Compatibility between Characteristics of Organic Solvents and Equipment Selection

DMF (Dimethylformamide) :It has strong polarity and high dissolving power, and is stable at room temperature. However, it can cause swelling to some elastomers. Sealing parts and pipelines made of PTFE (Polytetrafluoroethylene) orPFA (Perfluoroalkoxy) should be selected. 
DCM (Dichloromethane) :It has a low boiling point (40℃) , is volatile, has certain corrosiveness, and its vapor density is greater than that of air. The equipment needs to have an explosion-proof design. Pipeline joints need to be tightly sealed, and 316L stainless steel or PTFE is preferred as the material. 
MeOH (Methanol) :It is volatile and flammable. Explosion -proof pumps and valves should be used, and it is compatible with materials such as aluminum alloy (copper-based components should be avoided to prevent corrosion by methanol oxidation products) . 
PIPE (Piperazine-N, N'-bis (2-ethanesulfonic acid) ) :It is alkaline and volatile, and has certain corrosiveness to metals. Sealing parts need to be alkali-resistant (such as EPDM or PTFE) , and carbon steel equipment should be avoided. 

Flow and metering control

Give priority to selecting pneumatic diaphragm pumps, using the combination of "pump+ high-precision flow meter+pneumatic valve" ;

Choose mass flow meters ortube float flow meters as flow meters;

The feed metering needs to integrate an online weighing module. Forexample, install a high- precision weighing sensor (with an accuracy of 0.1g) at the bottom of the batching tank to achieve dual control of "volume metering+weight calibration".

Liquid Preparation Unit for Synthesis Reaction Kettle and Activation System

The synthesis reaction kettle adopts a closed liquid-preparing tank with stirring (made of 316L stainless steel, and the inner wall is electropolished to reduce wall -sticking). It is equipped with a jacket for temperature control (maintained at 20-25℃ through the TCU temperature self-control system to avoid volume changes of solvents such as DMF caused by temperature fluctuations). The liquid -preparing process requires nitrogen protection. Anchor-type or propeller-type stirring paddles are selected, and a filter plate structure is set at the bottom of the kettle to achieve online dead-corner-free filtration.
In the activation reaction unit, the activation reaction of amino acids and activators needs to be carried out in a low -temperature environment. Therefore, the activation tank needs to be connected to a low -temperature TCU. After activation,it passes through an online filter.

Nitrogen replacement and protection

All solvent storage tanks,liquid-preparation tanks, and reaction units need to be connected to the nitrogen system. The slightly positive pressure inside the tanks is controlled by pressure sensors to prevent air from entering. Before solvent transportation, the pipelines need to be purged with nitrogen,and the purging time is set according to the pipeline volume.

Online Cleaning CIP System

Design a fixed cleaning loop that covers the liquid-preparation tank,activation tank, transportation pipelines, and valves. Use cleaning agents in sequence: DCM (to remove organic residues)→ MeOH (to rinse DCM)→ purified water (to rinse methanol) →compressed air for drying. The cleaning pump needs to have a high flow rate (3-5m³/h), and the spray head should be of the rotary type (to ensure no cleaning dead -corners in the tank). During the cleaning process, monitor the water quality at the outlet with a conductivity meter (a conductivity of≤1μS/cm is regarded as a qualified cleaning result).

Process automation control requirements

Through the PLC system,the entire process of "organic solvent transportation -liquid preparation -activation transportation -synthesis reaction kettle and material collection -cleaning -recovery" can be linked, reducing human intervention and being traceable. Key parameters (such as flow rate,temperature,pressure,and weighing data) need to be recorded and stored in real-time (meeting GMP data integrity requirements), supporting historical queries and audit trails. This ensures that when the synthetic batching module processes organic solvents, it not only meets the high -precision requirements of polypeptide synthesis but also complies with safety production and environmental protection requirements, providing a reliable guarantee for the efficiency and purity of subsequent peptide chain synthesis.