6) 精晶干燥，包装称重。
4.3    主要设备生产控制
1) 配料锅：温度计控制终点90℃，取样测酸度。
2) 酰化锅：温度计控制终点135℃。
3) 冷却结晶锅：温度计控制终点20℃。
4) 溶解脱色锅：取样观察色泽。
5) 精馏塔：转子流量计计流量，中和滴定测塔顶酸度≤5%。
6) 外循环蒸发器：转子流量计计进料流量，温度计控制温度，温度低于燃点，压力计控制第二效P=0.266kgf/cm2。
7) 旋风干燥：进口使用XCT-162型热电偶温度计测温度，并用可控硅电压调整器自动调节温度。
 
Design Specification
1 Basis of Design
This design is well based on real data from pharmaceutical factory.
2 Principles of Design
During the design of chemical engineering, the design are required to use advanced technology, reasonable economical cost and proposed treatment of waste water、waste gas and waste solid disposal.
Generally, we need to consider as the followed:
1) The process route must firstly meet the performance and quality requirements of the products.
2) The raw material consumption should be on the reasonable level. The source should be reliable, abundant and the market supply should be unimpeded.
3) The device has a certain scale. It should be conducive to continuous productions, implementing and strengthening the level of automation.
4) Mature and advanced technology and equipment should be used as far as possible.
5) Meet the GMP requirements.
6) Decrease the three wastes emissions as far as possible. The control measures should be used to the waste that have been generated, such as waste water, waste gas, other waste and pollutants.
7) Comprehensive economic indicators are used to measure the process, which requires reasonable and efficient.
3 Technical Introduction
3.1 Product introduction
Acetaminophel, shortly named as APAP, is an ordorless white crystalline powder with slight bitter taste. It’s density is 1.293g/cm3 and m.p. is 169-170.5℃. Acetaminophen can be dissolved in organic solvents such as methanol, acetone, ethyl acetate etc. and hot water, but it can hardly be dissolved in cold water and ethyl ether.
APAP is an antipyretic analgestic with antiphlogistic and antiviral function. Compared with Aspirin, APAP is better in many aspects such as antipyretic effect, side effect etc. It also can be used for synthesizing pharmaceutical.
In recent years, studies on the clinical application of APAP also found a new clinical indications. It has been reported that women suffering from long-term use can greatly reduce the risk of ovarian cancer. Western authoritative medical journal "Lancet" reported that taking APAP for a long term can reduce the incidence of heart attack or stroke because APAP is an excellent antioxidant, which can resist free radical damage in the body. Thereby, it promote the sales of APAP preparation in the world pharmaceutical market to grow steadily.
3.2 Synthesis of paracetamol
There are many ways to synthetize the paracetamol. One-step and two-step are the main method. The traditional two-step method is to use nitrophenol (PNP) and other raw materials to reduce aminophenol (PAP), then acylated APAP. One-step is directly acylated APAP by the reduction product PAP without isolation in the same reactor. It is a synthetic route that doing reduction and acylate simultaneously. Furthermore, there are other synthesis methods of APAP, such as rearrangement, biochemical synthesis routes and so on.
Now in China the one-step synthesis with iron powder as a reductant has been adopted, but the cost is high and the iron pollution is hard to treat. In recent years, developed country use the hydrogenation process, especially catalytic hydrogenation and one-step synthesis, to replace the iron powder reduction. The one-step synthesis does not need to separate PAP intermediate, shortens the craft route and reduces the oxidation of PAP. Also it needs fewer procedure, saves the energy and reduces the pollution. 扑热息痛生产工艺设计+CAD图纸(2):http://www.751com.cn/yixue/lunwen_8971.html