Life cycle assessment of two palm oil production systems
2011
Stichnothe, Heinz | Schuchardt, Frank
In 2009 approx. 40Â Mt of palm oil were produced globally. Growing demand for palm oil is driven by an increasing human population as well as subsidies for biodiesel and is likely to increase further in coming years. The production of 1Â t crude palm oil requires 5Â t of fresh fruit bunches (FFB). On average processing of 1Â t FFB in palm oil mills generates 0.23Â t empty fruit bunches (EFB) and 0.65Â t palm oil mill effluents (POME) as residues. In this study it is assumed that land use change does not occur. In order to estimate the environmental impacts of palm oil production a worst and a best case scenario are assessed and compared in the present study using 1000Â kg of FFB as functional unit. The production and treatment of one t FFB causes more than 460Â kg CO₂âq in the worst case scenario and 110Â kg CO₂âq in the best case scenario. The significant greenhouse gas (GHG) emission reduction is achieved by co-composting residues of the palm oil mill. Thus treating those residues appropriately is paramount for reducing environmental impacts particularly global warming potential (GWP) and eutrophication potential (EP). Another important contributor to the EP but also to the human toxicity potential (HTP) is the biomass powered combined heat and power (CHP) plant of palm oil mills. Frequently CHP plants of palm oil mills operate without flue gas cleaning. The CHP plant emits heavy metals and nitrogen oxides and these account for 93% of the HTP of the advanced palm oil production system, of which heavy metal emissions to air are responsible for 79%. The exact emission reduction potential from CHP plants could not be quantified due to existing data gaps, but it is apparent that cleaning the exhaust gas would reduce eutrophication, acidification and toxicity considerably.
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