Development and demonstration of an innovative method for converting waste into bioethanol

PROJECT DESCRIPTION

BACKGROUND

The management of municipal solid waste (MSW) in Europe remains a challenge. Landfilling is still the predominant method for managing MSW in most European countries, resulting in the unnecessary waste of materials and energy, environmental pollution, and negative effects on health, quality of life and the economies of EU Member States. Approximately 40-60% of all MSW in the EU is biowaste. The remainder is recyclable waste such as paper, metals and packaging. Biowaste, which has a high water content (65-98%), decomposes easily, causing many environmental and economic problems. The main environmental threat is the production of methane, a powerful greenhouse gas, 25 times more potent than carbon dioxide. If the treatment of biowaste was maximised, associated greenhouse gas emissions, estimated at about 10 million tonnes of CO2 equivalent in 2020, could be significantly reduced. Methods such as landfilling, incineration, composting and anaerobic digestion provide a limited solution to this problem.

OBJECTIVES

The overall goal of the Waste2Bio project was to develop a method of converting biowaste into bioethanol fuel. This involved the following actions:

To design, develop, test, optimise and evaluate an innovative pilot-scale plant for the production of bioethanol from biowaste via bioconversion. Located in Athens, this pilot plant would be able to convert more than 70% of the biowaste feed into second-generation bioethanol. The bioethanol would be used in place of fossil fuels;

To significantly reduce the amount of household biowaste going to landfill, while reducing emissions to air, water and soil;

To provide a template for the implementation of this innovative bioconversion technology in other municipalities in Greece and elsewhere in the EU, following an evaluation of the process's environmental, economic and technical viability; and

To identify key issues and indicators in relation to meeting the targets set out in relevant EU directives, such as the Landfill Directive (1999/31/EEC), the Directive on the Promotion of Renewable Electricity (2001/77/EC), and the Biofuels Directive (2003/30/EC), thus demonstrating in concrete terms how EU legislation governing waste management and biofuel production can be implemented.

RESULTS

The Waste2Bio project successfully built and operated the proposed pilot plant, the first time that bioeathanol has been produced from pre-dried, source separated biowaste. It achieved a maximum theoretical bioethanol yield ranging from 72.56% to 77.34% efficiency. This equates to 13.85 to 16.70 g / 100 g of dried biowaste. It encouraged 200 households in the municipalities of Aspropyrsgos and Papagos-Cholargos to take part in a scheme to separate biowaste at source. Over the course of 2 years, more than 60 tonnes of biowaste was diverted from landfill, dried and used as feedstock for the bioconversion unit; drying the biowaste reduced its volume and weight by 70. Furthermore, the bioethanol met technical requirements for its production, making it suitable for use as a fuel additive. The project produced a feasibility report which found that the Waste2bio scheme is a competitive option for managing biowaste and reducing greenhouse gas emissions under certain conditions: the estimated cost for municipalities would be in the range of 60 euros per tonne of wet waste, while the gate fee for disposal to landfills is in the range of 50 euros per tonne and is expected to exceed 100 euros per tonne in the near future. The feasibility study also concluded that a full-scale version of the scheme could create between 27 and 138 full-time equivalent jobs. Other project results were:

The development of a multi-criteria analysis tool for comparison of different available biowaste management methods;

A market analysis which indicated that there is increased market demand for bioethanol, as a fuel, as a solvent in the chemical industry and elsewhere;

The identification of targets for the market uptake of the technology and its future upscaling; and

The identification that the developed technology can be used in combination with other biowaste streams, such as food industry waste and catering waste, as well as household organic waste.

This sustainable and replicable project can contribute to achieving waste management targets set out in the Waste Framework Directive and promote EU policy trends for the management of municipal solid waste related to the circular economy and the emerging bio-economy. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).