With the world’s population on the rise, people concerned about their impact on the earth are looking for sustainable resources that meet both the world’s household and industrial needs. But can sustainable materials benefit both the environment and our quality of life?
A team of researchers in Nigeria think so—at least when it comes to neem oil.
The team used Minitab Statistical Software to maximize neem oil production in order to meet the demands of a growing population. Their results led to a new process that produces quality neem oil and provides jobs where raw materials are available.
But why neem oil? And while we’re on the subject, what is neem oil?
A fatty-acid extract of Neem tree seeds, neem oil possesses medicinal properties and is used in cosmetics such as soaps, creams, and hair products. The oil also repels insects and is commonly used as a pesticide on organic farms.
The neem oil yield varies from about 25% to 45% of the Neem seed by weight, depending on quality of the seed and the processing method. But even if the same method is used to expel oil, oil concentration will vary from one extraction to the next.
To better understand these variations in oil concentration, the team of researchers created an experiment using Minitab Statistical Software to assess the influence of multiple variables on neem oil production. They applied a statistical technique called design of experiments (DOE) to measure the effect of input variables—impeller speed and contact time—on the percentage yield of oil. For the experiment, the researchers used a two-level factorial design to investigate the effect of the factors on percentage yield of oil. They set each input variable at two levels for two impeller types—a flat blade turbine impeller and a Rushton turbine impeller—and replicated each experiment. The two-level factorial design enabled the team to measure the effects of all possible combinations of the input variables on the neem oil produced. After conducting the experimental runs and analyzing the data using Minitab, the team was able to find optimum input settings to maximize the percentage of neem oil yield.When the team looked at their results using Minitab graphs, they discovered that the maximum predicted yield of neem seed oil was 36.86%, obtained with the flat blade turbine impeller. The Rushton turbine impeller’s best yield under similar conditions was 31.25%.
Using Minitab, the researchers created surface plots to visualize the relationship between the input variables and the response for each impeller type. In the plot below, the predictors Impeller Speed and Contact Time appear on the X-Y axes, and the response variable (Yield) is represented by the smooth surface in the middle.
From the surface plot, the researchers learned that the optimum yield could be obtained from the flat blade turbine impeller when the speed and contact time were operated at their high levels—84 rpm for 40 minutes. Further analysis revealed that the difference in percentage yield from the two impellers could be attributed to the presence of a disc in the Rushton turbine impeller that hindered the rate of oil flow from the Neem seed.
This work has standardized the production of quality neem oil and resulted in smarter decisions when choosing and designing equipment. As a key ingredient in pest management, neem oil provides an alternative to synthetic pesticides and protects crops against disease. Availability of the oil is essential to food production, and its variety of uses improves the quality of life for people worldwide.
Although this project cannot address every concern associated with the world’s growing population, it can provide options for sustainable resources and production jobs where Neem seeds are available. While it’s already known that the cultivation of Neem trees enriches the surrounding area, the results of this project have validated that efficiency in neem oil production can be improved. Moving away from methods that produce smaller amounts of neem oil and reducing the resources necessary for production translate into money that can be invested into expanding operations. Each job created is an opportunity to meet the demands of both commercial and household neem oil use—and the environment will naturally reap the benefits.
This story was adapted from an article published in the August 2013 issue of the International Journal of Applied Science and Technology.
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