Potential Greenhouse Gas Mitigation for Converting High Moisture Food Waste into Bio-Coal from Hydrothermal Carbonisation in India, Europe and China

Nicholas Davison,Divya Gupta,Jaime Borbolla Gaxiola,Timothy Cockerill,Anurag Garg,Xueliang Yuan,Yuzhou Tang,Andrew Ross

doi:10.3390/en15041372

Nicholas Davison, Divya Gupta + Show 6 more

Open Access

https://doi.org/10.3390/en15041372

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Abstract

Hydrothermal carbonisation is a promising technology for greenhouse gas (GHG) mitigation through landfill avoidance and power generation, as it can convert high-moisture wastes into bio-coal which can be used for coal substitution. The GHG mitigation potential associated with landfill avoidance of high-moisture food waste (FW) generated in India, China and the EU was calculated and the potential for coal substitution to replace either grid energy, hard coal, or lignite consumption were determined. Different HTC processing conditions were evaluated including temperature and residence times and their effect on energy consumption and energy recovery. The greatest mitigation potential was observed at lower HTC temperatures and shorter residence times with the bio-coal replacing lignite. China had the greatest total mitigation potential (194 MT CO2 eq), whereas India had the greatest mitigation per kg of FW (1.2 kgCO2/kg FW). Significant proportions of overall lignite consumption could be substituted in India (12.4%) and China (7.1%), while sizable levels of methane could be mitigated in India (12.5%), China (19.3%), and the EU (7.2%). GHG savings from conversion of high-moisture FW into bio-coal and subsequent coal replacement has significant potential for reducing total GHG emissions and represents in India (3%), China (2.4%), and the EU (1%).

Highlights

The overall aim of the paper was to investigate the opportunities and limitations that the adoption of food waste (FW) Hydrothermal carbonisation (HTC) could have on greenhouse gas (GHG) mitigation in India, the EU, and China
Region specific findings for India, the EU, and China are discussed. These sections consider the individual contributions of the GHG mitigation components; GHG mitigation from landfill avoidance, GHG mitigation through the energy generated from FW HTC substituting grid energy in the region assessed, and GHG mitigation through the energy generated from HTC substituting coal
This section compares the scale of mitigation opportunities in the different regions, before comparing GHG mitigation opportunities per kg of FW

Summary

Introduction

Around a third of all food is wasted [1]. This is estimated to equate to around 1.3 billion tonnes of edible food being wasted annually around the world, resulting in the equivalent of approximately 3.5 billion tonnes of CO2 [2], as large quantities of greenhouse gases (GHGs) are released as a result of producing, processing, transporting, and treating the wasted food [3]. FW treatment is of particular interest due to it having a greater level of impact on climate change when compared to other waste types. This is to do with its large organic content and the fact that a large proportion of FW is landfilled [4]. FW decomposes anaerobically forming methane, a potent GHG, around 25 times more potent than CO2 as a climate forcer [5]

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