Hardwood chips, a typical feedstock for biomaterial production using supercritical water technology. Image credit:Renmatix.
This post offers an overview of a patented new process being used by Renmatix to achieve physical transformation of sustainably produced plant cellulose to bio-available sugars (the kind of affordable sugars industrial bugs will thrive on). The process involves no hazardous chemical reactions, no chemical additives, no biological cultures in tubes tanks or ponds, and no use of destructive distillation. Principal inputs are plant cellulose, water, and heat. Renmatix 'sugar chain' products are marketed as building blocks for assembly of a wide variety of chemical products, sustainable fuels, lubricants, and more.Overview of Renmatix manufacturing technology.
At the heart of the process is continuously run supercritical water hydrolysis of plant cellulose. Hardwood chips in the form of waste wood are what they use now; but, the horizon holds other possibilities.
The Renmatix process features a very fast start-up time and - important to Tree Huggers - waste output per unit of production is very low.The product stream includes mixtures of low-cost, non-edible sugars that could be competitive on world markets but which are expected to see rapid demand growth in North America as a raw material for other industrial processes.
Controls are highly automated. Water and heat are 'tightly' recycled.
Where the heat comes from.
Lignin, a direct co-product of the extraction, is physically purified in a side-stream, and continuously burned for energy recovery within the process, keeping fossil needs to a minimum. (Steady state, continuous operation of throughput and thermal conservation are key reasons the process economics are good.)
For some background on lignin, Wikipedia has a nice overview here. To understand it's significance to the Renmatix process, this sentence from the Wiki entry is helpful:
It [lignin] is one of the most abundant organic polymers on Earth, exceeded only by cellulose, employing 30% of non-fossil organic carbon and constituting from a quarter to a third of the dry mass of wood.
Renmatix customers typically buy "sugar chains" to feed bio-engineered microorganisms used to make more sophisticated industrial materials.
Such synthetic biological manufacturing processes are rapidly being developed as a living replacement for the old-style petrochemical plants and fuel refineries that were full of toxic components and multiple waste streams. You'll sometimes hear synthetic biological manufacturing referred to as 'industrial biotech.'
The more sugar customers buy, the faster biomass and microorganisms can replace traditional oil extraction, refining, and petrochemical production technologies as the dominant material basis for Western consumer culture.
If this is going to scale up significantly, state and Federal governments have an important role to play. Agencies could, for example, help make biomass producers aware of the market and facilitate distribution. They also could offer investor incentives to help match the scale up of sustainable biomaterial production with industrial biotech demand.
Working with the input of both industry partners and conservationists, government can help speed transformation of 'the dirty old' manufacturing paradigm into a green one.
Renmatix has pre-commercial production underway and customers are using their products.
Detailed discussion follows.
USDOE estimates a billion tons of harvestable biomass is produced per year in USA. For more on USDOE programs related to biomass, visit this site.
Renmatix plans initially to use primarily waste wood from sawmills or the low-value, "small trees" thinned to prevent the spread of disease or reduce fire load.
You may be wondering where the long term feedstock opportunities are concentrated. Here's a USDA-produced forest land cover map which gives a pretty good indication.
Fascinating that the best hardwood resources for this new use appear to overlay where coal production once ruled.
Process is 'biomass agnostic.'
The portion of that estimated billion ton which is byproduct or residue, commonly let to decay or be burned as a waste, is the focus.
Crop waste or cultivated grasses are also feasible choices.
Logistics is key to good economics.
The Renmatix business plan is contingent on use of existing transit infrastructure, requiring standard harvest and material handling equipment, and reliance on existing distributors. (Ideally, the wood residues have already been accumulated by others.)
A spokesperson, Tim Brown, VP of Corporate Strategy , offered this remark on sourcing and sustainability.
"We are very focused on sustainability not only for the environmental benefits but also it is in our best economic interest- we will need local, available, economical feedstock for the next several decades wherever we locate a commercial facility. We have had a lot of discussion with potential suppliers and others in the industry and understand there are a handful of sustainability certifications.
Based on these discussions - and our wood supply partner who has been in this market for several decades - we believe SFI is a relevant certification for the type of low value woody biomass residuals and pulpwood we utilize and our supplier is SFI certified.
We will re-evaluate and adapt as needed if another standard becomes the gold standard for the industry."
Manufacturing Process Technology
The process requires no chemical additives, chemical processing aids, metal-based catalysts, or halogenated solvents. Hence, toxic byproducts and emissions are minimal and relatively benign.
Supercritical water, brought to temperature mostly be processing the lignin byproduct and, if needed, combustion of natural gas, is the principal solvent used.
Scale up potential is massive --- the relatively small footprint of the manufacturing process can go anywhere there is a nearby sustainable source of biomass. Having to ship biomass in from a great distance increases operating cost; which means there is an intrinsic incentive to keep the forest alive once the factory is sited.
Markets and Consumers
Renmatix uses sustainable, non-food biomass to produce low-cost sugars, the basic building block for renewable fuels and chemicals.
Customers are expected to utilize 'synthetic biology' or commercial catalysis with Renmatix-made sugars: producing commercial chemicals immediately suitable for fuel, fuel components, polymeric intermediates, and so on.
The price competition benchmark would be imported cane sugar syrup, currently at 12 to 14 cents per pound in Brazil or corn sugar syrup in the U.S. at roughly 20 cents per pound..
Customer product examples:
Using a suitable Renmatix-made sugar food stream, synthetic organisms can make diesel directly, with very little additional refining needed. The usual biodiesel processing steps and byproducts are thereby side-stepped, lowering product cost and environmental burden. Plus, the product produced is a more pure diesel substitute mitigating concerns with biodiesel blends.
Another genetically modified yeast, growing on the same sugar mix, could produce a base lubricant suitable for many industrial or commercial products. (Substituting for oil-based lubricants.)
Positive Economic, Social, & Environmental Impact Prospects
- Process is capable of boosting rural economies by dispersing production operations close to sustainable sources of plant cellulose.
- The sugar supply chain has long term potential for significant domestic transportation fuel production - without the disadvantages of corn-based ethanol.
- Success of the supply chain would have 'domino effect' on related industries (both upstream and downstream) as society shifts away from reliance on petroleum to home-grown renewable feedstocks.
- Would created local jobs could not be outsourced due to logistics costs of moving biomass long distances.
- Does not drive conversion of land use from agriculture to forestry - all existing farm land will be needed to feed a still-growing human population.
- Once access to affordable sugar is achieved, it will be possible to enter an economy in which manufactured goods and transportation are based on sustainable biomass rather than oil.
One sentence recap:
"People want goods, mobility, and sustainability. We think we can have all three without any kind of compromise,..."
The above quote is by investor John Doerr as he addressed a crowd of bioindustry professionals in late September, 2011.