Hydrothermal hydrolysis of starch with CO2 and detoxification of the hydrolysates with activated carbon for bio-hydrogen fermentation

Abstract

The imminent use of hydrogen as an energy vector establishes the need for sustainable production technologies based on renewable resources. Starch is an abundant renewable resource suitable for bio-hydrogen generation. It was hypothesised that starch hydrolysates from a large (250 mL) hydrothermal reactor could support bioH 2 fermentation without inhibition by toxic byproducts.Starch was hydrolysed at high concentrations (40-200 g.L -1 ) in hot compressed water (HCW) with CO 2 at 30 bar in a 250 mL reactor, the largest so far for polysaccharide hydrolysis, at 180-235 °C, 15 min. Hydrolysates were detoxified with activated carbon (AC) and tested in biohydrogen fermentations. The maximum yield of glucose was 548 g.kg starch -1 carbon at 200 °C. 5-hydroxymethyl furfural, the main fermentation inhibitor, was removed by AC to support 70% more hydrogen production than the untreated hydrolysates. The potential utilization of starch hydrolysates from HCW treatment for upscaled fermentations is promising.

Evaluation of Aqueous Product from Hydrothermal Liquefaction of Cardboard as Bacterial Growth Medium: Co-Liquefaction of Cardboard and Bacteria for Higher Bio-Oil Production

“…Detailed analysis of the macro and micro nutrient composition of the AP was performed. Activated charcoal which has been used to detoxify hydrothermal hydrolysates of cellulosic biomass and starch was used to remove inhibitory compounds in the AP [24] [25]. We further demonstrate that co-liquefaction of microbial biomass with the cardboard feedstock induced a synergistic increase in bio-oil production and quality.…”

“…Hydrothermal liquefaction (HTL) process converts wet biomass under subcritical temperature (280˚C -374˚C) and pressure (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) to aqueous, solid char and gaseous products wherein process conditions, catalyst and biomass feedstock dictate product composition, distribution and yield [1] [2]. We have reported sub-critical HTL of lignocellulosic biomass (LCB) using homogeneous acid (Ca and Ni nitrate) catalyst [3] [4].…”

Electro-extractive fermentation for efficient biohydrogen production

“…This was confirmed more recently as E. coli cultivated aerobically on nutrient broth (growing up to ~0.8 g DW/L), would produce H 2 when mixed directly with phosphate buffer but not when harvested, washed and resuspended in phosphate buffer (Penfold et al, 2006). Later, this was overcome by adding formate (100 mM) to the aerobic pre-growth medium, which enabled H 2 production by washed cells in a range of nutrient-poor buffers (Orozco et al, 2011;Redwood et al, 2008). Similarly, Yoshida et al (2007) designed a 3-step process in which cells were grown aerobically, then activated with formate before entering anaerobic H 2 production.…”

“…starch, cellulose and lignocellulose) requiring hydrolysis to enable rapid fermentation and also to prevent fouling of the narrow channels of the ED cell with solid particles. Such upstream hydrolysis of starch was achieved (Orozco et al, 2011) and EF took place with high separation efficiency with H 2 production from a range of biowastes. This work will be reported in subsequent publications.…”

Studi Konversi Pati Ubi Kayu (Cassava Starch) menjadi Glukosa secara Enzimatik

“…pH yang tidak sesuai akan menyebabkan penurunan aktifitas enzim. Untuk proses likuifikasi pH yang optimal 6 sedangkan pada sakarifikasi pH yang optimal adalah 4,5 [36].…”