Clean air and energy for industries at the same time

Clean air and energy for industries at the same time

Innovaterm S.r.l. got the best results in energy and ecology fields thanks to RTOs (Rigenerative Thermal Plants)

Society nowadays is looking for solving XXI century energetic and ecologic problems with greater and greater efforts and pragmatism.
At the same time we don’t want to loose sight of the main goal of every entrepreneurial activity: high technology productions, low costs and better and better quality in working processes.
This is the desire of a very important firm in Treviso that has brought them to strengthen their own environmental policy which is now very strong and successful.
This Company is the leading manufacturer of self-adhesive products in the world and one of their recurrent thinking is to innovate materials and production technology.
Since 1999 they have created an authentic synergy with Innovaterm S.r.l. in Saronno (VA) which projects and realizes RTOs.
In this article we analyze exactly this aspect: the real renewable energy starts with the maximum exploitation of the used energy and the best way of burning exhaust solvents without wasting their potential.
In fact the processing of self-adhesive products, inks, varnishes, plastic materials, cause the emission of injurious gas with high calorific power: for instance just think about methane having low calorific power of 8200Kcal/Nm3 whereas a mixture of solvents produced by self-adhesive drying may be of 6000/7000Kcal/ Nm3.
D.Lgs 152/2006 which will limit, from October 31th 2007, emissions strongly, reducing the use of solvents in ton/year (limits change according to production fields) and fixing emission values earlier in the process cycle. COV is normally limited at 20mg/Nm3, CO at 100mg/Nm3 and NOx at 100mg/Nm3 as well)
A well-known Company that exports their products either in the USA or in Far East is able to manage controlled productions up to 120kg/h of solvents thanks to RTOs that recover more than 50% of thermal energy. Moreover they reach auto-thermal without using even a meter cube of methan and emissions are really lower than the values imposed by Veneto authorities.
During these years the production self-adhesives paper has greatly increased, 5 RTOs have been installed, heat exchangers have developed: from simple aluminum sheets welded to smooth carbon steel pipes.
The old idea that thermal plants involve very expensive maintenance costs, now is definitely overcome thanks to regenerative system: heat necessary for complete solvent oxidation is given only in the beginning by a CH4 burner, then thermal ceramics of the circulation beds of exhaust air in RTOs provide keeping the needed heat inside the plant, whereas heat exchangers placed in the exit provide recovering thermal energy, precious for drying ovens, for the production of hot water and to give heat to heating plants, reducing and even set at zero fuel costs.
We would like to describe briefly the way of exhaust air inside the RTO.
Air containing solvent enters a recovery chamber to be preheated (by the ceramic bed), before going into the oxidation chamber. Here, thanks to the presence of oxygen, the auto-ignition point is reached with temperature exceeding 750°C.In the combustion chamber, with residence time always longer than 0,8 s, the process of oxidation and neutralization of organic solvents takes place.
After combustion purification, the air heats a second recuperative bed, allowing a thermal recovery which is fixed according to the project from 92% up to 97%.
The technology is supported by a SCADA (Supervision Controller and Data Acquisition) provided with electrical sensors like K-Thermocouples that control temperatures of ceramic beds and combustion chamber continuously and a PLC (Logic Process Control) which takes measurements and registers data in the relevant memory, completing the system.
In conclusion: a working process already characterized by high performances, by introducing RTOs is now also provided with a great means of environmental protection and a valid instrument to recover energy that otherwise will be lost in atmosphere.
This kind of system allows to amortize in time also the initial investment to buy an RTO, supporting even more the idea of productions according environmental rules and competitive working costs.
In the latest years we often hear talking about solar panels, wind energy, biomass, but at first it should be much better to make completely profit of well tested technologies and to recover the energy that otherwise will be lost in atmosphere as heat or exhaust fumes.
This is the first reasonable step to optimize our own resources.