Assessment of biomass energy potential for SRC willow woodchips in a pilot scale bubbling fluidized bed gasifier

The current study investigates the short rotation coppice (SRC) gasification in a bubbling fluidized bed gasifier (BFBG) with air as gasifying medium. The thermochemical processes during combustion were studied to get better control over the air gasification and to improve its effectiveness. The combustion process of SRC was studied by different thermo-analytical techniques. The thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were performed to examine the thermal degradation and heat flow rates. The product gas composition (CO, CO2, CH4 and H2) produced during gasification was analyzed systematically by using an online gas analyzer and an offline GC analyzer. The influence of different equivalence ratios on product gas composition and temperature profile was investigated during SRC gasification. TG/DTG results showed degradation occur in four stages; drying, devolatilization, char combustion and ash formation. Maximum mass loss ~70% was observed in devolatilization stage and two sharp peaks at 315–500 °C in TG/DSC curves indicate the exothermic reactions. The temperature of gasifier was increased in the range of 650–850 °C along with the height of the reactor with increasing equivalent ratio (ER) from 0.25 to 0.32. The experimental results showed that with an increment in ER from 0.25 to 0.32, the average gas composition of H2, CO, CH4 decreased in the range of 9–6%, 16–12%, 4–3% and CO2 concentration increased from 17 to 19% respectively. The gasifier performance parameters showed a maximum high heating value (HHV) of 4.70 MJ/m3, Low heating value (LHV) of 4.37 MJ/m3 and cold gas efficiency (CGE) of 49.63% at 0.25 ER. The ER displayed direct effect on carbon conversion efficiency (CCE) of 95.76% at 0.32 ER and tar yield reduced from 16.78 to 7.24 g/m3 with increasing ER from 0.25 to 0.32. All parametric results confirmed the reliability of the gasification process and showed a positive impact of ER on CCE and tar yield

Sugar cane trash processing for heat and power production

The paper summarizes an investigation into methods for treating sugar cane trash in preparation for combustion in a spreader stoker boiler designed for bagasse and supplementary fuel oil. Due to the herbaceaous nature of sugar cane trash, water leaching was proposed and investigated as a means of reducing the slagging and fouling potential of the raw fuel.Validerat; 20101217 (root

Production of Syngas from Short-Rotation Coppice Willow

Bioenergy and biofuels are a low-carbon alternative to fossil fuels in Canada. Greenhouse gas emissions from sectors such as heavy transport with few non-fossil fuel alternatives can be reduced using land base renewable energy. The proliferation of coppice willow plantations is a potential reliable and effective source of biomass, particularly in the Canadian Prairies. A feedback control methodology is proposed for the development of biomass with enhanced chemical characteristics from short-rotation coppice willow. In particular, torrefaction is proposed as a pretreatment process for fluidized bed gasification, one thermochemical pathway for the production of liquid fuels and chemicals from biomass. The thesis shows that syngas quality from fluidized bed gasification of willow can be improved by torrefaction of the feedstock. Syngas quality metrics including H2/CO ratio, higher heating value of the syngas, water vapour in syngas, tar concentration and tar species concentration were used to quantify an improvement in syngas quality. The extent of torrefaction was evaluated based on the volatilization of hemicelluloses. Hemicelluloses were found to decrease linearly and significantly (p<0.05) for five torrefaction temperatures (240-280 °C). During gasification, H2/CO ratio was increased by torrefaction. The water vapour concentration in syngas was less for torrefied willow compared to non-torrefied willow. Tar concentration decreased by as much as 47 % as a result of torrefaction. The decrease in tar concentration occurred when hemicelluloses were reduced to 12 % by torrefaction. The higher heating value of the syngas, however, was lower for syngas from torrefied versus non-torrefied willow due to the increase in concentration of hydrogen in the syngas. Finally, greenhouse gas emissions were evaluated on a life-cycle basis for direct and indirect co-firing of SRC willow with lignite coal in an existing generating station in Saskatchewan. Indirect co-firing of non-torrefied willow using a circulating fluidized bed produced the largest emissions reduction. However, the indirect pathway reduced the land use efficiency of the system. Torrefied willow pellets co-fired with coal used the least land area per kWh of electricity produced. Evaluating gas composition from the torrefaction process, studying the yield of soot in syngas, and investigating the fate of alkali metals and their effect on the process are recommended extensions of this work

P.: Matchmaker: Interpersonal Touch in Gaming

Abstract. Acts of interpersonal touch – a touch shared between two people – are used by couples to communicate in a simple and emotionally intimate way. In this paper, we argue that the intimacy afforded by acts of interpersonal touch can be used in computer entertainment to support enjoyable and engaging activities for couples. To support this notion, we have developed Matchmaker; a two-player, cooperative tabletop video game based on themes of love and romance. Matchmaker’s gameplay is directly controlled by a set of collaborative tabletop interaction techniques, as well as by acts of interpersonal touch between its players. In this paper we present a detailed description of Matchmaker’s design and the results of an exploratory user suggesting that Matchmaker is enjoyable to play and that its use of interpersonal touch contributes to players ’ enjoyment