What is microchannel continuous flow reactor?

Microchannel continuous flow reactor is a new type of reaction device based on microscale channel structure to achieve "continuous" chemical reactions. Its core is to replace traditional batch reactors (such as flasks and reaction tanks) with channel networks with sizes in the micrometer range (usually 10-1000 μ m), allowing reactants to complete mixing, mass transfer, heat transfer, and reaction in a continuous flow process.

1、 Core working principle

The traditional batch reaction is "batch feeding static reaction one-time discharge", while the core logic of microchannel continuous flow reactor is "continuous material input, continuous reaction, and continuous product output". The specific process can be divided into three steps:

1）. Material transportation: Two or more reaction materials are continuously injected into the feed channel of the reactor through precision pumps (such as plunger pumps, peristaltic pumps) in precise proportions and flow rates;

2）. Microscale reaction: The raw materials are rapidly mixed in micrometer level channels (due to the small channel size and short diffusion distance, the mixing time can be shortened to milliseconds), and undergo set temperature and pressure conditions in the channel. As the material continues to flow, the reaction is gradually completed;

3）. Product collection: The reacted material continuously flows out from the reactor outlet and enters subsequent separation, purification, or detection systems (such as chromatography, mass spectrometry).

Its essence is to utilize microscale effects (channel size much smaller than traditional reaction vessels) to enhance the efficiency of "mass transfer" and "heat transfer" in the reaction - this is also its core advantage that distinguishes it from traditional reactors.

2、 Core advantage: Why replace traditional batch reactions?

Compared to traditional batch reactors, the advantages of microchannel continuous flow reactors stem from two major characteristics: "microscale" and "continuous", which can be summarized into five points:

1）. Extremely high mass/heat transfer efficiency

The specific surface area (surface area/volume ratio) of microchannels is much larger than that of traditional reactors (such as a 1L reactor with a specific surface area of about 10 m ²/m ³, while microchannels can reach 10 ⁴ -10 ⁵ m ²/m ³):

Fast heat transfer: It can quickly remove or replenish reaction heat, avoiding local overheating (solving the risk of traditional reaction "flying temperature"), especially suitable for exothermic reactions (such as nitrification and oxidation reactions);

Fast mass transfer: The diffusion distance of the material is short, and the mixing time can be shortened from the traditional minute level to the millisecond level, reducing side reactions (such as avoiding the generation of impurities caused by excessive local raw materials).

2）. Accurate and controllable reaction conditions

Accurate flow rate and ratio: The precision pump controls the raw material flow rate, and the ratio error can be less than 1%, avoiding the "manual weighing deviation" during traditional feeding;

Temperature and pressure stability: The temperature fluctuation in the microchannel can be controlled within ± 0.5 ℃, and the pressure is stable to ensure reaction repeatability (traditional reaction vessels have poor temperature and pressure uniformity and large batch differences).

3）. Significant improvement in safety

The reaction volume within microchannels is extremely small (usually only a few micrometers to a few milliliters per channel), and even in the event of hazardous reactions (such as flammability, explosiveness, and toxicity), the total amount of materials involved in the reaction is extremely small, which can significantly reduce the risk of explosion and leakage - this is one of its core competitiveness in the fields of fine chemicals and pharmaceuticals.

4）. Efficient energy saving and space saving

Continuous production does not require a waiting time of "feeding reaction discharging", and the production efficiency is several times to tens of times higher than that of batch reactions;

The device has a small volume (one microchannel system can replace ten liter reactors), saving workshop space and high heat transfer efficiency, reducing energy consumption.

5）. Easy to enlarge and integrate

The traditional batch reaction process of "small-scale trial → pilot scale → industrialization" is difficult to scale up (the reaction conditions are difficult to match), while microchannel reactors can achieve rapid amplification through "quantity amplification" (i.e. increasing the number of microchannel modules of the same specifications) without changing the core reaction parameters, reducing amplification risks; At the same time, it can integrate modules such as mixing, reaction, separation, and detection to achieve "integrated" production.