h i g h l i g h t sA carbon utilisation plant that synthesise methanol is simulated in CHEMCAD. The total amount of CO 2 demand is 1.46 t/t methanol . The CO 2 not-produced compared to a conventional plant is 0.54 t/t methanol . Production costs results too high for a financially attractive project. There is a net potential for CO 2 emissions reduction of 2.71 MtCO 2 /yr in Europe. g r a p h i c a l a b s t r a c t a b s t r a c t The purpose of this paper is to assess via techno-economic and environmental metrics the production of methanol (MeOH) using H 2 and captured CO 2 as raw materials. It evaluates the potential of this type of carbon capture and utilisation (CCU) plant on (i) the net reduction of CO 2 emissions and (ii) the cost of production, in comparison with the conventional synthesis process of MeOH Europe. Process flow modelling is used to estimate the operational performance and the total purchased equipment cost; the flowsheet is implemented in CHEMCAD, and the obtained mass and energy flows are utilised as input to calculate the selected key performance indicators (KPIs). CO 2 -based metrics are used to assess the environmental impact. The evaluated MeOH plant produces 440 ktMeOH/yr, and its configuration is the result of a heat integration process. Its specific capital cost is lower than for conventional plants. However, raw materials prices, i.e. H 2 and captured CO 2 , do not allow such a project to be financially viable. In order to make the CCU plant financially attractive, the price of MeOH should increase in a factor of almost 2, or H 2 costs should decrease almost 2.5 times, or CO 2 should have a value of around 222 €/t, under the assumptions of this work. The MeOH CCU-plant studied can utilise about 21.5% of the CO 2 emissions of a pulverised coal (PC) power plant that produces 550 MW net of electricity. The net CO 2 emissions savings represent 8% of the emissions of the PC plant (mainly due to the avoidance of consuming fossil fuels as in the conventional MeOH synthesis process). The results demonstrate that there is a net but small potential for CO 2 emissions reduction; assuming that such CCU plants are constructed in http://dx.Europe to meet the MeOH demand growth and the quantities that are currently imported, the net CO 2 emissions reduction could be of 2.71 MtCO 2 /yr.

Available online xxxKeywords: Carbon dioxide utilisation Process modelling Conceptual design Formic acid synthesis Hydrogen carrier Storage of renewable electricity a b s t r a c tThe future of carbon dioxide utilisation (CDU) processes, depend on (i) the future demand of synthesised products with CO 2 , (ii) the availability of captured and anthropogenic CO 2 , (iii) the overall CO 2 not emitted because of the use of the CDU process, and (iv) the economics of the plant. The current work analyses the mentioned statements through different technological, economic and environmental key performance indicators to produce formic acid from CO 2 , along with their potential use and penetration in the European context. Formic acid is a well-known chemical that has potential as hydrogen carrier and as fuel for fuel cells.This work utilises process flow modelling, with simulations developed in CHEMCAD, to obtain the energy and mass balances, and the purchase equipment cost of the formic acid plant. Through a financial analysis, with the net present value as selected metric, the price of the tonne of formic acid and of CO 2 are varied to make the CDU project financially feasible. According to our research, the process saves CO 2 emissions when compared to its corresponding conventional process, under specific conditions. The success or effectiveness of the CDU process will also depend on other technologies and/or developments, like the availability of renewable electricity and steam.

With the increasing utilization and trade of biomass, there is a growing need for quick and reliable quantitative chemical analysis of the inorganic elemental composition of biomass. X-ray fluorescence (XRF) spectrometry performed directly on the raw biomass with limited prior sample preparation is an attractive method to this end. However, reliable calibration of XRF spectrometers for universal multi-element analysis can be very hard to implement mainly due to problems with matrix corrections. XRF users thus often rely on commercial precalibrated or standardless methods delivered with their XRF spectrometer. These methods are often sold without any guarantee on performance. Given the actual frequent use of these methods, along with their potential as ready-to-use methods for multi-element analysis of biomass, we investigate here the performance of a typical commercial precalibrated/standardless method recently purchased with a 4 kW wavelength dispersive (WD) XRF spectrometer. The accuracy (trueness and precision) is determined by analyzing the certified inorganic elements in 13 certified reference materials (CRMs) of diverse vegetal/plant origin. The certified elements detected by the XRF are Na, Mg,

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Quick and reliable inorganic elemental chemical analysis of biomass (incl. solid biofuels) is of importance in the increasing utilization and trade of biomass. In particular, it is important for the exploitation of contaminated / dirty biomass / biomass waste, and potentially also as a tool in ascertaining the type/origin of biomass. X-ray fluorescence (XRF) spectrometry performed directly on the raw biomass with limited prior sample preparation is an attractive method for performing such inorganic elemental analysis. In the present study we therefore carefully investigate the performance of a commercial multi-element standardless XRF method by analyzing 5 common biomass types (switchgrass, corn stover, eucalyptus, beech, and pine wood). Sample preparation involves milling the raw biomass using cutter and rotor mills (avoiding ball-milling) and cold-pressing the powdered samples into pellets using binder (vax).XRF users often rely on this type of commercial pre-calibrated or 'standardless' methods delivered with their XRF spectrometer. However, these methods are often sold without any guarantee on performance. We recently demonstrated the quite good performance of a typical commercial pre-calibrated / standardless method when analyzing biomass in the ideal form of certified reference material. In the present article, we report now on analysis of common raw biomass using the same method purchased with a 4 kW wavelength dispersive (WD) XRF spectrometer. The accuracy (trueness and precision) is determined by comparing the XRF data with the elemental composition obtained by standard elemental analysis (ICP-OES and ionchromatography). The certified elements consistently detected by the XRF are: Na, Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo. For elements above 25 ppm, the XRF data show a relative systematic error (bias, trueness) typically better than ±15% independent of the concentration. The elements present with > 1000 ppm (Mg, Si, Cl, K, Ca) consistently show a positive bias of 3 -18% relative. The relative precision (measured as the relative standard error) is better than ±5% (typically ±1%) for concentrations > 25 ppm (obtained with 10 -30 measurements). Quantifying elements below 25 ppm (Co, Ni, Cu, Zn, Sr, Mo) is possible in some cases, but it requires a more detailed study for each specific element. E.g. Cu can be determined down to a few ppm with an appropriate correction for the method bias. Occasionally, larger relative biases of up to 45% to 90% can occur for certain elements (Cl, Si) in certain samples, so care should be taken to carefully test the applied method for the particular samples and elements of interest. Quantification of silicon (Si) by XRF works well for concentrations > 100 ppm. The XRF method can further be used to estimate the ash yield from biomass combustion with a relative bias better than ±10%.It is shown that the errors on the elemental composition are dominated by systematic errors (biases) and therefore measuring the two sides of a single pellet combined with corre...

This study presents the life cycle assessment of electricity generation from straw bales and pellets. Straw is the most abundant biomass residue in Europe and its use for energy purposes is promoted on the premise of high greenhouse gas savings. This assumption has delayed the study of sustainability of straw-fired systems on a broader sense and the literature on the topic is almost absent. This study uses data from specific literature and emissions inventories to model a number of straw pathways. The plant modeled is a medium-scale straw-fired power plant of 50 MWth capacity. The results show that electricity from straw-fired power plants can indeed realize high greenhouse gas savings compared both with existing coal plants and with the European electricity mix. The savings are in the range 70-94%. The influence of the geographical origin of straw is analyzed by using datasets for the cultivation of wheat in five different European countries. The highest emissions are recorded for the case of straw from Spain due to the small yields, whereas cultivation processes in United Kingdom and the Netherlands show high environmental impacts due to the high level of fertilization. Other environmental impacts are evaluated, such as acidification potential, eutrophication, particulate matter emissions, and photochemical ozone formation. The bioenergy system scores worse than the current European electricity mix for all the categories. However, it is important to notice that in Spain and United Kingdom the straw system shows lower impacts compared with the local average coal electricity. Finally, the study investigates the 'break-even' distance at which the higher emissions from the pellets production are paid off by the saved emissions in their transport compared with the bales. The results show that no reasonable break-even distance exists for road transport, whereas advantages for pellets are evident in any configuration for transoceanic transport.