Cellulac to retrofit brewery for production of 2G feedstock-based lactic acid

Circumventing the debate about using food/feed crops for plastics, Cellulac is the first company to produce 99%+ optically pure L(+) and D(-) LA from both C6 and C5 sugars derived from lignocellulosic biomass. While current lactic acid producers base their production on sugar and food crops, Cellulac uses wheat straw, spent brewery grains from beer production, dried distilled grains from ethanol production and lactose whey as feedstocks to produce bio-chemicals such as lactic acid, polylactic acid, ethyl lactate and sodium lactate.

The company developed and successfully scaled up this technology within the scope of a EU-funded project and has already produced lactic acid at a pilot plant in Potsdam, Germany. The new industrial scale plant is initially targeted to produce 20,000 metric tons annually and to create 30 full-time new jobs in the area.  In a second phase, this is projected to rise to 100,000 metric tons while adding an additional 30 jobs along the way. According to Gerard Brandon, CEO of Cellulac, the agreement is an important step in accelerating the company's plans for commercial production. "We look forward to commissioning the retrofitted and repurposed facility by mid-2014," he said.

The company's  proprietary end-to-end platform involves the integration of a number of complementary technologies that Cellulac has acquired or developed, all of which are protected by an extensive portfolio of 136 patents (granted and pending), putting it way ahead of a variety of research companies attempting to develop second-generation feedstock technology. One main distinguishing feature is the use of the SoniqueFlo process for the biomass pre-treatment process, rather than e.g. organic solvents or ionic liquids. Pre-treatment is required, as the sugars in biomass are chemically bonded to a polymer called lignin, in a structure known as lignocellulose. Pre-treatment involves disrupting the lignocellulosic structure and depolymerizing the sugars, which is the only way to access these sugars.

In the SoniqueFlo process, to which Cellulac has secured the IP rights, use is made of a supersonic flow reactor into which the biomass is introduced at the relatively slow speed of 5 meters per second . There, it is exposed to steam at 6 bar pressure, causing the acceleration of the biomass to a supersonic 1000ms-1 with a low vapor pressure. The shear and cavitation forces of the high velocity and pressure drop causes structural changes to the biomass, such as cell wall opening and disruption of the lignocellulose structure. The process is flexible enough to handle a variety of feedstocks, Cellulac said. Moreover, it results in lower enzyme requirements and hence lower process costs; plus, trials have confirmed a 50% reduction in energy requirement.

After pre-treatment, the next step is cellulose hydrolysis, which is achieved through the use of an enzyme cocktail based on cellulase enzymes. This is followed by the fermentation of cellulosic sugars to lactic acid. A key cost component of fermentation is the need for nutrient inputs to the fermentation. Cellulac recirculates bacterial cells isolated as part of the downstream processing back into the fermentation to reduce nutrient costs.

The lower cost of the raw material used, combined with these novel process innovations means that Cellulac can realize up to a 40% reduction in production costs versus those of current market leaders. These processes also ensure that the technology is 'greentech' , with a carbon neutral footprint.

It looks like this may actually be one of those rare deals where everyone is happy.

As Gerard Brandon pointed out: "With the support of the European Union we will convert, part of what was until recently, the second largest brewery in Ireland into what will be the largest producer of lactic acid from agricultural waste and dairy by-products. This will not only directly breathe new opportunity into Dundalk by creating 30 jobs, but it will also indirectly support agricultural jobs in the rural community and generate local taxes that will benefit the area."

To which Sean Sherlock, TD, minister of research & innovation added: "We are delighted to be involved in this environmentally friendly project that not only creates new jobs, increases GDP and exports but contributes to the reduction of our country's lower carbon emission targets to benefit the community as a whole."