**Case Study**
Desulfurization Wastewater Treatment with Low-Temperature Evaporator Crystallizer in Chongqing
**Project Overview**
The largest natural gas production and supply enterprise in the southwest region.
**Project Disposal Pain Points**
The proportion of sour gas containing sulfur in the gas extracted by the client exceeds 15%. Using the Cansolv tail gas treatment process can effectively absorb SO2. However, the absorption of SO2 generates high-salt organic wastewater, which is characterized by high salt concentration, high organic matter concentration, difficulty in degradation, and high color.
**WSD Environmental Solution**
In order to better achieve the reduction and resource utilization of desulfurization wastewater, after a series of process comparisons, the client ultimately chose the WSD low-temperature evaporator crystallizer. After the waste liquid is injected into the low-temperature evaporator crystallizer, steam is automatically introduced, and the distillation tank is heated using steam as the heat source in the jacket. Under vacuum conditions, the boiling point of water is lowered, and the waste liquid in the evaporation kettle is continuously concentrated. The water vapor is filtered and enters the condenser for recovery and output. The internal scraper automatically reverses to prevent scaling/coking. The residual moisture content after disposal is ≤15%, in solid form, with no fluidity, automatically discharged and disposed of externally.
△ Site of WSD Low-Temperature Evaporator Crystallizer
**Disposal Effect**
The WSD low-temperature evaporator crystallizer LT-ZQ-500 helps the client neutralize salt-containing wastewater from the Cansolv process for purifying 10m³ of natural gas per day, reducing wastewater concentration by 95%-98%.
– The pH value of the produced water is between 6 and 9, meeting the requirements for entry into the biochemical pool and external discharge (pH 6-9).
– The concentration of sulfite + sulfate ions in the produced water is <10mg/L, meeting the requirements for entry into the biochemical pool treatment or external discharge water index.
– The COD of the produced water is <40mg/L, meeting the requirements for entry into the biochemical pool and external discharge (COD ≤ 100mg/L).
– The produced water is a clear liquid with no color or pungent odor. Through analysis and comparison, the produced water meets the standards for entry into the biochemical pool treatment and external discharge.
**Comprehensive Benefits**
The WSD low-temperature evaporator crystallizer effectively solves the client’s desulfurization wastewater problem in the Cansolv process, and also has significant implications for local environmental protection, water conservation, and sustainable development.