perte des essences forestières commercialisables. La présente étude, réalisée dans la forêt classée de la Besso s’inscrit dans une vision d’amélioration de la productivité des plantations forestières pour un meilleur approvisionnement des industries du bois. Elle vise à identifier le modèle de reboisement offrant une diversité floristique élevée avec une meilleure croissance et qualité du bois. Les espèces utilisées sont Cedrela odorata L. (Meliaceae) et Gmelina arborea Roxb (Verbenaceae). Les travaux ont été effectués sur deux types de reboisement (plantation pure et agroforêt à base de caféier ou de cacaoyer). Plusieurs paramètres (quantitatifs et qualitatifs) ont été évalués suivant les types de reboisement. Il en ressort que l’agroforêt de type Cedrela odorata en association avec le caféier est le système le plus hétérogène avec un indice de Shannon de 3,47 et une valeur d’équitabilité de Piélou de 0,93. Cependant, Gmelina arborea en agroforêt avec le cacaoyer présente une bonne croissance annuelle (0,04 m). L’agroforêt de type Gmelina arborea associée au cacaoyer a fourni les meilleures valeurs de cylindricité et de rectitude. Les résultats de cette étude devraient aider à la réhabilitation des écosystèmes forestiers dégradés.   The forest cover of Côte d'Ivoire estimated at around 16 million hectares in the 1900s has undergone a significant reduction and it is estimated today at under three million hectares. This reduction is the combined effect of a high rate of urbanization, agriculture, and logging industry. This reduction has led to a depletion of the forests in marketable species. This study on the Besso classified forest is part of a vision to improve the productivity of forest plantations for a better supply of wood industries. It aims to identify a reforestation model with a high floristic diversity with better growth and wood quality. The species used are Cedrela odorata L. (Meliaceae) and Gmelina arborea Roxb (Verbenaceae). Two types of reforestation in the Besso classified forest were carried out namely, pure reforestation plantation and agroforest (coffee and cocoa based). Several parameters (quantitative and qualitative) were evaluated according to the types of reforestation. The results show that the reforestation of Cedrela odorata-coffee agroforest is the most system environment with a Shannon index of 3.47 and a Pielou equitability value of 0.93. However, the Gmelina arborea-cocoa agroforest has the best annual growth rate (0.04 m). The qualitative parameters (cylindricity and straightness) are better in the Gmelina arborea-cocoa agroforest. All these results should help in the rehabilitation of degraded ecosystems and forests