• Energy Research

Bio-based polymers are increasingly attracting attention as a solution to reducing the consumption of non-renewable resources and curbing the accumulation of fossil-based plastic waste. In this study, we analyze the economics of a new packaging film based on a polylactic acid-polyhydroxybutyrate blend (PLA-PHB), with PHB obtained from agro-industrial residues (potato peels). We model various sizes of biorefineries using the new biotechnology in Europe. For a four-year payback period, which is generally accepted in the industry, the calculated minimum product selling price ranges from 9.7 euros per kilogram to 37.2 euros per kilogram, depending, among other factors, on the production capacity of the biorefinery. We have incorporated the uncertainty over the model parameters in a Monte Carlo simulation and investigated the relative impact of individual factors on the minimum product selling price. Overall, the results indicate that the bio-based feedstock availability is the most influential factor on the profitability of the new biotechnology.

Abstract Even though hydrogen is considered the future of energy carrier, it is still produced from fossil fuels therefore with no benefits for the CO2 emission reduction. This paper discusses an innovative concept for hydrogen production which combines the Acid Gas to Syngas (AG2S™) concept and the Sorption Enhanced Water Gas Shift (SEWGS) process. The AG2S™ process produces H2 and elemental Sulfur from H2S and CO2, then H2 purification is performed through amine scrubbing. The SEWGS technology is a Pressure Swing Adsorption process where the CO2 and H2S are adsorbed on hydrotalcite-based material. With respect to amine scrubbing, SEWGS takes advantage of a higher operating temperature of 350°C–400 °C which reduces temperature swing losses, lower regeneration energy and the possibility to recycle the H2S while capturing the CO2. This study aims at exploring the potential of the SEWGS technology by means of the evaluation of detailed mass and energy balances, showing the potentialities of the AG2S™+SEWGS technologies which more than double the H2 production efficiency (25.0%) with respect to the amine scrubbing configuration (10.7%). Including the steam production, the overall process efficiency can be higher than 90% which is again more than twice the value of the AG2S™ reference case.

Gasification is a thermo-chemical process aiming at the production of high heating value syngas, starting from biomass, coal, or refuse derived fuels. Depending on the solid fuel and on the operating parameters of the process, the quality and the chemical composition of the produced syngas is differently affected. The final applications of syngas include the power generation and the production of chemicals, with special reference to methanol/ammonia synthesis and Gas-to-Liquid technologies. The aim of this work is to propose a comprehensive mathematical model of a biomass and coal gasifier. The first complexity relies in the characterization of the solid fuels and their pyrolysis and devolatilization process. The pyrolysis of the different solid fuels is characterized by a multistep kinetic model, with a detailed characterization of gas, tar and solid residue. The secondary gas phase reactions describe the successive evolution of the released gas and tar components, while heterogeneous gasification and combustion reactions allow to account for the evolution of the solid residue. Moreover, the mathematical model of the gasifier requires a comprehensive description of the coupled transport and kinetic processes, both at the particle and the reactor scale. The complexity of the resulting numerical problem is due both to the dimension of the differential algebraic system and to the stiffness of radical reactions. A validation example of the overall model with proper experimental data supports the reliability of the comprehensive approach here discussed. Comparisons between the performances of a countercurrent coal and biomass gasifier are proposed. Proceedings of the 23rd European Biomass Conference and Exhibition, 1-4 June 2015, Vienna, Austria, pp. 834-839

The techno-economic feasibility of three biogas utilization processes was assessed through computer simulations on commercial process simulator Aspen HYSYS: HPC (biogas to methanol), BioCH (biogas to biomethane) and CHP (biogas to heat & electricity). The last two processes are already used commercially with the aid of subsidy policies. The economic analysis indicates that, without these policies, none of these attain economic self-sustainability due to high overall manufacturing costs. The estimated minimum support cost (MSCs) were 108, 62 and 109 EUR/MWh for the HPC, BioCH and CHP processes, respectively. The model could explain currently practised government subsidies in Italy and Germany. It was seen that the newly proposed HPC process is economically comparable to the traditional CHP process. Therefore, the HPC process is a possible alternative to biogas usage. A support policy was proposed: 50, 66, 158 and 148 EUR/MWh for available heat, methane, electricity and methanol (respectively); the proposed energy policy results in a 10% OpEx rate of return for any of the processes, thus avoiding a disparity in the production of different products.

The paper deals with the application of the novel Acid Gas To Syngas (AG2S™) technology to the gasification of solid fuels. The AG2S technology is a completely new effective route of processing acid gases: H2S and CO2 are converted into syngas (CO and H2) by means of a regenerative thermal reactor. To show the application of the AG2S technology, modeling and simulation advances for gasification systems are initially discussed. The multi-scale, multi-phase, and multi-component coal gasification system is described by means of detailed kinetic mechanisms for coal pyrolysis, char heterogeneous reactions and for successive gas-phase reactions. These kinetic mechanisms are then coupled with transport resistances resulting in first-principles dynamic modeling of non-ideal reactors of different types (e.g., downdraft, updraft, traveling grate), also including the catalytic effect of ashes. The generalized approach pursued in developing the model allows characterizing the main phenomena involved in the coal gasification process, including the formation of secondary species (e.g., COS, CS2). This tool is here further validated on literature data and, then, adopted to demonstrate the AG2S effectiveness, where H2S and CO2 emissions are reduced with an increase of syngas production. The resulting process solution is more economically appealing with respect to the traditional Claus process and finds several application areas.

Abstract In economy nowadays, methanol is already a key compound widely employed as building block for producing intermediates or synthetic hydrocarbons, solvent, energy storage medium, and fuel. In recent times, methanol has been employed in a number of innovative applications. It is a clean and sustainable energy resource that can be produced starting from different sources traditional or renewable: natural gas, coal, biomass, landfill gas and power plant/industrial emissions. In this work is proposed an innovative low impact process for methanol production starting from coal gasification. The most important features, instead the traditional ones, are the lower emissions of CO2 (about 2.5%) and the surplus production of methanol (about 1.7%) without any addiction of primary sources. Moreover, it is demonstrated that a coal charges with a high sulfur content means a higher reduction of CO2 emissions. The key idea is the application of AG2STM technology that is a completely new effective route of processing acid gases: H2S and CO2 are converted into syngas (CO and H2) by means of a regenerative thermal reactor.