Palm oil and the environment

by Raymond Cheah

The next time you’re out and about in Malaysia, whether on a bike, in a car or in the air, especially when you’re beyond the city limits, take a look around you.  Chances are, you will see palm trees. Rows and rows of them. Sometimes, as far as the eye can see in every direction.  The fruits of this tree are one of the primary drivers of the Malaysian economy.

Palm fruit is rich with natural oil, which, after processing, becomes the cooking oil that we Malaysians use in our daily lives, albeit sometimes a bit too generously.  There is much work put in, of course, to bring the oil from the plantations all the way into our kitchens.

Much has been said about the palm oil industry, and most of the words are not kind.  The fact that many of the oil palm plantations sit on what used to be pristine, virgin jungles doesn’t help.  In addition, the extraction and milling process emits foul smells and thick, black smoke, generates wastewater heavily laden with organic content, and also produces mountains of biomass. Considering this, the detractors may have a case!

Unfairly disparaged or not, the palm oil industry needs to get their act together, but truth be told, many of the palm oil plantations and palm oil mills are slowly but surely changing the way they operate, so as to be more environmentally and ecologically friendly.  Modern methods of planting, harvesting, processing and land management are being introduced into mainstream operations, replacing traditional methods.  Even the smaller players in the industry are looking at ways to self-regulate their processes.

The palm plantation sector has also been looking into ways to better protect the soil.  Among their strategies are   terrace planting on hill slopes and proper planning to minimise soil erosion.  Soil conditioning is also carried out to reduce the application of chemical fertilizers and thereby reducing the amount of chemical runoff into watercourses, which then reduces the risk of polluting groundwater.  These actions, along with many others, have come a long way in reducing the negative impacts of palm oil plantations on the environment.

Palm oil mills have also been doing their part by implementing various programs to reduce environmentally damaging impacts of oil extraction.  The mills require heat to ‘cook’ the raw palm fruits, which mostly comes from low efficiency boilers that emit thick black smoke.  Today, many of the mills have upgraded their boilers as well as placed particles-trapping facilities at the boiler chimneys.

The traditional practice of burning empty fruit bunches, palm fibres and palm kernel shells openly are no longer permitted as another necessary measure to reduce the environmental impact of the milling process.

The main challenge however, is in how liquid waste (palm oil mill effluent – POME) andsolid waste (biomass) is dealt with.  As the terms imply, POME and biomass are essentially waste products of the milling process.  They have no value, and are   foul smelling and detrimental to the environment if they are left to decay on their own.  Here’s where science and technology really comes into picture.

Figure 1 shows that palm oil mill waste may no longer be regarded as waste! Instead, it may be a source of wealth with the right technology, investment and proper management. In fact, all of the products shown above are not based on pipe dreams or the results of pilot projects, but are viable products from the palm oil industry.

What are we going to do with all that Biomass?

The palm oil mills in Malaysia alone contribute more than 80,000 metric tonnes of dry biomass annually [1] (figure taken for year 2010), and this figure will continue to rise in the coming years, with the projected increase in palm oil plantations and mills.  Unless otherwise reused in a productive way, the biomass will end up in landfills, be dumped indiscriminately or otherwise just left to rot in the open, emitting foul smells and worse, methane gas, which is a potent greenhouse gas.

More and more of the palm oil mills are already converting part of, if not all, of their biomass into some form of useful product.  The most common is to convert the biomass into bio-fertilizer, which can be applied onto fields.  The investment into producing bio-fertilizer is relatively low, and the process is easily replicable, making this process almost instantaneous in reducing the impact of leftover palm oil biomass.

Another benefit of the bio-fertilizer is that it enables reduced use of chemical fertilizers in plantations, thus reducing the chances of chemical contamination in runoff water.  The fibrous nature of the bio-fertilizer also helps the soil to be naturally held together, which will reduce erosion. The fiber also helps to retain moisture for the roots of palm trees thereby reducing irrigation water.

Some palm oil mills have taken a step further by extracting the long fibres of the fruit bunches and drying them, which can then be used as a substitute material for mattress and cushion fillings.  This method of extraction and drying has achieved some measure of success, and is highly sought after in China.

Coconut fibres are commonly used as filler material, but with the long palm fibres being made available now, a certain percentage of the filler material can be replaced with palm fibres. This has come a long way to addressing the shortage and seasonal nature of coconut fibres in the world market.

A downstream activity of the palm fibre extraction plant is the compression of the shorter fibres into bio-fuel pellets.  Although the carbon and chlorine content is relatively high, these pellets can be used to partly replace coal in power plants.  Some of these pellets have found their way into Korea and Japan, but with limited success so far.  Still, it wouldn’t be too far-fetched to say that one day, these bio-fuel pellets could replace coal as a main fuel source.

We can’t swim in wastewater!

Well, swimming in the palm oil mill effluent, or POME, would not be the best idea!  POME leaves the mill at close to 80⁰C and contains organic content measured as Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD), usually at around 80,000mg/l and 25,000mg/l respectively.  Only simple microbes and organisms are able to survive the harsh conditions of the wastewater but not too long ago, POME was released directly into rivers and lakes!  Again, this practise has since been banned.

Following its release, POME takes up to three days to cool to room temperature, by which time, the various bacteria and microbes would have completed a major portion of the acetonegesis phase (production of acetate from carbon dioxide), meaning that the next phase, i.e. methanogenesis can commence. Methanogenesis is the phase in which the anaerobic-type bacteria will act on the organic content in the wastewater to reduce the organic content, at the cost of releasing methane gas and carbon dioxide into the atmosphere.

Since the methane and carbon dioxide is produced biologically, the common term used for these gases is “biogas”.  Biogas can be harvested and used as an alternative fuel source since methane is highly combustible. The amount of biogas produced can easily supply renewable energy (RE) power of up to 3MW/hr, which is enough to supply electricity to 1,000 homes.  Many such projects have been successfully implemented and Tenaga Nasional has been offtaking the electricity generated from biogas.

It is no surprise then that many palm oil mills are seeking such opportunities to participate in the RE program, which is overseen by Sustainable Energy Development Authority (SEDA) a governmental body created to streamline RE activities in Malaysia.

Of course there may be some palm oil mills which are too remote or far away from electrical power lines and population centres which would need their own power.  Therefore, an option for these mills is to compress the biogas (known as “CBG”, or Compressed Biogas), and then transport the biogas to industrial users to replace fossil fuels such as light fuel oil, medium fuel oil or diesel.

The cost to implement this is substantially higher than the biogas-to-power plant, but the returns are still attractive, especially in view of the government’s decision to gradually remove the subsidies for natural gas.  In the foreseeable future, many palm oil mills will implement the CBG method, to cash in on additional revenue from the sale of the biogas.

Science, technology and innovation will continue to improve over the course of time, and with the right implementation, the waste from palm oil mills, which was once considered to be a nuisance, is fast becoming an important source of revenue for the palm oil industry. With human ingenuity, who knows what new products derived from the waste of palm oil mill are waiting to be discovered?

References:

[1] https://issuu.com/besustainablemagazine/docs/besustainablemagazine-issue_0 (“Malaysia’s Biomass Potential” – page 33)

About the Author:

Raymond Cheah is the Chief Operating Officer (COO) of Green Lagoon Technology Sdn Bhd (GLT), and has been involved in the renewable energy sector for the past seven years.  Having graduated as a civil engineer in 1996 from Universiti Teknologi Malaysia, he had been involved in several major building projects in Malaysia, before founding GLT with two other like-minded partners.  He has worked with owners of palm oil mills to extract the most out of POME, with recent successes in selling renewable energy to the national grid from the company’s two 1MW/hr biogas-to-power plants in Pahang.  He is a firm believer in the younger generation, having employed a team of young engineers and ‘dreamers’ like himself, and entrusting them to bring the company forward. To find out more about Raymond, visit his SciMy profile at http://www.scientificmalaysian.com/members/raymondcwc/