Holistic biorefinery approach for biogas and hydrogen production: Integration of anaerobic digestion with hydrothermal carbonization and steam gasification.

Recently, the integration of biochemical and thermochemical processes is recognized as a promising strategy for the valorization of lignocellulosic biomass into renewable energy production. In this study, different routes for the valorization of hemp hurd for biohydrogen and biomethane production were proposed, including anaerobic digestion (AD), hydrothermal carbonization, and steam gasification. AD results revealed that NaOH pre-treatment of hemp hurd improved biomethane production yield by 164%. Comparing hydrochars from raw hemp, digestate derived hydrochars had higher mass yield due to changes in composition during AD as well as high ash content of digestates. It was found that high ash content of digestates originated from inorganic compounds in inoculum that accumulated over hemp hurd during anaerobic digestion process. Among feedstocks (hydrochars and raw hemp hurd), hemp hurd derived hydrochar at 200 °C showed the best performance in terms of H2 yield (1278 mL/g) whereas carbon efficiency reached % 92 in case of digestate derived hydrochar at 200 °C. HTC improved the steam gasification performance of hemp hurd whereas hydrochars from NaOH pretreated digestate yielded lowest hydrogen production due to the high content of inorganics, particularly phosphorus (P) and aluminum (Al). According to BMP test, spent liquor obtained at the lowest HTC temperature (200 °C) exhibited the highest BMP, reaching 213 mL CH4/g COD. Considering the overall gas products of four different routes, it is concluded that HTC as a post-treatment exhibits slightly better performance than HTC as pre-treatment. Although alkali pretreatment enhanced the anaerobic digestion performance, the resulting hydrochars exhibited low gasification activity.

What type of different clinical manifestations can cardiac sarcoidosis present?

Cardiac sarcoidosis is an infiltrative, granulomatous inflammatory disease of the myocardium. Generally, it can be difficult to diagnose cardiac sarcoidosis clinically because of the non-specific nature of its clinical manifestations. This property can be based on the presence of any clinical evidence of sarcoidosis in the other organs. We present two cases of cardiac sarcoidosis so as to demonstrate its different clinical manifestations. The first patient displayed no cardiac symptoms; the electrocardiogram showed an incidental right bundle branch block. Her cardiac magnetic resonance imaging (CMRI) revealed late-phase opaque material enhancement involving the inferior and inferoseptal segment of the left ventricle. The second patient was severely symptomatic in terms of cardiac involvement, and a transthoracic echocardiogram revealed global hypokinesia and septal brightness; his ejection fraction decreased to 45%. These cases highlighted the challenges encountered in the diagnosis and treatment of cardiac sarcoidosis. CMRI should be considered in all patients who have suspected findings for cardiac involvement.