Improving the sustainability of palm oil mills

Biogas production from wastewater streams is one of the answers to the energy and environmental needs of the future.

With palm oil accounting for approximately 36% of global vegetable oil production in 2015 and only one tonne of palm oil produced for every six tonnes processed, there is a large amount of waste and wastewater.

The palm oil industry in Thailand processes more than 13 million tonnes of palm oil material in more than 90 processing plants. Many of these treat their wastewater streams though an anaerobic process to produce biogas energy and treat their wastewater simultaneously, which provides a significant economic boost for many of these companies.

Three of the key parameters in maximising the economics of biogas generation from anaerobic systems are the quantity and quality of the biogas produced, and the management of hydrogen sulphide (H2S) formation. The addition of an alkali is a critical part of maintaining pH and alkalinity, and stability of the anaerobic system, to perform at its optimum rate.

This case study was done on a palm oil plant in Thailand that processed around 40 tonnes of palm oil per day and had a waste stream of 500 – 1000 m3 per day, which was treated by four anaerobic reactors. The effluent stream was turned into renewable power to run the plant with excess electricity sold back onto the grid. The plant has a quota it was required to supply back onto the grid and was looking for a way to increase power generation and biogas quantity from the anaerobic reactors.

Calix started with a simple lab testing to determine the correct dosing rate of ACTI-Mag for the field trial.