Report: large scale imports and co-firing of palm oil products can be sustainable

Northern European countries import significant quantities of biomass for energy production, among which palm oil has been used increasingly for co-firing in existing gas-fired power plants for renewable electricity production. However, imported biomass is not automatically a sustainable energy source. The production and removal of biomass in other places in the world result in ecological, land-use and socio-economic changes and in greenhouse gas emissions (e.g. for transportation).

The International Energy Agency's Bioenergy Task 40, which analyses the technical opportunities and challenges for large-scale international bioenergy trade, refers to a new report which looks at the conditions that have to be met to make such imports sustainable.

To find out, Dr Veronika Dornburg, Dr André Faaij, Birka Wicke and Dr Martin Junginger of the Department of Science, Technology and Society at the Copernicus Institute (Utrecht University) used a set of strict sustainability criteria developed by the Cramer Commission in the Netherlands. This commission has formulated (draft) criteria and indicators for sustainable biomass production, taking into account social, environmental and emissions factors (earlier post).

In their study titled A Greenhouse Gas Balance of Electricity Production from Co-firing Palm Oil Products from Malaysia [*.pdf], the scientists applied these stringent criteria to a specific bio-electricity chain: the production of crude palm oil (CPO) and a palm oil derivative, palm fatty acid distillate (PFAD), in Northeast Borneo in Malaysia, their long-distance transport to the Netherlands and co-firing with natural gas for electricity production at the Essent Claus power plant in the province of Limburg.

The Cramer Commission sets a (very) high target for greenhouse gas emission reductions: a biofuel used for electricity production must reduce GHG emissions with no less than 70% compared to fossil fuels in order to be called green. The scientists found that for PFAD this target can be reached (graph, click to enlarge). For CPO, the picture is more complex. Only when palm oil plantations were established on degraded land, a reduction of well over 100% could be obtained. In that case, such plantations act as carbon sinks. When established on logged over land, the bio-electricity chain only reduces GHG emissions by more than 70% if specific plantation management improvements have been made; for plantations without such interventions, a reduction of more than 50% will only be obtained when compared to coal:
energy :: biomass :: bioenergy :: biofuels :: palm oil :: co-firing :: bio-electricity :: greenhouse gas emissions :: sustainability :: IEA ::

The bio-electricity chain is based on the co-firing of natural gas (NG) with palm fatty acid distillate (PFAD) and crude palm oil (CPO) at the power plant. CPO is the main product of an oil palm plantation, while PFAD is a by-product of CPO refining. Due to this difference (main product vs. by-product), two separate bio-energy chains are defined and their emissions are calculated independently.

The GHG emissions of by-products are calculated on the basis of system extension. This approach assumes that the by-product generated can replace the same or a similar product that was produced from another feedstock. Due to this replacement, an emission credit for the avoided GHG emission from the original production of the product can be determined. Allocation of emissions to by-products will be based on market prices when system extension is not possible.

The concept of GHG emission reductions from co-firing biomass, i.e. CPO and PFAD, for electricity production compares the emissions from this bio-electricity chain to a fossil reference system. The functional unit of this comparison is defined as producing 1 kWh electricity. The overall emissions of the whole electricity production chain, both fossil- and bio-based, include all emissions occurring anywhere during resource extraction, treatment, transport, and power production.

The three most important greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), are accounted for. For comparing the emissions of these three gases, the concept of global warming potential (GWP) is applied by which the radiative forcing of the different gases can be compared.

Results
Investigating the overall emissions for different land types, CPO production on peatland and natural rain forest was found not to be an option for producing sustainable electricity as its emission reduction potential is negative compared to fossil reference systems. Moreover, it was found that CPO production on logged-over forest also does not meet the Cramer Commission criterion of 70% emission reduction compared to various fossil reference systems and that the 50 percent emission reduction target can only be reach when compared to electricity production from coal.

However, when CPO is produced on degraded land, GHG emission reductions of well over 100 percent may be reached, indicating that oil palm plantations may serve as carbon sinks.

The study also investigated potential improvement options in the management of the oil palm plantation and the mill and their effect on the GHG emission reductions.

This investigation resulted in three options that can have large impacts on the emissions, with the largest effect being caused by planting oil palm on degraded land. Also, a fourth option (applying more organic fertilizer) was examined but it showed only very little effect on the GHG balance.

Together the four options cause the overall emissions of the CPO-based electricity chain to become negative so that the oil palm plantation may actually serve as a carbon sink.

The second source of bio-electricity that was investigated in this study is palm fatty acid distillate, a by-product of CPO refining. It was found that PFAD has a very positive GHG balance and compared to the fossil reference systems it can reduce GHG emissions by over 70 percent, meeting the Cramer Commission criteria in all cases.

Discussion and Conclusions
The study found that the land use conversion for oil palm plantation makes up a very large share of the overall emissions and, due to this significance, may not be neglected in the overall GHG emission calculations for palm oil-based electricity or, in fact, for any other biomass-based electricity.

However, especially this aspect has shown to be difficult to analyse because the conversion of specific land types to oil palm plantation and the quantities of land converted specifically for oil palm are not well studied.

The sensitivity analysis of the GHG emissions from CPO production illustrates how the emissions can vary when different values for CPO production parameters are assumed. This points out that the actually level of emissions depends largely on the local settings, the specific management of the plantation and the particular production methods.

The study has established further that methodological choices can have large impacts on the results and on whether the GHG emission reduction targets of the Cramer Commission may or may not be reached. Especially significant is the decision of the time period for which land use change emissions are accounted for. With respect to the allocation of emissions to by-products, the results have shown much less variation, even though a difference in results could be found between system extension and market price allocation.

PFAD-based electricity was found to have very small emissions, both compared to fossil reference systems and to CPO-based electricity production. The most important reason for why PFAD has such small emissions and so large GHG emission reduction potentials is that PFAD is treated as by-product so that, according to the Cramer Commission methodology, only those emissions need to be accounted for that are generated in direct connection with PFAD processing and use.

While, based on the mass balance of a refinery (where PFAD is a by-product produced at a rate of less than 5 percent by weight), this is a valid assumption, the choice to treat PFAD as a by-product may be debatable when considering that PFAD is a valuable product for the oleochemical and animal feed production industries.

Moreover, one might not want to consider PFAD sustainable just because the GHG balance is positive, especially when it comes from unsustainably produced CPO. It needs to be discussed again when a product is considered only a by-product and how to account for the possibly un-sustainability of the CPO that is used for PFAD production.

Based on the results of the calculation a simple decision tree for determining whether the Cramer Commission criteria on GHG emissions can be reached was made (schematic, click to enlarge). It must be noted that this decision tree is simple and crude, and that actual compliance with GHG emission criteria depends strongly on the local conditions.

The study demonstrates that it is possible to calculate the GHG emissions of a specific bio-electricity chain with an extended version of the Cramer Commission methodology for GHG emissions. While GHG emissions can vary strongly for different land use changes and methodological approaches, many of the chains studied were found not to be sustainable according to the Cramer Commission GHG emission criteria.

However, if CPO production takes place on previously degraded land, the management of the production of CPO is improved, or if the by-product PFAD is used for electricity production, the criteria can be achieved, and palm oil-based electricity can be considered sustainable from a GHG emission point of view.

If bioelectricity is to be produced from palm oil and its derivatives, these sustainable options should therefore be focussed on.


Picture: worker in Malaysia carrying fresh fruit bunches from the plantation. A new study by the Copernicus institute analysed the GHG balance of co-firing palm products in the Netherlands and imported from Malaysia.

References:
Birka Wicke, Veronika Dornburg, André Faaij, Martin Junginger, A Greenhouse Gas Balance of Electricity Production from Co-firing Palm Oil Products from Malaysia [*.pdf], Department of Science, Technology and Society, Copernicus Institute, University of Utrecht, May 2007.

IEA Task 40: Sustainable International Bioenergy Trade.