Feedstock Flexibility

by Matt Thompson (Ethanol Producer Magazine) Beyond Enerkem, a few companies around the world are looking to feedstocks outside of corn to produce cellulosic ethanol. -- A few well-known ethanol producers are developing cellulosic pathways that use feedstocks other than elements of corn.

Waste Gas
LanzaTech, a U.S.-based carbon capture and recycling company, produces cellulosic ethanol using waste gases from landfills, steel mills and other sources. The company has developed a gas fermentation process and has a commercial installation near Beijing.

“If you think about traditional fermentation, you’d use sugars and yeast to make beer or wine,” says Freya Burton, chief sustainability and people officer at LanzaTech. “We don’t use sugars, we use the gas, and we don’t use yeast, we use bacteria, and we’re not making wine, we’re making ethanol that can be blended in the fuel pool or converted into other products, and we’re making other chemicals as well.”

“Ethanol can be a building block for lots of other things—not just making ethylene, polyethylene and consumer goods, but also, we’ve developed a second-stage process that converts ethanol into a drop-in jet fuel.” She says jet fuel produced with LanzaTech’s process was used on a transatlantic flight last year. “We had enough to do a 5 percent blend last October,” she says. “And it was only a 5 percent blend because we just didn’t have the volume. So, that’s the next step is getting the volume from the commercial plants, or from any source of sustainable ethanol, and converting that into jet fuel.”

Forest to Fuels
Based in Finland, St1 is an energy company that operates primarily in the Nordic countries: Finland, Sweden and Norway, says Patrick Pitkänen, St1’s director of biorefining business development. In addition to producing biofuels, the company operates an oil refinery and retail stations in all three countries.

St1 began producing ethanol 12 years ago, from food industry waste, Pitkänen says. The company now has four operating plants in Finland, as well as one in Sweden.

The company is now looking to expand into wood feedstocks, with a demonstration plant in Finland. “When we started from food industry waste and sugars and starch from bakeries and so on, we realized that we don’t have the feedstocks or the volume,” he says. As much of the land in Nordic countries is forested, Pitkänen says the company explored using waste from the sawmills and forest industries as a feedstock for producing ethanol.

Circular Bioeconomy
Praj, based in India, has operations around the world. Pramod Chaudhari, executive chairman of Praj, says the technology developed by the 35-year-old company is the basis for many plants across the globe.

Enfinity allows plants to produce cellulosic ethanol from biomass feedstocks, such as rice and wheat straw, bagasse, corn cobs and stover, among others. Following the completion of a successful pilot plant, Praj in 2017 built a second-generation demonstration plant, which Chaudhari says was a logical extension of the company’s first-generation ethanol technology.

“The 2G biorefinery demo plant is in a field next to a sugar mill, so we get different types of inputs from the sugar mill,” Chaudhari says. “And it is quite flexible to accommodate a variety of feedstocks, whether it be bagasse or rice straw or wheat straw and different batches of palm oil. Most of the feedstocks can be tested there.”

Chaudhari says Praj has four contracts for commercial-scale plants in India. He adds that the first plant should be operational by the end of 2020 or early 2021. Chaudhari says the company is hoping to bring its technology to Europe, the U.S. and other parts of the world.

Praj is also moving into the renewable gas and renewable chemicals markets. “The biogas business the last so many years has been a part of our wastewater treatment solution, to the ethanol plant,” Chaudhari says. “But now it is getting its own standing, its own recognition as renewable fuel.”

A few other projects are coming up here and around the world that plan to use crop residues as feedstock. Expected to break ground in 2019, the New Energy Spirit Biomass Refinery near Spiritwood, North Dakota, is projected to use Inbicon technology to produce 16 MMgy of cellulosic ethanol. It will be the first commercial-scale implementation of the Danish technology in the U.S. The plant will use wheat straw, and possibly corn stover, as its feedstock, and its ethanol will be sold to the California market to take advantage of the state’s Low Carbon Fuel Standard, the plant’s developers say. In addition to ethanol, the plant will also produce fuel pellets from lignin. The project is financed using a Danish loan guarantee through Denmark’s export credit agency, the EKF.

In 2018, Clariant celebrated the groundbreaking of its sunliquid plant in Romania. The plant’s feedstock will include wheat and other cereal straw from local farmers.

Raizen Energia has been producing from sugarcane bagasse and straw since 2014. The plant uses Iogen technology and is located near a sugarcane mill in Piracicaba, São Paulo. GrandBio’s cellulosic ethanol plant in Alagoas uses sugarcane straw and bagasse. The plant began producing cellulosic ethanol in 2014.

Finally, the 13 MMgy Beta Renewables cellulosic ethanol plant in Crescentino, Italy, was purchased last year in a large acquisition of bankrupt parent company Mossi & Ghisolfi by Eni subsidiary Versalis. Versalis is a chemical producer and says it plans to launch plant operations to continue producing ethanol from ag waste. READ MORE