Application of PSI TFN Membranes in Petrochemical Desulfurization Wastewater Treatment

1. Addition of White Smoke Elimination Membrane Separation Facilities to the Flue Gas System of Shenghong Refining & Chemical's Sulfur Recovery Uni

Project Overview

Location: Lianyungang City, Jiangsu Province
Capacity: 31m³/h
Purpose: Zero Liquid Discharge (ZLD)

Water Source: Ammonium Sulfate Evaporation Condensate + Tertiary Circulating Water
User: Refining Division, Shenghong Refining & Chemical
Commissioning Date: December 2022

Project Information

1. Tertiary Circulating Water
Flow Rate: 15m³/h
Temperature: 50℃
pH=3～8
Ammonium Sulfate and Ammonium Bisulfate Concentration: 0.02–0.8% (wt)

2. Evaporation and Crystallization of Secondary Condensate
Flow Rate: 16m³/h
Temperature: 50℃
pH=3～8
Ammonium Sulfate Content: 0.005–0.2% (wt), Containing Trace Amounts of Ammonia (NH₃), SO₂, Sulfite, Bisulfite, Chloride Ions, etc.

Technical Proposal Result

n Within the water processing capacity of 60-150%, the maximum concentration of ammonium sulfate and ammonium bisulfate remains below 0.5% (wt). The TFN main unit achieves a 40-fold concentration, while combined with wastewater discharge, the total concentrated water entering the evaporator reaches a 20-fold concentration. With maximum influent concentrations of ammonium sulfate and ammonium bisulfite not exceeding 2%, normal operation is guaranteed.
n The maximum concentration of ammonium sulfate in the concentrated water shall not be less than 20% to ensure the normal operation of the equipment.
n The equipment meets the requirements of 1 year maintenance every 3 years and the service life of the equipment is more than 20 years.

Technical Proposal Treatment Process Flow

Application of PSI TFN Membranes in Petrochemical Desulfurization Wastewater Treatment

Core Technology & Advantages

The core of the project is the PSI TFN membrane separation system, which features the following characteristics:

n Optimized multi-layer membrane structure specifically designed for challenging ammonium ion removal in ammonium sulfate solutions, ensuring optimal sulfate retention efficiency;
n High flux performance, achieving higher water production without increasing operating pressure;
n Chemical cleaning resistance, with a broad pH cleaning range (pH 1–13), effectively removing inorganic scaling, organic foulants, and microbial contaminants;
n Fully automated and precision manufacturing technology, incorporating an advanced design with shortened membrane leaf length and increased leaf count, reducing overall fouling potential and maximizing membrane efficiency.

2. Installation of Skid-Mounted Membrane Separation Unit for Evaporation Condensate Treatment in the Ammonium Sulfate Plant of Zhongke Refining & Chemical

The custom-developed NF98-SPEC-8040 specialty nanofiltration membrane has successfully replaced imported membrane, achieving efficient separation of ammonium sulfate wastewater in the petrochemical industry. It enables purified water reuse and high-concentration enrichment of ammonium sulfate brine.

Project Overview

Location: Zhanjiang City, Guangdong Province
Water Source: Ammonium Sulfate Evaporation Condensate
Capacity: 20m³/h
User: Refining Department III, Zhongke Refining & Chemical
Purpose: Reuse of Evaporation Condensate Water
Commissioning Date: July 2022

Project Information

The raw feed liquid to be treated in this project is ammonium sulfate evaporation condensate from ammonia-based desulfurization units. It exhibits high ammonia nitrogen content, strong acidity, and elevated temperature. The key design parameters for feeding into the skid-mounted system are listed in the right table.

Medium		Evaporation Condensat
Treatment Capacity	m³/h	25
Inlet Temperature	℃	＜80
Operating Pressure	MPa	＜2.5
pH	-	2～5
Ammonia Nitrogen	mg/L	＜2000
Suspended Solids	mg/L	＜50
Conductivity	μS/cm	＜12000
Permeate Ratio	-	80%
Concentrate Ratio	-	20%
Piping & Flange Standards		SH/T 3405, SH/T 3406

NO.	Item	Value
1	pH	6.5～9.0
2	COD, mg/L	＜60
3	BOD, mg/L	＜10
4	Ammonia Nitrogen, mg/L	＜10
5	Suspended Solids (SS), mg/L	＜30
6	Turbidity, NTU	＜10
7	Sulfide Ion, mg/L	＜0.1
8	Petroleum Substances, mg/L	＜2.0
9	Volatile Phenols, mg/L	＜0.5
10	Calcium Hardness (as CaCO₃), mg/L	50-300
11	Total Alkalinity (as CaCO₃), mg/L	50-300
12	Chloride Ion, mg/L	＜30
13	Sulfate Ion, mg/L	＜50
14	Iron, mg/L	＜0.5
15	Conductivity, μS/cm	＜100

Technical Results

Under the condition that the raw water meets the designed inlet requirements, the purified water shall comply with the China Petrochemical Corporation Enterprise Standard Q/SH 0628.2-2014 for make-up water quality. Additionally, the outlet pressure shall be no less than 0.6 MPa(g), and the temperature shall be below 40°C. Specific indicators are listed in the above table.
Within 60-110% of the designed operational range, the purified water quality shall meet the Sinopec Q/SH 0628.2-2014 make-up water standard, with a recovery rate of no less than 80%.

n The equipment shall require maintenance only once every 4 years, with a service life exceeding 15 years.
n The system must support continuous operation for 4 years. For membrane treatment facilities incapable of continuous operation, a one-in-operation-and-one-standby.