Can Biosolids Save the Climate?

Recent weeks have been a whiplash. Against the shocking images of Hurricane Michael’s damage to Mexico Beach is the release of the report by the Intergovernmental Panel on Climate Change giving humanity barely more than a decade to mend its fossil-fuel dependent ways. Media commentary adds to the whiplash, when a prestigious, proudly conservative, journal National Review, gives space to commentator Jonathan Tobin’s glib assertion “The U.N.’s latest doomsaying comes off as hyperbole, not science.” In my not-so-humble opinion, Tobin must have confined his “background” on this topic to the IPCC report’s 3 page “headline statement,” rather than to the 1,136 pages of report authored by 91 scientists. Rush Limbaugh predictably sounded the alarm that Hurricane Michael would be used by liberals to “advance the whole politics-of-climate change agenda and everything,” and equally predictably Vox provide a platform to Mary Anaise Heglar (“How to deal with despair over climate change”), pointing out that the IPCC report revealed “a mere 100 companies are responsible for 71 percent of global climate emissions. These people are locking you and everything you love into a tomb… We can’t pretend this isn’t happening anymore. … We are the adults in this room.” 

Yes, humanity surely seems to be facing a climate crisis; I am absolutely certain that I am.

Vox’s article, despite its breathlessness, usefully pointed to “10 ways to accelerate progress against climate change. “  The ten ways are: price carbon emissions; subsidize clean energy, and end subsidies for dirty energy; electrify everything and get more efficient; Invest in innovation; require “zero deforestation” supply chains; discourage meat and dairy consumption, encourage plant-based diets; and, remove carbon dioxide from the atmosphere. I started to labor on teasing apart these topics into meaningful lessons for us, the biosolids industry, on how we might be a solution to the climate crisis. M

Before I had gotten very far, I heard from Vance. Vance, like me, is a Prius-owning, a cappella singer, but, unlike me, he is an activist vegan. Vance had fun calling me out: “Bill, there is one way that you, personally, can accelerate progress; you can, at this very moment, give up all meat, dairy and eggs, and thereby stop the slaughter of sentient beings, the pollution by manure of our rivers, and the increase of methane from cow farts. Pledge yourself to veganism right now! or at least buy a ticket to my next event on November 2.”

Oh man! I hate being called out. I was holding a handful of Doritos during our rehearsal “afterglow.” What?!! I learned that vegans won’t eat Doritos because whey is used in its manufacture?! How absurd to call veganism a pathway to climate salvation?! But there again I am sure my gut microbes scream in pain when doused with Doritos.

Well, is it any less absurd to argue that biosolids can be a meaningful way to respond to the IPCC 1.5C report? I believe it is NOT absurd.

Biosolids digestion produces biogas, which supplants fossil fuels. Bioas can be fuel for co-generation at WRRFs, which works toward energy resilience and neutrality. Hundreds of articles have focused on this source of decentralized electricity. We have companies set up to do just this: Anaergia and Energy Services Group are two with projects in the Mid Atlantic. Biogas can also be compressed as a vehicle fuel: Unison Solutions uses its BioCNG system to create a “green fuel.” If a WRRF takes in high strength organic liquids into its digesters, the prospect of “ Energy positive wastewater treatment and sludge management” is plausible.

Biosolids can be thermally “depolymerized” under high temperature and pressure to produce gases, bio-oils or charcoal. Aries Clean Energy and SüLZLE KOPF produce syngas. TerraNova Energy purports to make a coal substitute out of sludges using hydrothermal carbonization. Several West Coast agencies are supporting pilot operations by Genifuel of hydrothermal liquefaction to produce liquid biocrude. Another byproduct of non-burning thermal processes is biochar, which can have some beneficial soil properties. Biochar can be used for carbon sequestration.

But you don’t need to go as far as biochar to have carbon sequestration. Biosolids of the class B sort is a sufficiently stable carbon that it adds to soil carbon more than other amendments. Also, when applied to low carbon soils, the carbon added is fixed and builds soil fertility; the benefits are large and verifiable. MABA friend Sally Brown wrote on this subject in her BioCycle magazine article Building Carbon Credits With Biosolids Recycling

Someday (though increasingly that “some” is a far off day), carbon sequestration may have real monetary value. The New U.N. Climate Report Says Put a High Price on Carbon suggests you will be paid for the added benefit that biosolids is a perfect “low-carbon” fertilizer for agriculture and for the decreased Greenhouse Gas footprint of farming. Just imagine the solutions to biosolids management that might be possible if carbon (as CO2) is priced at $100 per ton.

I believe that in land restoration biosolids has its “highest and best” use, with its carbon and nutrients deployed to revitalize landscapes for production of cellulosic biomass crops.  Biomass can be used for bioenergy. In Experimental biomass harvest a step toward sustainable, biofuels-powered future, the authors write “We estimate that we can harvest 20 to 30 units of energy per unit of fossil energy invested in producing the crop, leading to fuel with a very low carbon footprint,… "The fact that this biomass can be converted to liquid fuel is one of the main advantages of shrub willow and other biomass crops. Low carbon liquid fuels are especially important for long distance transportation, shipping and aviation, where electric vehicles are not practical."

Cellulosic biomass may have uses beyond energy. New technologies are converting biomass into biopolymers, replacing fossil sources of these chemicals. The products are biodegradable and may be less harmful when discharged to the environment. This case was well presented in: Greenhouse Gas Emissions and the Interrelation of Urban and Forest Sectors in Reclaiming One Hectare of Land in the Pacific Northwest.

Can you imagine a day when bioenergy crops replace livestock feed as the principal crop in the Mid Atlantic?

The IPCC report also pointed to the opportunity of algae production as an offset to fossil fuel. I am particularly intrigued by the opportunity to combine algal systems with wastewater. Clearas is a technology that now has reference facilities showing high levels of nitrogen and phosphorus removal from effluent, while producing a new kind of “biosolids,” this one an algal biomass. Clearas has an “off-take” agreement for the beneficial use in bioproducts for high value personal care products. Greater Chicago WRD is working on a similar algae system -- a “revolving algal biofilm, consisting of disks rotating in nutrient rich wastewater on which from algae grows. It will use ceramic membranes to concentrate the algae for extraction of high value chemicals, in particular biopolymers to replace fossil-carbon based polymers.

If you chose technology sufficiently sophisticated as to produce algae, you might also be interested in extraction of biopolymers and proteins produced during fermentation. In one sense, WRRFs with anaerobic digester are already engaged in fermentation, as it is a part of the path to methane production. But if interrupted, anaerobic systems can stop at a stage of fermentation that yields chemical components of higher value than methane. These are PHAs, or Polyhydoxyalkanoates, particularly of the butyrate form (see Polyhydroxyalkanoates: An Overview). PHB can be used as inputs to production of bioplastic (“green plastic”), which can be used to manufacture plastic bottles. The science of biomass conversion to biopolymers is speeding along. The wastewater industry (PHA (polyhydroxyalkanoate) production potential of activated sludge treating wastewater) can look to catch the coattails and be part of the future of biodegradable bioplastics.

Proteins are another potential off-take of biosolids fermentation. Protein synthesis is another emerging technology area of vast interest in the fight against climate change, and a primary ingredient, ammonia, is a compound plentiful in wastewater. Researchers have already begun exploring means of producing proteins from wastewater (Can direct conversion of used nitrogen to new feed and protein help feed the world?). Once produced, proteins can be formulated into feed for animals and humans, even to the extent of manufacturing meat.

The replacement of livestock agriculture with plant-based meat substitutes was put forward by the IPCC report as a key action. Consider the possibility of Huge reduction in meat-eating ‘essential’ to avoid climate breakdown. An emerging industry in manufacture meats is unfolding, gently put forward by the Good Food Institute in its Plant-Based Meat Mind Maps, and which is underscored by rave reviews for Beyond Burger and Impossible Burger. But, for much of the world, meat consumption is a primary signal of reduced impoverishment (Global Meat Production and Consumption Continue to Rise), albeit a signal with serious environmental and human health consequences.

Just as the world may not be ready for manufactured meats, the world is not likely to respond to challenges put forth by the IPCC report. Nobel prize-winning economist (2018), William Nordhaus, with a 40-year-long career in carbon taxation research, admitted that the likely scenario is a terrible overshoot of the global temperature goals, resulting in famine, extreme heat and massive flooding (see After Nobel in Economics, William Nordhaus Talks About Who’s Getting His Pollution-Tax Ideas Right). This overshoot may be necessary to whiplash humanity into taking the kind of actions that will finally compel nations, including and especially the U.S, to change course. 

The biosolids industry could be a leader in this global course correction, and we need not wait to be whiplashed into doing so. We could deploy biosolids today to produce biofuels, biopolymers, and even proteins in place of fossil carbon. I thought I was being comical when in my 1998 paper, “Horror, Humor and Heroes,” I led off with a World Weekly News story proclaiming: “POTTY PATTIES! Hamburgers made from raw sewage are a big hit in Japan.” I had discovered back then that the story had derived from a kernel of truth -- Japanese researchers had experimented with protein production from biosolids, and had manufactured sausages. Here I am, in 2018, whiplashed by the realization that “potty patties” may be yet proved one way that biosolids can solve the climate crisis!