6Odour Concentrations OU/m3 Odour concentration may fluctuate significantly from plant to plant!
7ODOUR PERCEPTION AND INTENSITY Extremely strongVery strongStrongPerceptibleWeakVery weakNo odourOdour concentration Ou/m³Odour Intensity:When the concentration of (odorous) compounds is several times higher than the odour threshold, the human nose does not perceive it like that.The figure shows the relationship. It also explains why a relatively high reduction of the odour emission (in percentage) will not necessarily be perceived as such.
8ODOUR EMISSION OU/H PET FOOD FACTORY 2 LINES 13% of total odour emission
9Environmental Solutions Cleaning efficiency1. Chimney0 % (Only dilution)2. Ozone Reactor (Plasma)70 – 85 %3. Bio or Chemical Scrubber(s)70 – 90 %4. Bio Filter70 – 95 %5. RTO Oxidizing90 – 98 %6. Recirculation/Condensation incl. Coal Filter98 – 99 %
101. Chimney: Efficiency 0% Chimney Dryer/cooler Cyclone/filter Photo left:Plume of smoke (winter conditions)Photo right:Stack/chimney taller than 100 m is not unusual
156A. Total Recirculation incl. coal Filter: Efficiency 98 – 99% Dryer/coolerCyclone/filterAir treatmentBio/ Coal filterPhoto left:Air treatment unit incl. bag filterPhoto right:Cooling tower
166B. Energy recovery and odour reduction Reduction in odour emission: %Thermal energy recovery: ~ 15 – 50 kWh/ton
17SummarySolution:Cleaning efficiencyCapital investment costs for each cbm air/h to be cleanedAnnual operating costs for each cbm air/h to be cleanedChimney0 %Very lowVery LowOzone/plasma Reactor70 – 85 %LowHighBio/Chemical or Sea Water Scrubber(s)70 – 90 %Bio Filter70 – 95 %MediumRTO Oxidizing90 – 98 %Very HighRecirculation/Condensa-tion incl. Coal/Bio Filter98 – 99 %Low** The annual operating cost for this solution is very low because the solution includes energy recovery!
19Energy consumptionThe total energy consumption (thermal and electrical) can normally be reduced to less than 220 kWh per ton of final product in extruded feed, and drying is the most energy consuming process
20ENERGY DISTRIBUTION THERMAL ENERGY CONSUMPTION ELECTRICAL ENERGY CONSUMPTION
21THERMAL ENERGY RECOVERY SOLUTIONS Thermal energy for drying accounts for 60% of the total thermal energy consumption4 solutions to recover energy from drying:Cross flow air/air heat exchangerAir/water heat exchangerAir/water heat exchanger in combination with high temperature heat pumpsAir/water heat exchanger and recirculation of dryer airAll 4 solutions will in addition to energy recovery have an odour reduction effect off 30 – 85%Additionnal air treatment system can increase odour reduction effect to 99%
22SOLUTION 1: Cross flow AIR/AIR HEAT EXCHANGER Cross flow air to air exchanger (HE)Up to 50% energy recovery possibleCondensation in air and low temperature energy may be a problemOdour reduction effect below 50%HEDRYER/COOLER
23SOLUTION 2: AIR/WATER HEAT EXCHANGER Air to water exchangers (HE)Up to 40% energy recovery possibleCondensation and low temperature energy may be a problemOdour reduction effect below 50%HEHEDRYER/COOLER
24SOLUTION 3: AIR/WATER HEAT EXCHANGER IN COMBINATION WITH HIGH TEMPERATURE HEAT PUMP Air to water exchangers (HE) in combination with high temperature (80 – 110°C) heat pump (HP)Up to 70 % energy recovery possibleCondensation in air may be a problemOdour reduction effect above 50%HEHPHEDRYER/COOLER
25SOLUTION 4: AIR/WATER HEAT EXCHANGER AND RECIRCULATION OF DRYER AIR Air to water exchangers in combination with recirculation of dryer airUp to 20% energy recovery possibleCondensation in air may be a problemHygiene risk in recirculation air to be consideredOdour reduction effect above 85%HEDRYER/COOLER
27summaryEnergy recovery of dryer exhaust air and other process air sources may save 20 – 100 kWh of thermal energy per ton of final productIntegration of energy, odour and carbon dioxide reducing technologies are in most cases a very cost effective solutionNew technology inventions in the fields of heat exchangers and heat pumps will bring further future possibilities to recover energy and reduce carbon dioxide emissions from the pet food industry