Concept of Flocks Fragmentation and Averaging Method for the Application of Electrocoagulation in Process for Coke Oven Wastewater Treatment

The main objective of the article is to develop the concept of flock fragmentation and the averaging method for the application of electrocoagulation in the process of treating wastewater from coke ovens. The designed solution was part of an innovative system for the coke oven wastewater treatment process. The system is dedicated to removing the hazardous elements and compounds from wastewater from leaching ashes in municipal waste incineration plants. The design of the process and its automatization was based on a quantitative simulation method. The balance equations of mass, energy, and momentum of transport, complemented by the kinetics of the related reaction, are used during the calculation of the process. The main result achieved is a practical solution—the reactor’s scheme, classified due to a patent procedure in the Polish Patent Office.

First Steps: Synthetic Ammonia in the United States

The synthetic ammonia industry, originally based on Fritz Haber's 1909 invention of a catalytic high-pressure method as scaled up by Carl Bosch at BASF, grew globally in the years following World War I, based on the processes of Brunner, Mond & Co. (Britain), Luigi Casale (Italy), Georges Claude (France), and Giacomo Fauser (Italy). The ammonia was mainly converted into ammonium sulphate fertilizer. There was less impetus in the United States for taking up these developments, because America relied on ammonium sulphate from its by-product coke ovens, sodium nitrate (Chilean nitrate) from South America, ammonia from coal gas works, and calcium cyanamide as manufactured by the American Cyanamid Company. Even when a synthetic ammonia industry started up in the United States, it was on a smaller scale than in Europe. However there emerged just before the Wall Street Crash two major producers of synthetic ammonia, Allied Chemical and Du Pont. This article presents a historical reconstruction of the early synthetic ammonia industry in the United States focusing on the 1920s, paying particular attention to Du Pont's success, which relied on the ammonia process of Casale. Standard accounts suggest that Du Pont acquired Casale technology as the result of a straightforward business acquisition. However, the situation, as shown here, was far more complex. Du Pont had to engage in aggresive litigation in order to acquire rights to the Casale process in 1927.

Planned redesign of beehive coke ovens for pollution control and power generation

Fossil fuel based thermal power or ovens not only exude greenhouse gases and pollutants but transfer enormous amount of waste heat up in air. Heat gets enveloped in the stratosphere and circulate around the earth; escalating global warming. France, Czech Republic, Slovakia, Austria, Andorra, Luxembourg, Poland and Germany made it the hottest June on record in 2019. Around 50 coke ovens around Dhanbad are losing and facing closure, with fate of employees doomed. Jharkhand State Pollution Control Board, Dhanbad had been issuing letters to the small-scale refractory and beehive hard coke-ovens to bring down stack gas emissions to below 150mg/Nm3 of suspended particulate matter (SPM), equivalent to the standards of large thermal power plants, deploying electrostatic precipitators (ESP). Some locally made pollution control devices were deployed, but these reduced the chimney draft and coking time increased. Installation of wet scrubbing methods would not be economic and slow down production. With experience as the Manager of a by-product coke oven, the chimney detour method with mechanical exhauster suggested for beehive coke oven. Proposed design not only can generate power, but also trap pollutants by a kind of wet scrubbing and produce byproducts like coal tar. Various associations of small-scale hard coke ovens and refractory industries had approached The Institution of Engineers (India), Dhanbad Local Centre. In this paper, the authors briefly present how waste heat can be converted to power, while absorbing pollutants in hydraulic main in the unique chimney detour method and producing coal tar, exuding clean gas.

INVESTIGATION OF SUSPENDED SOLIDS IN WATER FOR COKE EXTINCTION

The article is devoted to the results of work for the study of the composition and quantitative content of suspended solids (SS) in the wastewater of coke plants before and after biochemical purification plants (BPP), as well as in other waters involved in the process of coke extinction. The characteristic indicators have been investigated of waters before and after BPP of five coke-chemical enterprises of Ukraine, as well as the chemical composition of suspended solids in water after BPP, etc. It is shown that SS in water after BPP is represented mainly by activated sludge, which is partially oxidized to CO2 when water is supplied to hot coke. The rest activated sludge is returned with water condensate to the settling tank of the extinction tower and, thus, is not emitted into the atmosphere in the form of SS. In addition to sludge, the particles of coke, coal and products of the equipment corrosion are present in the purified water after the BPP and in the water of the extinction tower settling tank. The possibility of the presence of concrete particles is also not excluded. To establish the nature of solid particles, their elemental composition and ash composition has been determined. In particular, it was found that the ash composition of suspended solids from water after BPP quantitatively differs from the both of ash composition of coal concentrates and the composition of concrete. For example, the mass fraction of silicon dioxide in the suspended solids of water after BTH is much lower than in concrete and in ash of coal concentrates. The detected predominance of iron (III) oxide in the composition of SS ash after BPP is explained by the presence in the selected samples of products of the equipment corrosion. Based on our research, it is proposed to make changes in the normative document "Technological standards of permissible emissions of pollutants from coke ovens", namely in chapter IV "Operating conditions of coke ovens" par. 8: to exclude such a normative value as the content of suspended solids in water after BPP, which is submitted for coke extinction. Keywords: water for coke extinction, water after biochemical purification, suspended solids (SS), content, chemical composition, elemental composition, ash composition. Corresponding author A.L. Borisenko, e-mail: [email protected]

INFLUENCE OF MOISTURE CONTENT OF COAL CHARGE ON ITS BULK DENSITY

The necessity of determining the bulk density of the coal charge for calculating the operation of coke ovens is argued, since this indicator affects the physicochemical properties of coke and the productivity of coke ovens. The diagram of the apparatus is provided and the method for determining the bulk density of the coal charge is presented. Each value obtained is the average of five parallel determinations. There has been presented the study of the dependence of the bulk density on moisture content for two research coal blends of different grades, compiled with the participation of domestic and imported grades of coal. For charge No. 1, it was concluded that the bulk density of the coal charge significantly depends on its working moisture. The minimum bulk density (798 kg/m3 ) is achieved at a working moisture of about 7 %. With a decrease in the value of the working moisture to 4 % or its growth to 12 %, the value of the bulk density of the coal charge increases to 820 and 871 kg/m3 , respectively. The minimum value of the bulk density of charge No. 2 (779 kg/m3 ) is noted at a working moisture of 7-8%. With a decrease in the value of the working moisture to 4.5 % or its increase to 12 %, the value of the bulk density of the coal charge increases to 845 and 892 kg/m3 , respectively. Based on the generalization of the results obtained, mathematical and graphic dependencies have been developed. They describe the effect of an increase in the moisture content of coal charges on the content of a class less than 0.5 mm in them, as well as the values of the average diameter of coal grains and bulk density. It was found that coal charges are characterized by a minimum bulk density at a moisture content of 7.2 %. With an increase in the moisture content of coal charges to 12 %, there is a sharp decrease in the content of the class less than 0.5 mm. This is due to the pelletization of small coal grains, which is reflected in an increase in their average diameter. Keywords: coal charge, bulk density, moisture content, particle size distribution, mathematical relationships. Corresponding author N.A. Desna, e-mail: [email protected]

Biological treatment of coke plant effluents: from a microbiological perspective

During coke production, large volume of effluent is generated, which has a very complex chemical composition and contains several toxic and carcinogenic substances, mainly aromatic compounds, cyanide, thiocyanate and ammonium. The composition of these high-strength effluents is very diverse and depends on the quality of coals used and the operating and technological parameters of coke ovens. In general, after initial physicochemical treatment, biological purification steps are applied in activated sludge bioreactors. This review summarizes the current knowledge on the anaerobic and aerobic transformation processes and describes key microorganisms, such as phenol- and thiocyanate-degrading, floc-forming, nitrifying and denitrifying bacteria, which contribute to the removal of pollutants from coke plant effluents. Providing the theoretical basis for technical issues (in this case the microbiology of coke plant effluent treatment) aids the optimization of existing technologies and the design of new management techniques.

Total p-PAH Levels Nearby a Complex Industrial Area: A Tailored Monitoring Experiment to Assess the Impact of Emission Sources

In this study, data on the hourly concentrations of the total particle-bound Polycyclic Aromatic Hydrocarbons (p-PAHs) collected between 1 August 2013 and 31 August 2014 by the air quality fence monitoring network of the biggest European steel plant, were analyzed. In contrast with what was predicted, the total p-PAH concentration did not decrease with distance from the steel plant, and higher concentrations were registered at the Orsini site, in the urban settlement, relative to the Parchi site, which is nearest to the coke ovens. Therefore, in order to identify and explain the cause of these high concentrations, a tailored monitoring experiment was carried out on a specific monitoring pathway by using a total p-PAHs monitor placed onto a cart. The real-time monitoring of the total p-PAH concentration on the road revealed to be a useful tool, which identified vehicular traffic as an important source of p-PAHs and highlighted the possible high short-term effect that vehicular traffic sources could have on the health of the exposed human population. Moreover, the study focused attention on the importance of the spatial representativeness of fixed monitoring stations, especially in a highly complex industrial area such as Taranto (Southern Italy).