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How to Achieve Leadership in Energy Efficiency in Methanol Production from Coke Oven Gas / Author/Source: Gasification World / Date: February 27, 2022 / Clicks: 14. A few days ago, the Ministry of Industry and Information Technology and the **State Administration for Market Regulation released the list of \"energy efficiency leaders\" in key energy-consuming industries for 2021; Shanxi Guangda Coking Gas Source Co., Ltd. was included on this list as a leader in energy efficiency for methanol production from coke and coke oven gas. Among them, a total of 5 enterprises in the coke industry made it onto the list; this company is the only enterprise producing methanol from coke oven gas. Through technological upgrades, Shanxi Guangda Coking Gas Source Co., Ltd., which produces 1.5 million tons of coke per year, employs a fully dry quenching process and is equipped with dry quenching and power generation systems with capacities of 85 tons per hour and 120 tons per hour respectively. In the dry quenching furnace, heat exchange occurs directly between the coke and inert gases, cooling the coke to an average temperature of below 150°C. The fully dry coke quenching process not only improves the quality of the finished coke, reduces production costs, and minimizes environmental pollution, but also ensures that the coke is moisture-free, thereby guaranteeing the stable operation of blast furnaces. At the same time, the waste heat from dry quenching of coke can be recovered for power generation; approximately 91,000 tons of standard coal can be recovered annually, generating around 240 million kWh of electricity. Since its establishment, the company has invested over 1 billion yuan in total on more than 30 energy-saving, environmental protection, and green low-carbon projects. These include the construction of fully enclosed industrial material plants, enclosure and covering of coke ovens, upgrading and advanced treatment of coking wastewater, power generation through utilization of waste heat from coke dry quenching, heating powered by waste heat from low-temperature circulating water, refrigeration using industrial waste heat, upgrading of desulfurization and denitrification systems for coke oven flue gas, control of VOCs emissions in the chemical production system, as well as improvements to the plant’s appearance and implementation of the “five modernizations” initiative. As a result, the company has achieved a cumulative energy saving equivalent to 190,000 tons of standard coal. Waste heat recovery: Shanxi Guangda Coking utilizes various equipment and processes in its production to recover waste heat from things such as circulating water, recycled ammonia water from chemical processes, and flue gases from coke ovens. This improves the efficiency of heat utilization and reduces energy losses. Shanxi Everbright Coking utilizes 4 heat pump units to achieve comprehensive utilization of the waste heat from circulating water. By recovering the heat from the cooling water generated in coking processes and feeding it into the urban heating system, 20,000 tons of standard coal worth of waste heat is recovered each year; this represents the largest project for the comprehensive utilization of waste heat from circulating water among coking enterprises in China at present. The waste heat from the circulating ammonia water is utilized by using it to cool coke oven gas; as a result, the gas at 650°C–750°C is cooled down to 85°C. During this process, a large amount of the circulating ammonia water evaporates. In summer, the waste heat from the circulating ammonia water can be used to drive a lithium bromide absorption chiller, producing chilled water at 16°C–18°C for use in equipment such as primary coolers, desulfurization pre-coolers, and final coolers. In winter, heat exchangers can be employed to utilize the heat from the circulating ammonia water for heating purposes. This system helps to save 3,000 tons of standard coal per year. By recovering the waste heat from coke oven flue gas, the flue gas at 280°C–300°C is cooled to around 150°C, while low-pressure steam can also be recovered, resulting in annual savings of 23,000 tons of standard coal. Material chain circulation: The coking industry is a typical industry involved in energy processing and conversion. Shanxi Everbright Coking adheres to the goal of building a resource-conserving and environment-friendly enterprise. It fully implements energy conservation and emission reduction projects for green factory construction, applies new energy-saving technologies, processes, and equipment, makes efficient use of primary energy, and fully recycles various types of secondary energy. At present, the purified coke oven gas is first used for residential purposes, and then used to produce methanol; the off-gases from methanol production are utilized to manufacture synthetic ammonia. The ammonia synthesis purge gas is reused for heating coke ovens; the heat generated after coke dry quenching is utilized for power generation to meet production needs. The waste heat from coke oven exhaust gases and raw coal gas is employed for centralized heating in winter or cooling in summer. After advanced treatment, coking wastewater is reused as make-up water in the circulating water system. These distinct characteristics of material chain circulation have essentially enabled the efficient utilization of resources. Reportedly, in 2021, the energy consumption for coke production at Shanxi Everbright Coke and Gas Co., Ltd. was 104.7 kg of standard coal per ton, which is 8.96% better than the advanced standard value ； The energy consumption for methanol production from coke oven gas is 1,133.75 kg of standard coal per ton, which is 12.79% better than the standard advanced value. The energy consumption for producing methanol from coke and coke oven gas decreased to record lows, at 2.9 kilograms of standard coal per ton and 14.25 kilograms of standard coal per ton respectively, compared to the values in 2020.