Electrolysis of coal slurries to produce hydrogen gas: Relationship between CO2 and H2 formation
Gözmen, Belgin
The purpose of this study was to produce hydrogen gas by electrolysis of coal slurries and to investigate the relation between hydrogen (H2) and carbon dioxide (CO2) formation. Electrolysis of coal slurries was evaluated at 40 °C and 1.0 V cell potential to examine H2 and CO2relationship. When electrolysis was performed after the coal slurry was mixed with Fe(II)/Fe(III) ions and stirred overnight (>12 h), no CO2 gas was observed at the anode compartment. The results of total organic carbon (TOC) indicated that after electrolysis, few organic compounds were transformed into the solution and these organic compounds did not convert into CO2. GC analysis, on the other hand, revealed that the H2 collected at the cathode was pure and did not require any further purification process. Hydrogen ge...
The effects of ammonia addition on the emission and performance characteristics of a diesel engine with variable compression ratio and injection timing
Okumuş, Fatih
Ammonia, future of the carbonless marine fuel, presents significant potential in achieving zero-emission targets within maritime transportation. In this context, this study explores the use of an ammonia/diesel fuel mixture in a diesel engine, employing both experimental and numerical methods. We focus on the impact of injection timing and compression ratio to optimize the engine while using ammonia/diesel mixture in terms of both engine performance and exhaust emissions. The results show a decrease in engine power with an increasing content of ammonia, reaching the lowest power of 4.53 kW at 60% ammonia content. On the other hand, the increase in compression ratio generally enhances engine power. Thermal efficiency shows an increase up to 40% ammonia content, followed by a decline. CO2 em...
Enhancement of biohydrogen production efficiency in dark co-fermentation of sewage sludge and fruit processing wastes through ultrasonic, alkali, acid, and thermal pretreatment
Akbay, Habibe Elif Gülşen | Deniz, Fatma
The development of urbanization and related treatment/infrastructure systems has increased the number of wastewater treatment plants in cities and the amount of sewage sludge (SS) with high organic matter content coming out of them. Dark co-fermentation (DcF) of such wastes with industrial wastes of food origin with high carbohydrate (CH) content is quite attractive to produce biohydrogen, which is considered as an efficient alternative fuel of the future. This study aimed to improve batch biohydrogen production by ultrasonic (US), thermal (T), acidic (AC) and alkali (AL) pretreatment of feedstock consisting of SS and various fruit processing industry wastes (3:1 mixing ratio based on total solids (TS)). Biohydrogen production yields were 96.48, 143.95, 121.79, 119.80, 114.73, and 100.32 m...