As biofuel is derived from natural products the particular feedstock used can have a material impact on the level of emissions produced in combustion. For example, if the fuel is based on used cooking oils then the heritage and age of the product is clearly a factor. Even fresh oils have different characteristics depending on the variety of crop grown and agricultural inputs applied by the farmer.
There are various standards regulating the exhaust emissions from a diesel engine. Howver, none are directly applicable to an engine driven CHP plant installed in a building. This type of installation is not in fact required to control specific emissions as would be the case in a vehicle engine.
To ensure our Biofuel CHP plant meets a recognised emissions standard we have chosen to use the EU Tier 3 regulations for mobile generating equipment as our benchmark. We belive we are the only company offering renewable CHP which complies with this standard and which regulates specific emissions from exhaust gases.
The table below indicates the importance of actively controlling exhaust emissions, comparing the likely emissions from an unmanaged engine with the Tier 3 standard and a Cantium Biofuel CHP plant.
|
Standard / Fuel Type
|
Category
|
Emissions gm / kWh
|
|
CO
|
NOx
|
HC
|
PM
|
|
Tier IIIA Standards
|
18-36 kW
|
5.5
|
7.5
|
0.6
|
|
37-74 kW
|
5.0
|
4.7
|
0.4
|
|
71-129 kW
|
5.0
|
4.0
|
0.3
|
|
130-560 kW
|
3.5
|
4.0
|
0.2
|
|
|
|
Standard 2010 Generating Engine
|
Fossil Diesel
|
0.45-0.55
|
4.5-5.5
|
0.015-0.025
|
0.09
|
|
Biodiesel (RME)
|
0.25-0.40
|
5.5-6.5
|
0.010-0.020
|
0.04
|
|
Rapeseed Oil
|
0.40-0.60
|
6.0-7.0
|
0.025-0.035
|
0.10
|
|
|
|
Cantium CHP*
|
UCO
|
0.025
|
2.0
|
0.02
|
0.06
|
|
Cantium CHP*
+SGR
|
UCO
|
0.015
|
0.50
|
0.02
|
0.05
|
* The Cantium CHP plant is over twice as efficient as a standard electrical generator, which halves emissions per kWh
Given that the emissions from an engine operating on biofuels can vary, the table above should be used as a guide only. | 
