Requirements for hydrogen chloride gas in vinyl chloride
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Dear sea friends: What are the specific requirements for vinyl chloride regarding hydrogen chloride gas? What are the specific requirements for CO2?
Requirements for hydrogen chloride, the raw material gas, in the production of polyvinyl chloride: 1. Purity of hydrogen chloride: The purity required at startup is ≥80%, while during normal production it should be ≥94% (this can vary among different manufacturers). 2. Free chlorine in hydrogen chloride: The level of free chlorine must be zero. 3. Water content in hydrogen chloride: The less, the better; no specific requirement is specified. After mixing with acetylene and dehydration, the water content should be less than 60 PPm. 4. Hydrogen chloride pressure: ≥0.06 MPa. 5. Temperature: ≤40℃
Agree with the view on the first floor. But there seems to be no CO2 (our device is used for synthesizing hydrogen chloride)
The analysis on the 2nd floor is good, but since the production scales of different manufacturers vary, the hydrogen chloride pressure also differs. For plants that produce 200,000 tons of PVC per year, the hydrogen chloride pressure at full capacity should be less than 60 kPa; however, I have seen plants where the mixer pressure is kept around 65 kPa, and their vinyl chloride production volume is likely to exceed 300,000 tons per year. Regarding the issue of carbon dioxide, the hydrogen chloride coming out of the synthesis furnace should contain very little of it, and there are no requirements set for it in the control specifications.
The requirements for our plant’s materials are: hydrogen chloride purity ≥92%, no free chlorine, and oxygen content ≤0.4%. It is particularly important to ensure that there is no free chlorine, as such chemical synthesis can easily lead to explosions; (the HCL production section must strictly control the levels to prevent excess chlorine)
Why can the purity be lower when starting up the process, when it should be ≥80%, while for normal production a purity of ≥94% is required for hydrogen chloride?
When the machine is first started, acetylene flow isn’t available; it doesn’t matter if the HCL purity is a bit low. Another thing to consider is preventing over-chlorination
The hydrochloric acid dissolution method is mainly used for water removal; in the case of direct combination, it is primarily aimed at preventing hyperchlorination, and a purity level between 90-95% is acceptable.