Cradle to Consumer
Identity ID
7e8a8eeb-1a9b-45fa-9a19-e009e67c4142
Materials
Associated ID
2c449ca5-8d68-4110-afbe-c9e91bc4563a
Included activities starts
Included activities ends
Description
This dataset is a market dataset, representing the consumption market of the region; the dataset includes the transport of the product from the gate to the consumer end, and the transport service is calculated according to the transport situation of this product in this region. Mixed C4 is mainly used for MTBE and alkylation feedstock, butadiene extraction, isobutylene utilisation and the downstream C4 deep-processing industrial chain; the dataset contains the main raw and auxiliary materials, energy, waste and atmospheric emissions of the production process, in which the preliminary treatment of wastewater in the auxiliary units and the waste gas treatment process are included within the dataset boundary, and infrastructure such as the manufacture of production equipment and the construction of plant buildings 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 and waste heat recovery; the dataset contains multiple products, allocated by mass.
Activity Description
The production activities of this product include raw material cracking, separation, waste heat recovery and other processes.
Process Description
Mixed C4 is a four-carbon hydrocarbon mixture stream obtained from the steam cracking separation section. It is mainly composed of 1-butene, 2-butene, isobutene, butane and a small amount of butadiene. The composition changes with the raw material structure and separation cutting point. This product is usually a hydrocarbon mixture that can be liquefied under pressure and has high reactivity and multi-path processing value. Mixed C4 is mainly used in MTBE and alkylation raw materials, butadiene extraction, isobutylene utilization and downstream C4 deep processing industry chain.
Time period
2016
2026
Geography
China,Shaanxi
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.