Historical Development of Coke:
– Coke production dates back to ancient China in the 4th century.
– Chinese began using coke for heating and cooking by the 9th century.
– By 1078 CE, coke replaced charcoal in iron production in China.
– China is the largest producer and exporter of coke globally.
– Coke played a crucial role in the industrial development of China and boosted iron production significantly.
– Technological advancements in China’s coke industry aim to improve energy efficiency.
Coke in Britain and the United States:
– Patents in the 16th and 17th centuries mentioned the use of coke in Britain.
– Abraham Darby I established a coke-fired blast furnace in Britain in 1709.
– The Industrial Revolution in Britain was fueled by inexpensive iron produced using coke.
– In the US, the first use of coke in an iron furnace occurred around 1817 in Pennsylvania.
– Pittsburgh alone produced nearly 18,000,000 tons of coke in the late 19th century.
– Environmental concerns regarding coke production were raised in both Britain and the US.
Coke Production and Processes:
– Industrial coke furnaces use high temperatures to produce coke from coal.
– Coking coal must meet specific criteria for moisture, ash, sulfur, volatile content, and more.
– Different types of coal are blended to achieve optimal volatility levels for coking.
– The hearth process and beehive coke ovens were traditional methods for coke production.
– Occupational safety measures are crucial due to exposure to coke oven emissions.
Uses and Properties of Coke:
– Coke is used as fuel and reducing agent in smelting iron ore.
– It is commonly used in blacksmithing, stoves, furnaces, and domestic heating.
– Coke is utilized in various industries, including whisky production and manufacturing dry cells.
– Properties of coke include bulk specific gravity, low ash and sulfur content, and specific crush indexes.
– Different types of coke such as bell coke, nut coke, and coke breeze serve various purposes.
Byproducts and Environmental Impact:
– Byproducts of coking include coal tar pitch, ammonia, and other carbon-based materials.
– Phenolic byproducts from coking wastewater are toxic and carcinogenic.
– Various treatment methods, such as using white rot fungus, are studied for phenolic removal.
– Environmental concerns about coke production’s impact have led to policy changes and technological shifts in the industry.
– Other processes like petroleum coke production and fluid coking also have environmental implications.
Coke is a grey, hard, and porous coal-based fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air—a destructive distillation process. It is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges when air pollution is a concern.
The unqualified term "coke" usually refers to the product derived from low-ash and low-sulphur bituminous coal by a process called coking. A similar product called petroleum coke, or pet coke, is obtained from crude oil in oil refineries. Coke may also be formed naturally by geologic processes.
