Abstract

Objectives

The objective of the project is to develop, integrate and prove a dry gas cleaning system on an existing biomass gasification combined heat and power plant (250 kWth). The innovative idea of this project is a newly developed dry gas cleaning and heat recovery system. The dry gas cleaning concept produces no waste water and, intends to solve and eliminate the tar problems associated with operation of biomass gasifiers by recirculating the tars back into the gasifier. The ultimate objective is therefore to create a new generation of energy efficient and environmentally friendly gasification systems.

Description of the work:

The project focuses on the following main points:

• Design and construct a hot producer gas (700-800C) particulate cleaning system, which can operate continuously and achieve separation efficiency acceptable for engine applications, preferably without further particulate removal;
• Design and construct a new generation small scale tar condensing, regenerative gas-gas heat exchanger able to provide a clean gas free from tars creating problems in an engine;
• Rebuild the carburettor and exhaust on an existing gas engine in order to achieve emissions of CO below 500 ppm, hydrocarbons below 100 ppm and NO_x below 500ppm;
• Test the complete small scale system including existing down-draft bio fuel fired gasifier of 250 kWth capacity, dust separator, regenerative heat exchanger and engine-generator for at least a regenerative cycle (500 hours);
• Study tar characteristics and tar behaviour under varying reactor and cooling conditions with special attention to engine quality
• Calculation of economical and environmental impact of the process in order to clarify whether the new gas treatment device used in small CHP gasification unit will be economically and environmentally beneficial to replace conventional plant.

Expected Results and Exploitation Plans:

The main outputs of the project will be:

• design, construction and testing of a complete biomass gasification combined heat and power small scale prototype plant (250 kWth);
• Information on the tar behaviour in gasification and in engine;
• Investment and running costs reduction;
• A cleaner and more efficient system for production of CHP based on gasification.

The exploitation of the results will be achieved though the involvement of two industrial partners specialised respectively in heat exchanger field and gasification field.

Contacts

Coordinator

• CIRAD Centre De Cooperation Internationale en Recherche Agronomique Pour Le Developpement / FRANCE

Participant

• DK Teknik Energy and Environment DENMARK
• Thomas KOCH / Thomas Koch Energi A/S DENMARK