The Chemical Exodus

RESEARCHES DESCRIPTION

 

1.0 DIRECT TRANSFORMATION OF EDIBLE VEGETABLE WASTE INTO BIOPLASTICS

            Bioplastics with a wide range of mechanical properties can directly be obtained from industrially processed edible vegetable and cereal wastes. As model systems, we present bioplastics synthesized from wastes of parsley and spinach stems, rice hulls, and cocoa pod husks by digesting in trifluoroacetic acid (TFA), casting, and evaporation. In this way, amorphous cellulose-based plastics are formed. Moreover, many other natural elements present in these plants are carried over into the bioplastics rendering them with many exceptional thermo-physical properties.(Sherman ,2002)

 

The researchers Athanassia Athanassiou, Ilker S. Bayer and colleagues at the Italian Institute of Technology(2008) point out that plastic's popularity is constantly growing. In 2012, its production reached 288 million tons worldwide, but its ubiquity comes at a cost. Athanassiou's team wanted to find a simple, less costly way to make the transition. They turned to an organic acid that also occurs naturally and can process cellulose, which is the main building component of plants and also the most abundant polymer in nature. They mixed the acid with parsley and spinach stems, and husks from rice and cocoa pods. Then, they poured the resulting solutions into lab dishes. When tested, the films that formed showed a promising range of traits from brittle and rigid to soft and stretchable—similar to commercial plastics. "This opens up possibilities for replacing some of the non-degrading polymers with the present bioplastics obtained from agro-waste," the researchers conclude.
 

1.1 The process and the reactions involved:                                                    

 

Isolation of non-edible parts

Dried and powdered

↓

Solution in Trifluoroacetic Acid(TFA)

Cel-OH +CFCOOH→Cel-OOCCF +H2O

↓

Centrifugation

↓

Drop casting and

TFA evaporation

[Cel-OOCCF + H2O→Cel-OH +CFCOOH (bioplastic) ]

 

 

1.2.1 Pros

1)The technology is cost effective since raw materials are readily available

2) The processing plant is not so complex.

3) Not costly

 

1.2.2 Cons

1)Some waste like, the cocoa pod husk various types of fatty acids (cocoa butter) and substantial amount of pectin are also present that can slow down interaction with TFA hence taking long aging time.

 

 

2.0  WASTE-TO-ENERGY (WTE) CONVERSION

 

            The food industry produces a large number of residues and by-products that can be used as biomass energy sources. These waste materials are generated from all sectors of the food industry with everything from meat production to confectionery producing waste that can be utilised as an energy source. Salman Zafar(2002) a renewable energy expert explained about the pathways of the waste conversion into energy.

 

2.1 Waste-To-Energy Conversion Pathways (Reaction Involved)

 

There are three main pathways for conversion of organic waste material to energy – thermochemical, biochemical and physicochemical.

 

1)     Thermochemical conversion, characterized by higher temperature and conversion rates, is best suited for lower moisture feedstock and is generally less selective for products. Thermochemical conversion includes incineration, pyrolysis and gasification. The incineration technology is the controlled combustion of waste with the recovery of heat to produce steam which in turn produces power through steam turbines. Pyrolysis and gasification represent refined thermal treatment methods as alternatives to incineration and are characterized by the transformation of the waste into product gas as energy carrier for later combustion in, for example, a boiler or a gas engine.

 

2)      The bio-chemical conversion processes, which include anaerobic digestion and fermentation, are preferred for wastes having high percentage of organic biodegradable (putrescible) matter and high moisture content. Anaerobic digestion can be used to recover both nutrients and energy contained in organic wastes such as animal manure. The process generates gases with a high content of methane (55–70 %) as well as biofertilizer. Alcohol fermentation is the transformation of organic fraction of waste to ethanol by a series of biochemical reactions using specialized microorganisms.

 

3)        The physico-chemical technology involves various processes to improve physical and chemical properties of solid waste. The combustible fraction of the waste is converted into high-energy fuel pellets which may be used in steam generation. Fuel pellets have several distinct advantages over coal and wood because it is cleaner, free from incombustibles, has lower ash and moisture contents, is of uniform size, cost-effective, and eco-friendly.

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2.2.1 Pros

 

1)The growing use of waste-to-energy as a method to dispose off solid and liquid wastes and generate power has greatly reduced environmental impacts of municipal solid waste management, including emissions of greenhouse gases. Waste-to-energy conversion reduces greenhouse gas emissions in two ways.

2)Electricity is generated which reduces the dependence on electrical production from power plants based on fossil fuels. The greenhouse gas emissions are significantly reduced by preventing methane emissions from landfills.

3)Waste-to-energy plants are highly efficient in harnessing the untapped sources of energy froa variety of wastes.

 

2.2.2 Cons

 

1)The public at large is still unconvinced that emissions from waste-to-energy plants are clean and free from harmful chemicals

2)Waste-to-energy facilities are expensive to construct.

 

 

3.0 BIOMAX - VEGETABLE WASTES TO ORGANIC FERTILIZER 

 

Biomax Technologies, Singapore introduced by Dr. Puah Chum Mok and Mr. Sim Eng Tong uses a similar concept but its patented technology converts organic wastes into organic fertilizer in 2012. Dr Phua cited that this technology can save a lot of energy and is environmment friendly.

 

3.1 The reaction involved to this technology:

           The use of enzymes which break down the wastes at an accelerated rate. However, the use of enzymes alone is not enough to make this process possible. A properly controlled space is required for wastes to be decomposed. That is where Biomax’s digestor comes in and provides temperature, aeration and mixing capabilities for wastes and enzymes. In a simple way, the digestor and enzymes work together to produce fertilizer from waste. 

            The backyard composting method seems to be economical, but it takes time, space and creates pathogen issues. Fertilizer born by pathogens, if used for plants, can be transferred to plants and once it happens, there is a risk of a serious outbreak. Biomax’s digestor prevents this by heating up the wastes at 80°C – a temperature where even the most notorious pathogens are killed. Because the process takes place under controlled environment, there is no compromise on the quality of fertilizer due to external factors such as weather conditions or mixing efficiency. Moreover, the otherwise occurrence of nutrient loss to the atmosphere is prevented. As a result, the organic fertilizer can retain not only high nutrient level but also organic matter level of more than 70%. 

 

3.2.1.Pros

1)It is cheap and not costly as it just need some equipment to produce the fertilizer.

2)This technology is long- lasting that will not need any maintenance in a long period of time.

3)It can retain nutrients and water, thus promoting the growth of plants while requiring lesser amount of water.

4) It also encourages the microbial activity which then improves the soil fertility.

 

3.2.2 Cons

1)It need a long aging time to disintegrate the waste product to fertilizer.