Introduction
In the edible oils industry, hydrogenation is a fat modification process which transforms the physical characteristics of natural oils and fats, lending them improved texture and stability. The chemical reaction involves the addition of hydrogen to natural oils and/or fats in the presence of a nickel catalyst. The hydrogen gets attached to the carbon-carbon double bonds in the fatty acid chains, transforming its physical properties.
A hydrogenation reactor can be batch type, semi-continuous or continuous.
This process isn't unique to the edible oils industry. It can be batch type, semi-continuous or continuous, depending on the product requirement for food-grade application. Batch-type or semi-continuous hydrogenation process are preferable, and for the non-edible application and large capacity continuous hydrogenation process is more economical.
Regardless of industry and application, hydrogenation reactors typically comprise a robust container and a high-pressure pump. The pump is used to inject hydrogen gas into the container, within which the pressure gradually increases. When the internal environment in the container reaches a certain gaseous pressure, the desired chemical reaction occurs inside, producing new compounds as a result of the hydrogenation process.
In the plant- and animal-based oils and fats, hydrogenation systems are an important part of the hydrotreated vegetable oil (HVO) production process. This process includes the reaction of waste cooking oils, animal fat, or other natural oils and fats with hydrogen (in the presence of a catalyst) to produce a renewable fuel.
Types of hydrogenation reactor equipment
Like with any other industrial project that requires a high CAPEX, selecting the right equipment is of utmost importance. Choosing the right equipment can do wonders for your operations - it can ensure efficient resource use, produce high-quality products, and promise the long-term health and profitability of your operations. Making a poor decision, on the other hand, can cost you in terms of time, money, and energy.
Selecting the right high-pressure hydrogenation reactors is no different.
But before we get into how you can choose the right hydrogenation reactor equipment, let's take a look at the basic types of hydrogenation reactions and hydrogenation systems:
Types of hydrogenation processes: Based on the application and the end product requirement or types of hydrogenation like fully or partial. Hydrogenation process can be divided into three categories i.e
- batch process: preferred in the small scale edible oil industry.
- semi-continuous process: preferred for large scale edible and non-edible oil industry.
- fully continuous process: non edible or oleochemicals industry for large scale production
Types of hydrogenation systems: Once you've chosen your preferred choice of processing type, you can narrow down the type of hydrogenation reactor equipment you need.
Batch hydrogenation can be carried out in either an agitator reactor or a loop reactor.
Agitator-type hydrogenation systems involve the mixing of oils or fats, hydrogen gas, and the catalyst in an autoclave, which is a pressurized vessel. A special sparger may be located at the bottom of the autoclave to introduce the hydrogen gas into the system.
Meanwhile, loop-type hydrogenation reactors include a venturi loop within which the reactants and catalyst are mixed. This hydrogenation system includes vigorous circulation of the reactants through the loop, resulting in a high-speed spontaneous reaction. These systems also use a candle filter to separate the catalyst from the products of the reaction.
Both agitator and loop reactors can also be used for semi-continuous hydrogenation, but the semi-continuous process would require appropriate mechanisms for feeding and discharge.
Finally, for continuous processing, you need continuous hydrogenation reactors which are single towers where the oil or fatty acid is mixed with the chosen catalyst. The tower has a high flow rate of hydrogen gas. This gas is supplied from one end of the tower, while the hydrogenated material is continuously discharged from the other end.
How to choose the right hydrogenation reactor equipment
When working with hydrogenation reactor manufacturers to choose the right systems for your operations, there are some important factors to consider. These not only include product specifications but also your own production requirements.
Material selection and equipment design. Since hydrogenation is a high-pressure, high-temperature reaction, the reactors made for this process must be able to withstand these conditions. Your hydrogenation reactor's material of construction must be durable, corrosion-resistant, pressure-resistant, and heat-resistant.
Further, the design of the reactor should allow you to adjust the speed, pressure, and temperature of the reaction with ease. This includes an easy-to-operate interface. Some hydrogenation reactor equipment also includes stirring systems to facilitate the uniform mixing of reactants. Design features such as these not only make operations easier but also improve reaction efficiency and product purity.
Safety mechanisms. Hydrogenation reactors are high-pressure systems, and like all pressurized vessels, they pose risks to the safety of those around them. The right hydrogenation reactor equipment will have safety measures like leakage alarm systems, explosion-proof devices, and other mechanisms to ensure that your personnel and infrastructure remain safe. It will also comply with the relevant ASME safety codes for pressure vessels.
Your desired plant capacity. Before you can zero in on a hydrogenation reactor, you need to have clarity about the scale of your operations. This will influence not only the size or capacity of the equipment you invest in; it will also influence the type of process and machine you choose. For instance, batch hydrogenation is ideal for small-capacity plants. Meanwhile, tower-type continuous hydrogenation reactors are typically preferred for large-capacity plants.
It doesn't end there. The volume of your hydrogenation reactor will also depend on the properties of your reacting substances and of the reaction itself. A hydrogenation reactor that is too small or too large can affect the progress of the reaction. So make sure your hydrogenation reactor manufacturer is clued in on your specific process requirements.
Desired level of automation. As the edible oils industry evolves, some manufacturers of oil-based products prefer to minimise the amount of manual labour in their plant to prevent errors and accidents. If you wish to have a completely automated hydrogenation process in your plant, you must get a tower-type reactor because only continuous hydrogenation supports full automation.
Your reaction requirements. Some hydrogenation applications call for a slow, selective process, while others may require full hydrogenation with low residence time. If you need the former, you should opt for agitator-type autoclaves. For the latter, loop-type reactors are a better choice.
Resource use. Given its high-temperature, high-pressure nature, the hydrogenation reaction is very energy-intensive. Since it can already be a high-CAPEX project, it is in your best interests to make efficient use of your resources. This includes which types of reactors you choose.
Batch hydrogenation minimizes nickel catalyst consumption. Semi-continuous hydrogenation reduces power consumption and steam consumption when the system provides regenerative heating and cooling. Meanwhile, in continuous hydrogenation, excess hydrogen is compressed and reused. You should consult with your hydrogenation reactor manufacturer and choose the plant setup that will ensure the most efficient utilization of your resources.
With more than eight decades in the industry, we, at Kumar, are industry veterans, complementing our deep expertise in the edible oils process engineering industry with our vast experience. We're committed to developing the right solutions for you. If you're on the hunt for a hydrogenation reactor or for turnkey solutions in the oleochemicals industry, reach out to our expert team today.
