PhD Thesis Defence Presentations - Alexis G. Pantziaros

In the present dissertation we study 3 basic agro-industrial wastes, olive mill wastes, winery wastes and espresso coffee residues after taking the coffee drink. Emphasis was placed on the extraction and isolation of phenolic substances contained in agro-industrial waste. Phenolic substances are referred to as antioxidants of added economic value with a particularly beneficial effect on humans. They are widely used in the pharmaceutical, cosmetology and food industries. The extensive parametric study carried out in the present work sought the optimal conditions for the extraction of phenolic substances using various physicochemical processes that are environmentally friendly. The extraction of marcs (solid agro-industrial waste of wine production), the solid waste of two-phase olive mill and solid waste produced after the production of espresso coffee were studied. The main criterion for selecting the appropriate waste in order to continue in a feasibility study was to have the highest purity in polyphenols (compared only to the amount of sugars) but also in the lowest possible cost of production. extraction with various solvents, separation using membranes, concentration and freeze drying. The choice of methods was made due to the wide application of these methods in the real industry and due to the relative ease of transferring the laboratory conditions to factory conditions. Finally, we defined as optimal extraction conditions those that would give the maximum yield of extracted phenolic substances per kilo of waste, but at the same time the minimum yield of extracted sugars per kilo of waste.

Once the basic parameters were defined, 3 different sub-experimental series were performed for each waste separately, in order to find the optimal combination of methods, which gives the optimal extraction results for each waste so that selecting more than 3 could be a profitable one. financially business plan.

In the next step and with the data of the first part, an economic model was developed for the construction and operation of a recycling unit of this waste with different volumes so that it can be seen that most of the above waste can be profitable.

Finally, a feasibility study was developed for an espresso coffee waste recycling plant, so that there is a more detailed picture of the volume of investment and operating costs that such a plant would have. The feasibility study was compared with a study by a private company (external offer), which specializes in feasibility studies and found that the investment cost that you match with the calculations of the present work, for a unit of one ton of waste espresso coffee, is of the order of 120,000 Euros.

The next step is to design and analyze the procedures for collecting espresso coffee waste from the scattered cafes in a city. Both the cost of collecting and compensating the cafeterias for collecting coffee in special bins were two unknown parameters for the present work. Also, because there is no corresponding recycling material on the market, it was very difficult to estimate the selling price of the antioxidant product. In discussions with companies, they reserved the right to answer for the exact price, when they were delivered a quantity of antioxidant of high purity and large in quantity. This will set the exact selling price according to the actual purchase and will examine whether the specific business plan can have a high return on investment. This process is ongoing with own resources. This paper presents the design and analysis of the business plan based on an estimated market price