Production Process - Environmental Aspects - Energy consumption : a closed monitoring

The energy consumed during the manufacture of clay products is primarily that used in forming, drying and firing. Since energy costs are an important part of total production costs (up to 30%), the clay industry has always closely monitored its energy usage. Ecology and economy are often linked and the European brick and tile industry has not waited for statutory regulation before investing in better energy efficiency. Firing is responsible for the exceptionally long life of our products. Moreover, some products are designed to save energy when incorporated into buildings and the thermal performance of such products has increased significantly over the last few years.

Choice of energy
Natural gas, LPG and fuel oil are used for most drying and firing operations, but solids fuels and electricity are also sometimes used, as is gas from landfills.
Natural gas is increasingly used in factories. This fossil energy produces the least carbon dioxide-CO₂ (57 kg CO₂ / GJ as opposed to fuel oil which produces 75 kg CO₂ / GJ).

Development of the Percentage of Various Fuels Used (Thermal Energy) Clay Brick & Roof-tile Industry
	COAL	OIL	NATURAL GAS
	1960	1975	1990	1995	2001	1960	1975	1990	1995	2001	1960	1975	1990	1995	2001
AUT			2	0	0^*			20	19	15^*			78	81	85^*
BEL	83	4	10	4	2^**	17	40	7	6	2^**	0	56	83	90	96^**
GER	77	5	3	3		20	76	17	15		3	19	80	82
DEN	68	11	5	4		32	89	9	9		0	0	86	87
FRA		4	15	0			56	9	5			40	76	95
ITA			0	2	0^*			49	19	10^*			51	79	90^*
NED	49	2	2	1		51	1	1	0		0	97	97	99
ESP	30	10	0	0		50	65	71	67		20	25	29	33
UK		50	11	4	3		14	4	2	1		36	85	94	96
HUN	94	60	26	15		6	8	0	0		0	32	74	85
CH			1	0	0			63	51	47			36	49	53

^* 2000 ^** 2002 Data listed in this table are based on information provided by the National federations and associations. (source : TBE)
Source: TBE

Reduction of energy consumption
Throughout the industry, the widespread change to gaseous fuels and improvements in drying, kiln technology and control have resulted in a progressive reduction in energy use and a marked reduction in emissions.
The primary process improvements are:

The EC/2003/87 Directive establishes a C0₂ emissions trading system. The European brick and tile industry is concerned by this Directive. Much effort has already been made to decrease its energy consumption (see table below) and levels of CO₂ emissions.

Specific Energy Consumption (GJ/tonne) – Brick & Roof-tile Industry
	1980	1985	1990	1995	2001	Reduction %⁶⁾
AUSTRIA	2.38	2.09	1.71	1.72	1.65^*	28
BELGIUM	3.30²⁾	2.73²⁾	2.16²⁾	2.37³⁾	2.23³⁾ ^**	32
GERMANY	2.43	2.31	1.93	1.63		33
DENMARK	2.73	- ¹⁾	2.41	2.67		2
SPAIN	2.38	2.29	2.24	2.18		8
FRANCE	2.87	2.62	2.76	2.61		9
ITALY	2.8	2.6	2.1	1.9	1.9	32
THE NETHERLANDS	3.63	2.93	2.86	2.7		26
UNITED KINGDOM	1.1⁴⁾ 3.58⁵⁾	1.01⁴⁾ 3.26⁵⁾	0.84⁴⁾ 2.97⁵⁾	0.83⁴⁾ 2.80⁵⁾	2.42⁴⁾ 1.4⁵⁾	25⁴⁾ 22⁵⁾
SWITZERLAND	- ¹⁾	2.55	2.62	2.53	2.32	1

^* 2000 ^** 2002 ¹⁾ not available ²⁾ only bricks - data based on NIS ³⁾ clay bricks and roof tiles - based on data provided by the federation ⁴⁾ UK Fletton & ⁵⁾ UK Non-Fletton / data for 1980 not available - data shown for 1984. The Fletton Industry cannot be compared to the previous figures. There have been large production changes to the output types at the 3 remaining fletton sites. ⁶⁾ 1995/1980 but 1995/1985 when the 1980 consumption data are not available - for Belgium ratio 1980/1990 Source : TBE

The substitution of non-renewable energy by renewable energy is in constant progress. In many ceramic production processes, biogenic additives, such as sawdust can be added to the raw clay. The utilisation of such additives offers two advantages. The first one is an additional energy source and the second one is to lighten the products and increase their insulating performance.

This additional energy works by reducing the consumption of fossil fuels and therefore the emission of CO₂.

These additives are primarily selected on technical, environmental and health grounds. They must have a beneficial effect on the product’s technical properties; they must not produce harmful emissions or if they do must be amenable to control. And they must not pose a health risk to factory and contruction workers.