Top Gas Recycling Blast Furnace Process Mar09

Top Gas Recycling Blast Furnace Process...

Top Gas Recycling Blast Furnace Process In the area of production of hot metal (HM) by blast furnace (BF), the most promising technology to significantly reduce the CO2 (carbon di-oxide) emission is recycling of CO (carbon mono oxide) and H2 (hydrogen) from the gas leaving the BF top. CO and H2 content of the top BF gas has a potential to act as reducing gas elements, and hence their recirculation to the BF is considered as an effective alternative to improve the BF performance, enhance the utilization of C (carbon) and H2, and reduce the emission of CO2. This ‘top gas recycling’ (TGR) technology is mainly based on lowering the usage of fossil C (coke and coal) with the re-usage of the reducing agents (CO and H2), after the removal of the CO2 from the top BF gas. This leads to lower the energy requirements. Because of the advantages of high productivity, high PCI (pulverized coal injection) rate, low fuel rate, and low CO2 emission etc., the TGR-BF process is considered to be one of the promising ironmaking processes in future. In TGR-BF, oxygen (O2) is blown into the BF instead of hot air to eliminate nitrogen (N2) in the top BF gas. Part of the top BF gas containing CO and H2 is utilized again as the reducing agent in the BF. CO2 from the BF top gas is captured and then stored. Several recycling processes have been suggested, evaluated or practically applied for different objectives. These processes are distinguished by (i) with or without CO2 removal, (ii) with or without preheating, and (iii) the position of injection. The concept of the TGR-BF (Fig 1) involves many technologies which include (i) injection of reducing top BF gas components CO and H2 in the...

Crude Benzol and its major Components...

Crude Benzol and its major Components Crude benzol is a product which is produced during carbonization of coking coal. Benzol (also called as benzole) is the name normally applied in the chemical industry to a mixture of hydrocarbons of the benzene series, in which benzene itself predominates, in association with certain of its homologues and various impurities. The term is not applied to any particular mixture or quality of the liquids. The recovery of benzol from the coke oven gas implies the removal of vapours of the benzene series, and their subsequent conversion by condensation into different liquid products. The CAS number of crude benzol is 65996-78-3. Benzol fraction produced during the high temperature carbonization of the coal is around 0.7 % to 1.1 % of dry coal. It is present in the coke oven gas in the range of 25 grams per normal cubic meters (g/N cum) to 40 g/N cum of coke oven gas. The benzene series is the most important group of substances in the class of aromatic hydrocarbons.  It is the series of carbon-hydrogen compounds based on the benzene ring, with the general formula CnH2n-6, where ‘n’ is 6 or more. Examples are benzene (C6H6), toluene (C7H8), and xylene (C8H10). The members of particular interest of this series are the first three namely benzene, toluene and xylene, which at normal temperatures are clear colourless liquids having very similar properties. Crude benzol also contains some amount of naphthalene (C10H8). Crude benzol is also known as light oil and contains small quantities of a large number of impurities which consists of the unsaturated and sulphur compounds. These impurities have negative effects on the organic processes. Even insignificant sulphur impurities in benzene and toluene used in organic processes cause fast poisoning of the catalyst, and resinous...

Management by Trust in an Organization...

Management by Trust in an Organization Trust is considered as an important component for the effective organizational performance since it ensures cooperation between two entities. In fact, trust is important in all spheres of social life. It binds friendships, facilitates bargaining and negotiations, reduces transaction costs in inter organizational exchanges, and even resolves conflicts. Trust also affects investment decisions. It is a fundamental component in any positive, productive, and social process. In an organization management trust significantly and positively contributes to organizational trust and organizational trust significantly and positively contributes to organizational performance (Fig 1). Fig 1 Relationship between trust and organizational performance For an organization, trust is also important for the positive outcome of the cooperative behaviour of the employees, the organizational commitment, and employee loyalty. In fact, the management’s prime and challenging objective in an organization is to be to build employees’ trust in the organization. There are two types of trust, one of which is exchange-based or relational in nature and the other character-based or cognitive in nature. Further, three factors can be identified which make it difficult to build trust. The first factor is that the trust building is an interactive process which involves (at least) two individuals learning about each other’s trustworthiness. The second factor is that the underlying systems dynamics of both trust and distrust are based on positive feedbacks, reinforcing the initial behaviour but with an important asymmetry. While the trust is built up gradually and incrementally, reinforced by previous trusting behaviour and previous positive experiences, the distrust is disastrous and instantaneous. The third factor is that there is no absolute certainty that the trust is going to be honoured. However, there is no satisfactory explanation available to account for these factors in the process of trust-building...

Methods of Refining of Crude Benzol Feb26

Methods of Refining of Crude Benzol...

Methods of Refining of Crude Benzol Benzol or benzole is a mixture of hydrocarbons of the benzene series, in which benzene itself predominates, in association with certain of its homologues and various impurities. Benzol recovered from coke oven gas is called as crude benzol (CB). Crude benzol contains small quantities of a large number of impurities which consists of the unsaturated and sulphur compounds. These impurities have negative effects on the organic processes. Even insignificant sulphur impurities in benzene and toluene used in organic processes cause fast poisoning of the catalyst, and resinous substances formed as a result of polymerization of unsaturated compounds coat the catalyst surface and deactivate it. Some of these impurities have the proximity of the boiling points of the pure products. To produce pure products from CB, it is necessary to have its preliminary treatment to remove these impurities. Hence, any processing scheme includes preliminary preparation stages which ensure the removal to the required extent the components of sulphurous unsaturated and saturated hydrocarbons. There are two processes for the refining of the CB. These are (i) sulphuric acid process, and (ii) hydro-refining process. Sulphuric acid refining The refining of the CB comprises the purification of the CB and its subsequent separation into the desired commercial products. This entails chemical washing and fractional distillation. The crude benzol is washed with concentrated sulphuric acid which sulphonates the more undesirable compounds and allows easier separation and recovery of the benzene, toluene and xylene (BTX) fractions. The sulphuric acid washing removes unsaturated compounds, olefins, dienes etc. together with any pyridine and some sulphur compounds. The olefins, dienes and other unsaturated compounds are removed by the sulphuric acid, partly by polymerization and resinification, and partly by solution in the acid. The sulphuric acid method of...

Comparison of By-product Coke Ovens and Heat Recovery Coke Ovens...

Comparison of By-product Coke Ovens and Heat Recovery Coke Ovens There are three proven processes for the carbonization of coal for the production of metallurgical coke. These are (i) beehive oven process, (ii) the by-product coke oven process, and (ii) the heat recovery coke oven process. The heat recovery coke oven process is also known as non-recovery or energy recovery coke oven process. It is a modification of the beehive oven process and, and hence, it has largely phased out the beehive oven process. Thus, for the carbonization of the metallurgical coal the only two cokemaking technologies which are being used are (i) the by-product coke oven technology, and (ii) heat recovery (HR) coke oven technology. Both of these cokemaking technologies offer opportunities to produce high quality coke and to develop the energy balance while achieving the lowest possible operating cost. The by-product coke ovens are prone to high level of pollution because of the positive pressure maintained in them. The stringent pollution laws and the high cost involved in the installation of pollution control equipment led to the revival of interest in the non-recovery coke oven technology during 1980s and 1990s. These non-recovery coke ovens complied with the stringent pollution control regulations. These non-recovery coke ovens are the heat recovery ovens since they are used not only for the production of coke, but also for the generation of power by means of waste gas heat recovery. Hence, the heat recovery type of coke ovens is energy efficient and environment friendly. The selection of the appropriate technology for a particular situation needs a careful study since many different factors can affect the decision, including, for example, availability of land, plant energy balance and available energy sources and their costs, steel plant configuration and energy...