Optimization of energy savings in shoe sole production

Od 1970-ih godina najpopularniji potplati cipela jesu EVA potplati, napravljeni od etilen vinil acetata, kopolimera koji se sastoji od etilena i vinil acetata. Duromeri i elastomeri (gume), među koje ubrajamo i EVA polimere, čine oko 30% ukupne proizvodnje u tonama svih proizvedenih sintetskih polimera, pri čemu gume sintetskog podrijetla premašuju količinom proizvodnju guma prirodnog podrijetla. Imajući tu činjenicu na umu, energetske uštede u tvornicama proizvodnje gume iznimno su važne, a ovaj rad analizira potencijale energetskih ušteda u proizvodnji potplata za cipele napravljenih od etilen vinil acetata (EVA). EVA potplati za cipele jesu lagani, jednostavni za modeliranje, vodootporni i vlagootporni, jako elastični, amortiziraju udarce, dobri su toplinski izolatori, iznimno su otporni itd. Energetske uštede povratom topline procesnoga kondenzata prezentirane su u procesu proizvodnje potplata za cipele. Povrat topline kondenzata rezultira smanjenom potrošnjom pojne vode, znatnim uštedama goriva potrebnog za proizvodnju pare i rezultiraju smanjenom potrošnjom kemikalija potrebnih u proizvodnom procesu. Povrat vreloga procesnoga kondenzata u kotao rezultira smanjenjem potrošnje nafte 14,9 %. Također se smanjuje toplinsko zagađenje 95,3 %, dok se volumen ispušnih plinova smanjuje od 17,11 m3FG/kgNEC do 14,57 m3FG/kgNEC ili 14,8 %. Ovakav sustav omogućuje istodobnu uštedu nafte i smanjenje toplinskog zagađenja. Usporedbom procesa s povratom topline dimnih plinova u odnosu prema procesu bez povratka topline dimnih plinova, pokazuje uštede od 18,76 %, uz smanjenje temperature dimnih plinova sa 221° C na 137,39° C, pri čemu se volumen dimnih plinova smanjuje na 13,90 m3FG/kgP.Since 1970’s, the most popular shoe soles are (EVA) soles, made from Ethylene Vinyl Acetate, copolymer consisting of ethylene and vinyl acetate. The thermosets and elastomers (rubbers), among them accounting EVA, encompasses around 30% of the tonnage of all synthetic polymers produced, with the synthetic rubbers exceeding the tonnage of natural rubber. With that in mind, the energy savings in rubber processing plants are of great importance and the paper analyses the potential of energy savings in shoe soles production process made of Ethylene Vinyl Acetate (EVA). The shoe soles made from EVA are lightweight, easy to mould, water and moisture resistant, highly elastic, shock absorbent, great thermal insulators, highly durable, etc. The energy savings using the process return condensate in shoe sole production process are presented. Using the return condensate results in lower make up water consumption, substantial fuel savings needed to produce steam
and lower chemical consumption. Returning hot process condensate to the boiler results in oil savings of 14,9%. Also, the thermal pollution is reduced by 95,3%, while the volume of the flue gases is lowered from 17,11 m3FG/kgNEC to 14,57 m3FG/kgNEC or by 14,8%. Such a system enables both the oil savings and reduces the thermal pollution. The comparison of process with and without flue gases heat recovery shows fuel savings of 18,76%, while the temperature reduces from 221°C to 137,39°C and while the volume of the flue gases is lowered to 13,90 m3FG/ kgP

ENERGY SAVINGS AND ENVIRONMENTAL PROTECTION APPLYING COGENERATION

Porast energetske učinkovitosti u industrijskoj proizvodnji uz istodobno smanjenje opterećenja okoliša može se postići primjenom kogeneracije kao i sekundarnih izvora, tj. povrata procesnog kondenzata. Predlaže se zamjena uobičajene odvojene opskrbe električnom energijom iz mreže i proizvodnjom topline u kotlovskom postrojenju kogeneracijom, odnosno kombiniranom proizvodnjom toplinske i električne energije (CHP). Analizirane opcije usmjerene na smanjenje potrošnje primarnog izvora ukazuju na značajne uštede. Usporedba odvojene proizvodnje toplinske i električne energije i konvencionalne proizvodnje električne energije rezultira poboljšanjem od oko 34%. Povrat procesnog kondenzata u konvencionalnom procesu daje uštedu od oko 7%, dok se u kogeneracijskom postiže oko 16%. Istovremeno sniženjem potrošnje goriva, za istu isporučenu energiju, uz porast ekonomičnosti ostvaruje se i smanjenje toplinskog i kemijskog opterećenja okoliša.Increased industrial energy efficiency and also lower environmental pollution could be achieved through the application of cogeneration as well as secondary sources i.e. reusing process condensate. Proposed here is replacement of the conventional system of separate electrical energy and thermal energy from a boiler plant with cogeneration, i.e. with combined heat and power production (CHP). Analysed options aimed at reducing the consumption of the primary source indicate significant savings. Comparison between cogeneration and conventional energy production results in savings of about 34%. Condensate heat recovery in the conventional process is about 7%, while in CHP process it reaches about 16%. In addition, fuel savings for the same amount of produced energy translate to gretaer economy and environmental benefits

Impact of hybrid system in polyester production

This study represents the evaluation of energy efficiency improvement using combination of natural gas, solar energy and flue gases heat recovery in polyester production. The analyzed energy sources are used for dry saturated steam generation. The energy consumption for combined system on location (φ = 45°49′) with collector field of 23.23 × 103 m2, was investigated. The hybrid system was calculated for four variants: (1) solarized process without flue gases heat recovery, (2) solarized processes with heat contend in flue gases using economizer, (3) solarized processes with heat contend in flue gases using an air preheater and (4) solarized processes with heat contend in flue gases using economizer and air preheater. The best method among presented sources is solution using economizer and the air preheater with natural gas, solar energy and flue gases heat recovery. The natural gas consumption is reduced for 67.82% which indicates that this solution is the optimal one. At the same time the volume of exhaust flue gases is diminished from 4947.1 to 1430.4 $m^3_{\text{FG}}$/h while simultaneously decreasing outlet temperature of 172.85°. Together with considerable energy savings, this hybrid system is sustainable and environmentally acceptable