electronic supplementary material

Packaging systems including recycling

PET bottle reverse logistics – environmental performance of California's CRV program

Brandon Kuczenski • Roland Geyer

Received: 23 May 2011 / Accepted: 26 August 2012

© Springer-Verlag 2012

Responsible editor: Hans-Jürgen Garvens

B. Kuczenski (*) • R. Geyer

Environmental Science and Management, University of California, Santa Barbara, CA 93106-5131

e-mail:

(*) Corresponding author:

Brandon Kuczenski

Tel: +1 805 893-5058

Fax: +1 805 893-7612

e-mail:

Supplementary 1 – Emission Factors for Truck Transport

An important aspect of the life cycle of beverage bottles is the impact of heavy truck transportation. There is no established reference data set for emission factors from truck transportation in the US. Instead, there are a number of emissions estimation tools produced by the California Air Resources Board (CARB), the US EPA, and others. There is a truck transportation process included in the US LCI database, but it is based on unpublished assumptions by researchers working at Franklin Associates, the consulting firm which generated much of the data for the US LCI database. Life cycle assessment software packages include a number of process inventories for freight transport, but most represent European conditions. Because of the inadequacies of existing US process inventories for freight transport, we elected to design our own process inventories based on the emissions data embedded in the CARB EMFAC model (California Air Resources Board 2006). This model has the benefits of being based on empirical measurements and representing California conditions.

We desired a process inventory which represented fuel use and tailpipe emissions per unit of freight services (mass × transport distance, for which we use the unit t·km, metric ton-kilometer. 1 t·km = 1000 kg·km = 0.684 short-ton·mile). We also wanted to account for transportation "backhaul," which is the movement of empty trucks after delivering a shipment (Cooper et al. 2008). The EMFAC model includes data on vehicle size and trip distance but not payload. EMFAC estimates total truck emissions, and not just emissions from trucks carrying payloads. Therefore, it was necessary to estimate average payload weights and the percentage of truck miles traveled with empty payloads in order to tie EMFAC data to freight transport.

We made use of a truck transportation survey published by the Federal Highway Administration (Mohammed Alam and Rajamanickam 2007, p. Table 1) to generate our estimates. Based on that report, we estimated the average payloads of Light-heavy-duty trucks (10,001--14,000 lb GVWR) to be 1.37 MT, of Medium-heavy-duty trucks (14,001--33,000 lb GVWR) to be 5.35 MT, and heavy-heavy-duty trucks (33,001--60,000 lb GVWR) to be 14.31 MT. We used another FHWA report (Maks Alam et al. 2007, Fig. 3.6 and Table 3.4) to estimate empty fraction, looking particularly at "bulk" and "other" freight categories. We estimated that 30% of truck miles were traveled empty.

We then combined those estimates with the outputs of aggregated emissions from EMFAC to estimate a process inventory. EMFAC can be used in to report average daily vehicle miles traveled, fuel use and emissions by vehicle class for a calendar year. We used the following formula to normalize a given emission data point to a tonne-kilometer basis:

emission_per_tkm = emission_per_day × (unit conversion) / tkm_per_day

where

tkm_per_day = VMT/day × (unit conversion) × avg_payload × ( 1 - empty_fraction )

As a consequence of EMFAC reporting aggregate values, the use of a larger empty-fraction estimate will result in an increase in apparent emissions per tonne kilometer.

The resulting emission factors are shown below. We used emissions of light-heavy-duty trucks to approximate the volume-limited transport of bulk recyclables.

Table S.1 Emission factors for truck transportation based on EMFAC Year 2007 data

Class / Fuel type / Share of class / Avg. Pay-load / CO2 / CO / NOx / CH4 / NM VOC / Other ROG / SOx / PM2.5-10 / PM2.5 / Fuel Use
MT / g/tkm / g/tkm / g/tkm / g/tkm / g/tkm / g/tkm / g/tkm / g/tkm / g/tkm / kg/tkm
LHD / gasoline / 51.1% / 1.37 / 575.32 / 11.871 / 1.639 / 0.0690 / 0.8462 / 0.5895 / 0.00531 / 0.01062 / 0.01416 / 0.1929
LHD / diesel / 48.9% / 1.37 / 349.35 / 0.721 / 4.283 / 0.0074 / 0.1534 / 0.0000 / 0.00370 / 0.01294 / 0.04436 / 0.1096
MHD / gasoline / 15.8% / 5.35 / 127.62 / 10.552 / 1.107 / 0.0635 / 0.7913 / 0.3097 / 0.00138 / 0.00276 / 0.00414 / 0.0475
MHD / diesel / 84.2% / 5.35 / 250.85 / 0.362 / 1.843 / 0.0018 / 0.0373 / 0.0000 / 0.00245 / 0.00646 / 0.04547 / 0.0789
HHD / gasoline / 2.9% / 14.31 / 39.83 / 7.273 / 1.038 / 0.0290 / 0.4050 / 0.0585 / 0.00052 / 0.00155 / 0.00207 / 0.0170
HHD / diesel / 97.1% / 14.31 / 117.47 / 0.362 / 1.233 / 0.0043 / 0.0872 / 0.0000 / 0.00112 / 0.00685 / 0.04942 / 0.0369

Key: LHD = Light-heavy-duty (10,001-14,000 lbs GVWR)

MHD = Medium-heavy-duty (14,001-33,000 lbs GVWR)

HHD = Heavy-heavy-duty (33,001-60,000 lbs GVWR)

GVWR = Gross Vehicle Weight Rating

NM VOC = Non-methane volatile organic compounds

Other ROG = Other reactive organic gases

All rows assume 30% empty fraction of total vehicle travel.

Supplementary 2 – Example Survey Instrument

Collection and Processing Survey

University of California, Santa Barbara

Thank you for offering to complete this survey about truck-based collection for recycling. All questions are optional, and all answers will be confidential. The purpose of the survey is to develop a description of the material requirements of recycling processes in order to describe their environmental impact. Your answers will be combined with those from similar services around California to create a state-wide average.

Approximate answers or rough estimates are still very useful (“about 1,000 lbs” is almost as helpful as “1,120 lbs”). A range of values is also very helpful (“1,000-1,500 lbs”).

Collection Questions

In our telephone conversation, you indicated your fleet was composed of 21 front-loaders, 21 4x4 pickups, and 10 rolloff trucks. What is their load capacity?
Describe load capacity of trucks:
How many collection routes are run out of your facility in a given period?
Amount: / These figures are:
daily weekly
monthly other:
How many rolloff containers do you retrieve in a given period?
Amount: / These figures are:
daily weekly
monthly other:
How much fuel do your heavy front-loaders use?
Amount: / These figures are:
typical truck
whole group / daily weekly
monthly other:
How much fuel do your 4x4 pickups use?
Amount: / These figures are:
typical truck
whole group / daily weekly
monthly other:
How far do your front-loaders travel?
Distance: / These figures are:
typical truck
group total / typical route weekly
monthly other:
How far do your pickups travel?
Distance: / These figures are:
typical truck
group total / typical route weekly
monthly other:
Notes:

Please continue to Page 2


MRF Questions

How much total material does your program typically process in a given period?
Amount: / Units (select one) / These figures are:
pounds
tons
other: / Average daily volume
Average monthly vol.
Exact amount for the period:
Notes:
PET plastic (#1 Resin Code) makes up about what share of the total amount?
Amount: / Units (select one) / These figures are:
pounds
tons
percent
other: / Average daily amount
Average monthly amt.
Exact amount for the period:
Notes:
About what portion of your incoming material is disposed of as waste (i.e. not recycled)?
Amount: / Units (select one) / These figures are:
pounds
tons
percent
other: / Average daily amount
Average monthly amt.
Exact amount for the period:
Notes:

Utility Usage

For the following questions, please refer to your facility’s utility bills.

What is your facility’s Electricity usage?
Amount: / Units (select one) / These figures are:
kWh
other: / Average daily usage
Average monthly usage
other:
What is your facility’s Water usage?
Amount: / hcf
mcf
other: / Average daily usage
Average monthly usage
other:
What is your facility’s Natural Gas usage?
Amount: / mcf
Therms
other: / Average daily usage
Average monthly usage
other:
How much Diesel fuel do you use in heavy equipment (forklifts, loaders, etc) ?
Amount: / gallons
other: / Average daily usage
Average monthly usage
other:
How much LP Gas do you use in heavy equipment?
Amount: / gallons
other: / Average daily usage
Average monthly usage
other:
Notes:

Thank you very much for completing the survey.

Please return by 02/28/2009

Mailing address: Brandon Kuczenski
Bren Hall #3514
University of California, Santa Barbara
Santa Barbara, CA 93106-5131 / Email address:
Telephone: 805-893-5058
Fax: 805-893-7612

Supplementary references

Alam Maks, Fekpe E, Majed M (2007) FAF2 Freight Traffic Analysis. Federal Highway Administration, Office of Freight Management and Operations, Washington, D.C. Retrieved from http://ops.fhwa.dot.gov/freight/freight_analysis/faf/faf2_reports/reports7/

Alam Mohammed, Rajamanickam G (2007) Development of Truck Payload Equivalent Factor (TPEF). Federal Highway Administration, Office of Freight Management and Operations, Washington, D.C. Retrieved from http://ops.fhwa.dot.gov/freight/freight_analysis/faf/faf2_reports/reports9/

California Air Resources Board (2006) EMFAC2007 Release. Retrieved May 3, 2011, from http://www.arb.ca.gov/msei/onroad/latest_version.htm

Cooper JS, Woods L, Lee SJ (2008) Distance and backhaul in commodity transport modeling. Int J Life Cycle Assess 13(5):389-400