Emission Reduction

CO2 reduction

CO2 reduction is basically energy consumption reduction, but also e-boosting can be used to reduce the CO2 emissions of the glass production. Experiments with green fuels like waste gas etc. did not end up with satisfying results. Due to the CO2 release from the batch, energy saving results are not in the same percentaged CO2 reduction range. Figure 2 shows the CO2 reduction depending on fuel consumption reduction and batch fraction of a typical container glass furnace.

Table: CO2 reduction depending on fuel reduction and batch fraction

Varying excess oxygen concentrations

A reduction of the oxygen concentration in the flue gas by reducing the total quantity of combustion air results in a decreased energy consumption, because there is less nitrogen that has to be heated up uselessly. Additionally, the flame temperature rises and the heat transfer to the glass bath is increased. Depending on the furnace, values down to 1% O2 in the flue gas can be reached without producing noteworthy CO concentrations. Thus, energy savings in the range of several percent are possible and can result in profit increases by several hundred thousand Euros per year. Normally, the cost for the optimisation is almost zero and the effect is only limited by the furnace condition.

YIELD allows the calculation of the profit increase by excess oxygen reduction and provides the operator with all technical data to evaluate the applicability.

Switching from Recuperative to Regenerative Preheating

Preheating the combustion air regeneratively instead of recuperatively increases the preheating efficiency dramatically. The preheat temperature increases from around 500°C up to 1,350°C, and the energy cost savings exceed the increased investment cost by far.

YIELD allows the calculation of these values and compares both kinds of preheating from the technical as well as from the financial point of view.

Oxy-Fuel Conversion

Oxy-Fuel conversion means converting the furnace from air-firing to complete oxy-fuel firing. The increased combustion temperatures and efficiency can be used for an energy consumption reduction. As the financial and technical considerations are quite complex, YIELD includes all required background information to calculate the financial and technical effects. The calculation includes factors like oxygen price, reduced wall losses, increased heat transfer, reduced flue gas volume and allows to compare liquid versus VPSA oxygen supply.

Oxy-Fuel Boosting

The installation of additional oxy-fuel burners can decrease the fuel consumption, especially near the end of the furnace life time. YIELD allows to calculate the technical and financial aspects of oxy-fuel boosting and contains all required technical and financial background information. The calculation considers factors like oxygen price, reduced wall losses, increased heat transfer, reduced flue gas volume and allows to compare liquid versus VPSA oxygen supply.

Leackage Air Reduction

Reducing the leakage air will result in a controlled combustion and will reduce the energy consumption. Especially large leakage air volumes increase the required excess oxygen concentration at negligible CO concentrations. YIELD provides all required subroutines to calculate the profit increase by reducing the leakage air.

Glass temperature reduction

The glass temperature is one of the key parameters in glass melting and is considered as critical. But nevertheless, in some cases it is worth to reduce the glass exit temperature. A temperature decrease of 1% results in a reduction of the energy consumption of up to 1.6%.The actual CO2 reduction depends on many parameters. YIELD is able to calculate the potential CO2 reduction based on a given glass temperature reduction.

Changes of glass temperature require always a detailed analysis in advance to consider effect on glass quality.

Fuel Changes

Switching the fuel can reduce the CO2 emissions. Important to consider are the lower calorific values of the fuels and of course the fuel costs. Changing the fuel requires a change of the burners and the related fuel supply equipment. The costs and profits can be calculated with YIELD.

E-Boosting

Electrical boosting can be used to increase the pull of a glass melting furnace by supplying additional energy for the melting. With YIELD, the operator is able to calculate the costs related with the e-boosting considering CDM.

Consulting/CFD

The financial and technical effects of the presented CO2 reduction approaches can be calculated by YIELD. YIELD is a powerful tool to get evaluations of different technologies. The installation of the approaches require a more sophisticated analysis of limiting boundary conditions. We suggest to contact our engineering team at consulting@glassglobal.com, before starting the installation.

We can help you by initiating CFD-Studies, contacting suppliers and providing sophisticated studies.

NOx Reduction

Upcoming pressure due to environmental registration is forcing all glass producers to shift the prior fuel costs driven decisions to NOx reduction. Generally speaking, all primary NOx reduction methods go hand in hand with fuel consumption increases, due to downgraded heat transfer. The pressure can result in decisions for results with increased fuel consumption but fitted registrations for NOx. The only available alternatives are secondary measures like DeNOx.

YIELD can calculate the effects of most of the available primary measures. Following two examples are given. Besides, glass global consulting just finished the development of an innovative burner concept to reduce the NOx emission at simultaneous fuel reduction or pull increase.

Varying excess oxygen concentrations

A reduction of the oxygen concentration in the flue gas by reducing the total quantity of combustion air results in a decreased energy consumption, because there is less nitrogen that has to be heated up uselessly. Additionally, the flame temperature rises and the heat transfer to the glass bath is increased. Depending on the furnace, values down to 1% O2 in the flue gas can be reached without producing noteworthy CO concentrations. Thus, energy savings in the range of several percent are possible and can result in profit increases by several hundred thousand Euros per year. Normally, the cost for the optimisation is almost zero and the effect is only limited by the furnace condition.

YIELD allows calculating the profit increase of excess oxygen reduction and gives all technical data to evaluate the applicability.

CFD/Consulting

The financial and technical effects of the presented NOx reduction approaches can be calculated by YIELD. YIELD is a powerful tool to get evaluations of different technologies. A prediction of the reached NOx-concentration with YIELD , however, is not yet available. We suggest contacting our engineering team at consulting@glassglobal.com. We can help you by initiating CFD-Studies, contacting suppliers and providing sophisticated studies.

For further information please contact our engineering team at consulting@glassglobal.com.