• Energy Research

This paper reviews and assesses conditions for increased and efficient use of biomass in Central America (CA), providing an overview of conditions for biomass supply in each country. Then, a Fuzzy Multi-Actor Multi-Criteria Decision-Making (MCDM) method is applied to identify a portfolio of biomass conversion technologies appropriate for CA, considering technical, economic, environmental and socio-political aspects. The work is motivated by the relatively large availability of biomass in CA at the same time as current conversion of biomass is carried out in inefficient processes. The assessment of technologies includes thermochemical processes (pyrolysis, combustion and gasification) for production of different energy carriers, including improved cooking stoves (ICSs). The most promising biomass feedstocks in the region are residue based; animal (manure), forest and agricultural origin. We show that around 250 PJ/year could be available for the energy sector, which is equivalent to 34% of primary energy supply for CA. It is concluded that in the short term promoting and implementing ICSs will give the largest improvement in the efficiency of biomass use, whereas on the long term small combustion plants seem to be the best choice for transforming CA's biomass into a clean and sustainable energy carriers, boosting economy and industrial development. Results show that the introduction of ICSs will result in an annual saving in the range of 4-8 Mt of fuelwood (59-113 PJ). Moreover, even when the investment cost of the cooking stoves is considered, ICSs yield economic savings to fuelwood consumers compared to traditional stoves. The total savings during the first year of implementation would be in the range of 19-152 US$/stove. (C) 2016 Elsevier Ltd. All rights reserved.

The assessment of sustainability of the production of ethylene from biomass (bio-ethylene) differs from that of biofuels, because of the different final use of the bio-ethylene (in general of all bio-chemicals). Several alternative routes for the production of bio-ethylene are identified, although only two platform chemicals: ethanol and DME (dimethyl ether). Using a modified version of the European methodology for the sustainability assessment of biofuels, the GHG emissions for the production of bio-ethylene have been estimated. The results show that negative emissions are core in the fulfillment of the sustainability criterion of GHG emissions. Nonetheless, in the case of bio­chemical production there are two options to achieve them: the securing of carbon retention in the final products, or the incorporation of BECCS (BioEnergy with Carbon Capture and Storage). Proceedings of the 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark, pp. 1578-1580

The aim of this study is to model and assess different biomass-to-liquid (BtL) pathways for the production of fuels and chemicals via dimethyl ether (DME) synthesis as well as via Fischer-Tropsch (FT) synthesis. The conversion of lignocellulosic biomass, such as residual wood or straw, to synthetic fuels and chemicals is currently under development at the Karlsruhe Institute of Technology (KIT). Within the considered bioliq® concept, so-called slurry is produced by multiple decentralized fast pyrolysis plants and is then processed in a single centralized pressurized entrained flow gasifier. The resulting syngas has to be conditioned and cleaned before it is converted in a DME or FT synthesis in order to complete the biomass-to-liquid (BtL) production. This two-stage concept allows the economic transportation of biomass over long distances, due to the relatively high energy density of the slurry produced in the first stage. In addition, reductions in specific investments and costs for further processing in the second stage are enabled by economies of scale. This study addresses possibilities for further process development and presents an outlook for a commercial implementation of biomass-derived fuels and chemicals. Proceedings of the 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark, pp. 1975-1983

The use of biomass for production of chemicals is gaining interest because of its potential to contribute towards a reduction in greenhouse gas emissions and other environmental benefits linked to the substitution of fossil resources. But, conversely to biofuels, studies focusing on environmental impacts of biomass-derived chemicals are scarce. This paper uses life cycle assessment to evaluate the environmental sustainability of bio-ethylene from poplar produced by the following three thermo-chemical routes: direct and indirect dehydration of ethanol and production of olefins via dimethyl ether. The indirect route is the best option for most impact categories for all three allocation methods considered: system expansion, economic and energy basis. However, the dimethyl ether-to-olefins route has the lowest global warming potential. In comparison to ethylene produced bio-chemically from sugar beet, the thermo-chemical indirect route has lower impacts for all categories except human, terrestrial and freshwater toxicities. All three thermo-chemical alternatives show a significant reduction in global warming potential (up to 105% in the case of dimethyl ether-to-olefins) and depletion of fossil fuels when compared to conventional ethylene production from fossil fuels. However, the results also suggest that bioethylene produced by any of the three thermo-chemical routes would lead to a significant increase in most other impact categories relative to fossil fuels. Therefore, while trying to reduce greenhouse gas emissions, the overall environmental sustainability of bio-ethylene suffers from the increase in other environmental impacts. Universidad de Sevilla VPPI-US

This study evaluates the benefits of integrating a full renewable dual back-up system (biomass and Thermal Energy Storage (TES)) in Concentrated Solar Power (CSP) plants. Two plants of 50 MWe capacity each are modelled and simulated, based on Parabolic Trough and Solar Tower technologies, with the integration of a biomass grate boiler in parallel to the power island. The Analytic Hierarchy Process is used as a Multi-Criteria Decision Method to compare the performance according to technical, economic, and operational criteria of 7 operating strategies. These strategies have been defined for integrating the biomass block for five levels of TES (No-TES, 5, 10, 15 and 20 h). The results show that the participation of biomass back-up favours the operation of the system as a base-load plant, increasing the capacity factor (CF) up to 71%, the net electric efficiency up to 10%, and reducing the cost of generation down to 56%, compared to stand-alone CSP plants. For the considered solar resource (Seville, Spain), reasonable generation costs (0.153 USD/kWh) can be achieved for a balanced trade-off between biomass and TES while allowing a firm energy supply (CF ≥ 80%) and reducing the required flexibility to the boiler. In addition, generation with a high solar share (over 50%) can be achieved with the proposed dual supporting system, favouring access to solar-driven incentives, as well as reducing the sensitivity of the system to the risks associated with biomass supply. Premio Trimestral Publicación Científica Destacada de la US. Escuela Técnica Superior de Ingeniería European Regional Development Fund/European Social Fund “A way to make Europe” Spanish National Plan I+D+i CTM2016-78089-R Junta de Andalucía P18-RT-4512

This paper provides a first approach on changing the present olefin production via fossil fuels by using biomass instead. The BioMTO process is an interesting alternative concept, inside the biomass thermochemical conversion platform, which could be cost competitive in the medium term. Other biomass­to­olefins processes, included biochemical and thermochemical platforms, are briefly reviewed. A techno­economic assessment for the selected case (high ethylene production mode) is presented, which is subdivided into several sections, i.e. biomass pretreatment and gasification, gas clean­up and conditioning, methanol synthesis, and methanol cracking to olefins. Preliminary results from the economic assessment reveal that the BioMTO could be competitive with present olefins market prices. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 1113-1116

In this study, a simplified methodology for the calculation of the balance of greenhouse gas (GHG) emissions and corresponding saving compared with the fossil reference is presented. The proposed methodology allows the estimation of the anthropogenic GHG emissions of thermochemical biorefineries (net emitted to the atmosphere). In the calculation of the GHG balance, all relevant factors have been identified and analyzed including multiproduction, emissions from biogenic carbon capture and storage (Bio-CCS), co-feeding of fossil fuels (secondary feedstock) and possible carbon storage in biomass-derived products (chemicals). Therefore, it is possible to calculate the balance of GHG emissions of a hypothetical thermochemical biorefinery considering different alternatives of land-use, biomass feedstock, co-feeding of fossil fuels, Bio-CCS incorporation and final use of the products. The comparison of the estimated GHG balance with the corresponding fossil reference for each product is of special relevance in the methodology since it is the parameter used in European regulation for the fulfillment of sustainability criteria in biomass-derived fuels and liquids. The proposed methodology is tested using a previously assessed set of different process concepts of thermochemical biorefineries (techno-economic analysis). The resulting GHG balance and saving are analyzed to identify uncertainties and provide recommendations for future regulation. In all process concepts, the GHG savings are above the minimum requirement of GHG emissions for 2018. In the case of incorporating Bio-CCS, cradle-to-grave negative GHG emissions are obtained. However, in order to assess the role of chemical co-production from biomass, they need to be included in future regulation.

Integrating thermochemical biomass conversion and solar thermal energy is an emerging concept for the sustainable production of electricity, biofuels, and other renewable products. This study uses a utility supply approach to assess the techno-economic feasibility of thermochemical biorefineries (TBRF) assisted by concentrated solar power (CSP) systems. Three TBRF scenarios were modelled to produce dimethyl ether (DME) from gasified biomass (500 MWth), considering different alternatives for syngas upgrading. A CSP plant of 50 MWe and 15 h of thermal energy storage (TES) was incorporated to increase the system power generation. The assessment of the six scenarios (3 stand-alone and 3 CSP-assisted) was based on a specific location to show its potential: the solar resource of Seville (Spain) and the electricity prices in the Iberian market, both at hourly resolution. The CSP-assisted scenarios show fuel upgrading in the range of 2–4%, up to 85% of electricity demand coverage and power surpluses of up to 52% of its annual demand. However, the inclusion of a CSP block leads to an increase in investment costs of up to 74% and a decrease in the internal rate of return (IRR) of 9.2 points compared to a stand-alone TRBF. The DME minimum selling price ranged from 14 to 18.1 USD/GJ for the stand-alone scenarios and between 18.3 and 21.2 USD/GJ for the CSP-assisted scenarios. Furthermore, these results suggest that modular integration based on commercially available technologies may constitute a first step towards the feasibility of future biorefineries. Unión Europea - Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación GH2T PID2020-114725RA-I00 Junta de Andalucía - FEDER P18-RT-4512