Process simulation of a dual-stage Selexol process for 95% carbon capture efficiency at an integrated gasification combined cycle power plant

AbstractIt was aimed to simulate a conventional dual-stage Selexol process for removing CO2 and H2S simultaneously from a synthesis gas (syngas) originated from a typical Integrated Gasification Combined Cycle (IGCC) power plant driven by a dry-coal fed gasifier using Honeywell UniSim R400. The solubilities of syngas components on Selexol were predicted by temperature-dependant Henry’s law constants being newly evaluated in this study based on the experimental data in Xu et al. (1992). The operating conditions of the dual-stage Selexol unit were determined so as to meet simultaneously various performance targets, such as 99+% H2 recovery, 90% CO2 recovery, 99+% H2S recovery, and less than 20ppm H2S in CO2 product. By and large the resulting energy consumptions of the Selexol process were in good agreement with those reported in DOE NETL (2010) that this study was based on. It was shown that the integrated dual-stage Selexol unit could achieve 95% carbon capture rate as well as 90% by simply changing the operating conditions. By contrast a CO2 removal Selexol process having not an input of lean solvent generated by thermal regeneration could not achieve 95% carbon capture rate due to a pinch point formed at the top of the CO2 absorber

Process simulation of a dual-stage Selexol unit for pre-combustion carbon capture at an IGCC power plant

AbstractIt is aimed to simulate a dual-stage Selexol process for removing CO2 as well as H2S from the syngas typically found in the IGCC power plant with a dry-coal fed gasifier. Temperature-dependent Henry's law is employed in the process simulation to estimate the solubilities of gas components in Selexol. The operating conditions of dual-stage Selexol unit were found so as to meet simultaneously various specifications such as 99+% H2 recovery, 90% or 95% CO2 recovery and 99+% H2S recovery. The power consumptions for auxiliary units and CO2 compression estimated by the simulation are in good agreement with those reported in the literature [1]. It is shown that the conventional, integrated dual-stage Selexol unit can achieve 95% carbon capture rate as well as 90% by simply changing the operating conditions

Correction to: Thick melanoma in Tuscany

This corrects the article DOI: 10.23736/S0392-0488.17.05584-5

Multiple Lymph Node Basin Drainage in Trunk Melanoma Is Not Associated with Survival of Sentinel Lymph Node-Positive Patients

OBJECTIVES: This study was aimed at investigating the prognostic role of multiple lymph node basin drainage (MLBD) in patients with positive sentinel lymph node (SLN) biopsy. BACKGROUND: MLBD is frequently observed in patients with trunk melanoma undergoing SLN. The prognostic value of MLBD in SLN-positive patients is still debated. METHODS: Retrospective data from 312 trunk melanoma patients with positive SLN biopsy (1991-2012) at 6 Italian referral centres were gathered in a multicentre database. MLBD was defined at preoperative lymphoscintigraphy. Clinical and pathological data were analysed for their association with disease-free interval (DFI) and disease-specific (DSS) survival. RESULTS: MLBD was identified in 34.6% of patients (108/312) and was significantly associated with >1 positive SLN (37 vs. 15.2%; p 1 positive lymph node (LN) after complete lymph node dissection (CLND) (50.9 vs. 34.8%; p = 0.033). No differences were observed according to drainage pattern in patients who had negative and positive non-SLN at CLND. MLBD was not associated with either DFI or DSS. Multivariate analyses showed that tumour thickness, ulceration, and number of metastatic LNs were associated with worse DFI and DSS, while regression confirmed its protective role in survival. CONCLUSION: In positive SLN patients, MLBD has no association with survival, which is mainly related to American Joint Committee on Cancer (AJCC) prognostic factors. Since the overall number of positive LNs drives the prognosis, the importance of a CLND in all the positive basins is confirmed

Prognostic Role of Multiple Lymphatic Basin Drainage in Sentinel Lymph Node-Negative Trunk Melanoma Patients: A Multicenter Study from the Italian Melanoma Intergroup

Multiple lymphatic basin drainage (MLBD) is frequently observed in patients with trunk melanoma undergoing sentinel lymph node (SLN) biopsy. Conflicting data regarding the prognostic association of MLBD in SLN-negative patients have been reported. This study aimed to investigate the prognostic role of MLBD in patients with negative SLN biopsy. Retrospective data from 656 melanoma patients who underwent a SLN biopsy (1991-2012) at six Italian centers were gathered in a multicenter database. MLBD was defined as lymphoscintigraphic and intraoperative identification of an SLN in more than one nodal basin. Clinical and pathologic variables were recorded and analyzed for their impact on survival. SLN-negative patients with MLBD were at lower risk of melanoma recurrence [hazard ratio (HR) 0.73, P = 0.05) and melanoma-related death (HR 0.68, P = 0.001) independent of common staging features. Multivariable Cox analyses of disease-free interval (DFI) and disease-specific survival (DSS) showed that MLBD maintained a favorable role and ulceration an unfavorable role. Histologic regression was independently associated only with DFI. When survival was stratified according to presence of MLBD, histologic regression and Breslow thickness < 2 mm were associated with improved DFI (5-year DFI: 96.9 vs. 66,1 %, respectively; HR 0.48, P < 0.001) and DSS (5-year DSS: 96.7 vs. 71.8 %, respectively; HR 0.52, P = 0.005) compared to patients without these three favorable parameters. Patients with negative SLN biopsy results have better prognosis when two or more lymphatic basins are identified and analyzed. Further research is required to investigate the mechanisms behind this evidence