Mobile Gasification Units for Sustainable Electricity Production in Rural Areas: The SMARt-CHP Project

Abstract

This paper presents a 5 kW th biomass gasification pilot unit along with experimental results concerning producer gas composition. A chemical equilibrium mathematical model is also introduced and a comparison of measured and calculated results is presented. The experience gained from the unit operation led to the idea of manufacturing a mobile gasification unit able to utilize agricultural wastes in rural areas of Greece. In this project, called SMARt-CHP, the biomass gasifier coupled to an internal combustion engine will be extensively used under real world conditions for combined heat and power production, using different types of residues (wine prunings, corn stalks, etc.) characteristic of agriculture in Northern Greece. The main aims of SMARt-CHP are to attempt to demonstrate how logistics and biomass availability problems can be addressed, to inform the general public about the particular environmental issues, concerns, and opportunities in decentralized bioenergy production from agricultural residues, and to promote the applicability of a mature technology, bridging the gap between technology development and application.

Review of Biomass Thermal Gasification

“…The steam enhances the reforming and heterogeneous gasification reactions, the temperature inside the gasifier should be kept enough to support such reactions [38]. Combining gasification unit with heat and power generation systems will improve the economics of the process [3]. Gasification units combined with heat and power generation systems are expected to have an overall efficiency of 85% compared to a maximum efficiency of 35-55% for conventional power station, in addition to a substantial saving in carbon emissions.…”

“…The heat required for water gas phase and Boudouard reactions is provided by complete and partial oxidation reactions, and complete oxidation provides around 60% of the heat requirements during gasification [3,17]. In addition to the previous reactions that are common in combustion and gasification, hydrogen, steam, and carbon monoxide undergo further reactions as shown below [3,24]:…”

“…In addition to the previous reactions that are common in combustion and gasification, hydrogen, steam, and carbon monoxide undergo further reactions as shown below [3,24]:…”

“…Biomass covers 35% of the energy demand of the developing countries corresponding to 13% of the world energy demand. Biomass is widely available in quantities enough to meet the world energy demand [1][2][3][4][5][6][7].…”

“…Cocurrent flow regime throughout the oxidation and reduction zones reduces the tars and particulates in syngas, which will reduce the necessity of complicated cleaning methods compared to updraft gasifiers especially if the gas is used as a burnable gas in a small community. It is important to ensure homogenous distribution of gasifying agent at the downdraft gasifier throat [1][2][3].…”