TEKA Kom. Mot. Eneg. Roln. OL PAN, 2007, 7, 277 285 FACTORS INFLUENCING ENERGY CONSUMPTION IN FRUIT AND VEGETABLE PROCESSING PLANTS Janusz Wojdalski, Bogdan DóŜdŜ, Michał Lubach Poduction Engineeing Depatment, Wasa Agicultual Univesity Noousynoska St. 166, 02-787 Wasa, Poland, e-mail: ip koip@sgg.a.pl Summay. Results have been pesented of eseach on vaiability of total enegy in fuit and vegetable pocessing plants. Reasons have been explained fo the vaiability of pe unit enegy consumption indices taking into account the impact of vaious technical and technological factos. Pe unit fuel and enegy consumption indices have been obtained that can be applied in detemining envionment standads and poduction costs. Key ods: fuit and vegetable pocessing industy, poduction enegy consumption, company pe unit fuel and enegy consumption indices SPECIFICATION OF DESIGNATION CODES 6 A c heat enegy consumption pe tenty-fou hou peiod (A c = B z Q 10 ), GJ/24 h A e active electical enegy consumption, kw h/24 h A t1 total enegy consumption (taking into account convesion facto 1 kw h = 0.012 GJ), GJ/24 h A t2 total enegy consumption (taking into account convesion facto 1 kw h = 0.0036 GJ), GJ/24 h B pu coal equivalent consumption pe tenty-fou hou peiod, kg/24 h B z eal fuel consumption, kg/24 h K 2 pocessing plant cubic capacity pe 1000 kg (1 Mg) of pocessed a mateial pe tenty-fou hou peiod, m 3 /Mg K m installed capacity pe 1000 kg (1 Mg) of pocessed a mateial pe tenty-fou hou peiod, kw/mg P total installed capacity of electical appliances in the pocessing plant, kw P 1 total installed capacity of electical appliances in the pocessing plant boile-house, hydophoe-oom, ate teatment station, kw P 2 installed capacity of electical appliances elated to fuel stoage and tanspotation, kw P 3 installed capacity of electical appliances used in stoage, feezing and aiconditioning (inclusive of ammonia compessos), kw
278 Janusz Wojdalski, Bogdan DóŜdŜ, Michał Lubach P 4 installed capacity of electical appliances used fo the poduction of pepaed food and fuit and vegetable peseves, kw R 2 coefficient of detemination, Q u caloific value of coal equivalent (0.0293076 GJ/kg), Q caloific value of eal fuel, kj/kg W pu1 pe unit coal equivalent consumption company index, ith the inclusion of the elation 1 kw h = 0.012 GJ, kg of coal equivalent/mg of a mateial pocessed W pu2 company index of pe unit coal equivalent consumption, ith the inclusion of the elation 1 kw h = 0.0036 GJ, kg of coal equivalent/mg of a mateials pocessed W z1 company index of pe unit eal fuel consumption, ith the inclusion of the elation 1 kw h = 0.012 GJ, kg of eal fuel/mg of a mateials pocessed W z2 company index of pe unit eal fuel consumption, ith the inclusion of the elation 1 kw h = 0.0036 GJ, kg of eal fuel/mg of a mateials pocessed W t1 company index of total pe unit fuel consumption, ith the inclusion of the elation 1 kw h = 0.012 GJ, GJ/Mg of a mateials pocessed W t2 company index of total pe unit fuel consumption, ith the inclusion of the elation 1 kw h = 0.0036 GJ, GJ/Mg of a mateials pocessed Z pocessing of a mateials in tenty-fou hou peiod, Mg/24 h Z 1 fozen vegetables poduction volume, Mg/24 h Z 2 fuit concentates poduction volume, Mg/24 h Z 3 fuit juice poduction volume, Mg/24 h Z 4 beveage poduction volume, Mg/24 h INTRODUCTION Most fequently, subject liteatue souces epot esults of enegy consumption eseach ith egad to selected poduction lines o to specific enegy caies. In industial poduction and its effects on the natual envionment it is also necessay to detemine a joint consumption of enegy caies inclusive of altenative ones, and also seeking solutions esulting in a eduction of pollution emission into the envionment. Both enegy consumption and its pattens in individual pocessing plants ae dependent on the folloing factos: seasonability in poduction, poduction technology, divesity of peiodically applied pocesses and unit opeations, multidiectional a mateial pocessing (pocessing stuctue), changeable sevice conditions and absence of simultaneity in sevice duty. The enegy consumption pattens in individual plants in this industy banch also diffe fom one anothe depending on the popotion of heat teatment applied and on the application of efigeation and feezing [Singh 1986, Wojdalski et al. 1993, and Hackett et al. 2005]. Fo example, papes published by Classen [1992] and Gzybek [2003] do not fully explain hat factos affect enegy consumption volume of entie pocessing plants inclusive of aggegate enegy consumption. Up to date publications by Wojdalski et al. [2006a and b] povide sepaate explanations fo easons of vaiability in electical and heat enegy consumption. Pe unit consumption of individual enegy caies diffes depending on poduction technology and pocessing plant technical equipment. Thee is also a lage vaiability of pe unit consumption of heat and electical enegy and cooling ate, e.g. duing the poduction of thickened apple juice hich aises fom Koalczyk's pape [2006].
FACTORS INFLUENCING ENERGY CONSUMPTION... 279 In the subject liteatue, no vaiability anges have been found of plant pe unit enegy consumption indices compising the gand total of electical and heat enegy, the latte being factos that might also affect numeical value theeof. The taget of this pape is to modify the up-to-date applied methods of poduction enegy consumption analysis by the inclusion of indices of pimay pe unit enegy consumption as conveted into coal/oil equivalent and into eal fuel, especially fom eneable souces. Besides, one of the tagets of this pape is to povide mateials helpful in the constuction of models of plants in this industy in the capacity of enegy uses as ell as to seek elationships beteen assumed independent vaiables and a demand fo enegy supplied in the fom of vaious fuels. MATERIAL AND METHODOLOGY Mateials and measuement esults fom 16 fuit and vegetable pocessing plants ee collected in the summe season. The measuements in each of the plants fo hich necessay data sets ee obtained compised fifty tenty-fou-hou peiods. Detailed eseach methods can be found in papes published by Wojdalski and DóŜdŜ [2006], and by Lubach [1999]. Definitions of company pe unit enegy consumption indices ae included in Wojdalski et al. [1998]. Table 1 includes facto goups (independent vaiables) affecting the total enegy consumption at a company index level. Goup (Vaiant) I II Table 1. Factos conditioning enegy consumption in the examined pocessing plants Factos analysed Designation codes applied Z, P P 1, P 2, P 3, P 4 A physical sense, impotance fo the conducted analyses A geneal chaacteistic of the pocessing plants The stuctue of the installed capacity in electical devices used in the pocessing plants III IV Z 1, Z 2, Z 3, Z 4 K 2 The stuctue of 24-hou thoughput o the stuctue of poduction (manufactuing pofile) Indices epesenting the technical and technological equipment level, the manufactuing pocess oganization level, and the land development level Table 1 compises only those vaiables hich ee found to be elevant in the conducted eseach. Papes published up to this date have pesented solely heat o electical enegy consumption. It should be pointed out that in tems of costs and the choice of a specific technology it is impotant to employ the concept of cumulative poduct enegy consumption o an index that ould compise aggegate enegy consumption both in a pocessing plant and afte convesion into pimay enegy. Fo this aim the folloing pe unit enegy consumption indices ee adopted:
280 Janusz Wojdalski, Bogdan DóŜdŜ, Michał Lubach 6 A 0. 012 A + B Q 10 t1 e z W = = t1 Z Z GJ/Mg 6 A 0. 0036 A + B Q 10 t 2 e z W = = t 2 Z Z GJ/Mg The heein above pesented indices ee conveted into coal equivalent and into eal fuel, based on the folloing fomulas: Pocessing plant W pu1 = W t1 /Q u, W z1 = W t1 / Q W pu2 = W t2 /Q u, W z2 = W t2 / Q Table 2. A chaacteistic of the examined fuit and vegetable pocessing plants taking into account selected technical and technological factos Geneal chaacteistic of the plants Max. 24- hou a mateial thoughput Z, Mg Poduction pofile* Mean value of K m facto pe 24-hou peiod kw/mg Mean indices of pe unit enegy consumption fo a 24-hou peiod Aggegate enegy consumption GJ/Mg Coal equivalent kg/mg W t1 W t2 W pu1 W pu2 I 12.4 1; 2; 3 95.0 4.70 4.52 160.4 154.2 II 14.0 1; 4 167.4 19.14 16.49 653.1 562.6 III 137.5 1; 2; 3; 4 177.3 5.87 1.91 200.3 65.2 IV 161.1 3; 4; 5; 6 54.3 5.08 1.66 173.3 56.6 V 154.4 2; 3; 6; 8; 10 59.2 11.92 10.70 406.7 365.1 VI 622.0 1; 2; 4; 7; 8 250.8 11.60 3.80 395.8 129.7 VII 83.4 5; 7; 9 141.3 16.03 8.34 546.9 284.6 VIII 484.4 5; 6; 7 62.1 5.48 1.86 187.0 63.5 IX 232.9 1; 3; 5; 6; 7; 8 105.6 20.45 17.90 697.8 610.8 X 481.8 1; 5; 7; 8; 10 27.9 5.64 4.63 192.4 158.0 XI 351.5 2; 5; 6; 7; 8 182.5 22.36 12.84 762.9 438.1 XII 398.5 1; 4; 5; 7; 8; 10 76.0 11.62 9.46 396.5 322.8 XIII 778.2 5; 6; 7 95.5 13.69 7.79 467.1 265.8 XIV 312.3 3; 5; 6; 7; 8 156.7 17.39 10.88 593.4 371.2 XV 226.9 5; 6; 7; 11 163.1 24.26 11.97 827.8 408.4 XVI 287.9 6; 7; 8; 9 132.4 10.61 7.12 362.0 242.9 * poduction pofile designations: 1 beveages, 2 fuit peseves, 3 vegetable peseves, 4 othe peseves, 5 fozen fuit, 6 fozen vegetables, 7 fuit concentates, 8 juices, 9 iceceam, 10 vegetable concentates, 11 died fuit and vegetables. An assumption as made that the adopted factos (Table 1) as ell as othes specified in the detailed eseach method [Wojdalski and DóŜdŜ 2006] affect the aggegate enegy consumption in the pocessing plants. Those factos ee also adopted on account of thei usefulness fo the assessment of the effect the pocessing plants exet on the envionment and detemination of the best available techniques [Kubicki 1998, WS Atkins Int. 1998, Wojdalski and DóŜdŜ 2004].
FACTORS INFLUENCING ENERGY CONSUMPTION... 281 In ode to explain dependence of Y on a lot of independent vaiables (the eal values obseved in pactice o thei functions), an equation as adopted: Y = a 0 + a 1 x 1 + a 2 x 2 +...+a k x k hee: Y vaiables unde explanation (A t1, A t2, W t1, W t2 ), x explaining vaiables (e.g. K 2, P, P 1, P 2, P 3, P 4, Z, Z 1, Z 2, Z 3, Z 4 ). Once the folloing conditions ae met: a 1 x 1 + a 2 x 2 +...+a k x k a 0 and x i 0 fo i = 1...k. the application of esulting egession equations and taking into account coelation and detemination coefficients ( i R 2 ) enables patial explanation of the subject unde discussion in the analyzed fuit and vegetable pocessing plants. RESULTS The obtained esults make it possible to seek cause and effect elationships beteen the 24-hou-peiod poduction volume of the fuit and vegetable pocessing plants and the consumption of pimay enegy caies. Table 2 pesents data egading pocessing plants (maximum a mateials thoughput volume and stuctue pe 24-hou-peiod, K m indices epesenting the extent to hich thoughput capacity and installed capacity ae used in the thoughput of 1 Mg of a mateial as ell as company indices of pe unit pimay enegy and coal equivalent consumption. The heein pesented data indicate that the pocessing plants diffe significantly in tems of thei technical equipment. In the analyzed plants, values of mean total pe unit enegy consumption and of coal equivalent consumption consideably diffeed fom one anothe and ee dependent on the thoughput stuctue. The smallest values of pe unit enegy consumption and coal equivalent consumption ee found in those plants hee efigeation and feezing epesented a lage popotion of poduction technology. Table 3 compises egession equations epesenting the effect that factos included in the fou adopted goups exeted on the aggegate enegy consumption. Only those equations ee pesented hee the coelation coefficient as geate than 0.7. Taking into account the fist facto goup (Table 1) it can be seen that only the effect of the poduction volume pe 24-hou-peiod and that of the plants' total installed capacity ee elevant. The coelation coefficient () beteen the vaiables exceeded 0.74. Vaiables Goup II (Table 1) seved to sho elationships beteen the installed capacity stuctue and the aggegate enegy consumption. The eseach shoed that the 24- hou enegy consumption vaiability expessed as A t1 quantity as attibuted in 66.6% to the installed capacity of devices employed in stoage, feezing and ai-conditioning (inclusive of ammonia compessos) and electical devices used in the poduction of eadymade food and fuit and vegetable peseves. The incease in enegy consumption expessed by the A t2 equation depends mainly on the installed capacity of electical appliances in the company boile house, hydophoe oom and ate teatment station.
282 Janusz Wojdalski, Bogdan DóŜdŜ, Michał Lubach Independent vaiables goup I II III IV Table 3. Factos affecting vaiability of aggegate enegy consumption in the examined pocessing plants Equation R 2 designation, unit of measuement A t1 = -140.22 + 2.03 Z +0.11 P 0.762 P, kw A t2 = -266.74 + 1.53 Z + 8.02 P 0.556 Z Mg A t1 = 287.8 + 0.26 P 3 430.0/P 4 0.666 A t2 = - 182.6 + 35.06 2 P - 0.02 P 1 2 0.617 A t1 = 401.9 + 0.594 2 0.06 Z +449.89 logz 1 2 +315.28 log Z 3 A t2 = 480.5+4.25 Z 4 +327.79 log Z 2-280/Z 3 0.639 W t1 = - 0.06 + 0.0026 K 2 0.904 W t2 = - 0.29 + 0.0018 K 2 0.898 Independent vaiables P 1, kw P 2, kw P 3, kw P 4, kw Z 1, Mg Z 2, Mg Z 3, Mg Z 4, Mg K 2, m 3 /Mg numeic ange 413 14237 12.4 778.2 41 1715 3 220 81 6566 30 3178 0.1 282.0 0.6 773.0 0.5 312.3 0.8 191.1 307 307692 Ove 59.4% of the effect exeted on the aggegate enegy consumption pe 24-houpeiod epesented by the quantity A t1 as attibuted to quantities Z 1 (poduction of fozen vegetables), Z 2 (poduction of fuit concentates) and Z 3 (poduction of juices) compised in Goup III. The intoduction of quantity Z 4 (poduction of beveages) in the A t2 equation esulted in an incease of R 2 value to 0.639. Goup IV, the last one, supplies esults poving that the pe unit enegy consumption index W t1 as stongly coelated ith the K 2 quantity, since the coelation coefficient amounted to ove 0.95. Coefficient = 0.947, not much smalle, as obtained fo the equation epesenting vaiability of W t2 index, i.e. the aggegate pe unit enegy consumption fo the hole pocessing plant. The esults obtained heein confim a tendency esulting fom vaiant I of a stong effect of the cubic capacity of poduction ooms on the index of aggegate enegy consumption [Wojdalski et al., 2006a]. The K 2 index in the equation (Table 3) is the function of the total pocessing plant cubic capacity and of the thoughput in 24-hou peiod. The esulting equation has the highest usability in conditions of ell-established and faultless opeation, hen K 2 anges fom 1900 to 9300 m 3 /Mg. The application of the esulting equations equies taking the anges into account (Tables 2 and 3). The esulting equations include a lage numbe of vaiables as compaed ith esults of eseach ok conducted by Classen [1992] and Singh [1986] heein enegy consumption as analyzed in fuit and vegetable pocessing industy. Taking into consideation caloific values of vaious fuels included in the subject liteatue [Niedziółka and Zuchniaz 2006, Rosiński et al. 2006], Table 4 pesents the consumption of enegy caies (eal fuel) as a esult of conveting indices W t1 and W t2. Fo the calculations, caloific values Q expessed in GJ/kg of eal fuel ee applied. The calculation esults egad pocessing plant V (Table 3) fo hich the pe unit enegy
FACTORS INFLUENCING ENERGY CONSUMPTION... 283 consumption index W t1 = 10.92 GJ/Mg and hich is nea-aithmetic aveage fo the goup of pocessing plants unde examination. Enegy caies Table 4. Pe unit enegy caie consumption indices fo pocessing plant V Caloific value Q, MJ/kg Pe unit fuel consumption indices W z1 kg/mg of a mateial pocessed W z2 kg/mg of a mateial pocessed Lignite 14.0 851.4 764.3 Had coal 26.0 458.5 411.5 Natual Gas 32.0 372.5 334.4 Fuel Oil 42.6 279.8 251.2 Used Engine Oil 41.5 287.2 257.8 Vegetable Oil 37.5 317.8 285.3 Inflammable Waste 37.2 320.4 287.6 Liquids Wheat Sta 17.3 689.0 618.5 Baley Sta 16.1 740.4 664.6 Maize Sta 16.8 709.5 636.9 Colza Sta 15.0 794.7 713.3 Wood Dust 17.0 701.2 629.4 Sadust 19.3 617.6 554.4 Willo Chips 16.5 722.4 648.5 Pellets 18.0 662.2 594.4 Sta Biquettes 17.1 697.1 625.7 Wood Biquettes 18.0 662.2 594.4 CONCLUSIONS The pesented esults epesent a pogess ith espect to esults compised in the quoted subject liteatue souces. To a geate extent than befoe easons fo the vaiability of the aggegate enegy consumption pe 24-hous ee explained, having taken into account a numbe of technical and technological factos. The esulting equations may come useful fo the monitoing of enegy input and optimization of the aggegate pe unit enegy consumption indices. These esults may also have impotance in ecological suveys conducted in industial plants aimed at the detemination of envionmental standads. Enegy consumption levels of industial plants ith simila poduction pofile diffe fom one anothe a fe times hich poves that thee ae possibilities of enhancing poduction efficiency and deceasing emission of gas pollutants into the envionment.
284 Janusz Wojdalski, Bogdan DóŜdŜ, Michał Lubach The eseach esults also lead to the folloing conclusions: 1. The vaiability ange fom 55.6 to 76.2% of 24-hou enegy consumption level as explained by a plant's total installed capacity and the volume of its 24-hou thoughput. 2. The most useful facto in poviding explanation fo vaiability of aggegate pe unit enegy consumption indices pe a a mateial unit of thoughput is (K 2 ) facto hich is a function of the plant's total volume capacity and 24-hou thoughput, and to hich ca. 90 % of vaiability of fuel and enegy consumption indices W pu1, W pu2, W t1 i W t2 ee attibuted. 3. The aggegate 24-hou enegy consumption level and its pe unit consumption indices ae efeed to data defining poduction stuctue and technical equipment of pocessing plants and, patly, to land development; fo these easons the eseach esults can be found useful in industial pactice. 4. The esulting equations patly contibute to supplying explanation to athe pooly investigated poblems in this espect and can be used ith the vie of defining standads of the best available techniques and enegy saving by plants applying fo the issuance of integated pemits as ell as defining poduction costs hen an enegy caie is substituted. The esults pesented heein constitute a supplement to the knoledge compised in Gzybek's study [2003]. Besides, they ae coelated ith the ok of Hackett et al. [2005] including enegy saving calculation esults fo seven plants of diffeent sizes. REFERENCES Classen J. 1992: Pocessing Enegy Requiements fo Seveal Vegetables. Tans. ASEA, 35(3), 973 974. Gzybek A. 2003: Wpły ybanych technologii na śodoisko i enegochłonność pzetósta oocoo-azynego. Rozpay habilitacyjne n 12. InŜ. Roln. 2 (44). Hackett B., Cho S., Ganji A.R. 2005: Enegy Efficiency Oppotunities in Fesh and Vegetable Pocessing/Cold Stoage Facilities. Pape pesented in the 2005 ACEEE Summe Study on Enegy Efficiency in Industy, July 19 22. West Point, NY. Koalczyk R. 2006: Analiza technologiczno-techniczna podukcji zagęszczonego soku jabłkoego. Rozpay Naukoe i Monogafie. SGGW, Waszaa. Kubicki M. (ed.) 1998: Ochona śodoiska pzemyśle oocoo-azynym. Wyd. FAPA, Waszaa, 30 36, 38 43. Lubach M. 1999: Wpły ybanych czynnikó na enegochłonność zakładó pzemysłu oocoo-azynego. Rozpaa doktoska. SGGW, Waszaa. Niedziółka I., Zuchniaz A. 2006. Analiza enegetyczna ybanych odzajó biomasy pochodzenia oślinnego. MOTROL, Motoyzacja i Enegetyka Rolnicta. Lublin, tom 8A, 232 237. Rosiński M., Futak L., Łuksa A., Stępień A. 2006: Wykozystanie olejó oślinnych i uządzeń do spalania pocesach suszaniczych. MOTROL, Motoyzacja i Enegetyka Rolnicta. PAN Lublin, t. 8A, 243 250, Singh R.P. 1986: Enegy Accounting of Food Pocessing Opeations (in Enegy in Food Pocessing). Elsevie, Amstedam Oxfod Ne Yok Tokyo, 33, 36. Wojdalski J., Domagała A., Kaleta A., Janus P. 1998: Enegia i jej uŝytkoanie pzemyśle olno-spoŝyczym. SGGW, Waszaa, 10 11. Wojdalski J., DóŜdŜ B. 2006: Podstay analizy enegochłonności podukcji zakładó pzemysłu olno-spoŝyczego. MOTROL, Motoyzacja i Enegetyka Rolnicta. Lublin, t. 8A, 294 304.
FACTORS INFLUENCING ENERGY CONSUMPTION... 285 Wojdalski J., DóŜdŜ B., Lubach M. 2006a: Uaunkoania gospodaki cieplnej zakładach pzetósta oocoo-azynego. MOTROL, Motoyzacja i Enegetyka Rolnicta PAN Lublin, t. 8A, 286 293. Wojdalski J., DóŜdŜ B., Lubach M. 2006b: Factos Influencing Electical Enegy Consumption in Fuit and Vegetables Pocessing Plants. CIGR Intenational Symposium, Wasa. 2nd Technical Symposium of CIGR Section VI. XII BEMS 2006 (12th National Symposium on Food Engineeing). Collection of Extent Abstacts, Wasa, 26 28 Apil 2006, 243. Wojdalski J., Gzybek A., Rogulska M. 1993: Stuktua i moŝliości acjonalizacji zuŝycia enegii zakładach pzemysłu oocoo-azynego. Pzem. Fement. i Ooc.-Waz., 3, 12 16. WS Atkins Intenational 1998: Ochona śodoiska pzemyśle olno-spoŝyczym. Standady śodoiskoe. FAPA, Waszaa, 66 69, 107.