Investing in expensive equipment as you set up any large-scale facility can be a nerve wracking process. When it’s a state-of-the-art oil refining plant you have in mind, with sky high regulatory standards which are strictly implemented in sanitary industries, the pressure is even higher. But we don’t want you to feel like you’re being squeezed through an oil press machine; this blog article will help take some of the pressure off as you embark on your journey of understanding the soybean oil refining process, the steps that are involved in setting up a soybean oil refinery, and the things you should keep in mind before you zero in on degumming equipment, bleachers or deodourizers.
An overview of the soybean oil refining process
When oil is extracted from soybean via a combination of mechanical extraction using an expeller press and solvent extraction using an oil extractor machine, the end product of the process is soybean oil. But this oil is hardly edible. It still has a number of impurities in it which need to be eliminated via the soybean oil refinery process before a consumable product can be packaged and sold to consumers.
In general, oils are refined using chemical processes, physical processes or a combination of the two to remove impurities. For soybean oil in particular, the refining process involves degumming to eliminate gums or phosphatides (which soybean oil contains in large amounts), alkali neutralisation or alkali refining to remove free fatty acids (or FFAs), bleaching to remove unwanted colours, and deodourisation - you got it right - to eliminate undesirable smells imparted by odoriferous substances.
First things first: the need to remove phosphatides or phospholipids, from which different grades of lecithin are produced. Soybean oil is one of the primary sources of commercial phospholipids and given Kumar’s focus on sustainability, we prioritise not only good quality oil, but also as high as possible a yield of secondary substances which serve other industries.
To achieve this first step, we rely on degumming equipment. The raw extracted soybean oil is mixed with water and phosphoric acid and put through a calibrated dosing pump. The slightly high temperature results in the gums precipitating out of the mixture. A high-speed centrifuge does its magic next, separating the phospholipids from the soybean oil. The phospholipids still have a high water content, so they journey to another piece of equipment where the water is removed under high temperature vacuum conditions, giving rise to liquid lecithin.
Meanwhile, the oil makes its way to the next step in the soybean oil refining process. The degummed oil is mixed with an NaOH, or sodium hydroxide, solution in a particular amount and at a particular concentration using a dosing pump. As the addition of this alkaline solution suggests, this is the alkali refining process. The addition of this solution neutralises the FFAs to produce a more water-soluble soap precipitate, which is again separated using a centrifuge. While the soap stock progresses to other reactors to make acid oil or soap, the oil may go through one or more high-speed centrifuges again - you can never be too careful when it comes to eliminating impurities and producing good quality alkali-free oil.
Subsequently, bleaching takes place with the help of bleaching earth, activated carbon, heat and filters. Finally, the last step - deodorization - is carried out using sparging steam in a system which allows for maximum contact between super-heated steam and the oil. This final refined product is cooled before it is packaged, ready to make its way to its end consumers.
Choosing the right equipment for your soybean oil refinery
We’re sure your job is already fairly complex; we don’t want to add to that complexity. Keeping some fundamentals in mind will help you make good decisions as you search for the right soybean oil refinery plant for your business. In the spirit of keeping things simple, let’s see how we can balance efficiency, quality, and sustainability as we assess the merits of the different components of soybean oil refinery equipment.
Efficiency
As a busy professional, you certainly have a lot on your plate already. Getting involved in the nitty-gritties of each piece of equipment and their maintenance requirements is not something you should have to involve yourself in on a regular basis. This is why you should invest in durable and efficient soybean oil refining machines.
This may mean different things for different parts of the refining process. For the degumming step, seek out equipment with optimum hydration time for the highest possible level of precipitation of gums. Prioritise efficient design - usually a dish and doughnut design - with mechanical agitation which can save you energy and reduce the rate of wear and tear. A high shear mixer which ensures effective acid solution-oil mixing is just a cherry on the cake.
When it comes to a bleacher, an efficient machine is likely one which occupies as little space as possible, thereby reducing your CAPEX costs and providing you with more free space to work around it. This also makes it easier to access for routine cleaning and maintenance. An efficient deodorizer, meanwhile, typically guarantees uniform sparging steam and uniform vacuum in each compartment, improved stripping effect at low steam consumption, and sufficient retention time.
Ultimately, like all Kumar equipment, you want your machines to be durable, have a long service life, and cause no headaches when it comes to maintenance or repair of wear and tear.
Quality
When assessing the quality of a soybean oil refinery plant, look out for indications of not only good quality material of construction of the equipment, but also for indications that the oil you will get at the end of the soybean oil refinery process will be of the highest possible quality.
You can predict equipment quality through a number of features. For instance, completely static equipment ensures zero wear parts; this minimises your maintenance inventory. In bleachers, intelligently designed large-size pumps which can produce intensive agitation are great to have.
As for product quality - you cannot compromise, given the fact that the soybean oil refinery process is intended to produce an edible product which can have health impacts on consumers. Rely only on soybean oil refining partners who assure high quality oil with good stability and superior performance.
Sustainability
The planet we live on is warming rapidly. To prevent catastrophic effects on human and environmental health, there is no way around prioritising sustainability in every single thing we do. At Kumar, we focus on waste-as-resource, sending byproducts from our oil extraction and oil refining processes to the industries where they are useful.
Even in the operation of the equipment we manufacture, we try to minimise our environmental impact. Our degumming equipment requires relatively low water and energy consumption. In our bleachers, like the Ecopure Bleacher, the ultra-efficient agitation system reduces power consumption; in the Stable Bleacher, utility consumption is lowered by the absence of a gearbox and motor.
Equipment with durable construction, such as with special steel alloy, and specially treated parts are likely to last longer, making investing in them more sustainable, both economically and environmentally. Further, machines involved in the soybean oil refinery process which have long service lives and minimal maintenance (ideally with an AMC) and wear and tear parts are crucial to guaranteeing the long-term success of your operations. At the end of the day, when equipping your soybean oil refinery plant, efficiency, quality and sustainability are key.
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Since 1939, Kumar has been delivering dependable process engineering solutions to the oils and fats industry. We're known for our robustly engineered, versatile, and operationally profitable plant and machinery. It's why customers all over the world depend on us to solve their processing challenges, big or small. If you'd like to know more about our solutions, please fill out the form below:
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