The challenge of conversion of biomass – particularly lignocellulosic biomass and agricultural waste – into chemicals, materials and fuels is being approached in multiple directions and a slew of technologies are now being developed, tested and deployed in semicommercial or pilot stage. The range includes gasification, pyrolysis and fermentation, amongst others, and many involve tinkering with genes of bacteria, yeast and fungi, to produce metabolic pathways that can then go about turning cellulosc sugars and starches into chemicals or fuels.
Not all of these technologies – and not all of the companies – will make it to the finish line, failing at the vulnerable stage of scale-up from a bright idea in a laboratory or a pilot plant, to a commercial project with the right techno- economics. Many will not find the traction required to convert an idea in a garage to a sound business model that can sustain ups and downs.
But, as the following sections show, a host of ideas are emerging – many from Universities and research institutes – and have managed to attract the first few tranches of investments to prove concepts.
Bringing back the old
HCL Cleantech (USA), a California- based company founded just four years ago, is investing in reinventing a 70-year old idea, first developed in Germany around the Second World War for treating cellulosic biomass with hydrochloric acid (HCl). The process, as it then stood, was costly due to the extensive use of water to recover and dispose the acid.
According to Mr. Philippe Lavielle, CEO, HCL Cleantech, the company has pioneered a low temperature version that uses HCl to hydrolyse the pre-treated cellulosic biomass, with full recycle of acid. "The process is energy positive and extracts the economically important tall oils from the biomass and yields sugars in high yield. We get two clear and refined streams of lignin and sugars."
At a biomass price of US$60 per dry tonne, Mr. Lavielle claims the process can compete with alternate processes that produce sugars from corn at a price of US$4 per bushel.
The sugars can then be subjected to biochemical transformations to produce plastics, fibres, surfactant raw materials, fuel additives and amino acids; or can under catalytic chemical processes to give a variety of plastics or fuels (such as jet fuel or diesel). The lignin can be used for power generation.
While the technology has only been demonstrated at a scale of a few tonnes per day, Mr. Lavielle is optimistic it can leverage "serious economies of scale." The first commercial unit is planned for end-2013, somewhere in Southeast USA.
Isobutanol as feedstock
Gevo, headquartered in Englewood (Colorado, USA), is developing biobased alternatives to petroleum-based products using a combination of synthetic biology and chemistry. The company plans to produce isobutanol, a versatile platform chemical for liquid fuels and petrochemicals, using a novel technology that coaxes proprietary yeasts to produce the alcohol from sugars.
Isobutanol has broad market applications as a solvent and a gasoline blendstock that can help refiners to meet their renewable fuel and clean air obligations. It can also be further processed using well-known chemical processes into jet fuel and for raw materials for synthetic rubber, plastics and polyesters.
According to Mr. Jack Huttner, Executive Vice-President of Commercial and Public Affairs, Gevo's technology can be retrofitted to existing ethanol plants of all kinds, at a capital cost of about US$60 per gallon, and two such installations are now on the cards in the US, which has a significant corn-based ethanol industry.
While the isobutanol produced in the process does inhibit the activity of the yeast, it is removed as soon it is formed, allowing the conversion to go to completion. While the process currently uses corn and sugarcane as the source of sugars, Gevo's technologists are confident it can work on cellulosic biomass, just as well.
Gevo is taking the partnership route for the downstream development of the isobutanol produced. It has entered into an agreement with Sasol (South Africa) to address the opportunities in the significant solvents market; and with synthetic rubber producer (Lanxess) to produce isobutylene – a key raw material for butyl rubber – which is expected to start yielding revenues from 2013.
The alcohol to jet fuel technology is expected to get a leg-up following its certification by the ASTM – a currently ongoing process. As a drop-in replacement for gasoline, isobutanol has a lower octane rating than ethanol but is Reid Vapour Pressure (RVP) is also lower.
Also under development is a process to make p-xylene (PX), the key raw material for purified terephthalic acid (PTA), required for polyester resin and fibre, through an intermediate product (isooctane). "Toray has successfully made renewable fibre and sheets from Gevo's isobutanol," says Mr. Huttner.
Leveraging the glut of glycerol
Glycos Biotechnologies Inc. (Houston, TX, USA) is planning to take advantage of the glut of glycerine that is expected as biodiesel capacity expands. The company has developed technologies that first emerged from the laboratories at Rice University, to produce platform chemicals using proprietary strains of E. Coli. The first facility to deploy this technology on a commercial scale is being built in the Bio-Xcell Park in the southern part of Malaysia. The location is strategic, particularly from a feedstock standpoint: Malaysia is the hub of palm oil production and the biodiesel industry, and significant quantities of glycerine are expected to be available in the region.