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The technical and economical feasibility of CO2 sequestration in deep coal layers combined with enhanced coalbed methane (ECBM) production in the Netherlands has been explored. Annually, 3.4 Mtonne CO2 from chemical installations can be delivered to sequestration locations at 15 €/tonne and another 55 Mtonne from power generating facilities at 40–80 €/tonne. Four potential ECBM areas have been assessed, of which Zuid Limburg is the best location for a test site, while the Achterhoek is more suitable for future large-scale CO2 sequestration. Between 54 Mtonne and 9 Gtonne CO2 can be sequestered in the four areas together, heavily depending on available technology for accessing the coal seams. At the same time, between 0.3 and 60 EJ of coalbed methane can be produced. The optimal configuration may have 1000 m spacing between production wells, and extreme inseam drilling. The price of coalbed methane may become competitive with natural gas when a bonus for CO2 sequestration is applied of about 25 €/tonne. For the long term, on-site hydrogen or power (SOFC) production with direct injection of produced CO2 seems most attractive. Further study is required, most notably more accurate geological surveys, assessment of drilling costs in Dutch context, and environmental impacts of ECBM. [Copyright &y& Elsevier]

Abstract: The membrane reactor is a novel technology for the production of hydrogen from natural gas. It promises economic small-scale hydrogen production, e.g. at refuelling stations and has the potential of inexpensive CO2 separation. Four configurations of the membrane reactor have been modelled with Aspenplus to determine its thermodynamic and economic prospects. Overall energy efficiency is 84%HHV without H2 compression (78% with compression up to 482bar). The modelling results also indicate that by using a sweep gas, the membrane reactor can produce a reformer exit stream consisting mainly of CO2 and H2O (>90%mol) suited for CO2 sequestration after water removal with an efficiency loss of only 1%pt. Reforming with a 2MW membrane reactor (250 unit production volume) costs 14$/ including compression, which is more expensive than conventional steam reforming+compression (12$/GJ). It does, however, promise a cheap method of CO2 separation, 14$/t CO2 captured, due to the high purity of the exit stream. The well-to-wheel chain of the membrane reactor has been compared to centralised steam reforming to assess the trade-off between production scale and the construction of a hydrogen and a CO2 distribution infrastructure. If the scale of centralised hydrogen production is below 40MW, the trade-off could be favourable for the membrane reactor with small-scale CO2 capture (18$/GJ including H2 storage, dispensing and CO2 sequestration for 40MW SMR versus 19$/GJ for MR). The membrane reactor might become competitive with conventional steam reforming provided that thin membranes can be combined with high stability and a cheap manufacturing method for the membrane tubes. Thin membranes, industrial utility prices and larger production volumes (i.e. technological learning) might reduce the levelised hydrogen cost of the membrane reactor at the refuelling station to less than 14$/GJ including CO2 sequestration cost, below that of large-scale H2 production with CO2 sequestration (∼15$/GJ). [Copyright &y& Elsevier]

This paper aims to quantify the benefits of switching from a system dependent on traditional biomass to systems running on more efficient fuels and technologies. It is estimated that even when open fires burning fuelwood are replaced by improved cooking stoves (ICSs) and liquefied petroleum gas (LPG) stoves, and biomass is processed in dedicated biomass power plants, a net reduction in CO 2 emissions is still obtained. The ICS/LPG stove/biomass combustion power plant configuration could provide an average net reduction of 84 kg-C e /tDM. Meanwhile, a net reduction of 105 kg-C e /tDM could be obtained when implementing a ICS/LPG stove/biomass gasification power plant scheme. Main factors influencing the net reduction of CO 2 emissions are technology efficiency and the fraction of non-renewable fuelwood use. The switch from traditional biomass to modern biomass in traditional biomass intensive countries must not only be done to reduce CO 2 emissions but also to avoid indoor pollution and energy poverty. Health improvements should be more important than energy savings. Results also indicate that the use of modern biomass systems not only could provide a reduction of local environmental pollution, but also could boost the local economy by the creation of biomass infrastructures. [ABSTRACT FROM AUTHOR]

Abstract: Torrefaction is a promising bioenergy pre-treatment technology, with potential to make a major contribution to the commodification of biomass. However, there is limited scientific knowledge on the techno-economic performance of torrefaction. This study therefore improves available knowledge on torrefaction by providing detailed insights into state of the art prospects of the commercial utilisation of torrefaction technology over time. Focussing on and based on the current status of the compact moving bed reactor, we identify process performance characteristics such as thermal efficiency and mass yield and discuss their determining factors through analysis of mass and energy balances. This study has shown that woody biomass can be torrefied with a thermal and mass efficiency of 94% and 48% respectively (on a dry ash free basis). For straw, the corresponding theoretical energetic efficiency is 96% and mass efficiency is 65%. In the long term, the technical performance of torrefaction processes is expected to improve and energy efficiencies are expected to be at least 97% as optimal torgas use and efficient heat transfer are realised. Short term production costs for woody biomass TOPs (torrefied pellets) are estimated to be between 3.3 and 4.8 US$/GJLHV, falling to 2.1–5.1 US$/GJLHV in the long term. At such cost levels, torrefied pellets would become competitive with traditional pellets. For full commercialisation, torrefaction reactors still require to be optimised. Of importance to torrefaction system performance is the achievement of consistent and homogeneous, fully hydrophobic and stable product, capable of utilising different feedstocks, at desired end-use energy densities. [Copyright &y& Elsevier]