The importance of the municipal level in the transition to biogas

As more and more cities around the world are transiting to renewable energy or are considering doing so, this municipal trend towards energy transition cannot be ignored. No surprise it is at the municipal level that a stronger, more concrete and more widespread transition is observed. Indeed, the functional structure of a city is very complex in terms of direct and recurring services provided to the population considering the logistics of a dispersed, heterogeneous and very large population. The importance of the municipal level in the transition to biogas appears obvious.

Problem-inducing municipal duties

A city must provide its citizens several services that require considerable infrastructure and a lot of different vehicles. Waste management is one of those services and is part of municipal needs for many reasons. But in recent years, the increasing use of landfill sites has become a source of problems at the logistical and environmental levels. Logistical problems arise from the amount of increasingly massive and disparate waste to be collected despite their increasing spread over the territory. Environmental problems are for their part caused by the pollution that residual waste induces in the soil and groundwater through its flow of leachate, and in the air by methane emissions.

Thus, the first shift that was done and is now well established in many municipalities of industrialized countries is the recycling of residual waste such as plastic, metal as well as paper and cardboard. A second shift was observed, the one of composting, which also contributes to reducing the mentioned problems. On the other hand, its effects are limited to the fertilizing virtues of the resulting compost, and the energy potential of the organic municipal solid waste (OMSW) is not exploited.

The municipal solution offered by anaerobic digestion

That is where the anaerobic digestion of OMSW appears natural and logical to implant among an effective circular municipal management. Not only the production of biogas significantly reduces the amount of residual waste ending in landfills, it also optimizes the revaluation of OMSW by producing clean, renewable and carbon-neutral energy that can be used for transportation, heating and to produce electricity. In addition, anaerobic digestion generates no waste, other than the potential contaminants present in the treated OMSW, and what results apart from the biogas produced is a solid or liquid digestate which is then used as fertilizing material and compares to the soil obtained from compost. In short, anaerobic digestion is an optimized way to recycle OMSW in order to minimize the waste of its rich potential while reducing the amount of final residual waste.

Some cities have already made the leap and have implemented a municipal biogas plant while others are negotiating or planning such implantation. In Canada, the city of Saint-Hyacinthe in the province of Quebec invested back in 2010 in a biogas plant that processes OMSW from 50,000 citizens. The city is now able to provide heating to a certain proportion of its municipal buildings, as well as fuel for eleven vehicles, including the trucks of its fire protection service, thanks to the renewable natural gas it produces. Saint-Hyacinthe has had the audacity to transit to biogas and has managed to demonstrate its potential towards effective circular municipal management, and everything suggests that benefits would be exponentially more significant for a bigger city such as a metropolis.

By Simon Lefebvre | 2016-05-20

Sources : Le Devoir, Newswire