Estimation of the sustainable production of gaseous biofuels, generation of electricity, and reduction of greenhouse gas emissions using food waste in anaerobic digesters

AbstractThere are many economic, social and environmental reasons to reduce the occurrence of food that is wasted. As communities consider options for managing their food waste streams, an understanding of the volume, composition and variability of these streams is needed to inform the decision-making process and potentially justify the capital investments needed for separation and treatment operations. This more detailed inventory also allows for the estimation of embodied resources in food that is wasted, demonstrated herein for greenhouse gas emissions (GHGs). Pre- and post-consumer food waste was collected from four all-you-care-to-eat Campus Dining Services (CDS) facilities at the University of Missouri, Columbia over 3 months in 2014. During the study period approximately 246.3 metric tons (t) of food reached the retail level at the four facilities. 232.4 t of this food was served and 13.9 t of it (10.1 t of edible and 3.8 t of inedible), was lost as pre-consumer waste. Over the same time period, an estimated 26.4 t of post-consumer food waste was generated at these facilities, 21.2 t of the waste edible and 5.3 t of it inedible. Overall, 5.6% of food reaching the retail level was lost at the pre-consumer stage and 10.7% was lost at the post-consumer stage. Out of the food categories examined, ‘fruits and vegetables’ constituted the largest source of food waste by weight, with grains as the second largest source of food waste by weight. GHGs embodied in edible food waste were calculated. Over the study period an estimated 11.1 t CO2e (100-yr) were embodied in the pre-consumer food waste and 56.1 t were embodied in post-consumer food waste for a total of 67.2 t. The ‘meat and protein’ category represents the largest embodiment of GHG emissions in both the pre- and post-consumer categories despite ranking fourth in total weight. Beef represents the largest contribution to post-consumer GHG emissions embodied in food waste with an estimated 34.1 t CO2e. This distinction between the greatest sources of food waste by weight and the greatest sources of GHG emissions is relevant when considering alternative management options for food waste.

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Identification of decisive factors for greenhouse gas emissions in comparative life cycle assessments of food waste management – an analytical review

Journal of Cleaner Production ◽

10.1016/j.jclepro.2016.01.079 ◽

2016 ◽

Vol 119 ◽

pp. 13-24 ◽

Cited By ~ 63

Author(s):

Anna Bernstad Saraiva Schott ◽

Henrik Wenzel ◽

Jes la Cour Jansen

Keyword(s):

Life Cycle ◽

Waste Management ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Food Waste ◽

Life Cycle Assessments ◽

Gas Emissions ◽

Analytical Review

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Laboratory investigation of supported permeable organic covers for the management of odour emissions from anaerobic piggery waste ponds

Water Science & Technology ◽

10.2166/wst.2001.0563 ◽

2001 ◽

Vol 44 (9) ◽

pp. 317-326 ◽

Cited By ~ 4

Author(s):

N. Hudson ◽

K. Casey ◽

S. Melvin ◽

P. Nicholas

Keyword(s):

Life Expectancy ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Laboratory Investigation ◽

Published Data ◽

Gas Emissions ◽

Anaerobic Digesters ◽

Support Materials ◽

Odour Emissions ◽

The Impact

Australian research has linked much of the odour arising from intensive livestock operations to pond treatment systems. A reduction in emissions from treatment ponds would therefore generally reduce odour emissions from intensive livestock operations. Published data indicates that the application of straw and other biological materials to effluent pond surfaces as a continuous cover reduces odour emissions. The effectiveness of these covers has not, however, been researched under controlled conditions. Using locally available materials, the efficacy of supported covers has been investigated using a series of laboratory anaerobic digesters treating typical piggery effluent. Research to date has focused on:•identifying effective cover and cover support materials;•quantifying odour reduction;•• identifying the impact use these covers may have on greenhouse gas emissions;•• devising practical and effective methods for constructing these covers.Results have confirmed that a variety of cover materials are effective in reducing pond odour emissions. Supporting the pond cover appears to extend the cover life expectancy. While greenhouse gas emissions appear to vary according to cover type, the overall significance of these emissions is not yet clear. The impact of permeable pond covers on overall pond performance requires additional research.

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