PRODUCTION OF BIODEGRADABLE PLASTICS USING BAGASSE OF SUGAR CANE

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BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS

FACULTY OF CHEMICAL AND TECHNOLOGY AND BIOTECHNOLOGY

DEPARTMENT OF APPLIED BIOTECHNOLOGY AND FOOD SCIENCE

PRODUCTION OF BIODEGRADABLE PLASTICS USING BAGASSE OF SUGAR CANE

Luann Karlos Alves da Silva 

PRODUCTION OF BIODEGRADABLE PLASTICS USING BAGASSE OF SUGAR CANE

Review submitted to the Budapest University of Technology and Economics as requirement for approval in the discipline Individual Project. Request by the professor Zsolt Barta.                

SUMMARY

Introduction...................................................................................................................................4

Development of research..............................................................................................................6

Results and discussion..................................................................................................................8

Conclusion....................................................................................................................................9

References...................................................................................................................................10

Introduction

Grain ethanol is by far the most widely used biofuel for transportation worldwide and the United States accounts for nearly half of global ethanol production. US corn ethanol production volume increased eight-fold between 2000 and 2012.

The production of corn ethanol utilizes only the starch present in the corn, leaving protein, crude fat, and fi bers as by-products that are known, when combined, as dried distillers grains with solubles (DDGS). With every gallon of ethanol produced, approximately 2.6 kg of DDGS are produced.  Approximately 210 corn ethanol plants operating in the United States produced nearly 15 billion gallons ethanol along with 36 million metric tons (MT) of DDGS in 2012.

 Currently, DDGS is primarily used as enriched livestock feed, the proceeds from which considerably improve the economic viability of corn ethanol production. The price of DDGS has exhibited volatility in the past decade, varying in price from $70 to $330 per MT. This volatility makes the economic feasibility of the corn ethanol industry vulnerable.

 As the biofuel industry grows, the increasing supply of DDGS may saturate or eventually surpass the demand of the livestock feed market. Moreover, concerns about the negative effects of feeding DDGS to animals may constrain the demand from the livestock industry. All of these factors may have negative influences on the DDGS market price, which, if depressed, could in turn impair the economic performance of corn ethanol production. To increase the financial profitability of the corn ethanol industry, it is necessary to expand the application and improve the value of DDGS. Various process routes have been explored to convert DDGS into value-added by-products such as energy, biofuel, or bio-based chemicals.

DDGS has inherently high energy content, making it suitable for gasification for syngas production. The potential of DDGS as a feedstock for gasification was explored by various researchers. However, the cost of the fuel generated from this gasification pathway was predicted to be twice the price of conventional gasoline due to high capital costs.

 Pyrolysis has also been explored to convert DDGS to bio-oil, which may then be upgraded to transportation biofuel.

 Although the bio-oil produced from DDGS exhibited some advantages compared with bio-oil produced from lignocellulosic biomass, the high nitrogen content in DDGS bio-oil can deactivate catalysts during bio-oil upgrading, leading to additional upgrading challenges.

 Catalytic pyrolysis using zeolite catalyst to produce aromatic and olefi n hydrocarbons from lignocellulosic biomass has been investigated extensively. Technoeconomic analysis indicates catalytic pyrolysis to be a promising pathway for the production of transportation fuels from lignocellulosic biomass.

 Considering this potential for value-added products, DDGS was explored as a potential feedstock for production of hydrocarbons from catalytic pyrolysis. Substantially higher yields of aromatics and olefi ns were observed with DDGS compared with yields from lignocellulosic biomass. Benzene, toluene, and xylene (BTX) were the predominant aromatic hydrocarbons while ethylene and propylene were the predominant olefi n hydrocarbons.

 BTX could be blended with gasoline as an octane booster, although there are eff orts to reduce the aromatics content of gasoline for health reasons. BTX, like ethylene and propylene, has a large market as a petrochemical:

 Benzene is used mainly as an intermediate to make other chemicals such as polymers, plastics, and resins. Toluene and xylene are common solvents in many applications. Para-xylene is the principal precursor to terephthalic acid and dimethyl terephthalate, which are used in the production of plastic bottles and polyester clothing. Ethylene and propylene are also widely used in the chemical industry to produce polymers. Currently, DDGS has an average market value of $242 per metric ton as an animal feed supplement over the last 12 months, while BTX, ethylene, and propylene have a tremendously higher market value of around $1300/MT over the same period.

This benefit may make hydrocarbon production from DDGS an appealing option for corn ethanol producers. Moreover, DDGS pricing has more variability than the pricing for petrochemicals.

Additionally, the fuel and petrochemical market is much larger than the animal feed market.

To maximize the efficiency of the corn biorefinery and to achieve significant market penetration, it may be economically more feasible to convert DDGS to hydrocarbons instead of selling it as animal feed supplement. In this study they propose an integrated biorefinery scenario with conventional corn ethanol production followed by DDGS catalytic pyrolysis to produce hydrocarbons. Total capital cost, operating cost, and MFSP were calculated to quantify the economic feasibility for the integrated process. Results obtained from the integrated scenario were compared with conventional stand-alone corn ethanol production with DDGS sold as animal feed.