SOLVAir® Contribution to Energy Efficiency
Transcript of SOLVAir® Contribution to Energy Efficiency
GBU Soda Ash and Derivatives
SOLVAir® Contribution to Energy Efficiency
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Energy Efficiency Directive 2012/27/EU
• The European Union is facing unprecedented challenges resulting from increased dependence on energy imports and scarce energy resources, and the need to overcome the economic crisis. Energy efficiency is a valuable means to address these challenges by reducing primary energy consumption and decreasing energy imports. It helps to reduce greenhouse gas emissions in a cost-effective way.
• On October 25th 2012, the EU adopted the Directive 2012/27/EU on energy efficiency. This Directive establishes a common framework of measures for the promotion of energy efficiency within the Union in order to ensure the achievement of the Union’s 2020 20% target on energy efficiency and to pave the way for further energy efficiency improvements beyond that date. It lays down rules designed to remove barriers in the energy market and provides for the establishment of indicative national energy efficiency targets for 2020.
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Waste Framework Directive 2008/98/EC - Factor R1
• Energy efficiency is becoming more and more critical for the waste-to- energy industry, as cheap fuels are becoming rare. This favors a stronger and stronger competition in the waste incineration market.
• The Waste Framework Directive 2008/98/EC includes an energy efficiency criterion, called R1, which sets the conditions for a municipal solid waste incineration facility to be considered as a recovery operation or, if not achieved, as a disposal operation.
• If an installation is rated with R1 lower than 0,60 (or 0,65 depending on permit date) the operation will not be accepted as energy recovery.
• In Italy R1 value has to be multiplied by a corrective factor Kc to consider local climate conditions. The corrective factor refers to HDDLLT (Heating Degree Days Local Long Term).
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R1 formula and local climate conditions - R1*Kclimate -
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R1 new correction factor
• As July 31, 2016 will come into force the new climate correction factor (CCF) for the calculation of R1, as required by Directive 2015/1127/EU. The value of energy efficiency calculated as described in note R1 of Annex II of Directive 2008/98/EC is multiplied by the new correction factor.
• All EU member states must harmonize their legislation with European provisions by that date.
• CCF allows to achieve a level playing field in the European Union because the plants located in countries with warmer climates have energy yields lower than those located in cold countries.
• Italy has anticipated Brussels decisions by introducing a correction factor Kc in the environmental code through Decree August 7, 2013
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From R1 value to marketable energy
• R1 formula assesses the overall energy efficiency of the waste-to-energy plants which includes the plant’s efficiency in recovering the waste’s energy as well as the effective use of this energy made available by the plant.
• The energy produced (Ep), in R1 formula, does not highlight the energy used for the optimization of flue gas treatment, such as for the heating of the flue gas upstream a catalytic reactor or a bag filter (this value can be around 4-5% of the available energy). Besides, the non-recovery of energy in flue gas treatment management may correspond to a value of up to 20-25% of the available energy.
• R1 factor will become binding for the building of new incineration plants, while marketable energy will be a key factor in a highly competitive scenario.
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SOLVAir® bicarbonate process: dry injection of BICAR®
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SOLVAir® bicarbonate process: dry injection of BICAR®
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SOLVAir® bicarbonate process: dry injection of BICAR® • The efficiency of BICAR® is optimal between 140 and 300 ◦C, this allows a
consistent temperature profile along the flue gas line and enables the use of the catalytic device at the same temperature as the bag filter, saving the energy often used to re-heat the gases.
• BICAR® has a high reactivity towards SO3 and SO2 minimizing the risk of ammonium bisulfates formation on the catalyst layers.
• A heat exchanger upstream the stack increases the marketable energy by globally improving recovery efficiency (in some practical applications a value of 131 kWh per ton of MSW has been evaluated in a temperature range from 185 to 135 ◦C).
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Energy recovery
• Thanks to its simplicity and its wide range of operating temperatures, SOLVAir® process allows recovering much more energy than any other kind of flue gas treatment.
• Waste-to-energy plants using SOLVAir® process with BICAR® showed very high net conversion yields on input, as ratio of marketable energy to waste calorific value input, from around 70% to 88%.
• According to CEWEP (Confederation of European waste-to-energy plants) reports dated 2013, gathering data from 314 waste-to-energy facilities, the average net conversion yield is about 40%.
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Energy flow sheet in a waste-to-energy plant
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Examples of net conversion yields vs flue gas treatment systems
Wet
F.G
.T.
MSW
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emi-w
et o
r sem
i-dry
F.G
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MSW
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SOLV
Air®
M
SWI
Uni
ts
A - Total heat produced and used 1176 1359 1621 kWh/t MSW
B - Total electricity produced and used 405 407 410 kWh/t MSW
C - Total imported energy (heat + electricity) 62 62 62 kWh/t MSW
D - Waste net calorific value 2813 2813 2813 kWh/t MSW
E - Heat internally spent 314 131 0 kWh/t MSW
F - Electricity internally spent 40 38 35 kWh/t MSW
G - Tail-end heat recovery 0 0 131 kWh/t MSW
I - Marketable heat 862 1228 1621 kWh/t MSW
J - Marketable electricity 365 369 375 kWh/t MSW
Overall losses (internal use + boiler losses) 1586 1216 817 kWh/t MSW
Heat net conversion yield on input 30% 43% 56% %
Electricity net conversion yield on input 13% 13% 13% %
Total net conversion yield on input 43% 56% 69% %
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Marketable energy
• R1 factor takes into consideration total heat produced and used and total electricity produced and used in relation to the waste net calorific value and the imported energy.
• R1 does not take into consideration the heat and the electricity internally spent or recovered to match the most stringent air emission levels, to operate catalytic DeNOx systems at lower temperature, as well as to extend the service life of flue gas treatment equipment.
• With the use of SOLVAir® Solutions with BICAR® sodium bicarbonate the marketable heat is particularly significant, influencing the heat net conversion yield on input.
• An existing facility in Italy using SOLVAir® Solutions with BICAR® and with an optimized CHP (combined heat and power) has demonstrated a net energy yield on input of almost 88%.
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SOLVAir® net conversion yield vs average CEWEP plants
Aver
age
CEW
EP
314
EU P
lant
s (2
013)
SOLV
Air®
M
SWI E
xam
ple
Italy
(2
011)
Uni
ts
A - Total heat produced and used (G included) 1001 2274 kWh/t MSW
B - Total electricity produced and used 431 544 kWh/t MSW
C - Total imported energy (heat + electricity) 31 0 kWh/t MSW
D - Waste net calorific value 2863 3055 kWh/t MSW
E - Heat internally spent 212 0 kWh/t MSW
F - Electricity internally spent 73 107 kWh/t MSW
G - Tail-end heat recovery - - kWh/t MSW
I - Marketable heat 789 2274 kWh/t MSW
J - Marketable electricity 358 437 kWh/t MSW
Overall losses (internal use + boiler losses) 1716 344 kWh/t MSW
Heat net conversion yield on input 27% 74% %
Electricity net conversion yield on input 12% 14% %
Total net conversion yield on input (approximate value) 40% 88% %
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Economic advantages of SOLVAir® Solutions
• Low capital expenditure required.
• Simplicity and reliability of SOLVAir® Solutions allow extending the service life of plant equipment.
• Particularly significant is the minimization of energy needed in combination with low temperature catalytic DeNOx systems.
• The increased marketable heat compared to other flue gas treatments results in a very significant economic advantage.
• Considering an energy index of 0,031 €/kWh, referring to natural gas price for industrial consumers in Italy, the energy savings are represented in the following charts
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Economic advantages of SOLVAir® Solutions ● medium capacity plants
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Economic advantages of SOLVAir® Solutions ● medium-large capacity plants
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Economic advantages of SOLVAir® Solutions ● large capacity plants
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Technical and economic advantages of SOLVAir® Solutions vs hydrated dry lime process • Reference plant:
- medium capacity (140 kt / year) - LHV 2820 kWh / t - output about 50 MW - catalytic DeNOx system (SCR) - temp. downstream HRSG (Heat Recovery Steam Generator) 200 ◦C - electricity net conversion yield 0,21 on input
• Temperature variations along the flue gas treatment line in the two dry processes (SOLVAir® bicarbonate process and hydrated dry lime process) are shown below
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Temperature variations in FGT flue gas treatment: SOLVAir® Solutions vs dry lime process
BICARBONATE
LIME
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Technical and economic advantages of SOLVAir® Solutions vs hydrated dry lime process
• Temperature variations in the two dry processes (SOLVAir® bicarbonate process and dry lime process) show key technical advantages of bicarbonate vs lime:
- consistent temperature profile from HRSG to SCR - SCR can operate at 200 ◦C thanks to the high efficiency removal of
SO3 and SO2 - in the case of lime it is necessary to cool down to 140 ◦C to allow
acid removal from flue gases and to reheat to 240 ◦C to operate in a safe way with the SCR
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Technical and economic advantages of SOLVAir® Solutions vs hydrated dry lime process
• High acid removal performance of bicarbonate in a wide range of operating temperature allows working at reduced risk of acidic condensate formation.
• Consistent temperature profile allows avoiding a regenerative gas / gas heat exchanger - needed instead in the hydrated lime process - with related economic advantages.
• High acid removal performance of bicarbonate allows a reduction of dew point which makes energy recovery downstream SCR actually available with related economic advantages.
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Economic advantages of SOLVAir® Solutions vs hydrated lime ● medium capacity plants
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0,6
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Economic value of marketable energy
• The reported charts show the following:
- in medium capacity plants with 120 kt/y the economic saving allowed by
SOLVAir® in comparison to semi wet / dry is around 1,5 M€/y and in comparison to wet is around 2,9 M€/y
- in medium-large capacity plants with 200 kt/y the economic saving allowed by SOLVAir® in comparison to semi wet/dry is around 2,4 M€/y and in comparison to wet is around 4,7 M€/y
- in large capacity plants with 480 kt/y the economic saving allowed by SOLVAir® with an optimized CHP (combined heat and power) in comparison to CEWEP average plant is around 23 M€/y
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Economic value of marketable energy
• The reported charts show the following:
- in medium capacity plants with 140 kt/y the economic saving allowed by SOLVAir® in comparison to hydrated lime dry process can vary from 0,4 to 0,6 M€ according to the efficiency of the heat exchanger prior to the stack.
- the regenerative gas / gas heat exchanger needed in the hydrated lime dry process to reheat the flue gases prior to SCR additionally influences the economic balance in favor of SOLVAir® solutions.
• The increased marketable heat allowed by SOLVAir® Solutions compared to other flue gas treatments is very significant for medium and large plants, determining a very valuable economic benefit, above all in the difficult waste-to-energy context.
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