11 Jul 2019

Reading time: 4 minutes

Donau Carbon Technologies develops solvent recovery plants for companies in several sectors. For these plants, the company chooses Cannon Bono Energia as its technological partner

Donau Carbon Tehcnologies headquarter

Donau Carbon Technologies (DCT) was founded in 1981 in Guanzate (CO), and today is one of the most important Italian companies in the development of high efficiency solvent recovery plants with activated carbon, employed in many different fields: from chemical, to edition print, to flexible packaging, etc.

DCT solutions’ main objective is to reduce the consumption of solvents by the industrial plants, reusing, where possible, those of the process: through steam, nitrogen or vacuum, the solvents are distilled and treated, in order to be utilized again, minimizing waste. This translates also into a significant reduction of polluting emissions into the atmosphere.

When solvents recovery and re-use are not possible (because they are mixed with other solvents or present in limited quantities) the problem of the correct disposal of these substances arises. For these customers DCT manufactures regenerative thermal oxidation plants (called RTO) that are able to eliminate solvents, breaking down the highly polluting volatile organic compounds (VOCs) present.

These systems are specifically created to minimize emissions, achieving high recovery levels in VOC removal and thermal efficiency.

RTO con caldaia a recupero Cannon Bono Energia

Tailor-made plants and boilers

DCT has supplied more than 300 plants worldwide, all moulded according to each individual customer’ specific needs. The variability the company deals with concerns primarily the type of solvent to be treated – not all companies use the same solvent -, as well as the quantity of solvent, and local regulations concerning health&safety and the environment.

The common factor, instead, is the high temperature required for the process: both in the case of solvent recovery systems and in thermal oxidation, heat is the key ingredient. In the first case it is used for the actual process; in the second one, in addition to being employed to remove solvents, heat is also recovered to be reused in other “secondary” processes.

Boilers, the heart of all these types of systems, must therefore be able to manage both the variability and the high (or very high) temperatures of these plants.

DCT has chosen a technological partner whose flagship is the  “tailor-made” concept: for more than twenty years Cannon Bono Energia has been collaborating with the company, offering its engineering capabilities, designing and manufacturing boilers which effectively respond to customers specific requests, in terms of process, of characteristics of the place of installation and compliance with European and American standars and regulations.

The very high temperatures (over 1000 ° C) required by a regenerative thermal oxidation plant for the elimination of VOCs generate fumes above 800 ° C, which can be recovered and used to feed other processes or utilities. For this application, DCT relies on Cannon Bono Energia heat recovery boilers, developed to recover the heat from the main solvent elimination process and reuse it to produce steam or to heat up diathermic oil, destined, for example, to the customer production process.

This reduces both the cost of harmful products by products disposing and the energy cost of the process.

In solvent recovery plants with activated carbon, instead, boilers are used to generate the heat required by nitrogen to strip the solvent and recover it. Also in this case, DCT has chosen Cannon Bono Energia and, in particular, its diathermic oil heaters, able to reach temperatures up to 350°C.

A winning collaboration

The Italian Polygraphic and State Mint Institute has recently awarded Donau Carbon Technologies for an integrated plant for diathermic oil heating and the treatment of vapours coming from a rotogravure printing machine. For this plant, Cannon Bono Energia has supplied two highly customized oil heaters, one of which is a recovery boiler.

The requirements were rather stringent for both boilers.

The heat recovery boiler has to reach very high levels of thermal recovery, and must be of such dimensions to fit into a confined space within an existing project. For this application, Cannon Bono Energia has completely redesigned its standard heat recovery boiler: the very compact design and the efficiency of the thermal recovery of the fumes coming out of the oven (at a temperature of about 900 ° C), has led DCT to win the tender.

Similarly, the OMV diathermic oil heater which Cannon Bono Energia has installed into the plant has also been designed and built to meet the need for a very high efficiency. The oversized body and, therefore, the increased heat exchange surface, allows to reach and exceed this aim.

We have focused a lot on the high efficiency of the two Cannon Bono Energia boilers, thanks to which we have won the important Italian Mint Institute tender” – Giuseppe Dell’Acqua, Managing Director of Donau Carbon Technologies.