A life cycle assessment on the dehairing of rawhides : chemical treatment versus enzymatic recovery through solid state fermentation

The leather industry needs to switch from the traditional chemically based dehairing process to an environmentally friendly one so that the overall burdens to the environment are reduced. The primary goal of the work was thus to compare the chemical leather dehairing process to an enzymatically based one using the enzymes that are extracted after the application of solid state fermentation (SSF) on hair wastes generated after dehairing. The environmental burdens of the dehairing stage were determined using a life cycle assessment (LCA) approach by comparing the two aforementioned management scenarios. The first scenario was the commonly used technology in which hair is removed via a chemical process and then composted in open piles. This scenario included two subscenarios where hair waste is either incinerated or landfilled. In the second scenario, the proteolytic enzymes extracted during the SSF of the residual hair are used to dehair the new rawhides instead of chemicals. Industrial and laboratory data were combined with international databases using the SimaPro 8.0 LCA software to make comparisons. The environmental impacts associated with the enzymatic dehairing were significantly lower than the ones associated to the conventional chemical dehairing process. This difference is attributed to the impacts associated with the original production of the chemicals and to the electricity consumed in the conventional method. A sensitivity analysis revealed that the results are affected by the amounts of chemicals used during dehairing

A comparison of repaired, remanufactured and new compressors used in Western Australian small- and medium-sized enterprises in terms of global warming

Repaired compressors are compared with remanufactured and new compressors in terms of economic andenvironmental benefits. A detailed life cycle assessment has been carried out for compressors under threemanufacturing strategies: repaired, remanufactured and new equipment. The life cycle assessment of the globalwarming potential of repaired compressors varies from 4.38 to 119 kg carbon dioxide equivalent (CO2-e),depending on the type of components replaced. While greenhouse gas emissions from the remanufacturedcompressors (110 to 168 kg CO2-e) are relatively higher than those from the repaired ones (4.4 to 119 kg CO2-e), anew compressor has been found to produce a larger amount of greenhouse gas emissions (1,590 kg CO2-e)compared to both repaired and remanufactured compressors. Repairing failed compressors has been found to offerend users both dollar and carbon savings in contrast to remanufactured and new compressors. The research alsofound that extended lifetime is more important than the manufacturing processes in terms of greenhouse gasemissions. Since a remanufactured compressor offers a longer life than a repaired compressor, the replacement ofthe latter with the former can avoid 33% to 66% of the greenhouse gas emissions associated with a newcompressor production with a lifetime of 15 to 25 years

Impact of repairs on embodied carbon dioxide expenditure for a reinforced-concrete quay

Studies on structural repair using life-cycle analysis are still lacking the environmental impact of repair actions. This research work shows that the choice of the best repair option for reinforced-concrete structures is a function of long-term environmental impact, considering the longevity of maintenance intervention and embodied carbon dioxide expenditure. The purpose of this work was to assess the lifetime of a quay superstructure exposed to an aggressive marine microenvironment by using a probabilistic performance-based approach and then to select the best repair option for its reinforced-concrete structures. The comparison is made for reinforced-concrete service life using three different concrete types and two different corrosion inhibitors. Longevity and embodied carbon dioxide were predicted for the expected number of repair actions per 100 years. It is shown that concretes may have a higher impact at the outset, although they result in a much lower impact across the service life of the structure

Evaluating the Sustainability of a Small-Scale Low-Input Organic Vegetable Supply System in the United Kingdom

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