On the road to making ceramic production greener

Up until now, ceramic production has had a pretty bad reputation when it comes to environmental issues. But that’s starting to change. Gabriele Frignani is responsible for applied research at SACMI FORNI SpA*, a company that manufactures machinery and turnkey plants for the ceramics, packaging, food and automation industries. He spoke to ESCI about what can be done to make ceramic production more sustainable.


You are co-ordinator of the DREAM project, an EU-funded research initiative that developed new systems to increase the energy efficiency and reduce the ecological impact of the ceramics production cycle. What is the current status of the DREAM project regarding energy recovery?


Frignani: A lot of work has already been done. We have recovered a huge amount of energy – energy that was normally released through the chimneys. We can say that the amount of energy emitted from these two chimneys covered, more or less, 70-80% of the total energy output from a thermal machine. But now the toughest part of the job is approaching, because there are other heat recovery aspects that need to be investigated. For example, recovering the energy dispersed through the refractory we use to manufacture our kilns, or the energy that is released from our thermal machines in general. And some other topics related to the application of combined heat and power machinery.


So, how does the DREAM project recover all this heat?


Frignani: We have some specific technologies that were investigated for the first time in the ceramics sector. In the DREAM project we are testing the application of micro turbines for heat and power machinery. A few years ago they were not available on the market. Unlike in the past, where large-sized turbines fed the entire production site, the micro turbine can supply thermal and electric energy to single thermal machines thus avoiding issues related to cost, maintenance and efficiency.

Besides that, we implemented a heat pipe heat exchanger (HPHE). One of the advantages in using heat pipe technology is that we are always sure that the air that we move to other thermal machines of the process is clean. I mean, there is no mixing between the air that we heat and the air that could potentially be contaminated from the firing area of the kiln, for example. This is one of the most interesting aspects. What we can also say is that the efficiency of heat pipes is a little higher compared to the standard heat exchangers that we use for similar applications.


What other technologies exist that reuse waste heat in the ceramics industry?


Frignani: One of the most interesting outputs from the DREAM project is the use of new refractory materials and new insulations for our kiln. These refractories are not on the market yet and were developed specifically for this application. They are still a lab product with a good potential to become an industrial product. The result we have is a very interesting reduction of heat transmission through the walls of our kilns. Just to give you an idea: we reduced the superficial temperature of our kiln by an average of 10 degrees. This is a huge achievement and it gave us a new perspective into the manufacturing and construction of kilns.


What else needs to be done to make ceramics industry more sustainable?


Frignani: You can take for example the consumption of water. Consider that the water used in ceramic production line is ground water, drinking water. A lot of this water just becomes waste water after being used as part of the production process and is thrown away. Another example is the natural gas supply. The cost now in Italy, just to give you an idea, is around 30 Eurocent per cubic metre. The total energy cost for a square metre of tiles is around ten, twelve percent. It’s a big amount, but it’s still not yet comparable with labour or other costs. People are clearly interested, especially people producing low quality tiles, in saving money – here the competition is very tough. But we can say that, at the moment, the tile manufacturers don’t seem so interested in changing things. Maybe with the next increase of natural gas or water prices this issue will become a focus. The only way to motivate these people is by economics. Or, for example, when you have international rules or laws that oblige you to do certain things. Just to give you an example, in Italy we filter the fumes from our thermal machines. We have been filtering like this for the past 25 or 30 years. No one else in Europe is still doing this. Spain? No. Germany? No. Holland? No. Poland? No. This one is a big cost factor. This is a situation that needs to be managed by the European Commission.


Are there any challenges that the ceramics industry is currently facing? 


Frignani: Definitely. The pollution situation is a challenge, and will be even more of a challenge in the future. The second point is an economic challenge, because everything you do in that sense, in reducing the quantity of polluting substances, is something that directly affects the costs of your tiles. It’s a complicated situation because competition around the world is becoming tougher and tougher. The solution for many tile manufacturers is to move to different countries, for example, where they don’t have to comply with costs related to the reduction of polluting substances or labour costs. In Europe, we have one of the highest labour costs around the world. We pay our workers well, so it’s difficult to say because the market generally tends to self-regulate. The other challenge for tile manufacturers is to try to sell even more tiles to even more customers. But doing so depends on the sensitivity of the market. For example, we should educate the consumer to use green products or to ask for ceramic products that require a certain kind of production process. That would help, but generally people who buy tiles know absolutely nothing about how the tiles are manufactured. So, they just understand: ‘like’, ‘dislike’, ‘good’, ‘not good’; ‘cheap, “expensive”. It’s a difficult issue to be dealt with in a few words.


*SACMI FORNI SpA is a subsidiary company of the multinational group SACMI located in Imola, Italy