Researches on biofuels gasification using the Lurgi process with homogeneous air inlet over the combustion space

The experimental investigations carried out within the present research focus on a simple gasification technology dedicated to biofuels conversion according to the Lurgi procedure. Specifically, an installation with a fixed grill and a homogeneous distribution of the air inlet over the combustion space are considered. In order to provide a thorough background for the experimental research, this paper presents first the challenges related to the air distribution. If for coal gasification the difficulty of the homogeneous penetration of the air inlet within the whole combustion volume is balanced by the possibility of the direct emission of CO valorization, for biomass gasification this factor becomes fundamental. The original contribution of the technology introduced in this paper assumes an improved combustion process for Lurgi-type gas generators. The experimental installation employed has a particular design, enabling a homogeneous distribution of the air inlet over the entire combustion zone, up to the top of the embers layer. This allows achieving a maximum CO2 content in the flue gas flux, effectively reducing it inside the embers bed. The high calorific value of biofuels used favors developing an efficient combustion process, occurring at high temperatures. Thus, the reduction process of the CO2 is self-controlled. The experimental installation operates at a slow fuel rate, with discontinued supply and precise airflow control. The quality of the gas obtained is evaluated based on the resulting open flame, analyzing its composition

Defining of criteria for flue gas decarbonization efficiency in methanation reactors with membrane technology

The paper presents an investigation on the conditions for implementing a methanation membrane decarbonator coupled to an energy installation that generates flue gases. The retention of the carbon dioxide content in the flue gases and its conversion to methane is envisaged. For start, low thermal power installations, employing natural gas as main fuel supply, are considered. Internal combustion engines (also working with natural gas fuel) are taken into account for the testing of the carbon dioxide retention process. For this, a classification of the flue gas composition by fuel categories is initially carried out. The decarbonation efficiency is defined and clarifications are made withal regarding the connection between the decarbonation installation and the energy plant. The first practical achievements are also presented, resulting from a decarbonator with a volume of 940 cm3 (having the inner diameter of 12 cm and a height of 50 cm). The results prove that the proposed solution has great potential for practical applications, further research being however necessary. In terms of operating costs (including hydrogen consumption), it is remarked that they can be reduced by exploiting the methane production and eliminating the carbon tax, extending the integration perspective form economic point of view

Experimental researches on poultry manure combustion in co-combustion with biomass

Combustion of pure avian waste is strongly affected by its humidity content. According to the results of composition analysis, the initial humidity reaches up to 50%, inhibiting direct combustion initiation and development. Drying of poultry waste is an alternative, but simple relatively long-term storage or thermal pre-processing, complicates the technological process of energy recovery and increases the associated costs. Co-combustion represents a promising solution to enrich the heating value of raw poultry manure. Experiments using biomass (in a mass fraction of up to 30%) led to positive results in terms of efficiency. It is highlighted that the process depends on the quality of the woody biomass used for the mixture, but also on its bulk density, which causes an accelerated diffusion of air and influences the burning speed. This paper presents the experimental investigations on the co-combustion of poultry manure and woody biomass, performed on a 55 kW pilot boiler equipped with a post-combustion grate. The focus of the analysis is on the influence of the biomass bulk density and its heating value on the co-combustion process. The results obtained favor the development of a technology that is easy to apply and has a reduced cost. The technology investigated here is suitable for onsite applications in poultry farms, enabling meeting the energy demand based on co-combustion of resulting poultry waste