Environmental Project No. 1092 2006 – Fuel use and emissions from non-road machinery in Denmark from 1985-2004 - and projections from 2005-2030

Fuel use and emissions from non-road machinery in Denmark from 1985-2004 - and projections from 2005-2030

7 Conclusion

The diesel fuelled machinery in agriculture and industry are the most important sources of fuel use and emissions of SO₂, NO_x, CO₂, N₂O, NH₃ and TSP in 2004. Agricultural tractors is the most dominant single source, with fuel use and emission totals of around one third of the grand totals for land based non road machinery.

For diesel machinery as a total, the fuel use and emissions of SO₂, CO₂, NMVOC, CH4, CO and TSP decrease by 6, 91, 6, 43, 43, 33 and 54%, respectively, from 1985-2004. In the same time period the emissions of NO_x, N₂O and NH₃ increase by 4, 2 and 2%, respectively.

The trend in total diesel fuel use (and CO₂) is dominated by a decrease in fuel use for agricultural machinery, and an increase in fuel use especially for non road construction machinery and fork lifts. The significant SO₂ emission decline is caused by a large reduction of the sulphur content in non road diesel. For NO_x, the slight emission increase is due to the relatively large 1991-stage I emission factors, whereas the large emission reductions for NMVOC, CH₄, CO and TSP are due to the gradually improved engine emission techonology for these emission components.

The development towards cleaner diesel engines continues in the future, and for NO_x, NMVOC, CH₄, CO and TSP the total emissions decrease by 81, 78, 78, 63 and 85% from 2004-2030. This is due to the gradually strengthened future EU emission standards. A significant reduction of the sulphur content for diesel in 2005 cuts down the diesel related SO₂ emissions by as much as 98%. In the 2004-2030 time period there is a moderate decline in fuel use and CO₂, N₂O and NH₃ emissions, mainly due to a decrease in the use of agricultural tractors.

Most of the NMVOC, CH₄ and CO emissions come from gasoline fuelled working machinery. Set in relation to the total land based non road emissions, the NMVOC emission share is 26% for chain saws used in forestry and for household, and for CH₄ and CO the emission shares for riders (private and professional) are 34 and 53%, respectively.

From 1985-2004 the emissions of NMVOC, CH₄ and CO from gasoline machinery increase by 18, 12 and 8%, respectively. From a broad perspective the engines have become more emission efficient, since the total gasoline fuel use has increased by 39% in the same time period. In the forecast period from 2004-2030 the gasoline related fuel use and emissions of NMVOC and CH₄ are expected to decrease by 5, 34 and 11%, respectively, whereas an emission increase of 9% is calculated for CO. Here, small or zero emission factor reductions for stage I and II engines in combination with higher deterioration factors cause the CO emissions for gasoline machinery to increase even after the time of stage I and II engines entering the market.

For recreational craft, most of the fuel use, SO₂, NO_x, CO₂, N₂O, NH₃ and TSP emissions are attributed to the diesel engine category, while most of the NMVOC, CH₄ and CO emissions come from gasoline fuelled engines, as is the case for land based non road machinery. However, compared with the latter machinery group, the fuel use and emissions from sailing vessels are small.

From 1985 to 2004 there has been a large increase in sailing activities, most significantly for diesel fuelled boats, and a gradual shift from 2-stroke to 4-stroke technology for gasoline engines. These tendencies are reflected in the increases of fuel use (188%), N₂O (300%), NH₃ (258%), NO_x (239%), SO₂ (201%), CO₂ (189%), TSP (106%), CO (81%), CH₄ (75%) and NMVOC (13%). The overall diesel fuel increase is the main reason for the SO₂, NO_x, CO₂, N₂O, NH₃ and TSP emission growths, whereas the increase in gasoline fuel use explains the CO and CH₄ emission inclines. The small NMVOC emission increase is explained by the gasoline engine shift to the more environmentally friendly 4-stroke technology, since total gasoline fuel use has gone up with 50% from 1985 to 2004.

From 2004 to 2030 the emissions of NMVOC and CO are expected to significantly decrease due to the 2-stroke/4-stroke technology shift (NMVOC) and the relatively low future EU 2003/44 directive emission limit. The latter explanation also applies for the NO_x and TSP emission decreases, mainly ruled by the emission trend for diesel fuelled boats.

For non road machinery in 2004 the uncertainties (given in brackets)for fuel use and CO₂ emissions are determined with the highest accuracy (18%), followed by SO₂ and TSP (35%), NO_x (37%), NMVOC (40%), CH₄ (43%), CO (48%), NH₃ (619%) and N₂O (621%). The uncertainties are calculated as the 95% confidence ratios.

Since tractors are the largest individual source of fuel use and emissions it is important to increase the accuracy of the operational background data used in the inventory calculations for this non road machinery type. Data for the load factor assessment made in this report originates from a study carried out in 1987. Even though the agricultural machinery stock in principle must match the farm work requirements on a daily basis, the load factor assessment rely on old data and it would be useful to make the load factor calculation once again with an updated data set.

For machine pool machinery it is also important to further evaluate the operational parameters engine size and annual working hours, and specifically for harvesters the kW:ft ratio needs to be reassessed.

An important outcome of the present study has been the establishment of contacts with Danish experts dealing with statistical data and experts from research institutes, relevant professional bodies, machinery manufacturers, etc. It is the future goal to obtain information of new sales and total stock on an annual basis, in order to ensure continuously updated inventories. To the extent that statistical numbers are produced, new sales figures for tractors, harvesters, construction machinery and fork lifts should be gathered together with total stock data for household/gardening machinery, and recreational craft.

Specifically for agriculture, two major inventory improvements are envisaged in the nearest future. By all means, total stock data for tractors and harvesters will be published by Statistics Denmark for 2005. These figures go directly into the inventory for 2005, and will in addition improve the 2001-2004 total stock numbers by means of interpolation. On the energy side and starting from 2005, more detailed fuel sales information from the Danish Energy Authority classifies the amount of diesel fuel used for non road mobile purposes. The latter figure is an important tool for fuel use quality control and enables a regular fuel balance to be made for the agricultural part.

On a European level, the purpose of the EMEP/CORINAIR guidebook published by the European Environment Agency is to provide inventory support for country estimates. However, the guidebook data are more than ten years old and consequently the demand for new data is becoming more and more urgent. The fuel use and emission data used in the German inventory (IFEU, 2004) and in the present report are able to support this task, and an effort should therefore be made to include these data in the EMEP/CORINAIR guidebook.