Pöl - Tec

Biokraftstoffe & Alternative Energie - Pflanzenöl Umrüsten / Tankstellen



<< Previous page    Index    Next page >>

English Document English Document

The road to pure plant oil in diesel engines?

Global analysis of alternative construction of the PPO chain

Evaluation of possible alternative farming systems

This analysis continues to focus on the current practice of growing winter rapeseed. The crop is treated with KAS, and conventional diesel is used to fuel the agricultural vehicles.
Grey electricity from the grid is also used for decentralised activities such as drying and small-scale oil production. The straw that remains after harvesting is generally ploughed back into the soil because there is very little market for this product.
In order to check how sensitive the results of the study are to these system assumptions, the research team has estimated the net contribution to climate change for a number of alternative systems, using the following alternatives:

  • Using renewable energy carriers. PPO is used for agricultural vehicles and other means of transport. Green electricity is purchased for drying and small-scale oil production;
  • For crop growing, the maximum amount of animal manure is used and minimum possible fertiliser;
  • Straw is not ploughed back into the soil, but used to fuel a decentralised cogeneration plant.

Using renewable energy carriers

Using PPO in agricultural vehicles and other means of transport, but purchasing green electricity for other tasks, does not seem to result in a significant reduction in the net contribution to climate change. This can be explained as follows:

  • The system used in this study assumes the use of conventional diesel and grey electricity as being only 15-20% of the total greenhouse gas emissions in the PPO chain;
  • For agricultural activities and transport only 100-150 g of the produced PPO ar required.

In other words, an important part of using renewable energy carriers would be cancelled out because there would be less net PPO to be used by the fuels market to replace PPO.
Replacing a maximum amount of fertiliser with animal manure.
Replacing KAS and TSP (TriSuperPhosphate) with animal manure has the potential advantage that the environmental impact associated with fertiliser production can be saved. The production of KAS, in particular, provides a significant contribution to the total greenhouse gas emissions in the PPO chain, due to the N2O emissions that occur during production.
The amount of fertiliser that animal manure can replace is fairly limited due to the maximum amount of nitrogen and phosphor that may be ploughed into the soil in the form of animal manure. Manure also has a lower efficiency as N-fertiliser, which means that more fertiliser/nitrogen would be required. Animal manure also has a higher emission of N2O
per unit of nitrogen.
These three effects ensure that replacing part of the fertiliser would not lead to a reduction in the net contribution to climate change, but could actually cause a slight increase. This is further explained in Appendix D. Using straw as an energy carrier Straw produced from rapeseed is currently ploughed back into the soil, due to the lack of sales possibilities. However, current technology means that it would be possible to use the straw as an energy carrier.
Processing options for rapeseed straw as an energy carrier are, in theory: co-incineration in a coal-fired power plant, or incineration in a specially built incineration plant31 , such as occurs in Denmark. The chance that this would take place in the Netherlands is fairly small. Due to the negative influence of the straw on the quality of the powder coal fly-ash, co-incineration is not a very attractive option. There are also extra costs involved in making plants suitable for co-incineration of straw, while it is expected that the management of coal-fired power plants would offer a lower price for this alternative fuel. The economic profit from residual flows, such as RWZI sludge (from sewage treatment plants) and B-grade wood are also looked at carefully by management teams. Incineration in a specially built plant would probably be too expensive.
In the case of using straw as an energy carrier, part of the environmental impact relating to the rapeseed crop should be accredited to straw, which means that (conform the LCA methodology), straw then becomes a valuable by-product.
Based on the current calculation methodology using economic value, it is expected that the straw-based environmental impact would be limited, because straw as a fuel will have a market price that will never be higher than a few dozen euro per ton. The value of the oil (€ 600/ton) is so high that, in comparison the turnover for straw will be only marginal.
This picture changes, however, when prices are attributed based on energy content. Straw, rapeseed cake and oil each represent around 40%, 25% and 35% respectively of the energy content of the entire plant.
When attributing these amounts based on energy content, and assuming that straw can be sold as an energy carrier, the crop-related environmental impact of the oil only amounts to 35%. This study assumes a percentage of 70-75%. In other words, the environmental impact attributed to the oil will then only amount to 50% of the environmental impact calculated by this study.


This publication has been produced by the GAVE programme. GAVE stands for Gaseous and Liquid Climate-Neutral Energy Carriers, and is a programme that aims to accelerate the development and introduction of climate-neutral fuels into the Dutch transport sector.
SenterNovem executes the GAVE programme for the Dutch Ministry for Spatial Planning, Housing and the Environment, in close collaboration with the Ministry of Economic Affairs and the Ministry of Transport, Public Works and Water Management.
Further information is available from:

Website: http://www.senternovem.nl/gave

<< Previous page    Index    Next page >>





Pöl-Tec Die Pflanzenöl und Autogas - Auto Informationsseite Stand: Partner von: AfricaExpedition Motorradreiseforum Tags24 Texte oder Teile davon aus Wikipedia Ihr Inhalt steht unter der GNU-Lizenz für freie Dokumentation. Pflanzenöl & Biokraftstoffe - Alternative Energie - Biokraftstoffe & Alternative Energie - Pflanzenöl Bioethanol Auto Technik und Tankstellen.