Physical refining - Let's get the gums out
Physical refining
In physical refining the free fatty acids are removed by distillation in one stage during deodorizing. This method requires lower investment and is simpler in installation and operation compared to chemical refining. However, crude oils that are refined physically have to be degummed as far as possible because residual gums affect the oil quality during the extensive heat treatment in distillation. For some oil qualities this is only possible to a limited extend. Other oils, i.e. cottonseed or fish oil, are fundamentally not suitable for physical refining.
The crude oils from the crushing plants still contain high amounts of phospholipids. They have to be removed as they harm the oil's storage stability as well as further processing. Some phospholipids can be hydrated (HP), some cannot (NHP). Most of the HPs have already been removed during water degumming. Thus, the degumming stage in physical refining attends to the NHPs. There are myriad of possibilities to engineer a degumming stage, the actual realization usually depends on customer preferences and oil type and quality respectively. In general, we recommend either TOP or cold degumming (aka dewaxing). Why? Read on, please.
TOP degumming
TOP degumming
What is so top about TOP degumming is that it is the only degumming method without waste water.
Feedstock: all oil types that do not contain waxes
What to consider:
Have we mentioned that this is the only degumming method that does not produce waste water? Well, it does incur of course, at least to some extend, but we have set up the process in such a way that the water is constantly recycled.
Benefits:
- No waste water
- No dealing with waste water high on BOD and COD
- Extremely short retention times of only 6 minutes which is perfect for anyone who processes different raw materials
- Oil losses are extremely low or oil yields are very high - depends on how you prefer to look at it
- HPs and NHPs are reliably and effectively removed
- Small footprint - you don't need lots of space to profit from all those benefits
Cold degumming
Cold degumming
Feedstock: for oils that contain waxes: sunflower, olive pomace or corn oil
What to consider:
You can also opt for dry dewaxing, a process that goes without centrifuges. In return you get higher product losses and filter aids. And with them the constant dealing, purchasing and disposal of the same. So either way, you have to invest. The question is only into what.
Benefits:
- Reliable and effective removals of HPs, NHPs and waxes
- No filter aids: no purchasing, no dealing with, no disposal of
