Читать книгу Agitator Design for Gas-Liquid Fermenters and Bioreactors - Gregory T. Benz - Страница 26

All of the above was for the process conditions chosen at the start. But for some processes, these conditions can also be varied within limits. For example, the back pressure on the vessel can be varied, though there may be an upper limit, such as that required to allow exit of CO₂. But, for example, raising the pressure from 0 to 0.5 bar‐g may reduce agitator power requirements by 15–20%. Operating at a lower temperature increases oxygen solubility, reducing power but also reducing the metabolic processes within the organism. Lowering the peak cell population density can lower OUR but because the production rate will also be lowered, more total volumetric capacity will be required, albeit with a lower total power input. This is a classic case of capex vs opex. So, there are many potential options here.