Plant Bioeconomy PDF

CHAPTER 4: PLANT BIOECONOMY NORBERT Q. ANGALAN, PHD. SCHOOL OF NURSING, ALLIED HEALTH & BIOLOGICAL SCIENCES DEPARTMENT OF BIOLOGY SAINT LOUIS UNIVERSITY Learning Objectives Discussproperties of plant-based materials with commercial applications....

CHAPTER 4: PLANT BIOECONOMY NORBERT Q. ANGALAN, PHD. SCHOOL OF NURSING, ALLIED HEALTH & BIOLOGICAL SCIENCES DEPARTMENT OF BIOLOGY SAINT LOUIS UNIVERSITY Learning Objectives Discussproperties of plant-based materials with commercial applications. Evaluate environmental benefits associated with plant-based materials. PLANT BIOECONOMY  begins with the extraction of primary plant resources and culminates in the cascading development of various biobased products  utilize all plant components as fully as possible  agricultural production provides a vast renewable resource that plays a major role in transitioning to a circular economy  PLANT-BASED MATERIALS...Biodegradable 1. Lignocellulosic materials  Cellulose – most abundant polymer, major structural element of plants derives mostly from wood, corn, wheat, soybeans and native grasses  Pulping – removes part of the lignin and hemicellulose which binds cellulose fibers together making it easier to disperse the fibers into a fine suspension  PLANT-BASED MATERIALS …. Lignocellulosic materials  advantage of cellulose over petroleum-based polymers is their biodegradability = occurs over a period of weeks to months vs hundreds or thousands of years to fully degrade  PLANT-BASED MATERIALS …. Lignocellulosic materials  cellulose can be disrupted into microfibrils (MFC) or nanofibrils (NFC) = used as thickeners, bulking agents and fiber in a variety of foods  anaerobic fermentation of lignocellulosic residues produces cellulosic ethanol and methane then utilized by bacteria to produce polyhydroxyalkanoates (PHA) PLANT-BASED MATERIALS 2. Starch-based composites  Starch – next most abundant natural polymers derived from cereals such as corn and wheat  uses in the food (as thickener and stabilizer) and industrial sectors (adhesive and binder in paper/ cardboard, pharmaceutical tablets) = advantage of its ability to be dispersed in hot water  can be utilized in materials in either their native, granular form or after heat processing = reinforcing filler in plastics  PLANT-BASED MATERIALS …. Starch-based composites  amylase digestion removes some of the amorphous domains from granular starch resulting in small particles with even higher crystallinity = increased modulus or stiffness of natural rubber  starch-filled tires had the advantage of decreased rolling resistance and better fuel economy  use for the production of Thermoplastic starch (TPS) bio- plastics by compounding starch from potato waste with other polymers having mechanical properties similar to commodity plastics PLANT-BASED MATERIALS 3. Polylactic acid (PLA)  compostable polyester that has long been used in biomedical devices, packaging, fabrics, agriculture (mulch film) and appliances  involves using renewable resources, converting waste materials into valuable products, and optimizing production processes to minimize waste and reduce greenhouse gas emissions  PLANT-BASED MATERIALS …. Polylactic acid (PLA)  Lacticacid is polymerized by heating under reduced pressure to form low molecular weight PLA, followed by purification of lactide then polymerization to high molecular weight PLA  rapidly biodegrades in a compost environment where temperatures exceed 60 ◦C PLANT-BASED MATERIALS 4. Polyhydroxyalkanoates (PHA)  family of natural polyesters produced by bacteria for energy storage  mechanical properties similar to petroleum-based plastics and are biodegradable  frying oil, discarded food, agricultural wastes, domestic wastewater, glycerol from biodiesel production and landfill gas have been used as free or low-cost fermentation substrates to produce PHA’s PLANT-BASED MATERIALS …. Polyhydroxyalkanoates (PHA)  Classification:  (1) short chain length (SCL) with 3–5 carbon,  (2) medium chain length (MCL) with 6– 14 carbon or SCL: MCL: E.g. 3-hydroxybutyrate, E.g. 3-hydroxyhexanote,  (3) copolymers of 3-hydroxyvalerate 3-hydroxyoctanoate both  PLANT-BASED MATERIALS …. Polyhydroxyalkanoates (PHA)  composition is determined by the type of bacteria and carbon substrate used for the fermentation  readily biodegradable, however, stable like paper in ambient conditions or in the absence of high concentrations of microorganisms PLANT-BASED MATERIALS 5. Other biodegradable polyesters [Polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT)]  flexible, semi-crystalline polymers with thermal and mechanical properties similar to polyethylene  used for production of compost bags, packaging, agricultural mulch film  disadvantage: slow hydrolysis in water or high temperature/humidity conditions leading to loss of mechanical properties over several months  PLANT-BASED MATERIALS...Non-biodegradable 1. Polyethylene (PE)  produce by fermentation of sugarcane juice to ethanol, followed by dehydration of ethanol to ethylene at high temperatures over a catalyst, and polymerization of ethylene to PE 2. Polyamides (PA)  known as nylons, produced from castor oil which contains hydroxylated fatty acid (ricinoleic acid) and sebacic acid  PLANT-BASED MATERIALS...Non-biodegradable 3. Polyurethanes and Epoxies  made from vegetable oils and petroleum  used as durable coatings, adhesives, sealants and insulating foams Environmental Benefits 1. Greenhouse gas emissions and mitigation of climate change impact  E.g. carbon dioxide, methane, nitrous oxide, fluorinated gases and water vapor  act as a transparent ‘‘blanket’’ around the earth trapping heat and warming the planet  due to burning of fossil fuels and other human activities such as drilling and agriculture Environmental Benefits …..Greenhouse gas emissions and mitigation of climate change impact  Lifecycle analyses of bio-based plastics and chemicals have shown significantly lower GHG emissions than for petroleum-based ones PLA GHG emissions = 0.62 kg CO2/kg & Thermosplastic starch GHG emissions = 0.8-1.2 kg CO2/kg vs Petroleum based polymers = 1.6-2.3 kg CO2/kg Environmental Benefits 2. Waste/pollution reduction  problems with disposal of plastics  expensive to build landfills, disposal or ‘‘tipping’’ fees  plant-based alternatives to petroleum-based plastics have additional or enhanced disposal options including composting, anaerobic digestion, easier recycling, environmental biodegradation and even use as animal feed Environmental Benefits 3. Less energy/resource consumption  non-renewable energy used (NREU) to manufacture plant-based materials is generally lower than for petroleum-based materials  2.1 million metric tons requires 0.81 million hectares or 0.016% of world farmland vs 330 million metric ton global plastic production require 126 million hectares or 2.5% of agricultural land. Economic Benefits 1. Promotion of circular economy — sustainable economic benefit  Plant-based materials made from renewable feedstocks biodegrade back into CO2 then reassimilated by plants or recycled back into more materials  Research and development to convert agricultural byproducts into feedstocks for material production and increased recycling efforts help reduce the need to use foods for materials Economic Benefits 2. More employment opportunities  Plants to convert agricultural commodities to chemicals and fuels are built in rural areas to be close to farms thus minimize the cost of transportation of farm products to biorefineries  Growth in bio-based manufacturing will in turn encourage rural investment in other areas such as schools, hospitals, roads/bridges, other businesses, recreation, and high-speed internet access Economic Benefits 3. Promotion of green technology innovation  Innovations in plant-based materials have been made possible largely through research and development of modern genetic engineering techniques as well as green chemical methods (less solvent use, safer and more efficient catalysts, fewer byproducts) and better understanding of structure property relationships. Health Benefits 1. Reduce prevalence of harmful chemicals/pollutants  plant-based materials have low toxicity and few hazards vs petroleum-based materials which are toxic and/or highly flammable and explosive under certain conditions (methanol, ethylene glycol, xylene, silica, toluene, ethylbenzene and formaldehyde have the potential to impact human health) Health Benefits …Reduce prevalence of harmful chemicals/pollutants  Acute exposure to styrene (plastics) can cause central nervous system symptoms such as headache, fatigue, dizziness and confusion  Vinyl chloride exposure can occur from water from PVC pipes or toys, packaging or medical tubing made from PVC  Toluene diisocyanate (TDI), a main component of polyurethane foams, is extremely toxic to respiratory mucosa causing asthma and other breathing problems Health Benefits 2. Mitigate health burdens associated with climate change – adopting plant-based materials alleviate the ff:  Rising air and water temperatures increase the frequency of waterborne and foodborne diseases  range of disease-carrying insects and pests (e.g. dengue, Zika)  mental health consequences of these disasters Health Benefits 3. Help conserve ecosystems and biodiversity  Demand for plant-based materials can help preserve forests used for lumber and paper production  Services provided by functioning ecosystems include oxygen production by plants, clean water, decomposition of wastes, storage of carbon, fertile soil, for crop production, pollination, flood control, recreation and repository of genetic information The foundation of any bio-based economy will rely on plants…