Search

The reported work deals with the use of lignin rich solid, which is available as residue from enzymatic hydrolysis of lignocellulosic biomass, to produce syngas. The tested process was an updraft gasification carried out at pilot scale of about 20 kg/h as dry feed. The thermal conversion of the residue was investigated by TGA in air, carbon dioxide and nitrogen atmospheres pointing out the relative contribute of pyrolysis, combustion and gasification at different temperatures. In the plant tests, the residue was completely converted in gaseous and liquid energy carriers with overall energy efficiency near 90%. Several process conditions were examined corresponding to different flows of O2 and steam. The molar ratio H2/CO in syngas increased by using steam as co-gasification agent. Steam was necessary to stabilize the process in the case of using oxygen as main gasification agent. Oxy-steam gasification provided the best results in terms of syngas heating value and highest thermal power output of the plant., Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 1241-1244

The aim of this work is to predict the reactivity and conversion profiles of the steam-char gasification step of residual biomasses that are typical of the Mediterranean area. In order to simulate the conversion profiles of chars in steam atmosphere, kinetic constants and reaction models were correlated with the main catalytic and inhibiting elements. The chars were obtained from ctrus peel, grape pomace, reed (Arundo Donax), and residues from 2nd generation bioethanol production. The study was carried out by means of isothermal thermogravimetric experiments of the selected biomass chars in the temperature range from 650°C to 825°C in 50% (v/v) steam atmosphere (N2 as balance gas). By indicating as Inorganic Catalytic Ratio, ICR = (Ca+K)/Si the ratio between the main inorganic elements with catalytic and inhibiting effects, it was found that samples with ICR > 1 showed a so called sigmoidal conversion, which can be described by classical Avrami type models. The chars with ICR < 1, showed a decelerating profile of conversion, described by n-order models. The computed char conversions were in good agreement to the experimental data., Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 760-763

The growing need to reduce the environmental impact of the modern lifestyle imposes a continuous development of novel technologies aimed at a severe reduction of pollutant emissions in order to ensure a tolerable quality of life in metropolitan areas. Among potential alternatives, particular attention has been recently addressed toward the exploitation of residual biomass and wastes as sources for syngas production by thermo-chemical processes for heat and power production. Fruits processing industries generate important amount of residues, which must be managed properly by recycling, incineration or land filling. Due to the high carbon content, these residues represent a significant source of energy that could be valorized by gasification processes. Hence, our attention was focused on the energy recovery from orange peels residues produced by a Sicilian agro-industrial company by steam gasification. Thermodynamic and experimental analysis were carried out. Experiments were performed in a fixed bed laboratory scale reactor working with catalytic materials (Ni/Al2O3, MgO and dolomite mineral) with the biomass in order to investigate the influence of experimental conditions on the outlet stream compositions, mainly in terms of hydrogen content of the produced syngas. Results were compared to thermodynamic data in order to gain information of the experimental method used. The results have confirmed successfully the experimental results compared with the simulation data. The highest concentration (65.9%) of hydrogen volume in the syngas mixture was reached with dolomite mineral as catalyst., Proceedings of the 24th European Biomass Conference and Exhibition, 6-9 June 2016, Amsterdam, The Netherlands, pp. 918-921

Bioethanol produced from lignocellulosic biomass is a promising alternative for fossil fuel substitution. Hydrolytic lignin rich residues could be exploited through gasification for more efficient bioethanol production processes. The char gasification is generally one of the slowest thermal steps and a fundamental understanding of the heterogeneous reaction kinetics is needed forreactors design. The aim of this work was to investigate the kinetic behavior of chars from byproducts of 2nd generation bioethanol production. Two chars were studied: hydrolytic reed lignin and hydrolytic wheat straw lignin.Isothermal experiments, using temperatures from 725°C to 825°C were conducted in a thermobalance. The atmosphere was 50%(volmol%) steam and 50%(vol%)N2. Additional tests at 10% and 20% of steam (N2as complement) were performed in order to determine the effect of steam partial pressure. Additional sample characterizations, such as the proximate and ultimate analyses of the two residues, as well as the metals content in chars, and morphological characterization were also performed. The apparent activation energy, Ea, of steam-char reaction was determined at different degrees of char conversion. The results showed that the Ea increases with conversion for both samples, ranging from 135 to 188 kJ/mol., Proceedings of the 24th European Biomass Conference and Exhibition, 6-9 June 2016, Amsterdam, The Netherlands, pp. 549-552

The aim of this work is to assess the integration of citrus residues gasification in a Sicilian medium size enterprise, which processes about 85,000 t/year of fresh fruit. In this work, gasification tests were performed in a bench-scale fluidized bed reactor working with both air and air-steam mixtures as gasification mediums. The gasification experiments were carried out at 700, 750, and 850 °C and at different steam to biomass ratios (0 – 1.25). Thus, evaluations on syngas composition and gasification efficiencies were carried out. According to the experimental results, the highest net cold gas efficiency (0.71) was achieved at 850°C and S/B =0.5. A combined heat and power (CHP) unit, using a reciprocating engine, was selected in order to simulate the combination of the gasification unit with an internal combustion engine (ICE).The results showed that the proposed system allows to produce about 8,256 MWhe/year and 10,224MWht/year as electrical and thermal output, respectively, by using two CHP units of 516 kWe, and consuming about 7,112 t/year of dry citrus peel (10%wt moisture). The thermal power output produced by CHP system may be used for drying the fresh citrus peels up to the desired water content, being this step the most energy demanding step., Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 106-110