Recovery of Ammonia during Production of Coke from Coking Coal Jan26

Recovery of Ammonia during Production of Coke from Coking Coal...

Recovery of Ammonia during Production of Coke from Coking Coal Ammonia (NH3) is a by-product produced during the production of coke from coking coal in the by-product coke ovens. It is a constituent of the coke oven gas (COG) leaving the coke ovens, with a typical concentration in raw COG of 6 grams per normal cubic meters (g/N cum). The solubility of NH3 in water leads to its presence in the flushing liquor of coke oven battery (COB) with a typical concentration of 5 grams per litre (g/l) to 6 g/l of total NH3. Therefore, due to the net production of flushing liquor in the COB, also sometimes being referred to as excess flushing liquor, there arises a liquid stream as well as a gas stream from which NH3 is required to be removed. The quantity of excess liquor is around 12 % of the dry coal throughput, which depends on the coal moisture content. Removal of NH3 from the gas stream is a universal feature of a coke oven and by-product plant. This is because NH3, in the presence of the other COG contaminants hydrogen cyanide (HCN), hydrogen sulphide (H2S), oxygen (O2), and water, is extremely corrosive to pipelines made of carbon steel. Also, when ammonia is uncontrollably burnt in any combustion chamber, it forms nitrogen oxides (NOx) which causes air pollution. Hence, removal of NH3 from COG and liquid stream is required to be also done due to environmental reasons. The primary NH3 handling process in the coke oven and by-product plant deals with the removal and disposal of the NH3 present in the COG. However, NH3 recovery systems often include facilities to handle the NH3 arising in the excess flushing liquor. For proper understanding of how these facilities are incorporated into...

Understanding Coke Making in Byproduct Coke Oven Battery Mar09

Understanding Coke Making in Byproduct Coke Oven Battery...

Understanding Coke Making in Byproduct Coke Oven Battery  Coke is one of the basic materials used in blast furnaces for the conversion of iron ore into hot metal (liquid iron), most of which is subsequently processed into steel. The major portion of coke produced is used for the production of hot metal. Coke is also used by a number of other industries, namely iron foundries, nonferrous smelters, and chemical plants. It is also used in steel making as a carburizing material. Coke and coke by-products, including coke oven gas, are produced by the pyrolysis (heating in the absence of air) of suitable grades of coal. The process also includes the processing of coke oven gas to remove tar,  ammonia (usually recovered as ammonium sulphate), phenol, naphthalene, light oil, and sulphl, and sulfs under links n of coal)  period.e doorg nitrogen gas is used for the production of steam and then power.ur before the gas is used as fuel for heating the ovens. The coke making industry consists of two sectors, integrated plants and merchant plants. Integrated plants are owned by or affiliated with iron-and steel producing plants who produce blast furnace coke primarily for consumption in their own blast furnaces. Independent merchant plants produce furnace and/or foundry coke for sale in the open market. These plants sell most of their products to other plants engaged in blast furnace, foundry, and nonferrous smelting operations. A good quality coke is generally made from carbonization of good quality coking coal. Coking coals are defined as those coals that on carbonization pass through softening, swelling, and re-solidification to coke. One important consideration in selecting a coal blend is that it should not exert a high coke oven wall pressure and should contract sufficiently to allow the coke to...