Gerard Antonini

The deashed charcoal-oil-water mixture : a liquid fuel for biomass energetical valorization

Abstract Biomass is often considered an important alternative resource for the worlds growing demand for energy resources. The problem of producing a high calorific value and low ash content charcoal slurry is discussed in this paper. The process presented is a deashing-slurry formation process based on selective oil agglomeration to prepare a ternary deashed charcoal—oil—water mixture (DCOWM). Non-ionic ethoxylated surfactants have been tested successfully for DCOWM preparation. A DCOWM of 45% solid content and 27% oil content has been prepared wit a Meranti tree charcoal deashed to 0.90 wt.% ash content. The charcoal, containing 29% volatile matter, was ground to 8 μm mean diameter. The slurry obtained has 24 671 kJ kg−1 low calorific value and 0.41 wt.% residual ash content.

Charcoal deashing by an oil agglomeration process : effect of various operating parameters

Abstract This paper describes our attempt to transfer current knowledge on mineral coal deashing by selective oil agglomeration to charcoal. The effects of various operating variables, e.g. particle size, conditioning, oil dose, oil type, amount of volatile matter and time of agglomeration were studied. It was found that a ratio of 0.2% hydrochloric acid (32% concentrated) to charcoal and a 5 min conditioning time are ideal for deashing. Domestic fuel oil and crude palm oil were used as bridging liquids. The results show that by reducing the particle size (8 μm mean diameter), charcoal can be deashed to as low as 0.8% in weight, whilst recovery stay virtually at 100%. The use of charcoal with a high volatile matter content (more than 20%) allows easy deashing even with larger particle sizes (15 μm diameter).