electronic supplementary material
LCA for machines
Life cycle assessment of horizontal-axis washing machines in China
Zengwei Yuan1 • You Zhang1 • Xin Liu1
Received: 20 November 2014 / Accepted: 27 October 2015
© Springer-Verlag Berlin Heidelberg 2015
Responsible editor: Chris Yuan
1State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
Zengwei Yuan
1Data sources
The background processes are from Ecoinvent and PE professional database. The detailed information about background processes is shown in Table SI 1.
Table SI 1 The detailed information about background processes
Name / SourceCH: heavy fuel oil, at refinery [fuels] / Ecoinvent database
CN: electricity, production mix CN [production mix] / Ecoinvent database
DE: concrete block, at plant [concrete] / Ecoinvent database
DE: natural rubber based sealing, at plant [others] / Ecoinvent database
GLO: cable, ribbon cable, 20-pin, with plugs, at plant [Parts] / Ecoinvent database
GLO: coke oven gas, at plant [fuels] / Ecoinvent database
RER: acrylonitrile-butadiene-styrene copolymer, ABS, at plant [polymers] / Ecoinvent database
RER: carbon monoxide, CO, at plant [inorganics] / Ecoinvent database
RER: cast iron, at plant [Benefication] / Ecoinvent database
RER: compressed air, average generation, <30kW, 12 bar gauge, at compressor [Compressed air generation] / Ecoinvent database
RER: copper product manufacturing, average metal working [General manufacturing] / Ecoinvent database
RER: copper, secondary, at refinery [Benefication] / Ecoinvent database
RER: corrugated board base paper, kraftliner, at plant [cardboard & corrugated board] / Ecoinvent database
RER: epoxy resin, liquid, at plant [monomers] / Ecoinvent database
RER: inron scrap, at plant / Ecoinvent database
RER: flat glass, uncoated, at plant [construction] / Ecoinvent database
RER: nylon 6, at plant [polymers] / Ecoinvent database
RER: paper, woodcontaining, supercalendred (SC), at plant [graphic paper] / Ecoinvent database
RER: phosphoric acid, industrial grade, 85% in H2O, at plant [inorganics] / Ecoinvent database
RER: polyethylene, HDPE, granulate, at plant [polymers] / Ecoinvent database
RER: polypropylene, granulate, at plant [polymers] / Ecoinvent database
RER: polystyrene, general purpose, GPPS, at plant [polymers] / Ecoinvent database
RER: polyvinylchloride, at regional storage [polymers] / Ecoinvent database
RER: polyvinylidenchloride, granulate, at plant [polymers] / Ecoinvent database
RER: sheet rolling, steel [processing] / Ecoinvent database
RER: soap, at plant [Surfactants (tensides)] / Ecoinvent database
RER: soda, powder, at plant [inorganics] / Ecoinvent database
RER: sodium hydroxide, 50% in H2O, diaphragm cell, at plant [inorganics] / Ecoinvent database
RER: steam, for chemical processes, at plant [Auxiliary material] / Ecoinvent database
RER: steel, low-alloyed, at plant [Benefication] / Ecoinvent database
RER: sulphuric acid, liquid, at plant [inorganics] / Ecoinvent database
RER: synthetic rubber, at plant [polymers] / Ecoinvent database
RER: tap water, at user [Appropriation] / Ecoinvent database
RER: transport, lorry 16-32t, EURO4 [Street] / Ecoinvent database
DE: Calcium hydroxide, 50% in H2O, diaphragm cell, at plant / PE database
EU-27: landfill of ferro metals PE / PE database
EU-27: landfill of glass/inert waste PE / PE database
EU-27: landfill of plastic waste PE / PE database
RER: Aluminum ingot mix (2005) EAA / PE database
1.1 Production phase
These enterprises were chosen to be representative considering their large market shares in China, as shown inFig. SI 1.
Fig. SI 1 Market shares of washing machines in China in 2012 (Li 2013)
The main information about the investigated enterprises is shown inTable SI 2.
Table SI 2 Information on the surveyed enterprises
Mill / Production Scale / Survey contentProduction capacity / Area(m3) / Total investment(RMB)
NO.1 / 3.6 million washing machines / 123,947 / 5.4 billion / Its main products are tumble washing machines, vertical-axis washing machines, frequency conversion washing machines, twin-tub washing machines and dryers. Through the interview, we understood the production technology, and collected data on material consumption, as well as the main products and waste flows of washing machines.
NO.2 / 3.5 million washing machines / 66,000 / 1.2 billion / Its main products are refrigerators, air conditioners, washing machines, compressors and other supporting components. The main washing machine products are the horizontal-axis washing machine type. The processes of washing machine manufacturing include injection molding, stamping and bending, powder spraying and assembly.
NO.3 / 5 million washing machines / 490,000 / 2.5 billion / Its main products are refrigerators, air conditioners, and washing machines. The main washing machine products are the horizontal-axis washing machine type. We visited the assembly of washing machines in the industrial park and collected data on the energy and water consumptions, as well as the waste discharge for the processes of injection molding, stamping and bending and powder spraying.
1.2 Transportation phase
Detailed information on the gravity model (Yang and Liu 2006) is shown inTable SI 3andTable SI 4. The following equation demonstrates the calculation for the average transportation distance of a washing machine.
Here i (i=1,…,7) refers to output province, j (j=1,…,24) refers to input province, Qi,j refers to the numbers of washing machine shipments from i to j, qi refers to the washing machine yield of output province i, ri,j refers to the distance between i and j, and S represents the average transportation distance of a washing machine.
Table SI 3 Yield of output provinces
Province / Shanghai / Jiangsu / Zhejiang / Anhui / Shandong / Guangdong / ChongqingYield (sets) / 1,971,200 / 11,770,900 / 19,064,300 / 14,993,400 / 6,240,000 / 6,069,600 / 2,806,200
Table SI 4 Distance matrix between provinces
Distance (km) / Shanghai / Jiangsu / Zhejiang / Anhui / Shandong / Guangdong / ChongqingBeijing / 1,238 / 1,028 / 1,278 / 1,043 / 441 / 2,158 / 1,762
Tianjin / 1,098 / 895 / 1,145 / 944 / 338 / 2,142 / 1,791
Hebei / 1,130 / 919 / 1,179 / 944 / 313 / 1,882 / 1,473
Shanxi / 1,346 / 1,100 / 1,361 / 1,008 / 530 / 1,898 / 1,283
Neimenggu / 1,716 / 1,502 / 1,752 / 1,517 / 918 / 2,429 / 1,666
Liaoning / 1,748 / 1,538 / 1,788 / 1,621 / 1,019 / 2,809 / 2,439
Jilin / 2,039 / 1,821 / 2,071 / 1,905 / 1,306 / 3,092 / 2,723
Heilongjiang / 2,301 / 2,091 / 2,341 / 2,174 / 1,567 / 3,362 / 2,992
Fujian / 781 / 912 / 635 / 940 / 1,545 / 929 / 1,800
Jiangxi / 732 / 590 / 549 / 438 / 1,084 / 802 / 1,252
Hubei / 839 / 537 / 725 / 390 / 858 / 1,020 / 901
Hunan / 1,099 / 898 / 915 / 751 / 1,219 / 702 / 878
Guangxi / 1,901 / 1,781 / 1,717 / 1,629 / 2,060 / 605 / 937
Hainan / 2,057 / 1,968 / 1,873 / 1,816 / 2,442 / 589 / 1,407
Sichuan / 1,973 / 1,672 / 1,865 / 1,525 / 1,691 / 1,788 / 325
Guizhou / 1,859 / 1,739 / 1,675 / 1,587 / 1,950 / 1,126 / 377
Yunnan / 2,374 / 2,253 / 2,189 / 2,101 / 2,473 / 1,413 / 877
Xizang / 4,211 / 3,913 / 4,181 / 3,763 / 3,657 / 3,654 / 2,402
Shanxi / 1,382 / 1,081 / 1,333 / 934 / 916 / 1,671 / 710
Gansu / 2,025 / 1,724 / 1,976 / 1,576 / 1,504 / 2,314 / 1,139
Qinghai / 2,257 / 1,955 / 2,208 / 1,808 / 1,701 / 2,615 / 1,371
Ningxia / 1,997 / 1,720 / 1,981 / 1,628 / 1,197 / 2,467 / 1,433
Xinjiang / 3,927 / 3,626 / 3,878 / 3,478 / 3,180 / 4,285 / 3,041
Henan / 958 / 675 / 938 / 583 / 466 / 1,479 / 1,155
1.3 Use phase
We compiled questionnaires from more than 1,330 families in China through online and onsite collection. Among them, approximately 700 questionnaires were derived from face-to-face interviews and the rest were from online surveys. The onsite interviewees were selected randomly in long-distance bus stations, railway stations and the airport in Nanjing city during April 2014.
The washing frequency of each season is calculated according to the following equation:
Here, C is the average washing frequency per week, n is the washing frequency per week with the range from 0 to 8, and An is the respective proportion. Then, we calculate an average for each season, namely summer, spring and autumn combined, and winter. The calculation methods for the washing load and the amount of detergent are similar to that of washing frequency.
Although the normal program is the most commonly used program according to the questionnaires, the studied horizontal-axis washing machine does not have this option. Hence, in this research, we choose the cotton program which is the most commonly used program for a horizontal-axis washing machine, and study the consumption figures based on this program. The cotton program has the following default settings: (1) temperature: 30°C, (2) washing time: 30min (excluding water injection time and water discharge time), (3) rinsing times: 2 times, and (4) dehydration time: 6min. For the selected program, approximately 64.9% of people we interviewed operate the washing machine by default and the others are willing to reset settings by themselves. The average values are adopted for the washing time, dehydration time and rinsing time that they reset.Fig.SI 2and Fig. SI 3give an overview of the resetting options of temperatures and water levels.
Fig. SI 2 Popularity of washing temperatures reset by users
Fig. SI 3 Popularity of water levels of reset by users
Data on the energy for mechanical actions, water use and wastewater discharge per wash cycle are calculated using expert estimation and the washing machine instruction manuals. The contaminant concentration of laundry wastewater is determined according to a previous study(Zhao et al. 2010). The energy consumption for heating water is calculated according to the following equation.
Here, Q is the energy demand, c is the heat capacity of water (4,200J/kg/°C), and ∆t is the temperature difference (here, the room temperature is 20°C). The electricity and water consumptions and the wastewater discharge per wash cycle based on the different options for the cotton program are presented inTable SI 5.
Table SI 5 Water and energy consumptions in different wash cycle types
Wash type / Proportionof users / Consumption per cycle / Wastewater
(kg)
Electricity
(kWh) / Tap water (kg)
Normal water level, room temp / 21.38% / 0.199 / 66 / 63.12
Normal water level, 30°C / 59.35% / 0.432 / 66 / 63.12
Normal water level, 40°C / 3.57% / 0.666 / 66 / 63.12
Normal water level, 60°C / 0.68% / 1.132 / 66 / 63.12
Normal water level, 90°C / 0.13% / 1.832 / 66 / 63.12
Low water level, room temp / 1.40% / 0.199 / 60 / 57.12
Low water level, 30°C / 3.90% / 0.409 / 60 / 57.12
Low water level, 40°C / 0.23% / 0.619 / 60 / 57.12
Low water level, 60°C / 0.04% / 1.039 / 60 / 57.12
Low water level, 90°C / 0.01% / 1.669 / 60 / 57.12
High water level, room temp / 2.34% / 0.199 / 74 / 71.12
High water level, 30°C / 6.49% / 0.456 / 74 / 71.12
High water level, 40°C / 0.39% / 0.712 / 74 / 71.12
High water level, 60°C / 0.07% / 1.226 / 74 / 71.12
High water level, 90°C / 0.01% / 1.996 / 74 / 71.12
1.4 End-of-life phase
Fig. SI 4shows the disposal process of a waste washing machine. Washing machine disassembly is mainly a manual operation. After removing the components such as cabinets, the residues are shredded and separated into metals and plastics. The materials that can be recycled include steel, copper, iron, aluminum, PP, ABS and PVC, and their recycling rates are from the literature(Liu 2011; Matsuto et al. 2004). Table SI 6gives an overview of recovered material contents.
Fig. SI 4 Disposal process of a waste washing machine
Table SI 6 Overview of the recovered material contents
Material / Amount of recovery (kg)Steel / 30.17
Copper / 1.5
Iron / 0.91
Aluminum / 4.76
Plastic / 27.42
2Gabi modeling
The detailed Gabi modeling of different life cycle stages is shown in Fig. SI 5, Fig. SI 6, Fig. SI 7, Fig. SI 8, Fig. SI 9respectively.
Fig. SI 5 Gabi modeling of the whole life cycle
Fig. SI 6 Gabi modeling of transportation stage
Fig. SI 7 Gabi modeling of production stage
Fig. SI 8 Gabi modeling of use phase
Fig. SI 9 Gabi modeling of end-of-life stage
References
Li C (2013) The Research Report of Washing Machine Market in China in 2012-2013.
Liu Y (2011) A Study on Life Cycle Assessment Method of Green Products Based on a Refrigerator. Taiyuan University of Science & Technology
Matsuto T, Jung C, Tanaka N (2004) Material and heavy metal balance in a recycling facility for home electrical appliances Waste Manage 24:425-436
Yang T, Liu J (2006) Study on Applying Improved Gravity Model to Forecast the OD Freight Volume of Railway Luggage and Parcel Railw Transp Econ 28:84-87
Zhao K, Chen J, Xu Z, Huang H, Cai N, Yang D, Yang J (2010) Research on the generation and discharge characteristics of domestic pollutants from urban households Ecol Environ Sci 19:2192-2198
3Questionnaires on laundry washing habits in China
1. What is the main method of washing laundry by your family? Please tick the box.
laundry washing methodSeason / By washing machine / By hand
Summer
Spring and autumn
Winter
(If hand wash only, please go to question 12; if not please continue)
2. What type of washing machine is used by your family?
A. A vertical-axis washing machine B. A horizontal-axis washing machine
C. Other
3. What is the energy label category of the washing machine used by your family?
A. Level1 B. Level2 C. Level3 D. Level4 E. Level5 F. Not noticed
4. For how many years hasthis washing machine been used by your family?
A.1-3 years B.4-6 years C.7-9 years D.10-12 years E.13-15 years
F. More than 15 years
5. What is the rated capacity of the washing machine used by your family?
A. ≤4kg B.5kg C.6kg D. ≥7kg
6. What is the normal washing load per wash cycle when your family uses the washing machine? Please tick the box.
Washing loadSeason / nonuse / 30% / 50% / 70% / 90% / 100%
Summer
Spring and autumn
Winter
7. What is the washing frequency per week in your family? Please tick the box.
Washing frequencySeason / 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / Over8
Summer
Spring and autumn
Winter
8. What is the most commonly used program when using a washing machine?
A. Normal B. Cotton program C. Quick wash D. Synthetic fiber E. Wool F. Soak G. Memory H. Reducing wrinkles I. Allergen J. Others
9. What are your options of temperature, washing time, dehydration time and rinsing times for the selected program?
A. Default B. Resetting
If reset (if choose default, you don’t need to fill):
(1) What temperature is usually chosen?
A. tap water B. 30°C C. 40 D. 60°C E.90°C F. Other
(2) What is the washing time you usually choose? min
(3) What is the dehydration time you usually choose? min
(4) How many rinsing times do you usually choose?
A. 1 time B. 2 times C. 3 times D. 4 times
10. Which water level do you usually choose?
A. Default B. Low C. Middle D. High
11. Does your washing machine have a drying function?
A. Yes B. No
12. How do you dry the clothes after washing?
A. Dry with a washing machine B. Air drying
13. How much detergent is used per month? (Tip: a small package of detergent contains approximately 500 g, a medium package contains 1 kg, and a large package contains 2 kg)
A. ≤100g B. 100-200g C. 200-300g D. 300-400g E. ≥400g
14. What is your gender?
A. Male B. Female
15. What is your age?
A. Under 18 B. 19-22 C. 23-30 D. 31-40 E. 41-55 F. Over 55
16. Which province do you live in?