The fourth National Climate Assessment report (NCA4) was published on November 30, 2018, as mandated by the Global Change Act of 1990. Among its recommendations are the ‘increased deployment of renewable energy.’ The report was written to help inform a wide variety of stakeholders from decision-makers through to public health officials, by providing a thorough examination of the effects of climate change on the United States.
The good news is that adaptation planning and implementation activities are already occurring across the country in the public, the private and nonprofit sector, although these are still not commonplace; for example, major livestock producer Smithfield Foods, Inc. has announced plans to implement ‘manure-to-energy’ projects across 90% of its hog finishing facilities3. These mitigation and adaptation activities often present opportunities for additional immediate and localized benefits, such as improving local air quality and investments in infrastructure.
One renewable energy technology which provides a number of benefits in addition to low-carbon energy generation is the production of biogas through anaerobic digestion (AD). As well as producing low-carbon energy (the biogas produced can be used to generate heat and/or electricity, or can be converted into biomethane fuel), anaerobic digestion provides a method for the efficient treatment and disposal of certain biological wastes, prevents methane emissions from the uncontrolled decomposition of such waste, and provides a valuable product (known as digestate) which can improve soil health and, with long-term use, increase the ability of soils to sequester carbon. Using digestate to fertilize soils also reduces the need for synthetic nitrogen, phosphorus and potassium fertilizers.
As a member of the American Biogas Council (ABC), HRS Heat Exchangers agrees with the Council’s response4to the NCA4 report that ‘Building more biogas systems to recycle our organic waste into renewable energy and soil products is a critical near-term action we can take to make a significant beneficial impact.’ However, from working with the developers and operators of AD plants around the world, HRS Heat Exchangers knows that not every AD facility is equal. While all provide the above benefits, the overall efficiency of the plant determines how much energy is used or wasted in processes such as pre-treating feedstock or drying digestate.
Matt Hale, International Sales and Marketing Director at HRS Heat Exchangers, comments: “The American Biogas Council is right to say that, ‘one of the most obvious actions we must take to protect our climate is recycling organics in the waste stream, and to do that, we need to policies that ensure the construction of more biogas systems.’ Making biogas plants as efficient as possible will not only increase the environmental benefits they provide but will also improve economic returns for developers and operators, helping to increase the deployment of this vital technology. HRS provides a number of systems, from feedstock pre-treatment right through to digestate management, that not only increase plant efficiency and product value but which often do so using existing heat so as to further improve the overall environmental benefits.”