PROJECTS

This project evaluates small scale conversion of biomass (cellulosic materials) into market grade pulp, mixed fermentable sugars and usable sulfur free lignin. While the technology has been established using other agriculture residues, no work to date has been conducted to determine that it can be applied to Southern Yellow Pine. The research involves a multi-phase approach to prove out the technology for conversion of Southern Yellow Pine for small scale commercial-size applications.

Phase One (the “Research Phase”) involves research that provides for the bench development specific to Southern Yellow Pine to achieve the production of Kraft-grade pulp (potentially, dissolving grade pulp) and depolymerized C5/C6 sugars and capture of lignin. The research utilizes a patented technology known as Mixed Super Critical Fluid Process that uses steam, pressure and gaseous chemical additives to produce a brown stock pulp.

Phases Two through Four, dependent on the outcomes determined in Phase One, involve proving the technology in scalable applications beginning with a laboratory model, moving to a larger demonstration pilot plant culminating with a commercial scale process plant.

There are many uses for the various grades of produced pulp including; paper, paper based products (cups, napkins, toilet tissue, etc.), cardboard, diapers and baby wipes, LCD screens, shoes, textiles, filters, binding agents and in food and pharmaceuticals. Dissolving pulp is bleached wood pulp that has a high cellulose content (>90%) and has a high level of brightness and uniform molecular-weight distribution and is manufactured for uses that require a high chemical purity, such as spinning into textile fibers (Lyocell Fiber is an example, produced by Lenzing with a plant in Mobile, Alabama).

This conversion technology, if proven successful, has the potential to foster a complete paradigm shift in the timber industry allowing for the construction and operation of “micro” pulp mills to be located adjacent to and in conjunction with existing sawmills. Simply put, the technology will allow landowners to access value-added opportunities to their timber holdings that previously were only accessible to major corporations and huge capital investments.

It is difficult to estimate the consequences of plastic pollution. With recent efforts to reduce the impact of plastics globally, it is evident the issue is a worldwide emergency with the need for innovative alternatives.

The numbers are terrifying. According to National Geographic, every year, about 8 million tons of plastic waste escapes into the oceans from coastal nations. That’s the equivalent of emptying five dustbin bags full of rubbish on every foot of coastline around the world.

What can be done? The obvious solution is to stop using plastics, but this is near impossible due to their versatility and cost. Polyolefins are undoubtedly overused in the packaging space and have become irreplaceable based on ease of access and application. In some instances, for example, in the medical sector, these plastics are relied on for their price and ease of sterilization making them difficult to replace. In 2018, the world produced 359 million tons of plastic, while in 1950 it was only 2 million.

Added to the incessant rise in production is the fact that plastics are just too durable. The chemical structure of the most common plastics, such as polyethylene (PE), polypropylene (PP) and polystyrene, is such that it requires thousands of years to fully degrade.

One proposed solution is biodegradable bioplastics. Bioplastics are plastic materials produced from renewable biomass resources, such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. Some bioplastics are obtained by processing directly from natural biopolymers including polysaccharides (e.g. starch, cellulose, chitosan and alginate,) and proteins (e.g. soy protein, gluten and gelatin), while others are chemically synthesized from sugar derivatives (e.g. lactic acid) and lipids (oils and fats) from either plants or animals, or biologically generated by fermentation of sugars or lipids. In contrast, common plastics, such as fossil-fuel plastics (also called petro-based polymers) are derived from petroleum or natural gas.

One advantage of bioplastics is their independence from fossil fuel as a raw material, which is a finite and globally unevenly distributed resource that is linked to petroleum politics and the associated environmental impacts.

The distinction between non-fossil-based (bio)plastic and fossil-based plastic is of limited relevance since materials such as petroleum are themselves merely fossilized biomass. As such, whether any kind of plastic is degradable or non-degradable (durable) depends on its molecular structure, not on whether or not the biomass constituting the raw material is fossilized. Non-degradable (durable) bioplastics must be recycled similar to fossil-based plastics to avoid plastic pollution.

Biodegradability may offer an end-of-life pathway in certain applications, but the concept of biodegradation is not as straightforward as many believe. Susceptibility to biodegradation is highly dependent on the chemical backbone structure of the polymer, and different bioplastics have different structures, thus it cannot be assumed that bioplastic in the environment will readily disintegrate.

As of 2018, bioplastics represented approximately 2% of the global plastics output. With continued research on bioplastics, investment in bioplastic companies and rising scrutiny on fossil-based plastics, bioplastics are becoming more dominant in some markets, however, the output of fossil plastics also steadily increases.

Polylactic acid (PLA) has become one of the most fast-growing bioplastics due to it being economically produced from renewable resources, currently is primarily manufactured from dextrose derived from cornstarch. A significant limitation of PLA is the lack of biodegradation at ambient temperatures. The hydrophobic nature of PLA also discourages the diffusion of water, ions or enzymes into the interior of its molecular structure. Therefore, PLA must be modified to achieve a more favorable degradation profile which currently limits its widespread application.

One effective conceptual approach to overcoming this disadvantage is by introducing cellulose to disrupt the packing structure of PLA and allowing water penetration and enzymatic activity to facilitate biodegradation.

The objective of this research is to develop composites of cellulose pulp (fluff pulp and/or dissolving pulp), polylactic acid and surface modified starch for applications such as packaging, 3D printing, medical implants (screws, pins or plates) and medical materials for pills and capsules.

The tasks will include synthesizing surface modified starch, producing composites through extrusion and injection molding, and evaluating the effect of various parameters; including cellulose fiber size, moisture content, composition, and order of the additions of cellule pulp, modified starch and PLA processing conditions on the structural characteristics, physical and barrier properties and biodegradability of the composite products. Based on these analyses, the research will be utilized to establish optimized formulation and process conditions and produce prototype composite products.

The project involves research to use a byproduct stream from pulping to produce an oligosaccharide prebiotic to enhance the feed efficiency of poultry. Feed efficiency and animal health is a key consideration of animal husbandry. Past practice had utilized antibiotics in animal feed as growth promoters; however, beginning in 2006 the EU banned all antibiotic growth promoters in feed. This trend has also been underway in the US for the past several years and is well over 50% of the market today. Part of the expressed reason for the bans was the concern that the antibiotics were creating multi-drug resistant strains of bacteria that would impair human health.

With the elimination of the antibiotic growth promoters, there have been unintended consequences of an increase in animal infections, concern over impact on bird welfare and safety, as well as challenges for the animal industry to maintain cost-effective production. A number of alternative approaches are being utilized in the absence of antibiotic growth promoters to improve poultry gut health and improve overall weight gain. Enzymes, probiotics and prebiotics are emerging as possible alternatives.

Utilizing a waste stream that is rich in xylan and mannan (byproducts of the specialty cellulose manufacturing process), the research will evaluate enzymatically reducing these sugars to oligosaccharide-based prebiotics.

Numerous studies suggest that oligosaccharide-based prebiotics, specifically xylooligosaccharides and mannan-oligosaccharides (XOS and MOS, respectively), are fibers that will pass through the upper digestive tract of animals, and ultimately be utilized as a food source by beneficial bacteria in the lower digestive tract. As these bacteria thrive, two outcomes may occur: (1) XOS and MOS is broken down by the beneficial bacteria to fatty acids aiding intestinal health and structure of the bird and (2) the beneficial bacteria crowds out harmful bacteria that would normally produce toxins harmful to the overall health of the animal. These prebiotics may prove to be beneficial to a range of animal species and may also be beneficial for human health. The research is currently focused on the poultry industry, specifically targeting broiler production, of which over 9 billion chickens are produced annually in the US.