Zero Waste Solution : VIRIDIS Engineering

We Design, Engineer, Supply, Construct, Operate and Maintain a complete advanced treatment plant to treat solid waste products and aqueous effluent that result from palm oil mill process to ensure zero waste production.

Treatment of Solid Waste Products

In a well-run palm oil mill, it is expected that each 100 tonnes of FFB processed yields 20 to 24 tonnes of crude palm oil and about 4 tonnes of palm kernels. Thus between 72 to 76 percent of the FFB comes out at various stages of the process as waste.

The solid wastes that result from the milling operations are:
1. Empty fruit bunches,
2. Palm fibre, and
3. Palm kernel shell.

In the large- and medium-scale mills the above-mentioned waste products are all put to economically useful purpose. They could therefore be referred to as by-products rather than waste products.

Wet, empty bunches	partly dried in the sun and later used as fuel return them to the plantation as a mulch to enhance moisture retention and organic matter in the soil.
palm kernel shell	source of fuel for the boilers
fibre recovered from the nut/fibre separation stage	good combustible material and finds ready use as fuel to boil the fruit fire the large boilers used to generate superheated steam to drive turbines for electrical power generation in large-scale plants.
Boiler ash	recycled as fertilizer factory floor cleaning agent

Treatment of Aqueous Effluent

Mills produce liquid waste from the sterilizer, clarifying centrifuges and hydrocyclones. This effluent must be treated before discharge to avoid serious environmental pollution.

Generated wastewater from the palm oil mill typically goes to a biological wastewater treatment process to ensure that effluent quality meets industrial standard. However, in some palm oil mills, this generated wastewater with high organic content (BOD ̴ 30,000 mg/l, and COD ̴ 90,000mg/l) undergoes anaerobic digestion process as part of the biogas system for generating electricity.

Since palm oil wastewater has high organic load, it is suitable for producing biogas by using an anaerobic treatment system. In the past, the most popular wastewater treatment plant was pond treatment system, comprising anaerobic pond, facultative pond, and polishing pond.

Biogas generated from anaerobic ponds was neither captured nor utilised. Some mills use biogas system. Biogas generated from the system is used for generating electricity and selling back to grid. In addition, organic loading of the processed wastewater can be reduced, which eventually minimises effect on water pollution.

Process Overview

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