Increasing biomass resource availability through supply chain analysis

Increased inclusion of biomass in energy strategies all over the world means that greater mobilisation of biomass resources will be required to meet demand. Strategies of many EU countries assume the future use of non-EU sourced biomass. An increasing number of studies call for the UK to consider alternative options, principally to better utilise indigenous resources. This research identifies the indigenous biomass resources that demonstrate the greatest promise for the UK bioenergy sector and evaluates the extent that different supply chain drivers influence resource availability. The analysis finds that the UK's resources with greatest primary bioenergy potential are household wastes (>115 TWh by 2050), energy crops (>100 TWh by 2050) and agricultural residues (>80 TWh by 2050). The availability of biomass waste resources was found to demonstrate great promise for the bioenergy sector, although are highly susceptible to influences, most notably by the focus of adopted waste management strategies. Biomass residue resources were found to be the resource category least susceptible to influence, with relatively high near-term availability that is forecast to increase – therefore representing a potentially robust resource for the bioenergy sector. The near-term availability of UK energy crops was found to be much less significant compared to other resource categories. Energy crops represent long-term potential for the bioenergy sector, although achieving higher limits of availability will be dependent on the successful management of key influencing drivers. The research highlights that the availability of indigenous resources is largely influenced by a few key drivers, this contradicting areas of consensus of current UK bioenergy policy

The Definition of the Minimum Miscibility Pressure

In this work the definition of the minimum miscibility pressure is reviewed from literature sources. This pressure is a key concept in the miscible displacement in reservoir engineering, marking the limit between complete and partial miscibility development in a reservoir upon the injection of a driving gas. The processes taking place in miscible displacement are reviewed after Hutchinson and Braun. They are based on the concept of multiple batch contacts between oil and gas, leading to a likeness and miscibility between the two coexisting phases. Two processes are identified: A vaporizing gas drive appears when the vaporization of intermediate components from the oil in the gas is the main miscibility developing force. In a condensing gas drive the condensation of intermediates into the oil is the main driving force. The MMP is reached when oil or gas lie outside the region of tie line extensions. Two methods are presented to calculated the MMP in a multiple contact miscibility process. The critical tie line concept and the simulation of the phase behavior in the process rendered the same result, as was contradicted in the literature. Prove of this postulation is given. The experimental procedures for determining the MMP are reviewed. To cope with the anomalies in the MMP experiments some authors revealed, a combined model based on the mathematical method of characteristics of phase and flow behavior is reviewed from the literature. Applying the model the potential recovery under ideal circumstances can be established under immiscible and miscible conditions. The effects disrupting the miscibility development can be isolated. Under its prerequisites, the model confirms the Hutchinson and Braun concept of miscible displacement. The proposed definition of the minimum miscibility pressure is the following: The multicomponent minimum miscibility pressure is the lowest pressure at which the critical tie-line passes through either the original gas or oil composition, establishing a condensing or vaporizing gas drive, respectively. This pressure is indicated by the distinct break which can be constructed in the recovery-pressure diagram.Applied SciencesToegepaste thermodynamica en fasenleerAnorganische en Fysische Chemi

Mitral valve repair-related hemolysis: a report of two cases

Two patients are described who suffered from progressive intravascular hemolysis following different kinds of reconstructive surgery of the mitral valve. Within the context of increasing numbers of operations aimed to preserve the mitral valve, the importance and difficulty of prompt recognition and adequate treatment of this very uncommon but potential lethal complication are emphasised. (C) 1997 Elsevier Science Ireland Lt