Renewable Diesel and Power from Sweet Sorghum

Producers of advanced biofuels and high value products from biomass and engineered crops and microbes, are still out there working hard in labs around the world. The global bonanza of cheap shale gas may postpone the commercial debut of many of these products, processes, and systems, for a decade or more. But that will give these labs and field scientists more time to perfect their systems. In fact, there are many ways in which cheap methane could be a boon to the production of high value chemicals and fuels. And it is undeniable that high value bio-products can be grown and produced in almost any terrestrial location -- often in places far from hydrocarbon deposits or depots.

The following report demonstrates that top quality scientists are continuing to pursue viable paths to the production of renewable fuels, chemicals, polymers, lubricants, and other high value products.

GCC Amyris Scientists from Amyris and Ceres are presenting new findings at a biotechnology conference in New Orleans on the production of renewable diesel and power from sweet sorghum. Here's more:

The pilot-scale project use both free (soluble) sugars and biomass (cellulosic) sugars from Ceres’ sweet sorghum hybrids grown in Alabama, Florida, Hawaii, Louisiana and Tennessee. To process the soluble sugars that accumulate in the plants, the sorghum juice was first extracted from the stems and concentrated into sugar syrup by Ceres. The syrup was then processed by Amyris at its California pilot facility using its proprietary yeast fermentation system that converts plant sugars into its trademarked product, Biofene, a renewable hydrocarbon commonly known as farnesene....

The inedible plant fibers of the sweet sorghum provided an additional source of cellulosic sugars. The DOE’s National Renewable Energy Laboratory (NREL), at its Colorado pilot-scale biochemical conversion facility, converted the biomass from Ceres’ hybrids into cellulosic sugars, which Amyris subsequently fermented into renewable farnesene.

Farnesene is a 15-carbon isoprenoid hydrocarbon molecule that forms the basis for a wide range of products varying from specialty chemical applications to transportation fuels such as diesel. When used as a fuel precursor, farnesene can be hydrogenated to farnesane, which has a high cetane number (58). Amyris modifies farnesene to become renewable diesel.

Life-cycle analysis of Amyris Diesel production from sweet sorghum indicates Greenhouse Gas (GHG) emission reductions of greater than 80%.

Secondary products from the biorefinery project include lubricants, polymers and other petrochemical substitutes. These secondary products are derived from the same C15 fermentation intermediate (farnesene) as Amyris Renewable Diesel, providing opportunities to de-risk commercial production. _GCC

Expanding Earth's Usable Biomass Production

There are several ways that the Earth's industrial production from biomass could be expanded significantly:

• Grow biomass in places currently thought unsuitable for growing
• Grow more useful biomass crops per year on the same surface area
• Achieve higher yield from each crop that is grown
• Improve the quality of biomass feedstocks

And so on. DuPont's investment in new hybrid varieties of sorghum aims to make improvements in all four areas above. By investing in hybrid sorghum that produces both sugar and higher yield biomass, can be planted on dry marginal pasture land, and has a short growing season suitable for crop rotation -- all of these point to perhaps 100 billion gallons of additional US biofuels without using valuable cropland or significant water resources.

DuPont and NexSteppe have entered into a collaboration to develop advanced feedstocks for biofuels, biopower and biobased products. The collaboration will focus on the development of new sweet sorghum and high biomass sorghum hybrids which will create additional feedstock options for these industries.

...Sorghum is naturally drought- and heat-tolerant and has the ability to grow in marginal rainfall areas with high temperatures where it is difficult to grow other crops. It has a relatively short growing season and is suitable for crop rotation systems. Sorghum is increasingly grown as a source of feedstock for industrial value chains.

Sweet sorghum can be used as a complement to sugarcane in existing Brazilian sugar to ethanol mills, and as a feedstock for advanced biofuels and other biobased products produced from sugars. High Biomass Sorghum is a high-yielding crop that can be used as a feedstock for biopower and cellulosic biofuels. DuPont, through its Industrial Biosciences business, operates and develops industrial processes that use sugar as a feedstock. _GCC

This represents a relatively modest increase in potential for biofuels and industrial biomass on the scale of the US economy, but in terms of regional benefits and downward pressure on fuel and food costs, it could lead to significant incremental benefit.

Of course the truly huge potential for boosting planet Earth's biomass output will lie in the oceans, coastal and tidal areas, saline soils, and deserts. Planet Earth is the only biological planet that we know of. Life grows wild high in the atmosphere, at the bottoms of the seas, deep inside the rocky crust of the planet. Even on the most isolated mid-sea islands, no sooner does a new volcanic lava cool, than new outposts of living matter spring up -- from the microscopic to the macroscopic.

One of the greatest limitations to the growth of biomass on the planet is the quite low concentration of CO2 in Earth's atmosphere -- compared to earlier levels when most life evolved. Perhaps we will need to find more efficient ways of generating CO2 and releasing it into the atmosphere, so that we can grow as much biomass as we may need?

Smart Chemistry: Catalysing a Better Biodiesel

Turning plant oils into high quality liquid fuels is not easy. Most biodiesels are actually methyl or ethyl esters, rather than pure hydrocarbons. They may not perform the same as petro-diesel -- particularly at cold temperatures. In addition, if you can create pure hydrocarbons, you can refine them into any hydrocarbon fuel that you want.

A new, potentially low cost catalytic process that produces hydrocarbons instead of esters, has been announced by researchers at Applied Research Associates' labs in Florida.

Benefits of the non-ester fuels can include higher energy content than alcohols or ester-based fuels; excellent combustion quality, similar to Fischer-Tropsch fuels (low soot and high cetane); good low-temperature properties (viscosity, freeze point, pour point, and cloud point); and superior thermal stability, storage stability, and materials compatibility.

...The process involves three main production steps:
The CH process that converts triglyceride to biocrude. The CH reaction is the key conversion step in the triglyceride to biofuel process.
Decarboxylation and hydrotreatment of the biocrude resulting from step 1.
Fractionation of the resulting non-ester biofuel into JP-8, naval distillate, and gasoline cuts. _GCC

Of course, you have to grow the bio-oils first, before you can convert them to jet fuel, diesel, and gasoline.

In other biofuels news, researchers in Thailand are looking at sweet sorghum as an alternative to sugar cane -- as an ethanol feedstock.

Thailand's current ethanol production depends on cassava and sugarcane, both of which are winter crops.

"Sweet sorghum would be the new option for the ethanol producer. Since farm products are seasonal, which we cannot control, we need different crops in different seasons to ensure we have raw materials all through the year," said Mr Krairit. Feedstock prices would also be less volatile, he added.

Sweet sorghum supplies would be ready in the rainy season, said Mr Krairit.

Khon Kaen University began research and development into sweet sorghum at its fields and laboratories several years ago after it found the crop's high sugar content could suit production of ethanol as well as sugar.

"We also plan to develop further products from sweet sorghum. We think it could be a material for bioplastic as well as chemical substances for food ingredients."

India and China are also looking at developing sweet sorghum as a raw material to secure ethanol raw materials, he said.

Sugarcane is currently cheaper than sweet sorghum as a source for ethanol in Thailand but sorghum could be competitive when cane and cassava are out of season, he said. _BangkokPost_via_Biofuelsdigest

Sorghum has a much wider climate range than sugar cane, is more resistant to cold, and requires less water.

Versatile Sorghum Can Grow in 80% of World

Sorghum is not yet well known as an energy crop, but it is being situated as an important ethanol feedstock across parts of Texas and the US mid-southwest.

“Sorghum, by nature, is drought tolerant,” he said. “That provides a unique opportunity.” Studies in West Texas show sorghum can produce significant tonnage on relatively small amounts of water.

“It’s also adaptable. Sorghum bicolor (the most common sorghum) will grow in 80 percent of the world.”

He said the sorghum genome has recently been sequenced, “the second cereal to be sequenced. We now have tools available (for enhanced research).”

....Sorghum offers an opportunity to deliver tons of biomass on a limited amount of water. Sorghum can withstand conditions with either limited water or too much.”

Lust said a new generation of researchers and entrepreneurs offers potential for improved opportunities for sorghum as a renewable fuels crop. “Increased acreage worldwide is another advantage. Sorghum can be part of an international solution to renewable fuels.”

He said an advanced definition of biofuels in the energy bill “makes sorghum unique. It also leaves a small carbon and nitrogen footprint. We’re just learning about the compositional analysis of biomass.

“New sorghums have the potential to be some of the great biofuels crops,” he said. “Sweet sorghum could double the gallons per acre when combined with cellulosic or ligno-cellulosic ethanol.” That’s accomplished by using the sweet sorghum sugar extraction for ethanol and then using the biomass for cellulosic conversion. _Source

As scientists learn which biomass crops do best on what land, and in particular crop rotations, farmers will be able to produce much more biomass than at present--just at the time when producers will be gearing up to produce more cellulosic electricity and cellulosic biofuels.

Nigeria Hedging Its Bets With Sweet Sorghum

Nigeria is better known for its petroleum reserves--and the troubles revolving around them--than its biofuels leadership. But Global Biofuels Limited, a company with headquarters in Lagos State, plans to expand biofuels in Nigeria using sweet sorghum.

Babatunde Obilana, director of the company, said the process of refining the crop involved three stages: "Crushing to produce a sugary juice; fermentation to convert the sugary juice into ethanol" and the utilisation of what he called "bagasse" (gotten from the dried stalks of the crop), which he said, could be used as a renewable energy source for electricity and serve as fertiliser in farms. _NextEnergyNews

Global Biofuels is using feedstock from India, as well as developing new strains of sweet sorghum within Nigeria. Currently large plots are being cleared in preparation for planting in time to begin harvesting within 18 months.

Both sweet sorghum and grain sorghum offer improvements over both cane and maize ethanol--in terms of wider growing climates and much less water and cultivation required. Sorghum and cassava both seem particularly well suited to the wide range of soil and climatic conditions found in Africa.

In Africa, small, local solutions to problems is by far the best approach. Larger mega-plantations--as in palm oil plantations--tend to be environmentally disruptive and subject to looting by government officials and ragtag warlord/militia groups. By providing small farmers, villages, and local regions with the means of energy self-sufficiency plus a ready cash crop, you are empowering the continent from the bottom levels up.

Breeding High Energy Super-Sorghum Promising

Mendel Biotechnology and MMR Genetics are collaborating to create a new "super-sorghum" for biofuels and biomass.

MMR Genetics and Mendel will jointly establish a bioenergy nursery, which will be used to breed new, high-performing sorghum cultivars with unique biofuels characteristics. Richardson Seeds will produce commercial quantities of selected cultivars.

..."Sorghum has the genetic potential - because of its yield capacities, adaptation ranges, and germplasm diversity - to provide superior second-generation biofuels and assist in alleviating dependence on fossil energy sources,” said Dr. Fred Miller, senior sorghum breeder and owner of MMR Genetics. “MMR Genetics and Mendel will be able to move our high quality forage and biomass programs to exciting new levels through our association by creating tailor-made commercial feedstocks for these new markets.”

Under the terms of the agreement, MMR Genetics will contribute germplasm, breeding know-how and services, and nursery operations; Mendel will provide funding and research and breeding assistance and will have exclusive commercial rights to selected cultivars. Richardson Seeds will provide seed production research and produce commercial quantities of selected cultivars. __BioenergyCheckBiotech

Such biotech applications of gene engineering to biofuel feedstock should yield fairly quick results. Anyone judging the future of biofuels upon current maize-to-ethanol processes is apt to miss the mark quite badly.

Sorghum in Place of Corn and Cane

Sorghum can provide bio-alcohols by multiple routes. Sweet sorghum contains sugars that can be fermented directly. Grain sorghum produces starches that can be converted to fermentable sugars similarly to maize starches. And the prolific cellulosic fibre in sorghum provides a plentiful cellulosic feedstock for newer cellulose-to-bioalcohol processes.

"Currently, feedstock for commercial ethanol production is about 95 percent from corn grain and about 4 percent from sorghum grain," Wang said. "Grain sorghum is a reasonable feedstock for ethanol and could make a larger contribution to the nation's fuel ethanol requirements.

"Due to climate variability and continuing decline of water resources, utilization of dry land to grow sorghum and forage sorghum is critically important to ensure available energy resources and sustainable economic development. Sorghum requires 40 percent less water than corn to grow and can be produced in the semiarid regions of the nation and the world," he said.

Major sorghum-producing states include Kansas, Oklahoma and Texas. Sorghum outperforms corn on dry land. However, Wang said that sorghum has been underused for industrial applications, especially for bioenergy. He said there has been little research conducted on performance of grain sorghum for ethanol, especially on sorghum biomass - stalks and leaves - for biofuel production.
__CheckBioenergy

Al Fin is famous for saying: ethanol is for drinking, not for fuel. But given the high price for gasoline and diesel, even Al Fin is amenable to compromise on this point. In the long run, butanol and bio-gasoline make better fuels than ethanol. And neither butanol nor bio-gasoline are worth very much as beverages.

Sweet Sorghum Ethanol Instead of Maize or Cane

Sweet sorghum requires half the water and fertilizer of corn, and uses less electricity. Compared to sugar cane, sorghum uses only 1/3 the amount of water, and grows in a wider range of climates.

The timing may be right for sweet sorghum. The United States is reaching its limits on using corn for ethanol, and global concerns are rising about using grains to make fuel while food prices soar. At the same time, researchers are looking for ways to make biofuels that would do more to reduce carbon dioxide emissions. Sweet sorghum gets good marks on all counts.

In India, where researchers have made ethanol from sweet sorghum recently, it’s known as a smart crop, because farmers can grow it for grain for food or for the stalks for animal feed or ethanol. It will grow in hot and dry conditions, and it tolerates salty land and waterlogging.

Sweet sorghum is harvested for its juice before the mature plant forms clusters of grain. The stalks are pressed, and the juice is fermented and distilled to make ethanol. The process is simpler and requires less electricity than making ethanol from corn.

Growing sweet sorghum requires only about half the water needed for corn and about half the nitrogen fertilizer. And unlike sugarcane, which grows best in tropical conditions, fast-growing sweet sorghum can be grown in much of the country during the summer. __Source

Sorghum is bulky, and requires local and regional processing and/or pre-processing. This encourages the growth of local industry, which is beneficial for small to medium sized communities.

"Its water requirement is one-third that of sugarcane, and its growing period is short enough to allow harvesting twice a year. While sugarcane is propagated from stem cuttings, sweet sorghum is sown with seed - just 4.5 kg is enough for a hectare of land, compared to 4,500-6,000 kg of sugarcane cuttings." Sweet sorghum's potential as an energy crop - it produces up to 7,000 litres of ethanol per hectare - makes it highly attractive for countries like China [and the US], which is expected to exhaust its economically recoverable petroleum reserves by 2016. __Source

Sugar cane is particular about its growing climate, and likes moist tropical areas the best. In the US, cane grows well in Hawaii, Florida, Louisiana, and parts of Texas. But sweet sorghum grows well across much of the traditional US farm belt, in a much wider growing region than cane. Given its advantages as an ethanol crop over both cane and corn, sweet sorghum should see more acreage soon.

Sorghum should be seen as a "bridge" crop. Currently, its sugar-producing properties are most valued in ethanol production. Eventually, the sheer biomass capacity of sorghum may become its most valued property.