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Lake Kivu Methane. Can Ethanol double its Energy Yield?

Can we produce ethanol from Lake Kivu in addition to methane? If so, how? Methane is the primary energy form in the lake, which contains five times as much unusable CO2 in the reservoir. Some research news offers a challenge and an opportunity to do so much more.

A research team led by scientists from Argonne National Laboratory, the University of Chicago’s Pritzker School of Molecular Engineering and Northern Illinois University has discovered a new electrocatalyst that can consistently convert carbon dioxide and water into ethanol with very high energy efficiency and low cost.

Argonne’s Laboratory Directed Research and Development (U.S. Department of Energy Office of Science).

Hydragas Energy worked for a decade to prove the leading gas extraction method from Lake Kivu. It gets tens of billions worth of methane out cheaply and effectively. But what if the waste product is worth even more?

Ethanol Production Potential

Can we now achieve this with another innovation? The lake is already a hugely important case for carbon reduction through producing renewable natural gas (RNG). But we do return gigatons of carbon dioxide to the lake – a huge carbon sink. It is essentially a low-value waste product that continues to accumulate. The carbon dioxide is a by-product of the natural digestion process producing methane. It is removed during methane extraction to upgrade the product gas. We currently return it to the lake.

Panoramic photo of Mt Nyiragongo from Lake Kivu during wet season showing steam plume
Panoramic of Mt Nyiragongo from Lake Kivu in wet season

What if we could take the methane out but also convert the CO2 to ethanol? Could this be a cheap supplement to regional gasoline supply, in the form of a carbon-negative fuel? If so, we can do this by using a newly developed catalyst from the University of Chicago’s Pritzker School. In addition, all one needs is CO2, water and electrical power – all abundant from the lake. So what is the potential?

That is where the numbers would add up to a massive economic injection for the region. That is a big number where the Kivu methane potential is already $40 billion over 50 years. How would the economics look for ethanol? Can we produce even more value?

Cheaper fuel – Ethanol from Lake Kivu

Gasoline has a vast, still growing market internationally. Many markets promote the use of up to 15% ethanol blended in the gasoline. Subsidy is usually needed to make production economic as ethanol is mostly derived from corn (maize) or sugar cane. These substrates are expensive to produce – hence their subsidy needs. But where the CO2 substrate is available for this alternative production process at virtually at no cost, the fuel produced is much cheaper. One would expect that it reduces the cost of fuel and can also be sold competitively within the region for fuel blending.

The contribution to a circular regional economy for East Africa is a real contribution to reducing reliance on imports. It enhances the use of the lake for CCUS, or carbon capture, usage and storage. It is already a vast opportunity, but further enhanced. 

“The process resulting from our catalyst would contribute to the circular carbon economy, which entails the reuse of carbon dioxide.” — Di-Jia Liu, senior chemist in Argonne’s Chemical Sciences and Engineering division and a UChicago CASE scientist

Advancing a Clean Economy in Africa

We are looking to build onto an established energy case for a cleaner regional economy. Methane from Lake Kivu can eliminate diesel fuel imports for power generation, while replacing charcoal as a domestic fuel. With power production potential of 600 MW, the produced power can supply power at half the region’s marginal cost of power. But the use of gasoline as the primary transport fuel in Rwanda, DRC and other regional users was a complex opportunity. Ethanol production is an important alternative to supplement imports at a lower cost.

It uses some of a vast store of accumulated CO2 gas in Lake Kivu. We currently need to wash this CO2 out of raw gas produced, to make 80% pure renewable natural gas (RNG) as pipeline natural gas.

But now instead of returning the washed out CO2 to the lake, we can process the wash water to make ethanol. If testing shows that the process is successful and economic, we can hugely enhance ethanol from Lake Kivu as part of a clean energy production phenomenon. Rwanda can, with the Kivu gas project, become 100% supplied with clean non-transport energy. With this added gasoline substitution it can commence the displacement of a significant percentage of transport fuel too.