Energy products from source-separated organic waste

Abstract

An effective strategy adopted in recent years for municipal solid waste management is the source-separation of solid waste, most commonly into organics, recyclables such as glass, plastics and papers, and refuse. It has been proposed that source-separated organic waste (SSO) is an excellent lignocellulosic biomass of fermentable carbohydrates, and has the potential to serve as a low-cost feedstock for bioconversion into energy products such as ethanol and hydrogen. To evaluate the feasibility of converting SSO to energy products, a better understanding on the energy contents and highly-variable composition of SSO is needed. This paper is based on the results obtained from a ten-month analysis on the SSO collected from the City of Toronto, Ontario, Canada. Detailed analyses on the composition in terms of the VOC, cellulose, hemicellulose, and lignin contents, as well the amounts of carbohydrates, glucose, xylose and other fermentable sugars are carried out. The experimental results show that the average values of moisture content, at 55%, and VOC, from 65% to 96% per dry mass, was sufficiently high to support microbial growth, making it an acceptable feedstock for anaerobic digestion. The results of SSO are compared to other traditional cellulosic feedstock, such as hardwood, agricultural products, food and herbaceous crops, and it was demonstrated that comparable amount of fermentable sugars are contained in SSO.

Comparison of Two Process Schemes Combining Hydrothermal Treatment and Acidogenic Fermentation of Source-Separated Organics

“…Source separated collection has been an effective management strategy to separate organic waste from other waste streams at the source, thereby minimizing the contamination of organic waste for the downstream process. Source-separated organics (SSO) is the term used to describe the organic waste stream collected at the source [3]. Besides food waste, SSO also contains other organic components, including yard trimmings (grass, leaves, etc.…”

Recycling, waste management and urban vegetable gardens

“…Several researches dealt with the technical aspects of recycling of those materials which can be immediately re-used (e.g. Mark E. Schlesinger at Missouri University deals with aluminium recycling [11] or the thorough close examination by Paul T. Williams [7]), of the use of incinerators and organic waste in order to obtain energy [12,13], of the inefficiencies that still today can be noticed in the whole cycle (a subject that MacBride [14] at the New York University has recently dealt with and that in Italy can be found in the annual report issued by the ISPRA, the Advanced Institute for Environmental Protection and Research [15]), of the alternative solutions to digestion for the disposal of organic components (e.g. the growing interest towards vermicomposting shown by Quintern [16] as well as by Soobhany et al [17]).…”