Our customers have many applications with chemical reactions that are conducted at high pressures. These applications frequently require precise gas dosing. You can replace organic solvents with more effective alternatives, like liquefied gases.
What is Liquefied Gas Dosing?
It is a gas at atmospheric pressure and room temperature turned into a liquid by cooling or compression. An example of this is liquefied carbon dioxide (CO2) which is an excellent extraction solvent for non-polar chemical compounds.
There are obstacles when using liquefied gas, such as difficulty in handling these liquid/gas substances and lack of dosing precision. Bronkhorst has taken note of these obstacles and worked on a solution.
Requirements for Precise Liquefied Gas Dosing
The liquefied gases need to be dosed in the liquefied state for the application which operates at high pressure. To provide accurate dosing of these gases the process conditions must be precise so that the liquid gas will not be out gassed.
Considerations for Evaporative Gas Dosing System
- Avoid out gassing liquids
- Dosing at high pressures
- Accurate measurement of dosed liquid with low flows
Best Controlled Evaporative System
Our partners at Bronkhorst engineered a solution carefully considering the requirements of the application. The process solution for this dosing application consists of a WADose HP Lite pump with an attached heat exchanger, combined with a Bronkhorst Coriolis Mass Flow and an EL-PRESS pressure meter. The heat exchanger cools the pump to below freezing temperature to stimulate liquid forming and prevent outgassing. This provides steady pressure and prevents an unsteady liquid flow when dosing chemical compounds.
The combination of the WADose piston pump and the Coriolis allows accurate dosing of the liquefied gases. When stand-alone piston pumps are used, they are not sealed airtight and may exhibit wear over time. Their set point may deviate from the amount of chemical compound dosed. This is even more prevalent when dosing low flows in the range of ml/min. With this Bronkhorst solution, the dosed quantity is measured accurately in-situ using the Coriolis mass flow controller. This controls the pump by adjusting the flow. This self-monitoring system works continuously controlling the supply of liquefied gases ensuring necessary precision.