Ways of loss for calcium carbide
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In the production of vinyl chloride via the calcium carbide method, what are the pathways for the loss of calcium carbide? In other words, the acetylene gas produced from calcium carbide loses less during transmission. One thing I know is that calcium carbide does not react completely in acetylene generators; what else? This post was last edited by yzhms on 2009-3-3 17:31]
1. Incomplete reaction. 2. Dissolution in water (wet method). 3. Loss due to reaction with moisture during storage. 4. Loss due to slight reaction with sodium hypochlorite (this is merely a personal opinion and cannot be confirmed)
Supplement: 1. Loading and exhaust loss； 2. Hyposodium should be made full use of and not discharged outside; once it is used up, it should go directly into the generator ； 3. Resin replacement in the alkali washing tower, dissolution loss ； 4. The seal area of the water ring pump. ......................... Last edited by shizhiyong001 on 2009-3-25 09:30 ]
We also have a lesson here: gas tank leak. The high consumption of calcium carbide couldn’t be traced for a long time; eventually, it was found that there were several leaks in the gas holder at 55% capacity – oh my god!
Mainly the loss of acetylene, side reactions in the synthesis of vinyl chloride, leaks during polymerization, and spills of dried materials
The weathering of calcium carbide represents the greatest loss; in addition, a low temperature of the generator is also one of the reasons for high calcium carbide consumption
Slag loss, incomplete calcium carbide formation, nitrogen loss, losses due to mixed dehydration and drainage, side reactions in the converter, losses from distillation tails, losses from crude monomer drainage, losses of polymerization crude material and material from sieve heads, losses due to entrainment in centrifugal mother liquor, and losses during the monomer recovery process. This post was last edited by shizhiyong001 on 2009-3-25 09:31.]
Weathering losses, dissolution losses, leaks and drips, incomplete calcium carbide reaction, etc. What’s really more important is to do a good job in management; the PVC we extract from the ditches is measured in tons.
1. Calcium carbide weathering: Maintain an appropriate inventory, keep the environment dry, or cover it with canvas to prevent contact with air. 2. Dissolve in water and discharge along with the slurry or sodium hypochlorite. Keep the generator temperature above 85°C. 3. When the generator displaces the storage hopper during charging, everything discharged can be acetylene gas. It is possible to consider using larger amounts of material per addition (but the equipment capacity must be taken into account). 4. Try to minimize the number of start-up and shutdown cycles, as a large amount of acetylene gas is required during replacement. 5. Reasonably control the particle size of calcium carbide to ensure that the slag discharged from it is free of uncooked material. 6. Pressure swing adsorption units are used for the conversion of vinyl chloride to recover acetylene gas.