Explosion pretreatments

Steam explosion pretreatment was carried out in a continuous Staketech digester processing 150 kg/h of DM. Water was added to the chips to raise the intrinsic humidity to 50%. The severity of the steam explosion pretreatment was expressed through the logarithm of the semiem-pirical relation described in Eq. 1 (11) ... 

Schultz, T. P., and McGinnis, G. D. (1984). Final Report, Evaluation of a Steam-Explosion Pretreatment for Alcohol Production from Biomass, USDA-SEA Grant No. 59-2281-1-2-098-0, September 15, 1981 to October 1, 1984. Mississppi State University, Mississippi State, MS. 

Carrasco et al. [58] analyzed the effect of dilute H2SO4 and steam explosion pretreatment on the fractionation and kinetics of several biomass materials. 

Five separate destruction technologies were tested for the destruction of waste HMX and PBX high explosives (HE). Since incineration is the baseline technology, a series of tests was conducted at a commercial two-stage, fixed-hearth incinerator. Destruction by molten salt injection was tested at LLNL. The last three destruction techniques are based on a base hydrolysis (BH) explosive pretreatment to produce a nonexplosive solution for further treatment. Three secondary treatments for BH were tested, including hydrothermal, biodegradation, and thermal decomposition. BH and hydrothermal techniques were tested at Los Alamos National Laboratory (LANL), and LLNL tested biological and thermal decomposition. 

Wet explosion Pretreatment Wheat straw High dry matter Ethanol... 

Wet explosion pretreatment [7] was perfonned batch-wise by suspending 350 g wheat straw pellets in 1.81 of deionized water in a 3.5-1 high-pressure reactor with a paddle stirrer with a maximum stirring speed of 2,000 rpm. The reactor was equipped with an injection device for injection of H2O2 solution, pure oxygen, or air. The reactor was heated by water jacket, which was coimected to a heat exchanger controlled by an oil heater. The highest temperature in the reactor was 190 C. The temperature and pressure inside the reactor were monitored by two temperature sensors (one in the bottom and one in the head space) and one pressure sensor. After the pretreatment, the material was flashed into a 5-1 container connected to the reactor. 

For evaluation of the effect of the different oxidants (H2O2, O2, or air) used in the wet-explosion pretreatment on convertibility of the material, enzymatic hydrolysis was carried out for 72 h using the different pretreated wheat straw materials (i.e., pretreated with H2O2, O2, or air). The experiment was performed in 57-ml vials with unwashed slurry (20 g) with... 

The advantages of steam explosion pretreatment include the low energy requirement compared with mechanical comminution and no recycling or environmental costs. 

Supercritical CO2 is used for carbon dioxide explosion pretreatment. CO2 is cheap, nontoxic, inflammable, and easy to extract after explosion (Taherzadeh and Karimi, 2008). Due to the release of carbon dioxide at high pressure, lignocelluloses are disturbed, which increases the surface area for further hydrolysis. Glucose release was observed to increase with increasing pressure and temperature of the carbon dioxide was applied in supercritical carbon dioxide explosion. However, using subcritical carbon dioxide results in opposite scenario. 

FIGURE 3.6 Schematic representation of an explosion pretreatment process, in which the explosive agents may he steam, ammonia, sulfur dioxide, and carbon dioxide. 

Tucker MP, Kim KH, Newman MM, Nguyen QA. (2003). Effects of temperature and moisture on dUute-acid steam explosion pretreatment of com stover and cellulase enzyme digestibility. Bioc/iem fi/oi/iec/jno/, 105,165-177. 

A pretreatment process of steam explosion on SCB along with newly isolated thermotol-erant strain Debaryomyces hansenii immobilized over Ca-alginate was carried out for xylitol production. The Ca-alginate immobilized system produced 73.8g of xylitol in comparison to 68.6 g/L by free cells. The steam explosion pretreatment approach and immobilized system were reus for five batches with steady bioconversion rates and yields (Prakash et al., 2011). 

Shafiei, M., Kabir, M.M., Zilouei, H., Sh vari Horvath, I., Karimi, K., 2013. Techno-economical smdy of biogas production improved by steam explosion pretreatment. Bioresource Technology 148, 53—60. 

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