Palm Oil: Better with Enzymes

Hong Wai Onn explains how enzyme technology could make the industry greener and more efficient

GIVEN the extensive list of challenges currently facing the world, some of which are food supply, energy, and the environment, there is a limited number of engineers readily available to address these challenges. So where could chemical engineering talent best be deployed?

One noteworthy option is the palm oil industry. This is an opportunity for chemical engineers for three main reasons. First, palm oil involves the kind of technologies that chemical engineers have a solid understanding in, especially in terms of heat transfer, thermodynamics, mass transfer, and separation processes. Second, the Food and Agriculture Organization of the United Nations projects world population to reach 9.1bn people – an increase of 33% – between 2009 and 2050.¹ This means that demand for food, including vegetable oils, is expected to continue to grow accordingly. Third, palm oil is by far the most productive vegetable crop, outdoing all others in terms of average oil yield per hectare (see Figure 1). Worldwide, palm oil is an important resource and the most-commonly used vegetable oil. According to the United States Department of Agriculture, palm oil accounts for about one-third of food use in 2018/19² and can be found in 50% of all supermarket products. The question is, therefore, how can chemical engineers contribute to producing enough palm oil to satisfy the global demand, and make it a better industry?

Can the World Produce Enough Palm Oil to Satisfy Global Demand?

Indonesia and Malaysia account for approximately 84% of the world’s total production of palm oil. However, due to the combination of existing and expected new moratoriums, along with palm oil buyers’ “no deforestation, no peatland, no exploitation” policies, land expansion could be at the bottom of the list of priorities for both countries’ palm oil industry. Given this land scarcity, it is pivotal to explore how new technology can further improve palm oil milling operations and yields.

While it is justified to claim that there were many incremental improvements and changes in various unit operations in the palm oil mills, they have not changed significantly since the publication of the Mongana report in the 1950s. The palm oil mills still rely heavily on sterilisers, threshers, digesters, screw presses, clarifier tanks and centrifuges or separators. Large quantities of steam and water are required to sterilise fresh fruit bunches (FFBs), digest palm fruits, and dilute press liquor for oil recovery in the clarification process. Oil extraction rate (OER) is the key performance indicator for palm oil mills. OER is a ratio of crude palm oil produced to FFB processed. As chemical engineers, let’s ask ourselves the question: can the existing thermo-mechanical extraction process continue to remain as it is for the next 100 years, whilst still satisfying the growing demand for palm oil? If the answer is no, then we ought to rejuvenate our minds in a proactive and creative manner to assist the palm oil milling sector in improving output and bottom lines.

Where are we in palm oil milling?

In traditional palm oil milling, the FFBs are steam sterilised and digested before mechanically extracting the oil. The main objective of these processes is to break up the oil-bearing cells to facilitate better oil release. The traditional thermo-mechanical extraction process is, however, reaching its limit, which explains why the oil extraction rate has remained stagnant for many years, with a gentle declining trend in recent years (see Figure 2). Biotechnology, ie enzymatic technology can help oil mill operators overcome this problem, due to the ability of enzymes to effectively break down plant cell walls. Hence, enzymes could be the next big operational breakthrough for the palm oil milling sector.

Chemical engineers will know that enzymes are proteins that act as catalysts. They are highly specific, allowing specific reactions and acting on specific substrates. They are fully biodegradable, breaking down into harmless amino acids. And while enzymes may be new to the palm oil milling industry, the technology has been proven and well established in many other industries for a long time. This entails industries such as chemical synthesis, where enzymes have been used to replace chemical catalysts in synthetic processes. Recently, enzyme use has gained momentum in the chemical and pharmaceutical industries, and it is an important tool for medicinal, process and polymer chemists to develop efficient and highly attractive organic synthetic processes on an industrial scale. For example, Pfizer has developed a biocatalytic process to boost the efficiency of its production of the epilepsy drug Pregabalin.³

Enzymatic palm oil extraction process: A boon

Applied to the palm oil industry, enzymes could aid several upstream as well as downstream processes and become a game-changing technology that benefits palm oil mills and addresses many of the challenges the industry faces today, particularly in the palm oil extraction process.

Novozymes is currently trialling its enzyme and claims to have several ongoing enzymatic palm oil extraction trials as well as full-scale mill operations across Indonesia and Malaysia,⁴ including with Sime Darby Plantation, the world’s largest palm oil plantation company by planted area.⁵

This enzymatic process can be adopted via just a few steps and reasonable capital investment and with significant improvement to the bottom line.⁴ Applied under the right conditions, the enzymes soften and break down the cellulose and hemicellulose matrices in the oil-bearing cell walls, thereby enabling easier oil release. One of the full-scale mill operations with enzymatic palm oil extraction process is recording 4% oil yield increases.⁵ If we assumed the entire Malaysian palm oil industry adopted enzymatic technology, an extra 0.8m t of crude palm oil (CPO) could be obtained with the same amount of land, which in turn would feed the entire population of Malaysia (31.6m) for nearly 11 months.⁶

Sustainability-wise, enzymatic palm oil extraction processes could enable a 9% reduction in greenhouse gas emissions, alongside 4% lower nature occupation impact, per tonne of crude palm oil produced, according to a peer-reviewed life cycle assessment study.⁷

It is also important to note that there is no evidence on the change of CPO quality following the adoption of the enzymatic palm oil extraction process. Results obtained from full-scale mill operations indicate that enzymatic technology does not affect the quality of the oil extracted and that the CPO quality is not significantly different from conventional milling operation.