Cradle to Gate
Identity ID
115079d0-7cbc-44fa-ba54-957f04537d4c
Materials
Associated ID
277cbcbb-af70-47ce-814a-4670e1878de1
Included activities starts
Included activities ends
Description
Sodium hydrosulfide is commonly used in fields such as chemical synthesis, mineral processing, leather making, wastewater treatment, paper and fertiliser production. Sodium hydrosulfide is modelled as a pure substance; when modelling this substance the user needs to add a solvent of their choice in the model; the dataset contains the main raw and auxiliary materials, energy, waste and atmospheric emissions of the production process, in which the waste gas treatment process is 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 raw material preparation, chemical reaction, neutralisation and purification, concentration and crystallisation, and drying.
Activity Description
The production activities of this product include raw material preparation, chemical reaction, filtration and impurity removal, concentration and crystallization, drying and other processes.
Process Description
Sodium hydrosulfide has the chemical formula NaHS and CAS number 16721-80-5. Industrial-grade material is generally supplied as pale-yellow to brown crystals or a molten solid with a pungent hydrogen sulfide odor. It is hygroscopic, readily soluble in water and ethanol at ambient temperature, and forms a strongly alkaline aqueous solution. It is chemically reactive, decomposes on contact with acids to release highly toxic hydrogen sulfide gas, decomposes when heated, and acts as a reducing agent. It also reacts with heavy-metal ions to form metal sulfide precipitates. It is mainly used in chemical synthesis and mineral processing as a flotation reagent for sulfide ores. Other applications include depilation in leather processing, removal of heavy metals from wastewater, pulping aids in the paper industry, and desulfurization in fertilizer production.
Time period
2024
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The alkali sulfide method is the mainstream technology for sodium hydrosulfide production, in which hydrogen sulfide is absorbed by a sodium sulfide solution. This process is simple and offers controllable product concentration, accounting for more than 90% of the total sodium hydrosulfide production in the country. This dataset represents the mainstream technology: using sodium sulfide aqueous solution and hydrogen sulfide gas as raw materials. First, a sodium sulfide aqueous solution is prepared by dissolving solid sodium sulfide in water to achieve a desired concentration. Then, in a reaction kettle at room temperature or low temperature, hydrogen sulfide gas is introduced into the sodium sulfide aqueous solution to react and produce sodium hydrosulfide. After the reaction is complete, the solution undergoes settling and filtration to remove impurities. Subsequently, the solid sodium hydrosulfide product is obtained through steps including evaporation and concentration, cooling crystallization, centrifugation, and drying. The main chemical reaction equation is: Na₂S + H₂S → 2NaHS.