Hydrogen rich gas production from catalytic gasification of biomass

Abstract

a b s t r a c tProduction of hydrogen rich gas from gasification of biomass was studied at bench-scale using oxygen as the gasifying agent. A series of experiments were performed to investigate the effects of different operating parameters on the performance of the gasification process. These included the oxygen to fuel equivalence ratio (0.12e0.4), reaction temperature (700e850 C), reaction residence time (45e120 min), and catalyst type. The catalysts selected are marly clay, calcium hydroxide, dolomite, and cement kiln dust. Within the range of the experimental conditions tested, the results suggest that the best operating conditions for the gasification process are; temperature, 800 C, an oxygen to fuel ratio of 0.25, a reaction time of 90 min, and calcined cement kiln dust as a catalyst. The results have also demonstrated that the product gas from gasification of cotton stalks with calcium hydroxide has higher H 2 and CO concentration (45 and 33%). In addition gasification of cotton stalks with calcined cement kiln dust resulted in higher hydrogen and CO enrichment as well as higher overall gas yield (39vol%, 33vol%, and 1.5 m 3 /kg) compared to other agriculture residues of corn stalks and rice straw.

Review of Biomass Thermal Gasification

“…The catalysts selected are USY zeolite, dolomite, CaO, granulated slag, red brick clay, olivine, and cement kiln dust. The results demonstrate that the cement kiln dust and calcium hydroxide are more effective for increasing the gas yield and decreasing the char yield [8,10].…”

“…Due to environmental and technical difficulties associated with burning biomass, innovative processes should be developed to utilize biomass [5,[8][9][10]. Developing more effective techniques to utilize biomass will reduce the disposal problem and create profits.…”

“…Hydrolysis, pyrolysis, gasification, and hydrogenation are the principal processes for biomass conversion in the literature [7,11]. Gasification represents efficient and environmentally friendly method for producing the syngas as a biofuel from different sources of biomass [12][13][14], and to produce second-generation biofuels such as methanol, ethanol, and hydrogen [8,10,12,15]. Gasification can be defined as the partial (incomplete) combustion of biomass, and gasification could extract up to 60-90% of the energy stored in biomass [16,17].…”

“…The charcoal is finally reduced to H 2 , CO, CO 2 , O 2 , N 2 , and CH 4 [6,[8][9][10]21]. Char gasification starts at temperatures above 350°C [7].…”

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“…In another research study, it was reported that gasification of cotton stalk at 850°C, with oxygen fuel ratio (0.12-0.4) in presence of Ca(OH) 2 yielded 45 % H 2 , and 33% CO (Hamad et al 2016). Gasification of woody biomass in fluidized bed using air as gasifying agent & fluidizing gas (with control flow rate) gave low calorific value syngas (Kim et al (2013 (Chen and Zhang 2015).…”