Transition to the circular economy: the story of four case companies

Shifting from a linear sales model to a circular service-based business model is far from straightforward. Many challenges accrue in the transition process, including finding the right market for the recirculated product/service, setting up the reverse supply chain, selecting the right partners, and making sure the new business model is sustainable in the short, medium and long term. This paper discusses the challenges of four companies trying to close the loop while preserving current profit levels. It describes their initial ideas on how the circular business model should be designed, the process they went through, challenges faced, and the eventual outcome. Based on the learnings of the four case companies, we summarise recommendations about preparatory steps required before making the transition towards a circular business model

An assessment of the sustainability of E-fulfilment models for the delivery of fast moving consumer goods to the home

Online retail sales are growing rapidly and have captured a significant proportion of the retail market in many countries. Although companies are under mounting pressure to reduce their environmental impact, the environmental effect of the different online distribution strategies remains unclear. Most previous studies of this subject have only included partial effects and consequences. To enable a more holistic understanding, this study proposes a more inclusive framework of environmental assessment based on life cycle analysis. This was applied to fast moving consumer goods (FMCG). Previous studies have shown that the last mile delivery contributes significantly to the environmental impact of online retailing, mainly because of the nature of the home delivery operations, including narrow time windows and short order lead times. If consumers were to buy products online on a subscription basis and give the supplier more control over the replenishment process there might be less need for fast deliveries, creating opportunities to improve the efficiency of home deliveries and reduce their environmental impact. The study classified different forms of subscription arrangement, assessed their relative attractiveness to consumers and examined their likely impact on the supply chain. Consumer views on subscriptions were surveyed by means of focus group discussions and interviews. To assess the likely supply chain impacts of subscriptions, the literature on vendor-managed inventory was consulted. A Life-Cycle Assessment (LCA) model was built to quantify and compare the environmental impact of various e-fulfilment models for FMCG products in the United Kingdom. This study reveals that the method of execution have a large influence on the environmental impact. In store-based retailing, the energy consumption within the supermarket is a significant contributor to the total greenhouse gas emissions. On the other hand, some forms of home delivery, involving for example the use of parcel networks with no pre-agreed time-slots and relatively high rates of delivery failure and customer collection, are also carbon-intensive. This contribution of consumer trips to the total footprint is much smaller in case of van-based deliveries where pre-agreed time-windows are used. Regardless of the business model, the total carbon footprint per item depends heavily on the number of items per delivery. Consequently, companies or consumers looking to decrease the environmental impact of online shopping should maximise the number of items per delivery. The study concludes with an assessment of the strengths, weaknesses and possible environmental improvements of each of the efulfilment methods, taking account of the possible role of subscriptions

Obscured Asymptotic Giant Branch Variables in the Large Magellanic Cloud and the Period-Luminosity Relation

The characteristics of oxygen-rich and carbon-rich, large amplitude (dK>0.4 mag), asymptotic giant branch variables in the Large Magellanic Clouds are discussed, with an emphasis on those obscured by dust. Near-infrared photometry, obtained over about 8 years, is combined with published mid-infrared observations from IRAS and ISO to determine bolometric magnitudes for 42 stars. Pulsation periods of the O-rich stars are in the range 116<P<1393 days, while those for C-rich stars have 298<P<939 days. In addition to the regular pulsations, one O-rich star and four C-rich stars show large amplitude, dK> 0.6 mag, secular or very long period variations which may be associated with changes in their mass-loss rates. We discuss and compare various methods of determining the bolometric magnitudes and show, perhaps surprisingly, that most of the very long period stars seem to follow an extrapolation of the period-luminosity relation determined for stars with shorter periods - although the details do depend on how the bolometric magnitudes are calculated. Three stars with thin shells, which are clearly more luminous than the obscured AGB stars, are undergoing hot bottom burning, while other stars with similar luminosities have yet to be investigated in sufficient detail to determine their status in this regard. We suggest that an apparent change in slope of the period luminosity relation around 400-420 days is caused by variables with luminosities brighter than the predictions of the core-mass luminosity relation, due to excess flux from hot bottom burning.Comment: 20 pages, 20 figures, accepted for MNRA

Circular products and business models and environmental impact reductions: current knowledge and knowledge gaps

The circular economy is billed as a solution to increase economic growth while reducing environmental impact. It is argued that retaining the value of products, components and materials by fostering the “inner loops”, such as reuse, refurbishment and remanufacturing, increases the resource-efficiency. However, published environmental assessments estimating the actual impact of these so-called circular outcomes are inconclusive. This paper presents the results of a systematic literature review of previous environmental assessments on circular products and circular business models, focusing on the tighter technical loops including reuse, refurbishment, and remanufacturing. Mapping reveals factors that influence the environmental impact of circular products and other aspects that should be incorporated in environmental assessments. Even though 239 papers were identified that discuss the environmental impact of circular products and/or circular business models, the far majority only considers a traditional product in a traditional sales model that is remanufactured and compares the impacts of remanufacturing with manufacturing new products. While it is important to quantify the impacts of remanufacturing, it is remarkable that product design strategies for circular economy (e.g. design for remanufacturing, upgradability, modularity) and product-service systems or other types of circular business models are usually not considered in the LCA studies. A lack of studies of products with so-called circular designs that are utilized within circular business models is apparent. In addition, many assessments are static analyses and limited consideration is given to future increases in the share of renewable energy. One can thus question how well the available environmental assessments quantify actual circular products/offerings and the environmental performance gains they could provide in a circular economy. The results show that there is an urgent need for more LCAs done in a way that better captures the potential benefits and deficiencies of circular products. Only then will it be possible to make robust claims about the environmental sustainability of circular products and circular business models and finally circular economy in total

Designing a circular business strategy: 7 years of evolution at a large washing machine manufacturer

This paper discusses the development of circular business models for a large white goods manufacturer. A 7-year journey in designing, discussing, adapting, and finally finding a potentially profitable circular offer is summarized, and the barriers that had to be overcome in this process are highlighted. The shift from selling washing machines to repeated leases with remanufacturing steps in-between turned out to be very challenging. Despite the numerous claims in the consulting world that both manufacturers and consumers can benefit from the transition to a circular economy, it took multiple iterations to find a business model with the potential of being economically attractive to both the company and the client. The transformation process of shifting to a circular business model tends to be highly underestimated by companies and involves many issues beyond product design such as customer relationships, return logistics, remanufacturing operations, and service contracts. Researchers will need to work with companies to address the transition issues and to increase the relevance of circular economy research

Metal and Plastic Recycling Flows in a Circular Value Chain

Material efficiency in manufacturing is an enabler of circular economy and captures value in industry through decreasing the amount of material used toproduce one unit of output, generating less waste per output and improving waste segregation and management. However, material types and fractions play an important role in successfulness of recycling initiatives. This study investigates two main fractions in automotive industry, namely, metal and plastic. For both material flows, information availability and standards and regulations are pivotal to increase segregation, optimize the collection and obtain the highest possible circulation rates with high quality of recyclables. This paper presents and compares the current information flows and standards and regulations of metals and plastics in the automotive value chain

Dust mass-loss rates from AGB stars in the Fornax and Sagittarius dwarf Spheroidal galaxies

To study the effect of metallicity on the mass-loss rate of asymptotic giant branch (AGB) stars, we have conducted mid-infrared photometric measurements of such stars in the Sagittarius (Sgr dSph) and Fornax dwarf spheroidal galaxies with the 10-$\mu$m camera VISIR at the VLT. We derive mass-loss rates for 29 AGB stars in Sgr dSph and 2 in Fornax. The dust mass-loss rates are estimated from the $K-[9]$ and $K-[11]$ colours. Radiative transfer models are used to check the consistency of the method. Published IRAS and Spitzer data confirm that the same tight correlation between $K-[12]$ colour and dust mass-loss rates is observed for AGB stars from galaxies with different metallicities, i.e. the Galaxy, the LMC and the SMC. The derived dust mass-loss rates are in the range 5$\times10^{-10}$ to 3$\times10^{-8}$ M$_{\odot}$yr$^{-1}$ for the observed AGB stars in Sgr dSph and around 5$\times10^{-9}$ M$_{\odot}$yr$^{-1}$ for those in Fornax; while values obtained with the two different methods are of the same order of magnitude. The mass-loss rates for these stars are higher than the nuclear burning rates, so they will terminate their AGB phase by the depletion of their stellar mantles before their core can grow significantly. Some observed stars have lower mass-loss rates than the minimum value predicted by theoretical models.Comment: 12 pages, 9 figures, accepted for publication in MNRA

The AGB superwind speed at low metallicity

We present the results of a survey for OH maser emission at 1612 MHz from dust-enshrouded AGB stars and supergiants in the LMC and SMC, with the Parkes radio telescope, aimed at deriving the speed of the superwind from the double-peaked OH maser profiles. Out of 8 targets in the LMC we detected 5, of which 3 are new detections - no maser emission was detected in the two SMC targets. We detected for the first time the redshifted components of the OH maser profile in the extreme red supergiant IRAS 04553-6825, confirming the suspicion that its wind speed had been severely underestimated. Despite a much improved spectrum for IRAS 04407-7000, which was known to exhibit a single-peaked OH maser, no complementary peak could be detected. The new detection in IRAS 05003-6712 was also single-peaked, but for two other new detections, IRAS 04498-6842 and IRAS 05558-7000, wind speeds could be determined from their double-peaked maser profiles. The complete sample of known OH/IR stars in the LMC is compared with a sample of OH/IR stars in the galactic centre. The LMC sources generally show a pronounced asymmetry between the bright blueshifted maser emission and weaker redshifted emission, which we attribute to the greater contribution of amplification of radiation coming directly from the star itself as the LMC sources are both more luminous and less dusty than their galactic centre counterparts. We confirm that the OH maser strength is a measure of the dust (rather than gas) mass-loss rate. At a given luminosity or pulsation period, the wind speed in LMC sources is lower than in galactic centre sources, and the observed trends confirm simple radiation-driven wind theory if the dust-to-gas ratio is approximately proportional to the metallicity.Comment: 13 pages, 18 figures. Accepted for publication in MNRA

Mass-loss rates and luminosity functions of dust-enshrouded AGB stars and red supergiants in the LMC

A radiative transfer code is used to model the spectral energy distributions of 57 mass-losing Asymptotic Giant Branch (AGB) stars and red supergiants (RSGs) in the Large Magellanic Cloud (LMC) for which ISO spectroscopic and photometric data are available. As a result we derive mass-loss rates and bolometric luminosities. A gap in the luminosity distribution around M_bol = -7.5 mag separates AGB stars from RSGs. The luminosity distributions of optically bright carbon stars, dust-enshrouded carbon stars and dust-enshrouded M-type stars have only little overlap, suggesting that the dust-enshrouded AGB stars are at the very tip of the AGB and will not evolve significantly in luminosity before mass loss ends their AGB evolution. Derived mass-loss rates span a range from Mdot about 10^-7 to 10^-3 M_sun/yr. More luminous and cooler stars are found to reach higher mass-loss rates. The highest mass-loss rates exceed the classical limit set by the momentum of the stellar radiation field, L/c, by a factor of a few due to multiple scattering of photons in the circumstellar dust envelope. Mass-loss rates are lower than the mass consumption rate by nuclear burning, Mdot_nuc, for most of the RSGs. Two RSGs have Mdot >> Mdot_nuc, however, suggesting that RSGs shed most of their stellar mantles in short phases of intense mass loss. Stars on the thermal pulsing AGB may also experience episodes of intensified mass loss, but their quiescent mass-loss rates are usually already higher than Mdot_nuc.Comment: 15 pages, 11 figures. Accepted for publication in Astronomy and Astrophysics Main Journa

A dearth of OH/IR stars in the Small Magellanic Cloud

We present the results of targeted observations and a survey of 1612-, 1665-, and 1667-MHz circumstellar OH maser emission from asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the Small Magellanic Cloud (SMC), using the Parkes and Australia Telescope Compact Array radio telescopes. No clear OH maser emission has been detected in any of our observations targeting luminous, long-period, large-amplitude variable stars, which have been confirmed spectroscopically and photometrically to be mid- to late-M spectral type. These observations have probed 3 - 4 times deeper than any OH maser survey in the SMC. Using a bootstrapping method with LMC and Galactic OH/IR star samples and our SMC observation upper limits, we have calculated the likelihood of not detecting maser emission in any of the two sources considered to be the top maser candidates to be less than 0.05%, assuming a similar pumping mechanism as the LMC and Galactic OH/IR sources. We have performed a population comparison of the Magellanic Clouds and used Spitzer IRAC and MIPS photometry to confirm that we have observed all high luminosity SMC sources that are expected to exhibit maser emission. We suspect that, compared to the OH/IR stars in the Galaxy and LMC, the reduction in metallicity may curtail the dusty wind phase at the end of the evolution of the most massive cool stars. We also suspect that the conditions in the circumstellar envelope change beyond a simple scaling of abundances and wind speed with metallicity