2011 Volume 22 Issue 3 Pages 201-209
The recycling of food waste poses a challenge mainly due to its widespread character and the instability of its composition. In this paper, we investigate the composition of food wastes with the aim of establishing a new recycling system using the process of carbonization.
To begin, food wastes were collected from various obvious sources: manufacturers, retailers and food service businesses. The waste was then sorted into categories such as grain, vegetable, animal, bone, impure wastes and so on. The physical and chemical characteristics of these different food wastes could then be analyzed.
A large amount of moisture was found to be included in the different types of food waste. The three major components—grains, vegetables and animals—all had varying percentages of moisture depending on the seasons. However, these categories occupied 85-95% of the wet weight for the total food wastes originating from all industry types. Similarly, these components contained about 50% carbon in the dry weight. The yield of char obtained from each component through carbonization at 500 °C was about 25-30%, and fixed carbon was estimated to be 60-80%. Based on the calculations of this experiment for yield of char and fixed carbon in the air-dried char, it was estimated that there was a decrease of 30-55% in carbon release. As a result, we conclude that utilizing carbonization for the recycling of food wastes can be a useful technique for addressing various environmental issues.