Cradle to Gate
Identity ID
26c5c2b7-cbda-4412-a3d4-4472807ee49d
Materials
Associated ID
2c449ca5-8d68-4110-afbe-c9e91bc4563a
Included activities starts
Included activities ends
Description
Medium pressure steam is mainly used in scenarios such as process heating, reboiling of column bottoms, heat tracing and insulation, and equipment preheating; it is an important carrier for heat integration and energy cascade utilization in chemical plants. The dataset includes the main raw and auxiliary materials, energy, wastes and atmospheric emissions of the production process, in which the preliminary treatment of wastewater in the utility/auxiliary processes and the waste-gas treatment process are included within the dataset boundary, while infrastructure such as the manufacture of production equipment and plant construction is not included within the dataset boundary; the data inventory is formed by merging data from multiple sources; the production activities of this product include feedstock cracking, separation, waste-heat recovery and other process steps; the dataset contains multiple products, allocated by mass combined with special rules.
Activity Description
The production activities of this product include raw material cracking, separation, waste heat recovery and other processes.
Process Description
Medium-pressure steam is a thermal energy medium product produced by steam cracking and supporting public works. The main component is water vapor. It is usually delivered at a specified pressure level and temperature level. It has the characteristics of condensable heat release and easy pipeline network transmission and distribution. This product is a colorless gas phase medium that forms liquid water after condensation and can be recycled. Medium-pressure steam is mainly used in process heating, tower kettle reboiling, heat tracing and insulation, and equipment preheating scenarios. It is an important carrier for heat integration and energy cascade utilization of chemical equipment.
Time period
2016
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
This dataset models a feedstock mix of naphtha, propane, and liquefied petroleum gas. At 800-900°C in a cracking furnace, longer-chain saturated hydrocarbons are broken down into shorter unsaturated compounds. The main products include ethylene and propylene, with hydrogen, mixed C4 hydrocarbons, and other co-products. Cracking-unit designs are broadly similar and require only minor modifications for local conditions. Naphtha remains the principal feedstock, although the shares of light components such as propane and butane and liquid feedstocks such as liquefied petroleum gas have increased in recent years. A portion of the by-product fuel gas is used in the cracking furnaces.
1. Cracking: Feedstocks entering the plant are preheated, mixed with dilution steam, and heated before cracking in the radiant section of the furnace. Liquid-feed furnaces use highly selective radiant coils for high-severity cracking, while gas-feed furnaces use multi-pass coils. Cracked gas is sent to the downstream separation section. Both liquid- and gas-feed furnaces are bottom-fired.
2. Separation: Heat is recovered from the cracked gas in a waste-heat boiler, after which the gas serves as stripping medium in the gasoline fractionator. The fractionator bottoms leave the plant as crude fuel oil, while the overhead stream is quenched in a quench-water tower and sent to compression. The demethanizer bottoms are sent to the deethanizer, and the deethanizer overhead enters an acetylene converter, where acetylene is selectively hydrogenated to ethylene and ethane.