Assessment of Energy Consumption in a Meat-Processing Plant—a Case Study
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Assessment of Energy Consumption in a Meat-ProcessingPlanta Case Study
Janusz Wojdalski & Bogdan Drd & Jzef Grochowicz &Anna Magry & Adam Ekielski
Received: 9 March 2012 /Accepted: 29 June 2012# Springer Science+Business Media, LLC 2012
Abstract Meat-processing plants have their specific character-istics due to quantity of raw materials processed, productiontechnology, degree of mechanisation of production and spaceutilization. These characteristics affect variability in consump-tion of energy carriers. This paper presents a case study ofenergy consumption in a small meat processing plant. It isattempting to identify and evaluate key factors which may beuseful in conducting an in-depth analysis of energy consumptionin the meat industry, and so this analysis may be important inselecting the best production techniques available. The results ofthe analysis are of critical importance for the selection of pro-duction technology selection assuming high plant efficiency.
Keywords Meat processing . Energy consumption . Energyefficiency
Abbreviationsa Regression coefficientAc Monthly thermal energy consumption (Ac0BrzQrw, for
Qrw043.1 MJ/kg of fuel)Ae Active electric energy monthly consumption kWh/
monthAt1 Total monthly energy consumption (after conversion
1 kWh012 MJ), in megajoules per monthAt2 Total monthly energy consumption (after conversion
1kWh03,6MJ), in megajoules per monthb Regression coefficient
Bce1 Monthly coal equivalent consumption based on At1,in kilograms CE per month
Bce2 Monthly coal equivalent consumption based on At2,in kilograms CE per month
Brz Monthly real fuel consumption, in kilograms per monthEE Energy efficiency megagrams of product per kilowatt
hour, megagrams of product per gigajoulesn Total number of employees in the plant personP Total capacity of installed electrical equipment, in
kilowattsR2 Determination coefficient (R20r2100 %) in percentUen Power of installed electrical equipment per employ-
ee, in kilowatts per personQce Calorific value of coal equivalent (29.3076 MJ/kg CE)Qrw Calorific value of real fuel, in megajoules per kilo-
gram of fuelV1 Volume of the plant production space, in cubic metersV2 Total volume of the plant, in cubic metersWA Aggregate indicator of energy consumption per unit
of physical output (aggregate indicator of specificenergy consumption SECA)
WP Production indicator of energy consumption per unitof physical output (production indicator of specificenergy consumption SECP)
WT Technological indicator of energy consumption perunit of physical output (technological indicator ofspecific energy consumption SECT)
WZ Plant indicator of energy consumption per unit ofphysical output (plant indicator of specific energyconsumption SECZ)
Z Monthly production, in megagrams of product per month
Meat processing is one of the branches of the food industry(see Grochowicz and Walczyski 2004; Jekayinfa and
J. Wojdalski : B. Drd :A. Magry :A. EkielskiDepartment of Production Management and Engineering Facultyof Production Engineering, Warsaw University of Life Sciences,Nowoursynowska 166,02-787 Warsaw, Poland
J. Grochowicz (*)Hotel Management and Catering Technology,Warsaw Academy of Tourism, Food and Hospitality,Chodakowska 50,03-816 Warsaw, Polande-mail: email@example.com
Food Bioprocess TechnolDOI 10.1007/s11947-012-0924-4
Bamgboye 2006; Wang 2008; Kleme et al. 2008; Neryng etal. 1990; Wilhite 2008) for discussion of some aspects ofenergy consumption in the food industry). The energy con-sumption is one of the key production factors in the industry.It has a great impact on the meat processing plant efficiencyand the natural environment. Consumption of energy car-riers in meat processing plants depends on many factorssuch as, for example, size and structure of output, produc-tion technology used, thermo-physical properties of rawmaterials, mechanisation of production processes and utili-zation of processing capacity (see Cierach et al. 2000; Tkaczet al. 2000;Tkacz and Iwaniak 2001; Markowski et al. 2004;Marcotte et al. 2008; Banach and ywica 2010; Houska etal. 2003; Li et al. 2010; Campaone et al.2010; Gogate2011; Norton and Sun 2008). Demand for energy carriersis taken into account, among others, in the EUs IntegratedPollution Prevention and Control Directive which deter-mines a set of rules and requirements for effective protectionof the environment and application of the best availableproduction techniques (WS Atkins Int 1998; EuropeanCommission 2006; Ramirez et al. 2006; IFCWorld BankGroup 2007). Moreover, modern methods of energy man-agement in small manufacturing plants require creation ofdatabases which are useful in analysing energy efficiency offood processing and supply of more detailed input data(Swords et al. 2008).
To assess energy efficiency, unit energy consumption indi-cators as well as energy efficiency indicators are most com-monly used. Efficiency is defined as a result of production(industrial) activity and it is expressed as a quotient of theresult obtained to the effort expended. Improvement in energyefficiency may involve a reduction in demand for energycarriers during their transformation, transmission, and finaluse. It may be due to changes in technology which are capableof providing a constant or a higher level of production. Suchimprovements may result in energy conservation, reducingconsumption of natural resources, reducing emissions andlimiting the amount of waste generated at each stage of meatproduction and processing (Ramirez et al. 2006; Pagan et al.2002; Pimentel et al. 2008).
The available sources in literature show that productionenergy consumption is expressed using different units, and thereasons for variation in energy carriers consumption in meat-processing plants of various sizes were not fully explained(WS Atkins Int 1998; European Commission 2006; Ramirezet al. 2006; Podfilipski and elazny 1985; Singh 1986; Budnyet al. 1987; Fritzson and Berntsson 2006).
Table 1 presents the figures for energy consumption in themeat processing plants referred to in the literature. Differentranges of unit energy consumption indicators listed in Fig. 1were taken into account. Energy efficiency in meat processingis given by using indicators which are difficult to comparebecause they do not relate to specific conditions found in meat
processing plants. Table 1 does not include data from poultry-processing plants which can be found in Drd (2010);Jekayinfa (2007); Wojdalski et al. (2009).
The aim of this study was to determine the energy con-sumption of a small-sized pork meat processing plant. Thisstudy aims to provide detailed data which could be useful increating models of enterprises of this kind as energy users aswell as for determining the relationship between productionvolume and energy carriers consumption which serves toevaluate energy efficiency of production. The aim of thestudy is also correlated with the study (Bunse et al. 2011),where the authors indicate a gap between the needs forresearch reported by manufacturing plants and scientificpublications currently on offer.
Materials and Methods
The research data were collected in a meat processing plant inMazowieckie Voivodship, Poland, employing 73 people intotal, among whom 33 were directly involved in production.
The plant did not slaughter animals. Pre-treated frozencarcasses were purchased from slaughter plants.
Monthly production (Z) during the study period rangedfrom 303 to 699 Mg. The annual plant production profile:meat products 78.4 % and unprocessed meat 21.6 % of totalproduction.
The plants production area was 994.28 m2; the totalvolume of the plant was 6,336.6 m3 of which the productionspace accounted for 78.1 %. The combined power of allinstalled electrical equipment in the plant (P) was 180 kW.Breakdown of power by type of electrical equipment in theplant is shown in Table 2.
Table 2 shows that the largest category on the powerbalance sheet was meat cutters and grinders (22 %).
The values of the indicator expressing the degree ofmechanisation of the production operations (Table 4) mea-sured in several 1-month intervals during study ranged from0.257 to 0.594 kW/Mg of processed products. The plantused conventional technologies to produce meat, meat prod-ucts, and raw and melted animal fat.
Meeting the goals of the study required, among others,using a model of the meat processing plant as the end-userof energy carriers (Fig. 1) and applying the plant indicatorsof energy carriers consumption, as applied in the study(Wojdalski et al. 2010). These indicators cover all energyreceivers associated with transformation and use of energycarriers in the plant as a whole. The indicators WA, WT andWP are less informative as far as energy consumption of theplant is concerned. A study of these indicators is not withinthe scope this paper. They are included however in Fig. 1because some of them are cited in the literature and reportedin Table 1.
Food Bioprocess Technol
It should be noted that these research methods could bemodified to include the issues concerning combined heat andpower as presented, among others, in the papers by Bianchi et al.(2006) and Bieranowski and Klonowski (2005).
To assess energy efficiency of production in the analysedplant, we used the indicator method, which allows onlineanalysis of the plant performance. It is possible, by compar-ison with results obtained in similar plants, to indicatedirections of possible changes aimed at increasing energy
efficiency. In order to characterise the energy managementof the plant, the indicators contained in Table 3 were adop-ted. These indicators cover the WZ range shown in Fig. 1.The indicators listed in rows 8, 10 and 13 take into accountthe efficiency (00.3) of electric energy generation and itstransmission too.
From the cost and specific technology evaluation stand-points, it is important to use a value indicator which includestotal energy consumption in the processing plant. To achieve
Table 1 Available research data on energy carriers consumption in the meat processing industry
Energy carriers Symbols and units Indicators Average Source
Electric energy We [kWh/Mg of meat batter] WZ 802,420 720 WS Atkins Int (1998)
We [kWh/Mg of product] WZ 708,140 1,260 WS Atkins Int (1998)
WT 65.396.3 Neryng et al. (1990)
WA 44112 Tkacz (2002)
WZ 269279 Kowalczyk & Netter (2008)
We [kWh/Mg of meat] WZ 37.052.0a 44.5a Wojdalski et al. (2010)
We [kJ/kg of meat batter] WA 420 Dolata (1992)
Thermal energy Wc [GJ/Mg of meat batter] WZ 5.8958.1 12.9 WS Atkins Int (1998)
Wc [MJ/Mg of meat] WZ 9701,110a 1,040a Wojdalski et al. (2010)
Wc [Mg of coal/Mg of meat batter] WZ 0.96 WS Atkins Int (1998)
Wc [GJ/Mg of product] WZ 0220 24.5 WS Atkins Int (1998)
WZ 3.144.27e 3.61e Skonecki et al. (2001)
WZ 2.102.26 Kowalczyk & Netter (2008)
Wc [kg of steam/Mg of product] WZ 800900 European Commission (2006)
Wc [MJ/unit] WT 31.863.0a 44.6a Neryng et al. (1990)
WT 22.845.2b 32.6b
Total energy Wc [MJ/Mg dress carcass weight]for whole and chilled
WZ 1,390c Ramirez et al.(2006)
Wt2 [MJ/Mg dress carcass weight]for whole and frozen
Wt2 [MJ/Mg dress carcass weight]for cut-up, deboned and chilled
Wt2 [MJ/Mg dress carcass weight]for cut-up, deboned and frozen
Wt1 [MJ/Mg of meat] WZ 1,4201,720a 1,570a Wojdalski et al. (2010)
Wt2 [MJ/Mg of meat] WZ 1,1101,280a 1,195a
Wt2 [MJ/Mg of HSCW] WZ 1,2004,800f Hansen et al. (2000)
Coal equivalent Wce1 [kg CE/Mg of meat] WZ 48.458.7a 53.6a Wojdalski et al. (2010)
Wce2 [kg CE/Mg of meat] WZ 37.943.7a 40.8a
a Pig slaughterb Cattle slaughterc Beef, veal and sheepd Porke Energy supplied by water steamfHSCW hot standard carcass weight
Food Bioprocess Technol
this aim, the unit energy consumption indicators were adop-ted (items 6 and 7 in Table 3).
These indicators (Wt1 and Wt2) were converted into unitenergy consumption of coal equivalent based on Eqs. 8 and9 (Table 3).
Indicators of total energy consumption (Wt1 and Wt2)were also converted into energy obtainable from various
alternative sources using the equations given (see items 10and 11 in Table 3). Thus, obtained results are mainly oftheoretical importance, since the change of energy carrier isassociated with the need to modify the energy conversionsystem in the boiler house. To express the energy efficiencyof meat processing, three sample indicators were applied(see items 1214, Table 3).
Similar research methodology for analysis of the en-ergy consumption in agro-food plants is presented in thecited literature (Wojdalski and Drd 2006; Kaleta andWojdalski 2008).
It is assumed that the monthly production volume (Z)has an impact on demand for energy carriers in theprocessing plant. Previous studies have shown that thisfactor has the greatest relevance because of environmen-tal impact assessment of meat processing plants anddetermination of the best production techniques avail-able (WS Atkins Int 1998; European Commission 2006;IFCWorld Bank Group 2007; Wojdalski et al. 2010;Simpson and Kubicki 1998).
t of m
Steaming and Cooking
Washing machines and
Meat products for distribution
Production of water vapor (steam
generator) and hot water
Preparation of refrigeration
(Ammonia compressor) and flakes ice
Water for process and manufacturing operations and for washing
Replenishment of water losses
water from the
Fig. 1 Material and energy flows in the analysed plant
Table 2 Breakdown of power by type of electrical equipment
Item Equipment Power installed [kW]
1 Cutters and grinders 40.0
2 Smoke houses, cookers 28.0
3 Cooling machine and ice generator 10.0
4 Electrical boilers 7.0
5 Tumbler 5.5
6 Plant lighting 9.0
7 Other devices up to 5 kW 80.5
8 Total 180.0
Food Bioprocess Technol
In order to determine the impact of meat production (Z)on the actual energy carriers consumption (Y), Eq. (1) wasapplied:
Y b aZ 1
where Y is the energy carriers consumption (the dependentvariable, e.g., We, Wt1) and Z is the mass of meat processing(the explanatory variable).
Assumption of border conditions:
aZ b 2
Z > 0 3
using the obtained regression equations with the borderconditions met can partly explain this issue in the analysedmeat-processing plant.
The use of regression equations to characterise energyconsumption in food plants in different seasons is shown indetail in Muller et al. (2007) and Wojdalski and Drd(2006). The methodology for determining energy consump-tion of production processes presented by Jekayinfa andBambgboye (2006) may also be found of use in meat-processing plants.
Results and Discussion
Table 4 shows the ra...