TRASH INTO CASH: CLOSING THE LOOP IN A CIRCULAR ECONOMY

By Victoria Prado Fernandes, Silvio F. Pupo


The circular model is an economic system aimed to combat resource depletion and pollution by minimizing extraction and waste production. Pro-circularity initiatives include reducing, reusing, recycling, remanufacturing, sharing, repairing, refurbishing, etc. Ultimately, this system is a result of rethinking our status quo: a linear — “take, make, dispose” — model which is outdated and unsustainable. The concept of circularity may seem simple, and the goal of eliminating waste is indisputably good. However, the implementation of this ideal set of practices is easier said than done. The big question is: how can we shift from our current system and implement a circular economy?

“Circularity Gap”

Here is an unsettling fact: nearly 92% of the world’s resources are used only once. Hence, our global economy is merely 8% circular. This fact becomes even more disquieting once we learn that the “circularity gap” is not closing. Instead, we are seeing an upward trend in resource extraction and greenhouse gas emissions. Over 2 billion tons of trash are generated each year globally — far beyond what can be appropriately processed or recycled. At the current rate, the world is expected to generate a disquieting 3.4 tons of solid waste by 2050. This is greatly due to the linear nature of our economy, with outdated business models, unsustainable waste infrastructure, and lacking government regulations. Our global waste problem is complex and multifaceted. The infrastructure side of things faces an unsettling reality: most of the waste generated in the US today still ends up in landfills. This is true even though we have better, cleaner, more efficient alternatives available. Here are some statistics that illustrate our current waste scenario: The US generates over 260 million tons of municipal solid waste (MSW) annually. That is, on average, around 4.5 pounds per person each day. From this MSW, more than half (~52%) still ends up in landfills, with about 30% being recycled or composted and only as little as 12.7% being converted into energy.

Landfills are the third primary human-induced source of methane in the United States, accounting for approximately 18.2% of global methane emissions. Methane is more than 80 times more powerful than carbon dioxide at warming the Earth over 20 years. In other words, waste, landfills, and methane are collectively contributing to global climate change. This is a problem that can be tackled with better waste infrastructure and technology that is currently available to us.

Waste-to-Energy

One of the viable solutions to our waste problem is a Waste-to-Energy system (WTE). The worldwide WTE technologies market is expected to grow by 6.54% by 2025. WTE can be described as a process of using organic waste material into heat or electricity, which is used to power vehicles while saving the environment at the same time. “Waste-to-energy technology is the critical ‘last mile’ link that ‘closes the loop’ in a circular economy. We must go beyond sustainability and into regeneration by redesigning our supply chains from ‘cradle to grave’ to ‘cradle to cradle.’ The world is polluted as far as the eye can see, even deep into the deepest corners of the sea. We need to accept responsibility and design for “systematic circularity,” says Silvio F. Pupo, Managing Director of Logos Capital.

“For example, demanding manufacturers design our phones and computers so that it’s easy to remove batteries and metals at the end of the products’ useful life. Making it easier to downcycle, upcycle, or recycle. In this example, it’s easier to ‘mine’ post-consumer products rather than copper ore. Processing this post-consumer copper requires one-tenth the amount of energy than raw ore.”

In today’s Sweden, trash heats homes, powers buses, and fuels taxi fleets. Although it involves a complicated sorting system, Swedes have managed to divert most of their waste either into recycling and compost efforts or into incinerators rather than landfills. According to Avfall Sverige, the Swedish Waste Management and Recycling Association, less than 1 percent (!!!) of household waste in this Scandinavian country finds its way to landfills. Converting waste into energy is not a new idea, and somewhat of a controversial one. But the controversy is in part due to misinformation, as there are different types of WTE technologies available to us today.

Incineration (burning trash to produce energy) is widely used in European countries, where there is limited space for landfills. It has also worked to keep trash off the streets and waters in Japan and Singapore. But burning waste is a polarizing method. While new waste incineration systems are extremely expensive, they cannot control the emission of toxic metals and acidic gases completely.

Newer WTEs don’t do direct burning, and instead use processes that claim to be safer for the environment like pyrolysis, gasification, and plasma arc gasification, which convert solid waste into synthetic gas or oils to create electricity.

“Less toxic trash or dioxins are produced. Instead, a controlled amount of oxygen and steam reacts with the waste, to turn it into a gas,” explained Bill Bivins, CEO of One World Clean Energy. “This synthetic gas has applications that go beyond heat and electricity generation, such as the production of chemicals and biofuels like diesel fuel, hydrogen fuel, and ethanol. These outputs are highly marketable, regardless of electricity prices. This way, waste to energy gasification plants have both upstream and downstream revenue potential.”

Biological WTE Technologies

Biochemical WTE technologies convert waste to energy in a more eco-friendly way compared to thermal-based ones. The market segment for biological techniques is growing at an estimated compound annual growth rate of 9.7% in the last six years. Emerging technology is Hydrothermal Carbonization (HTC) specially designed for the transformation of wet biomass feedstock through heat. Acid at high pressure is used as a catalyst to speed up the process and stimulate the generation of hydro-char that has properties similar to fossil fuels. The main advantage of this to Anaerobic Digestion (AD) is the lower processing time and similar operating conditions needed to generate the same amount of energy.

Dendro Liquid Energy (DLE) is a nearly ‘zero-waste’ WTE innovation from Germany. It is said to be four times more efficient than AD and costs less. Additionally, zero-emission discharge makes the plant facilities contaminated and unfit for operations. With the adoption of this zero-waste technology, market participants expect better opportunities in the future.


It’s crucial to support circular start-ups who are driving this fundamental change in production and consumption models. Collaborations with supply-chain partners, financial and governmental institutions, knowledge centers, and consumers should be focused on extending the lifetime of products and building a closed-loop business model that allows companies to recycle and reuse various products in new ways. Otherwise, it’s a dead-end street.

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