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Only through renewable carbon source valorization will it be possible to obtain a high-impact transition from a fossil-based system to a renewable-based system. On the other hand, attention has moved to biomass valorization to obtain high-added value compounds, replacing fossil-based products. These conclusions can be the basis for building conversion strategies for different kinds of biomass if dedicated to an energy conversion or a chemical application for the further chemical synthesis of fuels and chemicals. Marcon et al. [[7]] performed a techno-economic and environmental analysis to assess the integration of biomass gasification/Fischer-Tropsch synthesis into a conventional sugarcane distillery, to produce advanced liquid biofuels. [Extracted from the article]

Microbial lipids are renewable platforms for several applications including biofuels, green chemicals, and nutraceuticals that can be produced from several residual carbon sources. Lignocellulosic biomasses are abundant raw materials for the production of second-generation sugars with conversion yields depending on the quality of the hydrolysates and the metabolic efficiency of the microorganisms. In the present work, wheat straw pre-treated by steam explosion and enzymatically hydrolysed was converted into microbial lipids by Lipomyces tetrasporus DSM 70314. The preliminary optimization of the enzymatic hydrolysis was performed at the bench scale through the response surface methodology (RSM). The fermentation medium and set-up were optimized in terms of the nitrogen (N) source and carbon-to-nitrogen (C/N) ratio yielding to the selection of soy flour as a N source and C/N ratio of 160. The bench scale settings were scaled-up and further optimized at the 10 L-scale and finally at the 50 L pilot scale bioreactor. Process optimization also included oxygen supply strategies. Under optimized conditions, a lipid concentration of 14.8 gL−1 was achieved corresponding to a 23.1% w/w lipid yield and 67.4% w/w lipid cell content. Oleic acid was the most abundant fatty acid with a percentage of 57%. The overall process mass balance was assessed for the production of biodiesel from wheat straw. [ABSTRACT FROM AUTHOR]

The biomass-to-methanol process may play an important role in introducing renewables in the industry chain for chemical and fuel production. Gasification is a thermochemical process to produce syngas from biomass, but additional steps are requested to obtain a syngas composition suitable for methanol synthesis. The aim of this work is to perform a computer-aided process simulation to produce methanol starting from a syngas produced by oxygen–steam biomass gasification, whose details are reported in the literature. Syngas from biomass gasification was compressed to 80 bar, which may be considered an optimal pressure for methanol synthesis. The simulation was mainly focused on the water–gas shift/carbon capture sections requested to obtain a syngas with a (H2 – CO2)/(CO + CO2) molar ratio of about 2, which is optimal for methanol synthesis. Both capital and operating costs were calculated as a function of the CO conversion in the water–gas shift (WGS) step and CO2 absorption level in the carbon capture (CC) unit (by Selexol® process). The obtained results show the optimal CO conversion is 40% with CO2 capture from the syngas equal to 95%. The effect of the WGS conversion level on methanol production cost was also assessed. For the optimal case, a methanol production cost equal to 0.540 €/kg was calculated. [ABSTRACT FROM AUTHOR]

The need to protect sensitive data is growing, and environmental data are now considered sensitive. The application of last-generation procedures such as blockchains coupled with the implementation of new air quality monitoring technology allows the data protection and validation. In this work, the use of a blockchain applied to air pollution data is proposed. A blockchain procedure has been designed and tested. An Internet of Things (IoT)-based sensor network provides air quality data in terms of particulate matter of two different diameters, particulate matter (PM)10 and PM2.5, volatile organic compounds (VOC), and nitrogen dioxide (NO2) concentrations. The dataset also includes meteorological parameters and vehicular traffic information. This work foresees that the data, recovered from traditional Not Structured Query Language (NoSQL) database, and organized according to some specifications, are sent to the Ethereum blockchain daily automatically and with the possibility to choose the period of interest manually. There was also the development of a transaction management and recovery system aimed at retrieving data, formatting it according to the specifications and organizing it into files of various formats. The blockchain procedure has therefore been used to track data provided by air quality monitoring networks unequivocally. [ABSTRACT FROM AUTHOR]

Biorefineries are novel, productive models that are aimed at producing biobased alternatives to many fossil-based products. Biomass supply and overall energy consumptions are important issues determining the overall biorefinery sustainability. Low-profit lands appear to be a potential option for the sustainable production of raw materials without competition with the food chain. Cardoon particularly matches these characteristics, thanks to the rapid growth and the economy of the cultivation and harvesting steps. An integrated biorefinery processing 60 kton/y cardoon lignocellulosic biomass for the production of 1,4-butanediol (bio-BDO) is presented and discussed in this work. After designing the biorefinery flowsheet, the mass and energy balances were calculated. The results indicated that the energy recovery system has been designed to almost completely cover the entire energy requirement of the BDO production process. Despite the lower supply of electricity, the energy recovery system can cover around 78% of the total electricity demand. Instead, the thermal energy recovery system was able to satisfy the overall demand of the sugar production process entirely, while BDO purification columns require high-pressure steam. The thermal energy recovery system can cover around 83% of the total thermal demand. Finally, a cradle-to-gate simplified environmental assessment was conducted in order to evaluate the environmental impact of the process in terms of carbon footprint. The carbon footprint value calculated for the entire production process of BDO was 2.82 kgCO2eq/kgBDO. The cultivation phase accounted for 1.94 kgCO2eq/kgBDO, the transport had very little impact, only for 0.067 kgCO2eq/kgBDO, while the biorefinery phase contributes for 0.813 kgCO2eq/kgBDO. [ABSTRACT FROM AUTHOR]

This paper explores a possible waste-based economy transition strategy. Digestate from the organic fraction of municipal solid waste (OFMSW) is considered, as well as a low-added value product to be properly valorized. In this regard, air gasification may be used to produce syngas. In this work, the production of methanol, hydrogen, or electricity from digestate-derived syngas was assessed by ChemCAD process simulation software. The process scheme of methanol production comprises the following parts: water gas shift (WGS) with carbon capture and storage units (CCS), methanol synthesis, and methanol purification. In the case of hydrogen production, after WGS-CCS, hydrogen was purified from residual nitrogen by pressure swing absorption (PSA). Finally, for electricity production, the digestate-derived syngas was used as fuel in an internal combustion engine. The main objective of this work is to compare the proposed scenarios in terms of CO2 emission intensity and the effect of CO2 storage. In particular, CCS units were used for methanol or hydrogen production with the aim of obtaining high equilibrium yield toward these products. On the basis of 100 kt/year of digestate, results show that the global CO2 savings were 80, 71, and 69 ktCO2eq/year for electricity, methanol, and hydrogen production, respectively. If carbon storage was considered, savings of about 105 and 99 ktCO2eq/year were achieved with methanol and hydrogen production, respectively. The proposed scenarios may provide an attractive option for transitioning into methanol or hydrogen economy of the future. [ABSTRACT FROM AUTHOR]